The rapid development of urbanization has resulted in the accumulation of a large amount of waste concrete, which not only occupies land resources but also pollutes the air and the environment. Therefore, the recycling of waste concrete has become an important issue that the government needs to solve.
Abandoned concrete blocks are high-quality concrete aggregates which have many advantages. For example, after the buildings are dismantled, the high-quality concrete blocks and silt after crushing and screening can be used as recycled coarse and fine aggregates for concrete. The fine powder can be directly used as the raw material of cement. The concrete prepared from recycled cement and recycled aggregate can enter the next cycle, which realizes zero waste discharge throughout the whole cycle.
Concrete, cement and other wastes in construction waste can be used as building aggregates and recycled brick raw materials after being reasonably crushed, screened and crushed. And the main equipment used for crushing concrete can be divided into two types: traditional fixed crusher and mobile concrete crusher, among which small crushing equipment is favored by users.
Although the compressive strength and hardness of concrete are not high, due to the porosity and the formation type, the concrete has good toughness and can buffer the crushing force, which causes low crushing efficiency. So, what kind of crusher should be selected for concrete crushing? In the process of crushing waste concrete, according to the working principle of more crushing and less grinding, it is necessary to carefully configure the concrete crusher equipment.
Jaw Crusher, also known as concrete crusher, is usually used as the primary equipment for concrete crushing. It is also suitable for metallurgy, mining, construction, chemical, water conservancy and railway sectors, and used as a device for fine and medium crushing of ores and rocks with compressive strength below 250 Mpa.
In recent years, the small jaw crusher has been favored by foreign users because of its small size, easy transportation and installation, low price, and fast profit. The models like PE-150250, PE-200350 and PE-400600 have become the best choice for customers to crush concrete.
After the rough breaking, steel and iron equipment are added to remove the steel bars and iron blocks in the waste concrete, which will eliminate the damage of steel bars and iron blocks to the equipment without affecting the production. Generally, the impact crusher, the fine crushing jaw crusher or the cone crusher is used as the secondary crushing to crush the material to less than 2 cm, and the selected granularity can be basically achieved.
For smaller discharge sizes, a three-stage crusher can be used, for example, the fine crushing crusher or the roller crusher is used to further crush the ore to less than 10 mm. In the actual production, the suitable crusher can be selected according to the size of the concrete block. It can be combined in single or multi-machine operations, both of which have the characteristics of simple operation, strong controllability and high production efficiency.
In the international environment of the crusher industry, besides the traditional jaw crusher, high-efficiency and environmentally-friendly construction concrete crusher will be the trend of future development.
In view of the characteristics of concrete waste, Henan HXJQ Machinery designed a concrete crushing equipment-mobile concrete crusher. The waste concrete after crushing can be used for reinforcing the foundation, producing bricks, cement, etc, not only achieving its values but also solving the issue of land and environment problems, which can be described as two-fold.
The mobile concrete processing station produced by HXJQ Machinery adopts multi-stage combination mode, which includes jaw crusher, impact crusher, cone crusher and vibrating screening equipment, conveyor belt, etc. Generally, the concrete crushing station is composed of a concrete crusher (sand making machine), a screening machine, a feeder, a conveyor belt, a steel frame, a drive system, an electric control system, a motor unit and the like.
The concrete material is sent into the crusher by the feeding equipment, and the crushing machine converts the large concrete into gravel. The finished product which meets the standard is transported by the conveyor belt to the stacking place, and the products which don't meet the standard will be transported by the other conveying belt to the crusher again until it is qualified.
The integrated vibrating screen, feeder and the under-belt conveyor, the vibrating screen and the crusher integrated into the vehicle can reach any position on the working site under any terrain conditions. Thus the mobile concrete crusher has many advantages like reasonable material matching, smooth flow, reliable operation, convenient operation, high efficiency and energy saving.
1. According to the driving way, it is divided into tire type and crawler type: the tire type concrete crushing and sorting machine needs semi-trailer traction to run, while the crawler type can be remotely operated with buttons. Relatively speaking, the latter is more intelligent and the price is more expensive.
2. According to the function, it is divided into crushing type and sand making type: the concrete crushing and screening machine includes a combination of crushing equipment such as jaw crusher, cone crusher and impact crusher. The sand making type is mainly equipped with sand making machine and hammer sanding machine.
The mobile crushing station can prevent and control environmental pollution, improve the ecological environment, and protect natural resources. The size and model can be designed according to the different production needs of users. According to the statistics of the HXJQ machinery, the small mobile crusher is chosen by more foreign users because of its reasonable price, high quality, convenient transition, operation and maintenance.
A project introduction of construction concrete treatment: in October 2018, a customer found HXJQ, and hoped that we could provide him with the complete equipment for breaking construction waste. Our technical manager quickly contacted him and learned that the customer had a large amount of construction waste to be disposed of.
From the perspective of economic foundation and practical operation, the technical manager recommended the fixed crushing station to him and designed a complete set of equipment suitable for his actual needs. In the end, the customer introduced the PE-400600 jaw crusher and PF-1010 impact crusher produced by our company to break the concrete waste. The finished sandstone is used for brick making, roadbed materials, etc., and the separated steel is recycled.
The pretreated concrete with reinforcing steel is sent to the jaw crusher for initial breakage by the conveyor belt, then effectively separated by the iron remover, and sent to the impact crusher for fine crushing. The crushed material is sieved by the vibrating screen. The finished material is output by the conveyor. If the material does not meet the specifications, it will continue to return to the impact crusher and break again.
The development and utilization of waste concrete as a recycled material solves the problems of a large amount of waste concrete treatment and the resulting deterioration of the ecological environment; on the other hand, it can reduce the consumption of natural aggregates in the construction industry, thereby reducing exploitation of the natural sand and gravel, which has fundamentally solved the problem of the depletion of natural aggregates and the destruction of the ecological environment because of the lack of sandstones.
Under this circumstance, the crusher plays an irreplaceable role in the recycling of materials. Whether it is the traditional fixed crusher or the latest mobile crusher, both of them have their own advantages. As long as the size of the stone produced by the equipment can meet the standard, it is a good crusher.
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The introduction of a new machine for fine crushing, or The Blake multiple-jaw crusher, which, in combination with the ordinary Blake breaker, could be used in the reduction of ores or any hard and brittle substance to almost any degree of fineness. How can you use a jaw crusher to crush fine enough to feed a ball mill?
The construction of the multiple jaw-crusher, since the date of my first paper, is the same, except in the substitution of main swinging, instead of main sliding, or toggle jaw,thus doing away with the upward thrust on the tension rods and the wear incident thereunto. (See Fig. 1.) It has also been found, in case of the fine crusher, that is, in machines of not over inch width of opening, that the use of several small machines with a series of jaw openings, say 15 inches by inch, is better than one large machine with a series of openings 24 by inch, or 36 inches by inch, as at first constructed. Many details of the method of holding in jaw-plates, etc., have been perfected.
Without giving any details with respect to the different mills built upon the Blake system, let me state that, although it has proved possible to carry any hard and brittle material with crushers alone to a fineness such that all particles will pass a 30-mesh wire screen, still the economical limit of such crushing will be found somewhere between 14 and 20. If it is necessary to carry all the material to a fineness greater than this, the system must be supplemented with other arrangements. Furthermore, the material to be operated upon must be sufficiently dry to screen readily, to take out the fine as rapidly as made, or fed with such an excess of water as will insure successful screening. It is, of course, evident that if fines are not removed as rapidly as made, there must be an accumulation and consequent slowing down of feed, and greatly diminished product, or a stoppage.
The first mill on the Blake system was that built for the Chateaugay Ore and Iron Company in 1882, which was designed to crush two hundred tons per day down to pass a quarter inch round hole. This was run at irregular intervals, and idle much of the time up to the summer of 1886, owing to the depression of prices of iron ore. Since the summer of 1886 it has been running continuously, crushing many thousands of tons of the tough magnetic ores of that company. I am not informed as to the exact product and cost of operations of this mill, but they have been approximately the same as that of a mill of treble the capacity built for the same company oil the same general plan in the summer of 1886, for exact and accurate details respecting the operations of which I am indebted to the Chateaugay Ore and Iron Company, and enabled to give statistics which will be found in another part of this paper.
The second mill of any considerable magnitude is that of the Haile Gold-Mining Company, Lancaster County, South Carolina. The gold-ores derived from the different veins or mines upon the property are altered magnesian slates. That of the Blauvelt mine is a very tough, coarse quartzite, carrying a large percentage of sulphurets. Free gold is rarely, if ever, found in these mines. For purposes of amalgamation, the ore must be crushed extremely fine.
The mill was built in the most substantial and durable manner, timbers for the frame-work of any required dimensions being readily obtainable and cheap. Power was derived from a 150 horse-power Harris-Corliss engine and three 60 horse-power boilers, and the plant was complete in the three departments of crushing, amalgamating and concentration. As at first arranged, the crushing appliances of the system consisted of one 20 by 10 Blake breaker, the product of that going to a 30 by 5, product of the 30 by 5 going to two 60 by 2 multiple-jaw crushers, each with three jaws, receiving capacity of 20 by 2 inches. The product of the 60 by 2 multiple crushers, approximately of corn-grain size, was elevated and screened through one-quarter inch holes. That which did not pass the holes of the screens went to finer crushers. The material, inch fine and finer, was elevated, screened through 40-mesh wire screens, and all that did not pass 40-mesh, that is, material between inch and 40- mesh, went to two pairs of Kroms new swinging-block rolls, each 30 inches in diameter and 16 inches face, main driving pulleys 8 feet in diameter, 14 inches face. The product of the rolls was discharged into No. 2 elevator, elevated and screened; that which would not pass 40-mesh returning to them, together with the new supplies of coarse material from the fine crushers. The finer crushed product, 40 fine and under, was discharged from the spouts of hoppers beneath the fine screens, where it encountered a stream of water, mixing it and conveying to 10 Atwood amalgamators in two groups of 5 each. The pulp from each group of amalgamators, discharged at their lower ends, was carried by troughs to 20 Embrey tables, two groups of 10 each, arranged in pairs, each pair being fed from a spitzkasten on the line of the troughs conveying the pulp.
The final discharge of superfluous water and finest slimes was opposite to the central point of the concentrating room, where the flow of tailings from the two groups of Embrey tables (10 in each) was united, and finally discharged into the waste weir.
It is evident that from the 30 by 5 crusher on, the rest of the mill was arranged in two symmetrical halves, either of which, in case of necessity, could be run independently of the other. As so arranged, about 1000 tons were put through the mill, when it became evident that a change was imperative. The Krom rolls, one pair on each side of the mill, were the chief cause of frequent stoppages, often becoming surcharged and coming suddenly to a full stop, resulting either in throwing the belts or their slipping upon the pulleys, running at about 100 revolutions per minute.
Although the greatest care was taken to insure their being properly fed, this surcharging would happen. The shells or tires had in crushing 500 tons each worn down one-quarter inch; that is, one-half in the entire diameter. The surfaces had become more or less pitted and corrugated. The returns to them were increasing rapidly, and the cost of the wear of the wire cloth had been at least $1 per ton. It became evident that for purposes of fine crushing their use must be abandoned.
Accidental knowledge of the results obtained by many years use of a Chili mill at glass-sand works, near Pittsburgh, Pa., led to the immediate substitution of two Chili mills (see Figs. 2 and 3) for the two pairs of Krom rolls, and running the material after being crushed to one-quarter inch wet instead of dry. This proved at once to be a solution of the question of crushing and the difficulties of fine screening.
The capacity of these mills, run as they were, was something wonderful,no one who has not seen one run as it should be can form an idea of the rapidity, economy and certainty of their work, when dealing with material already carried to one-quarter of an inch and finer. The central spindle, carrying horizontal axis on which the wheels revolved, had a speed of 40 revolutions per minute. Each wheel of the mill, weighing about a ton, was 4 feet in diameter and 8 inches face. The distance from outside to outside of the wheels was 50 inches, and the tires were of hard white iron, having a cross-section 8 by 8 inches. The segmental dies on which the wheels ran were of best chilled iron. The shallow pan holding the dies was surrounded by an enclosure of sheet iron 4 feet high, to prevent water and ore being thrown out by the splash of the rapidly revolving wheels. On each side of each Chili mill was a revolving tub-shaped screen, 8 feet in diameter and 18 inches face, turning on a horizontal axis extending from the side furthest from the mill.
The outer periphery of this was covered with wire cloth 35 meshes to the linear inch, of the coarsest possible steel wire, equivalent to 40 meshes to the linear inch with wire of ordinary fineness. The inner periphery of this tub-shaped screen, provided with a rim about 4 inches deep, was divided into six segments by wooden pieces across its face, forming so many buckets which served to elevate the material which failed to pass the screens, and throw it on to an apron which carried it back to the mill. This screen was run in water, submerged to the depth of the rim,i. e., about 4 inches, and at the rate of 12 revolutions per minute.
The substitution of Chili mills for the rolls, and the adoption of the wet method, had solved not only the problem of crushing, but that of screening. The wear of the wire cloth was at once reduced to about 10 cents per ton, and the two Chili mills proved their capacity to readily handle 7 tons per hour of the hardest and toughest quartzite from the Blauvelt mineon the softer and in some cases decomposed ores, as high as 20 tons per hour were put through them ; in fact, the crusher could not supply the amount of softer ores they were enabled to handle.
As so arranged, the mill was run, crushing about 3000 more tons of ore. Very great improvements in economy of screening could be made, but all alterations had been made under the greatest pressure, and within the shortest possible limit of time. Material one-quarter of an inch coarse should not be thrown on to wire cloth 35 to 40 fine, especially when containing a large percentage of heavy sulphurets, as was the case in this instance, but should first go to a hydraulic separator or coarser screen. Only the approximately sufficiently fine should go to the screens, the remainder being carried back to the mill without touching the wire cloth.
For purposes of amalgamation, where concentration is not desired, it is evident that the use of the Richards-Coggin hydraulic separator would enable one to dispense with screening entirely. As to the power required, the mill showed the greatest possible economy. It was often run with capacity of 7 tons per hour, with boilers carrying only 40 pounds of steam; engine with 80 pounds of steam rating at 150 horse-power, and I think with consumption of about 4 cords of wood per diem.
It is to be hoped that Mr. E. Gybbon Spilsbury, then general manager and now consulting engineer of the Haile Gold-Mining Company, will in time give in detail many points and facts here necessarily omitted. I am without special items of cost of milling per ton of ore in the Blake mill at the Haile mine, and can only state in a very general way that it showed great economy of power and material after the introduction of the Chili mills. Its operations were not sufficiently great to determine the real facts with accuracy. Enough was shown by its working to prove that mills on this system for crushing and amalgamating or concentrating, or both, may in future come into general use, that their economy per ton of ore crushed, of power and material, is greater than that of the stamp mill, and that there is no reason why they should not run with quite as much if not with more certainty and as continuously as the best stamp mill ever built.
In the summer of 1886 I furnished plans and machinery for a second mill on the Blake system to the Chateaugay Ore and Iron Co., Lyon Mt., N. Y. This was a complete crushing and concentrating plant, the crushing being done entirely by Blake crushers, and with a daily capacity of 600 long tons, from 15 inches down to of an inch, and it was built in accordance with plans shown in Figs. 4, 5, and 6. The iron-ores of this company are well known as being among the best, if not the best, Bessemer ores in the country. The deposit or vein of magnetic iron-ore is enormous, and the output from this mine often exceeds 1500 tons daily. The richer portions are sorted out and shipped, the leaner ores, consisting of magnetic iron-ore in grains, disseminated through a tough quartzose and feldspathic gangue, are sent to the mills for concentration. In order to effect this by jigging, with best results, it must be reduced to a size to pass a -inch or 5/16 ths inch round hole. The jigs used are those known as the Conkling, with an annular revolving sieve and central discharge, said to be the invention of Mr. Hooper, of the American Graphite Co., Ticonderoga, and improved in some details by Mr. W. B. Hodgson, Superintendent of Separators for the Chateaugay Ore and Iron Co. The concentrates pass into a hutch from whence they are taken out by belt elevators. The capacity of one of the jigs, as run at Chateaugay, is 100 tons of crude ore in twenty hours, or 5 tons per hour. The elevation and plans of this mill, in accompanying plates, show very clearly its construction. The ore is brought to the mill by rail, in side dumping cars, carrying on the average 7 to 8 long tons each from the various dumps one-quarter to one-half of a mile distant. It consists of two groups or systems of crushers, with elevating and screening appliances, each group being an exact duplicate of the other; a jack-pulley on main-line shafting being placed centrally between them. Power is derived from a 250 horse-power Harris-Corliss engine, and battery of three 100 horse-power boilers of Parks Bros, best steel. Each group consists of the following crushers, all of Challenge pattern, one 20 x 15, crushing from 15 inches to 2 or 2 inches.
Product of 30 by 5s is elevated and screened; that passing a inch round hole is finished product, as far as crushing is concerned, and is carried to the jigs. The coarse, 1 to inch, goes to three 60 by 2 Multiple Crushers, each with three jaw openings 20 by 2 inches. Product of these is elevated in No. 2 elevator and screened, formerly through holes of an inch in diameter, now through 5/16ths holes. That passing through the 5/16-ths screen-holes goes to jigs; that going through 11/16ths inch holes goes to two 15 by fine-crushers. Each of the 15 by crushers has 7 jaw openings, with 7 openings each 15 by inch. Material not passing 11/16ths-inch holes, but going out the end of screen, goes back to the 60 by 2 Multiple Crushers. Product 15 by fine-crushers is elevated and screened, material not passing 5/16ths-holes returning to them. Each group of crushers has three Conkling jigs.
The mill was completed and started September the 26th, 1886, and was run in a desultory sort of way until the organization of day- and night-shifts, October 18th following, when its operations may be said to have commenced. Its normal capacity on ore reasonably dry was shown to be 30 long tons per hour. This was the average amount crushed hourly up to the 8th of November; then a heavy snow-storm came and difficulties due to the presence of fine wet ore interfering with proper screening were encountered. Grizzlies were
put in at the 20 by 15 crushers, the idea being to take out the fine wet ore and send it to the wet screens below. This was fairly successful, but soon, owing to the rigorous climate of that latitude, bringing heavy snows and severe cold, the fine wet ore would freeze in solid mass on the dumps or in the cars bringing it to the mill, and would fail to pass the grizzlies, but go to the crushers. It would pass the
first two crushers well enough, giving no trouble, but by the time it reached the 60 by 2 multiple crushers the heat evolved in the crushing would thaw out the cementing ice, giving damp product which would not screen readily. In this way, or by imperfect screening, the actual product of the mill was greatly reduced, and notwithstanding the impossibility of sending the ore to the mill dry, or the absence of a sufficient supply of water to run the mill wet, and in that way obviate the difficulties of screening fine or wet and frozen ore, the mill has since that day been running uninterruptedly and continuously, day and night, to this time.
The actual amount crushed from September 26th, 1886, to January 1st, 1888, being 122,814 long tons or 137,551 short tons, at a cost for crushing and concentration of $42,200.55, or 34.36 cents per long ton or 30.67 cents per short ton, distributed as follows:
This economy is certainly remarkable, and still more so when we consider the prevailing unfavorable conditions as regards successful screening of the ore. Had the ore been reasonably dry instead of being generally wet and, during the winter months, frozen, or if the crushing after the passage of the 30 by 5 crushers had been wet instead of dry and the screening in that way made perfect as it can be, the actual, average, daily product could have been increased, even doubled, and the cost of crushing and concentrating per ton of crude ore reduced to less than twenty-five cents. In a recent number of the Engineering and Mining Journal, January 28th, 1888, giving a description of the Tamarack steam-stamp, built by Messrs. E. P. Allis & Co., of Milwaukee, the capacity is given at 225 tons per day of 24 hours, on the basis of 34 to 36 tons of ore for every ton of coal consumed. In the Chateaugay mill the total consumption of coal in crushing from 15 inches down to inch, as opposed to 3 inches down to 3/16ths of an inch at Lake Superior, as proved by the results already stated, is one ton of coal to 68 tons of ore. If allowance were made for the coal used at Chateaugay mill in heating the mill itself and the water used in concentration, it is perfectly safe to assert that the Ball stamp, in its highest condition of development and efficiency will give crushed product in tons not more than half as great per ton of fuel burned as a mill constructed and run upon the Blake system. But the consumption of fuel in any method of stamping is, as a rule, a matter of small consequence compared to the losses due to the production of slimes not susceptible of concentration. This is, and must always be, an insuperable objection to their use where subsequent concentration or lixiviation are proposed.
If it were possible, and I believe it is, to so construct a crushing- plant consisting of crushers alone as to handle the copper-ores of Lake Superior, crushing first down to inch or larger, then jigging, recrushing, and jigging again, and so on, it would certainly be a great improvement on the very simple but extravagant methods at present pursued. Certainly a large percentage of the loss there is due to the abrasion of copper beneath the stamp, necessarily involved in carrying all the material to 3/16ths of an inch before it can escape from the battery. Only costly experiment can determine this, but there is every reason to believe that multiple-jaw crushers can be built of such design and strength as to enable them to flatten out and pass masses of included copper which may by accident escape the attention of the attendant and go to them. Ordinary Blake crushers are and have been in general use at Lake Superior for many years in preparing the rock for the stamp; that is, in breaking it down to 2 to 3 inches, pieces of metallic copper that will not pass the lower jaw opening being picked out by hand before going to them.
In the operation of multiple-jaw crushers as already built, the intrusion of foreign material, such as cast iron, bits of steel, pick, gad and drill points, is a frequent occurrence. They are either crushed or simply render the jaw in which they are found inoperative until they are removed, which is very easily done. No breakage of the machine has ever been known to occur from such causes. In a fine crusher I have known a inch steel set screw to remain for a day and to be actually drawn down to a perfect wedge-shaped mass, without any injury to the machine. The packing of all the jaws with damp, fine ore intermingled with the coarse is a far more serious matter, and must be avoided by proper screening.
Experience has fully demonstrated this remarkable fact, that the Blake multiple crusher will do its work with as much ease and certainty and with greater absolute economy for wear and tear per ton of ore crushed, than an ordinary Blake breaker. The explanation of this lies first, in the multiplicity of jaws affording a safety provision, and secondly, in the economy of the use of the finest quality of hardened tool-steel for wearing-surfaces.
Whether the quartz-mill of the future will consist of a system of breakers supplemented by Chili mills or other fine crushing devices, remains to be seen. Certainly, if we combine the results of crushing at the Chateaugay mill down to inch and at the Haile mill from inch down to 40 fine by means of a Chili mill, we show the greatest possible economy in crushing. The wear on the Chili mills used at the Haile mine, in crushing 3000 tons of ore was, on the diameter of the wheels, inch; on the segmental dies, to 3/8 of an inch. The total wear of iron in these mills per ton of ore is easily calculated. On the four wheels of the two Chili mills it would be 156.64 pounds, and on the two sets of segmental dies it would be 205 pounds, making a total of 361.64 pounds, equal, on 3000 tons, to .12 of a pound of iron to a ton of ore.
It would seem probable that multiple-jaw crushers could be used with advantage in supplementing the ordinary crusher for preliminary crushing before feeding stamps. This is only true to a certain extent. But if the crushing be carried beyond a certain limit or down to coarse sand, for example, the practical result would be to reduce the product of the stamp mill rather than to increase its capacity. The reason of it is that ore so crushed, when fed to the stamps would simply bank up or pack beneath them. It requires coarse with the fine to root up the fine under the stamp and prevent its packing. It is probable, also, that if material were confined in a Chili mill by screens surrounding it instead of being sent to screens entirely outside of the mill, as was the case at Haile, it would pack beneath the wheels and the results have fallen short of those obtained.
The Blake crusher, as a machine, has an extended and enviable reputation for strength, simplicity, and durability. Their use in a system forming complete crushing plants has already led to many improvements and perfection in their details. Their combination in a system so as to run continuously and without interruption is indeed a matter demanding no inconsiderable skill, care, and experience. But the results at Chateaugay and at the Haile mine have been such as to completely demonstrate the economy of this method of crushing, and it seems to me that these results possess more than ordinary interest for the engineer.
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In this case, we recommend the use of a PCZ1308 heavy hammer crusher with a feed size of 930x650mm, the feed particle size is less than 600mm, the motor power is 4P 132Kw, and the processing capacity of the equipment is 100-180t/h.
Eastman is a typical direct selling enterprise with green and standardized production plants. All the delivery of the equipment will be completed within the delivery period signed by the contract to ensure the smooth commissioning of the equipment.
Rock crushers have a wide range of suitable material to choose from, whether its soft or hard, or even very hard, rock crushers can reduce those large rocks into smaller rocks, gravel, or even rock dust.Here are some typical materials that break or compress by industry crushers, such as Granite, quartz stone, river pebble, limestone, calcite, concrete, dolomite, iron ore, silicon ore, basalt and other mines, rocks and slag.
Understanding the stages of crushing process and the types of crushers that best fit each stage can simplifies your equipment selection. Each type of crusher is different and used to achieve a certain end result.
Similarly, a certain output is expected at the end of each crushing stage for the next phase of the process. Aggregate producers who pair the correct crusher to the correct stage will be the most efficient and, in turn, the most profitable.
A jaw crusher is a compression type of crusher. Material is reduced by squeezing the feed material between a moving piece of steel and a stationary piece. The discharge size is controlled by the setting or the space between those two pieces of steel. The tighter the setting, the smaller the output size and the lower the throughput capacity.
As a compression crusher, jaw crushers generally produce the coarsest material because they break the rock by the natural inherent lines of weakness. Jaw crushers are an excellent primary crusher when used to prepare rock for subsequent processing stages.
Although the chamber is round in shape, the moving piece of steel is not meant to rotate. Instead, a wedge is driven around to create compression on one side of the chamber and discharge opening on the opposite side. Cone crushers are used in secondary and tertiary roles as an alternative to impact crushers when shape is an important requirement, but the proportion of fines produced needs to be minimized.
An impact crusher uses mass and velocity to break down feed material. First, the feed material is reduced as it enters the crusher with the rotating blow bars or hammers in the rotor. The secondary breakage occurs as the material is accelerated into the stationary aprons or breaker plates.
Impact crushers tend to be used where shape is a critical requirement and the feed material is not very abrasive. The crushing action of an impact crusher breaks a rock along natural cleavage planes, giving rise to better product quality in terms of shape.
Most aggregate producers are well acquainted with the selection of crushing equipment and know it is possible to select a piece of equipment based solely on spec sheets and gradation calculations. Still, theoretical conclusions must always be weighed against practical experience regarding the material at hand and of the operational, maintenance and economical aspects of different solutions.
The duty of the primary crusher is, above all, to make it possible to transport material on a conveyor belt. In most aggregate crushing plants, primary crushing is carried out in a jaw crusher, although a gyratory primary crusher may be used. If material is easily crushed and not excessively abrasive, an impact breaker could also be the best choice.
The most important characteristics of a primary crusher are the capacity and the ability to accept raw material without blockages. A large primary crusher is more expensive to purchase than a smaller machine. For this reason, investment cost calculations for primary crushers are weighed against the costs of blasting raw material to a smaller size.
A pit-portable primary crusher can be an economically sound solution in cases where the producer is crushing at the quarry face. In modern plants, it is often advantageous to use a moveable primary crusher so it can follow the movement of the face where raw material is extracted.
The purpose of intermediate crushing is to produce various coarser fractions or to prepare material for final crushing. If the intermediate crusher is used to make railway ballast, product quality is important.
In other cases, there are normally no quality requirements, although the product must be suitable for fine crushing. In most cases, the objective is to obtain the greatest possible reduction at the lowest possible cost.
In most cases, the fine crushing and cubicization functions are combined in a single crushing stage. The selection of a crusher for tertiary crushing calls for both practical experience and theoretical know-how. This is where producers should be sure to call in an experienced applications specialist to make sure a system is properly engineered.
Stone/Aggregate production line has been widely used for producing gravel and sand finished product with different particle size in highway, high railway, hydroelectric dam construction, mechanism sandstone, construction fields and so on. We can provide high performance stationary and mobile aggregate crushing plant with various capacity.
Stone crushing plant consists of a vibrating feeder, suitable crushers such as jaw crusher, cone crusher, impact crusher(according to the material and capacity), vibrating screen, belt conveyor and Central electric control system, etc. Its designed throughput generally is 50-600 t/h. Sand washing and other machines can be added to this line to meet the various customers requirements.
Improves the production capacity and crushing efficiency. It can be adopted to almost all types of materials from stone production to various ores crushing. Cone crushers can perform the unparalleled crushing function in operations of coarse crushing, fine crushing, and superfine crushing. Cone crusher can finely crush various ores and rocks with different high hardness, like iron ore, nonferrous metal, emery, bauxite, quartz sand, brown aluminum oxide, perlite, basalt, etc.
On the one hand, the crushed stone can be used directly as concrete aggregate in building industry. On the other hand, the crushed stone can be transported by the belt conveyor to the sand making machine for fine crushing. The crushed material is then screened through the circular vibrating screen for coarse sand, medium sand, fine sand and other specifications.
To meet the strict requirements, we need to add the sand washing machine behind fine sand. Sand washing machine discharge sewage can be recycled by fine sand recycling machine, reducing environmental pollution and improving the production of sand.
Dewo machinery can provides complete set of crushing and screening line, including Hydraulic Cone Crusher, Jaw Crusher, Impact Crusher, Vertical Shaft Impact Crusher (Sand Making Machine), fixed and movable rock crushing line, but also provides turnkey project for cement production line, ore beneficiation production line and drying production line.
For chemical and physical analytical methods such as AAS, NIR, ICP or XRF it is essential that the specimen is perfectly homogenizedto anadequate degree of analytical fineness. A reliable and accurate analysis can only be guaranteed by reproducible sample preparation. For these tasks RETSCH offers a comprehensive range of the most modern mills and crushers for coarse, fine and ultrafine size reduction of almost any material. The choice of grinding tools and accessories ensures that our instruments provide for contamination-free and reliable sample preparationprior tolaboratory analysis.
The cone crusherwas designed primarily with a view to achieving top performance in the field of fine-reduction crushing. It has also been adapted to what is designated simply as fine crushing, which extends into a range below that ordinarily defined by the term fine-reduction. Although the eccentric speeds of the various sizes of this type are not quite so high as the speeds used for the Newhouse crusher, the Hydro-cone crusher definitely rates as a high-speed machine, its product comparing quite closely to that of the former type, for equal close-side settings.Probably the outstanding feature of the. Hydrocone crusher is the hydraulic support, from which its name is derived and which is clearly shown in the sectional view. This device makes it possible to adjust the crusher to any desired setting within its range in a matter of seconds;adjustments may be made while the crusher is running, although the feed must be shut off before operating the adjusting pump. An accumulator in the hydraulic system provides protection against tramp iron or packing.
Cone crushers are used in AG and SAG grinding circuits to increase tonnage by effectively dealing with any pebble (critical size) build-up problem. Normally, heavy-duty short-head crushers are employed to crush pebbles. Power and crusher cavity level are the key variables for monitoring and controlling the crusher operation. Crusher product size is adjusted by changing the closed side setting.
On the left is a diagram of the Hydro-cone crushing chamber. A comparison of this chamber with those previously discussed is interesting. It will be noted that the choke-point has been raised far above the discharge level, in fact, to a point not far below the nip-point for the recommended maximum one-way feed dimension. By virtue of the decided flare of the head, and the corresponding flare of the top shell bore, the line-of-mean-diameters slopes sharply away from the crusher centerline. For some, distance above the discharge point the angle between head and concave is very acute; in fact, at the open-side position of the head, this zone is almost parallel. For recommended operating conditions, i.e., for safe combinations of throw and setting, and with screened feed, this type of crushing chamber does not approach anything like a choke or near-choke condition. For the combination shown in the diagram the ratio of volume reduction is almost 1:1 from zone 0-1 to zone 2-3 at the choke-point; consequently, if the crusher is given a screened feed (as all fine-reduction crushers should be) the reduction in voids by the time the choke-point is reached cannot very well reach serious proportions. The diagram shows the standard chamber. With screened feed, these crushers will operate at closed-side discharge settings equal to the throw of the head at the discharge point (usually spoken of as eccentric-throw.)
The level in the crusher feed pocket is an important variable since it can indicate whether the feed is building up. A build-up could lead to a plugin the feed chute, a spill through the skirting on the crusher feed, or a crusher plug. None of these are desirable.
In a normal feed situation, the level in the crusher cavity is kept fairly low, just enough to ensure that there is sufficient feed to keep the crusher working, but if the feed has to be suspended suddenly because of impending plugging, the crush-out wont take too long (10 seconds or less). Normal feed is usually used in standard crushers where the feed particle size is quite large, say greater than 65 mm.
Choke feed is when the crusher cavity is kept full, without spilling out through the skirting. Choke feeding is usually used in short-head crushers where the feed particle is smaller than that for a standard crusher.
This crusher is a modification of the standard machine, developed for fine-crushing duty. Mechanically, the machine is the same in every respect as the standard crusher of the same type, but for each developed size of machine a special top shell and the concave ring has been designed, with reduced receiving opening, reduced angularity between head and concave, and, consequently, superior characteristics at the finer settings. Medium crushing chambers may be operated at close-side settings of one-half the eccentric-throw, on screened feed; hence capacities at the finer settings are better than those of the standard type. Fine crushing chambers operate at one-fourth the eccentric throw. Inasmuch as the maximum feed size is smaller in the case of the fine chamber, the ratios of reduction are approximately the same for both machines.
There are two main types of cone crushers: standard and shorthead. They differ by the shape of the cavity. The standard crusher cavity is wider to accommodate larger feed-size material. The short head crusher is designed to crush finer material and to produce a finer product.
The closest approach between the mantle and the bowl liner is called the closed side setting. This is usually specified by the metallurgist to give the desired crusher product discharge size. It can be checked by running the crusher empty, hanging a lead plug into the crusher bowl, and then removing it to measure the gap. The gap is adjusted by rotating the bowl. Some crushers are equipped with a hydraulic jack mechanism on the crushing head assembly instead of having a bowl adjustment ring. The head can be raised or lowered to meet the operators needs. It can be very helpful in operation and process control.
The Symons Cone Crusher has come into almost universal use during the last few years for the final stage of crushing. It is a development of the secondary gyratory crusher, which is merely a small gyratory crusher designed to break the product of the primary machine down to about 1-in. size; but the main shaft of a cone crusher instead of being suspended from a spider is supported on a large socket bearing situated immediately under the crushing head and protected from grit and dust by a sealing assembly, this bearing taking the whole of the crushing load.
Fig. 8 gives a sectional view of the machine. The main shaft is carried in a long gear-driven eccentric, the rotation of which causes the gyration of the head in the usual way, but the center of gyration is at the apex of the crushing head instead of in the spider. At the top of the bowl, therefore, the lumps of ore entering the crushing zone are cracked by short powerful strokes; but at the bottom the head has a much longer but less powerful stroke, enabling the ore in the finishing stages to be rapidly crushed and quickly discharged without any tendency to choke, a condition which reduces over crushing to a minimum. This, together with the curved shape of the bowl, accounts for the large reduction ratio possible with this type of machine and makes it superior to other secondary crushers and coarse rolls.
It will be seen that the head and the bowl are parallel at the lower part of the crushing zone. The parallel space is deep enough, in conjunction with the speed of gyration, to ensure that no piece of ore can pass through it without being struck two or three times by the head before it falls clear. It follows that, unlike the jaw and gyratory crushers, the size of the product is determined by the distance apart of the bottom edges of the head and bowl in the position when they are closest together.
Coarse buttress threads on the outer circumference of the bowl fit into corresponding threads on the inner side of the adjusting ring, which is held down to the mainframe by a circle of long heavy springs, flexible enough to allow the whole assembly to rise should tramp iron or other uncrushable material enters the crushing zone. By means of a windlass and chain, the bowl can be rotated in the threads that support it in the adjusting ring while the machine is running, thus enabling the bowl liner to be adjusted for wear or the size of the product to be changed without stopping. The cone crusher is usually set to give a 3/8-in. or -in. product when discharging to ball mills.
Table 9 gives particulars of the different sizes of crushers. The capacity figures are based on material weighing 100 lb. per cubic foot and must be increased in direct proportions for heavier ores. It will be noted that each size of machine has two ranges of capacity; this is due to the fact that it can be fitted with a coarse or a fine crushing bowl according to the duty that is required of it. With either one, the range of reduction is greater than is economically possible with any other type of dry crushing machine.
A possible disadvantage of the cone crusher is that as a rule it cannot be choke-fed, but must be given an even feed of ore if it is to do efficient work. Should circumstances call for the installation of a machine that can be run if necessary with the ore piled up over the top of the head, a secondary gyratory crusher of the suspended shaft type will be required. The Traylor Reduction Crusher Type TZ, which is constructed on the principles of an ordinary gyratory crusher, but is fitted with a curved bowl liner similar to that of the Symons Cone Crusher, is designed to meet the case. Although the suspension of the shaft restricts the movement of the head to a smaller circle of gyration than that of the cone crusher, the ratio of reduction is still large enough to enable it to crush the product of the primary breaker to -in. size (-in. for the large machines), and it fulfills the condition that it can be choke-fed. Owing to the smaller movement of the head, however, the capacity for a given range is much less than that of the equivalent size of cone crusher, and the latter is therefore preferred when choke-feeding can be avoided.
The Symons Shorthead Cone Crusher, which is constructed on the same general principles as the larger machine, is designed to follow the latter, taking its product at 1-in. and reducing it to about -in. size. The strains imposed on the crushing members, however, would be very heavy if the machine were run with the discharge opening set to -in. or less. It is usual, therefore, to crush in closed circuit with a screen, the discharge opening of the bowl being set to 5/8 or in. Thus a circulating load is built up and a certain amount of choke-crushing takes place, but the method actually gives greater efficiency with a finer product than can be obtained in an open circuit, whatever the discharge setting of the bowl in the latter case.
In ordinary crushing practice, the grinding section is supplied with -in. or 3/8-in. material direct from Symons Cone Crushers. But the demand is for a finer feed and it seems likely that the Shorthead Cone Crusher will satisfy this demand to the exclusion of fine crushing rolls.
Symons Cone Crushers have been used extensively for secondary crushing in metallic, non-metallic, rock products, and industrial operations. The Symons Cone was developed to give large capacity, fine crushing. The combination of high speed and wide travel of the cone results in a series of rapid, hammer-like blows on the material as it passes through the crushing cavity and permits the free flow of material through the cavity.
Reduction in size of any particle, with each impact of the head, is regulated by the opening between the head and bowl at that point. A threaded arrangement of the bowl affords a quick and easy method for changing the size of the product or to compensate for wear. This adjustment can be made while the crusher is operating. A parallel zone between the lower portion of the crushing members assures uniform sizing.
Frame, adjustment ring, and cone are made of cast steel; gears are made of specially treated steel and have cut teeth; all bearings are bronze; mantle and bowl liners are manganese steel. The head and shaft can be removed as a unit, and other parts such as the eccentric and thrust bearings can easily be lifted out after the head is removed. The countershaft assembly can also be removed as a complete unit.
The circle of heavy coil springs, which holds the bowl and adjustment ring down firmly onto the frame, provides automatic protection against damage due to tramp iron. These springs compress, allowing the bowl to rise the full movement of the head until non-crushable material passes through. The springs then automatically return to their normal position.
Symons Cone Crushers are made in Standard and Short Head types. They are of the same general construction but differ in the shape of the crushing cavity. The Standard cone is used for intermediate crushing. The Short Head cone is used for finer crushing. It has a steeper angle of the head, a shorter crushing cavity, and greater movement of the head at the top of the crushing cavity.
If you observe the illustrations you will notice that the center line of the main shaft is at an angle to the center line of the crusher. The center of the main shaft bisects the center line of the crusher at the opening of the crushing chamber. As the MANTLE revolves that point is the pivot point of the mantle. This means that both the top and the bottom of the crusher mantle have a circular gyrating motion.
Tramp iron had long been a source of worry to those engaged in fine crushing.Here is what one operator had to say.Shutdowns were frequent, costs were uncertain because of enforced delays due to excessive breakage. Plugged machines had to be freed continually with a torch tocut out frozen and wedged-in tramp iron.The cone crusher overcame these troubles,helped reduce and stabilize costs. The bestevidence of this statement is the universalacceptance of the cone as the outstandingcrusher in its field.
While tramp iron is not recommended as a regular diet for a Cone Crusher, its construction is such that damage will not result should any ordinary noncrushable material get into the crushing cavity. The band of heavy coil springs encircling the frame allows the bowl to lift from its seat with each movement of the head until Such non-crushable object passes off into the discharge. The tramp iron shown in the accompanying illustration passed the protective devices installed for its removal and would have resulted in expensive repairs and long shutdown periods for any crusher except the Symons Cone.
Cone crushers can have two types of heads, standard and short head types. The principle difference between the two is in the shape (size and volume) of the crushing cavities and feed plate arrangements. Standard head cone crushers have cavities that are designed to take a primary crushed feed ranging up to 300mm generating product sizes around 20mm to 40mm. For finer products, short head cone crushers are normally used. They have a steeper angle of the head and a more parallel crushing cavity than the standard machines. Due to the more compact chamber volume and shorter working crushing length, the much needed higher crushing forces/power can be imparted to the smaller-sized material being fed to the crusher. Cavities for the short head machine are designed to produce a crushed product ranging from 5mm to 20mm in a closed circuit.
At the discharge end of the cone crusher is a parallel crushing section, where all material passing through must receive at least one impact. This ensures that all particles, which pass through the cone crusher, will have a maximum size, in at least one dimension, no larger than the set of the crusher. For this reason, the set of a cone crusher can be specified as the minimum discharge opening, being commonly known as the closed side setting (CSS).
Here are facts about the conecrusher known as Hydrocone. This line of hydraulically adjusted gyratory crushers was developed in smaller sizes some fifteen years ago by Allis-Chalmers to meet a demand for improved secondary or tertiary crushing units. The line is now expanded to include sizes up to 84-in. diameter cones.
This modern crusher is the result of many years of experience in building all types of crushing equipment, when the first gyratory or cone crusher, the Gates, was put into operation. Overall these years AC has followed a continuing policy of improvement in crusher engineering, changes in design being based on operating experience of crushers in actual operation.
The Hydrocone cone crusher is the logical outgrowth, a crusher having a means of rapidly changing product size or compensating for wear on the crushing surfaces a crusher which produces a better, more cubical product than any comparable crusher and a crusher so designed that it can be operated and maintained with a minimum of expense.
The most important fact about the Hydrocone crusher is its hydraulic principle of operation. Hydraulic control makes possible quick, accurate product size adjustments fast unloading of the crushing chamber in case of power failure or other emergency protection against tramp iron or other uncrushable materials in the crushing chamber. Another important fact about this crusher is its simplicity of design and operation. The accompanying sketch shows the simplicity of the Hydrocone crushers principle of operation. The main shaft assembly, including the crushing cone, is supported on a hydraulic jack. When oil is pumped into or out of the jack the mainshaft assembly is raised or lowered, changing the crusher setting.
Since the crushing cone is supported on a hydraulic jack, its position with respect to the concave ring, and therefore the crusher setting, can be controlled by the amount of oil in the hydraulic jack.
Speed-Set control raises or lowers the crushing shaft assembly hydraulically, and permits quick adjustment to produce precise product specifications without stopping the crusher. Speed-Set control also provides a convenient way to compensate for wear on crushing surfaces.
On Hydrocone crushers in sizes up to 48-in., the Speed-Set device is a hand-driven gear pump; on the larger sizes a motor-driven gear pump operated by push-button. On all sizes the setting can be changed in a matter of minutes by one man without additional equipment, reducing downtime materially.
Protection against tramp iron or other uncrushable materials is afforded by an accumulator in the hydraulic system. This consists of a neoprene rubber oil-resistant bladder inside a steel shell. This bladder is inflated with nitrogen to a predetermined pressure higher than the average pressures encountered during normal crushing.
Ordinarily, the Automatic Reset remains inoperative, but if steel or some other foreign material should enter the crushing chamber, the oil pressure in the hydraulic jack will exceed the gas pressure in the accumulator. The bladder will then compress, allowing the oil to enter the steel shell. This permits the crushing cone to lower and discharge the uncrushable material without damage to the crusher.
After the crushing chamber is freed of the foreign material, the gas pressure in the accumulator will again exceed the oil pressure in the hydraulic system. Oil is then expelled from the accumulator shell and the crushing cone is returned to its original operating setting automatically.
A Hydrocone crusher will produce a cubical product with excellent size distribution and a minimum of flats and slivers. This is especially important in the crushed stone industry where a cubical stone is required to meet rigid product specifications. It is also of considerable significance in the mining industry where the elimination of large amounts of tramp oversize reduces circulating loads or makes open circuit crushing possible.
The reason why the Hydrocone crusher will produce such a uniform, cubical product is that it has a small eccentric throw with respect to the crusher setting. This means a smaller effective ratio of reduction during each crushing stroke, and therefore, the production of fewer fines and slivers. Likewise, a small eccentric throw means a small open side setting, which results in a smaller top size of the product. A large percentage of the product from a Hydrocone crusher will be of a size equal to or finer than the close side setting.
For fine crushing, or in installations where the feed to the crusher is irregular, the use of a wobble plate feeder is recommended. This feeder is installed in place of the spider cap and affords a means of controlling the feed to the crusher, as well as a means of distributing the feed evenly around the crushing chamber.
Essentially, the feeder consists of a plate that is oscillated by a shaft extending down into the crushers main shaft. The motion of the main shaft oscillates or wobbles the feeder plate. The plate is supported on a rubber mounting which permits its motion and, at the same time, positively seals the top of the spider bearing against the entry of dust. Maintenance is reduced by the use of self-lubricating bushings between the feeder plate shaft and the crusher main shaft.
Hydrocone crushers are mounted on rubber machinery mountings in order to reduce installation costs and make it possible to locate these machines on the upper floors of crushing plants. These mountings operate without maintenance, absorb the gyrating motion of the crusher, thereby eliminating the need for massive foundations. Rubber mountings also prolong the life of the eccentric bearing, since this bearing is not subjected to the severe pounding encountered when rigid mountings are used.
The exclusion of dust and dirt from the internal mechanism of the crusher is of extreme importance from a maintenance standpoint. To accomplish this, Hydrocone crushers are equipped with one of the most effective dust seals yet devised.
This seal consists of a self-lubricating, graphite impregnated plastic ring which is supported from the head center in such a way that it is free to rotate, or gyrate, independently of the head center.
The plastic ring surrounds the dust collar with only a very slight clearance between the two parts. With the plastic ring being free to move as it is, it accommodates the rotation, gyration, and vertical movement of the main shaft assembly, maintaining the seal around the dust collar at all times. Because of its lightweight and self-lubricating characteristics, wear on the plastic ring is negligible.
The ease with which any wearing part can be replaced is of the utmost importance to any crusher operator. With this in mind, the Hydrocone crusher has been designed so that any part can be replaced by disturbing only a minimum number of other parts.
For example, the Mantalloy crushing surfaces are exposed by simply removing the top shell from the crusher. This can be done easily by removing the nuts from the studs at the top and bottom shell joint. The eccentric and hydraulic support mechanisms are serviced from underneath the crusher without disturbing any of the feeding arrangements, or the upper part of the crusher.
Efficient lubrication of all wearing parts is one of the reasons why crushing costs are low with the Hydrocone crusher. On most sizes, lubrication is divided into three distinct systems, each functioning independently.
This bearing, whether of the ball and socket type as on the smaller sizes, or of the hourglass design (as shown) found on the larger Hydrocone crushers, is pool lubricated. On the 51, 60 and 84-inch sizes, provision is made for introducing the lubricant from outside the top shell through the spider arm. On the smaller crushers, oil is introduced through an oil inlet in the spider cap. On all sizes, oil is retained in the bearing by a garter-type oil seal located in the base of the spider bearing.
All Hydrocone crushers are provided with a compact external lubrication system consisting of an oil storage tank, an independently motor-driven oil pump, a pressure-type oil filter, and a condenser-type cooler.
Cool, clean oil is pumped into the crusher from the conditioning tank, lubricating first the three-piece step bearing assembly. The oil then travels up the inner surface of the eccentric, lubricating the eccentric bearing and main shaft.
At the top of the eccentric, the oil is split into two paths. Part of the oil flow passes through ports in the eccentric and down its outer surface, lubricating the bronze bottom shell bushing, driving gears and wearing ring. On the 48-in. and smaller crushers, the balance of the oil overflows the eccentric and returns over the gears to the bottom of the crusher where it flows by gravity back into the conditioning tank. On the 51-in. and larger Hydrocone crushers, any oil which overflows the top of the eccentric is returned directly to the conditioning system without coming into contact with the gears.
On all but the 36 and 48-in. Hydrocone crushers, the countershaft bearings are of the anti-friction type with separate pool lubrication. Both ends of the countershaft bearing housing are sealed by garter spring-type oil seals to prevent dirt or other contaminants from entering the system.
Rather than use one eccentric throw under all operating conditions, Hydrocone crushers are designed to operate most efficiently with a predetermined ratio of eccentric throw to the crusher setting. By operating with an eccentric throw specifically selected for a given application, the most desirable crushing conditions are attained the most economical use of Mantalloy crushing surfaces reduced crusher maintenance a more cubical product.
The eccentric throw is controlled by a replaceable bronze sleeve in the cast steel eccentric. This sleeve, being a wearing part, can be renewed readily in the field. Also, should operating conditions change, the throw or motion of the crushing head can be changed accordingly.
Because of the large choice of eccentric throws available and the variety of crushing chambers that may be obtained a Hydrocone crusher may be selected that will fulfill the requirements of almost any secondary or tertiary crushing operation.
They may be used in the crushed stone industries to produce a premium cubical product in the mining industries to produce a grinding mill feed having a minimum of oversize, thereby reducing circulating loads and making open circuit crushing possible. The Hydrocone crusher is used in the cement industry to reduce cement clinker prior to finish grinding.
One of three general types of crushing chambers can be furnished for any size Hydrocone crusher to suit your specific needs. The selection of the proper chamber for a given application is dependent upon the feed size, the tonnage to be handled and the product desired. A crusher already in use can be readily converted to meet changing requirements, making this machine highly flexible in operation.
The Coarse crushing chamber affords the maximum feed opening for a given size crusher. Crushers fitted with a Coarse chamber can be choke fed, provided that product size material in the feed is removed.
The Coarse chamber has a relatively short parallel zone and is designed to be operated at a close side setting equal to or greater than the eccentric throw. For example, a crusher with a 3/8-in. the eccentric throw should be operated at a 3/8-in. (or more) close side setting, and therefore a -in. open side setting. Optimum capacity and product will result when operated under these conditions, as well as most economical wear on the mantalloy crushing surfaces.
One way dimension (slot size) of the feed to a crusher fitted with a Coarse chamber should not exceed two-thirds to 70 percent of the feed opening. The maximum feed size to an 848 Hydrocone crusher would therefore be about 5-in. one way dimension.
The use of a wobble plate feeder, furnished as optional equipment, is recommended if the feed size is relatively large, if the crusher is to be operated in closed circuit, or if the feed to the crusher is irregular.
If the Hydrocone crusher is operated with a Coarse crushing chamber, the product will average about 60% passing a square mesh testing sieve equal to the close side setting of the crusher. On certain materials which break very slabby, this percentage will be somewhat lower, and on cubically breaking material the percentage will be somewhat higher. As an average, approximately 90% of the product will pass a square mesh testing sieve corresponding to the open side setting, although this percentage frequently runs higher.
The Intermediate crushing chamber has a feed opening somewhat less than a coarse crushing chamber, but because of its longer parallel zone, is designed to be operated at a close side setting equal to or greater than half the eccentric throw. For example, with a -in. eccentric throw, the minimum close side setting would be 3/8-in.
Crushers fitted with this type of chamber can be choke fed, provided that product size material in the feed be removed ahead of the crusher. The one-way dimension or slot size of the feed to a crusher should not exceed approximately half the receiving opening. A 436 Hydrocone crusher with a 5/8-in. the eccentric throw could be operated at 5/16-in. close side setting and feed size should not exceed 2-in. one-way dimension.
The wobble plate feeder, although not required under most circumstances, is recommended if the feed is irregular, or if the crusher is operated as a re-crusher, at a relatively close setting, or in a closed circuit.
Because of the longer parallel zone in this crushing chamber, a somewhat greater percentage of the product will pass a square mesh testing sieve equal to the close side setting. This will usually average about 65 to 70%, with this percentage varying, depending on the material being crushed. Very frequently, 100% of the product will pass a square mesh testing sieve equal to the open side setting of the crusher.
The Fine crushing chamber has the longest parallel zone and therefore the smallest feed opening for any given size crusher. It can be operated at ratios of eccentric throw to close side setting of up to 4 to 1. With a -in. throw, for example, a 236 Hydro-cone crusher could be operated at 3/16-in. on the close side.
Because of their design, crushers with Fine crushing chambers cannot be choke fed but must be equipped with the wobble plate feeder. The maximum one-way dimension of the feed approaches the crusher feed opening. A 348 Hydrocone crusher can be fed with material up to 3-in. one-way dimension.
The Fine crushing chamber will give the highest percentage passing the close side setting of any of the chambers discussed here. The product will average approximately 75% passing a square mesh testing sieve equal to the close side setting. Because of the long parallel zone, the top size of the product will be only slightly larger than the close side setting of the crusher.
In addition to the three general types of crushing chambers described here, special chambers can be designed to meet varying operating requirements, giving the crusher even greater flexibility than can be obtained with these three main types.
For example, a special concave ring can be used in a 636 Hydro-cone crusher which will reduce the feed opening to 5 inches and permits a two to one ratio of eccentric throw to close side setting. Thus, the crusher can be furnished to fit the exact requirements of any application.
The following capacity table gives a complete range of all Hydrocone cone crusher capacities with varying crushing chambers and eccentric throws. This table shows the minimum recommended setting for any given eccentric throw, the recommended maximum one-way (slot size) dimension of the feed, and the maximum recommended horsepower for any eccentric throw.
Capacities given are based on crushing dry feed from which the product size material has been removed. The material must readily enter the feed opening and be evenly distributed around the crushing chamber. The table is based on material weighing 100 lb per cubic foot crushed. Any variation from this must be accounted for.
The curves on the following page can be used to approximate the screen analysis of the product from any given Hydrocone crusher. These curves are only approximations since the actual screen analysis of the product of a Hydrocone crusher will depend upon the nature of the material being crushed, the feed size and a number of other considerations which could not be taken into account in these curves. Within these limits, the curves should give fairly accurate estimates.
Note that the Coarse crushing chamber is represented as giving a product of which 60 percent will pass the close side setting, the Intermediate chamber 67 percent and the Fine chamber 75 percent passing the close side setting. These percentages are the averages of a large number of tests and some variations from these must be expected. If material breaks slabby the percentage with a coarse crushing chamber may be as low as 50 percent; if it breaks very cubically it might be as high as 70 percent, or even higher.
These curves have been prepared so that they can be used for any crushing chamber. To estimate the product of any Hydrocone crusher, it is necessary to know the type of crushing chamber used (Coarse, Intermediate or Fine), the close side setting and the eccentric throw.
If the crusher is a 636 Hydrocone crusher with a 3/8-in. throw and a 3/8-in. close side setting, the approximate screen analysis would be the curve that would pass through the 3/8-in. horizontal line and the vertical line representing the close side setting for the Coarse crushing chamber, which is the 60 percent passing line. If no curve passes through the precise point of intersection between the horizontal and vertical lines, an approximate curve can be sketched in which parallels the other curves. The same procedure can be used for approximating the products from any other crushing chamber.
Barite..170 Basalt.100 Cement Clinker.95 Coal..40-60 Coke.23-32 Glass..95 Granite100 Gravel.100 Gypsum..85 Iron Ore.125-150 Limestone..95-100 Magnesite.100 Perlite..95 Porphyry.100 Quartz..95 Sandstone..85 Slag..80 Taconite125 Talc..95 Trap Rock100
We canprovide testing to solve the most difficult crushing problems. Laboratory equipment makes it possible to measure the crushing strengths and characteristics of rock or ore samples accurately, and this data is used in the selection of a crusher of proper size and type.
Impact and batch tests are frequently sufficient to indicate the type and size crusher that will be the most economical for a particular application. However, batch testing is often followed by pilot plant tests to provide additional information about large-scale operations, or to observe rock or ore reduction under actual plant operating conditions.
Pilot plant tests duplicate a continuous crushing operation provide a practical demonstration of the commercial potential of the process on a pilot scale. Such tests are useful because they may disclose factors that affect the full-scale operation, favorably or otherwise, but which remain hidden in tests on limited samples.
All Laboratory tests are guided by modern scientific knowledge of crushing fundamentals and by ourinvaluable backlog of experience in engineering and building all types of crushing equipment for any crushing application.
In addition to the facilities for crushing tests, the Laboratory maintains complete batch and pilot mill facilities for use in investigating an entire process. Tests in grinding, sizing, concentrating, thickening, filtering, drying, and pyro- processing can be made.
The quality of every product, or material analysis, depends on the quality of the sample preparation. It is therefore extremely important to consider all individual milling parameters in order to make an informed choice: material properties, feed size and volume of the sample, grinding time and desired final particle size, any abrasion of the grinding parts all these factors are significant.
For this reason, LAVAL LAB offers a wide selection of high-performance mills, in various product groups, for every application and every specific need: Planetary Ball Mills, Ball Mills, Cutting and Beater Mills, Rotor Mills, Jaw Crushers, Roll Crushers, Cone Crushers, Disk Mills and Mortar Grinders.
Take advantage of our expertise, contact us to select the best equipment for your samples. [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Knife Mill Blender Pulverisette 11 $1.00 Knife Mill Blender Pulverisette 11 $1.00 The Knife Mill Homogenizer Pulverisette 11 is the ideal Laboratory Mixer for fast size reduction and homogenization of Food samples Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Cutting Mill Pulverisette 19 for Cannabis Processing $1.00 Cutting Mill Pulverisette 19 for Cannabis Processing $1.00 The Pulverisette 19 Universal Cutting Mill System has been optimized for Cannabis Processing. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders High Energy Planetary Ball Mill Pulverisette 5 Premium $1.00 High Energy Planetary Ball Mill Pulverisette 5 Premium $1.00 The High Energy Planetary Ball Mill Pulverisette 5 PREMIUM with 2 working stations is the ideal mill for fast, wet or dry, grinding of larger sample quantities down to the nanometer range, with the highest safety standards. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Variable Speed Rotor Mill Pulverisette 14 Premium $1.00 Variable Speed Rotor Mill Pulverisette 14 Premium $1.00 The Variable Speed Rotor Mill Pulverisette 14 Premium is a versatile, powerful mill for the fast grinding of medium-hard, brittle as well as fibrous materials and temperature sensitive samples. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders High-Tech Disc Pulverizer Pulverisette 13 Premium $1.00 High-Tech Disc Pulverizer Pulverisette 13 Premium $1.00 The Laboratory Disc Pulverizer Pulverisette 13 Premium Line is designed for batch or continuous fine grinding of hard-brittle to medium-hard solids, down to 50m. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders High-Tech Laboratory Jaw Crusher $1.00 High-Tech Laboratory Jaw Crusher $1.00 For fast and effective pre-crushing of very hard, hard, medium-hard, brittle materials, even ferrous alloys. Size reduction from 95 mm to 0.3 mm. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Vibratory Micro Mill Pulverisette 0 $1.00 Laboratory Vibratory Micro Mill Pulverisette 0 $1.00 The Micro Mill Pulverisette 0 is designed for fine grinding of dry laboratory samples or solids in suspension, and for homogenisation of emulsions or pastes. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Vibrating Cup Mill Pulverisette 9 $1.00 Laboratory Vibrating Cup Mill Pulverisette 9 $1.00 The Ring & Puck Mill Pulverisette 9 is designed for extremely fast pulverizing (speed up to 1500 rpm) of hard, brittle and fibrous laboratory samples, dry or in suspension, down to analytical fineness. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Rotor Mill Pulverisette 14 $1.00 Laboratory Rotor Mill Pulverisette 14 $1.00 The Variable Speed Rotor Mill Pulverisette 14 is an all-purpose mill for rapid crushing of medium-hard to soft materials, even temperature-sensitive products. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Power Cutting Mill Pulverisette 25 $1.00 Power Cutting Mill Pulverisette 25 $1.00 The Pulverisette 25 is a powerful cutting mill for the coarse grinding of dry, soft to medium-hard or fibrous materials and plastics. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Planetary Mono Mill Pulverisette 6 $1.00 Planetary Mono Mill Pulverisette 6 $1.00 The Planetary Mono Mill Pulverisette 6 is recommended for extremely rapid, batch grinding of hard to soft material, dry or in suspension, down to colloidal fineness. It is also an ideal laboratory instrument for mixing and homogenising of emulsions. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Planetary Micro Mill Pulverisette 7 $1.00 Planetary Micro Mill Pulverisette 7 $1.00 The Planetary Micro Mill Pulverisette 7 is designed for uniform, and extremely fine size reduction of very small samples of hard to soft material, dry or in suspension, down to colloidal fineness. Also designed for mixing and homogenising of emulsions or pastes. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Nano Range Planetary Mill Pulverisette 7 Premium $1.00 Nano Range Planetary Mill Pulverisette 7 Premium $1.00 Thanks to the high rotational speedof up to 1100 rpm for the main disc, this high-tech Planetary Mill, Pulverisette 7 Premium,easily grinds down to the nanometer range. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Planetary Ball Mill Pulverisette 5 $1.00 Planetary Ball Mill Pulverisette 5 $1.00 The Planetary Ball Mill Pulverisette 5 allows fast and very fine grinding of hard to soft material, dry or in suspension, down to colloidal fineness. It can also be used for mixing and homogenising of emulsions and pastes. Grinding capacity of up to 8 samples per operation. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Mini Mill Pulverisette 23 $1.00 Laboratory Mini Mill Pulverisette 23 $1.00 The Mini Ball Mill Pulverisette 23 is used for fine grinding of small quantities of dry samples or solids in suspensions, as well as mixing and homogenisation of emulsions. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Planetary Mill Pulverisette 4 for mechanical alloying and mechanical activation $1.00 Planetary Mill Pulverisette 4 for mechanical alloying and mechanical activation $1.00 The Vario Planetary Mill Pulverisette 4 is ideal for mechanical activation and alloying.It offers thefreedom toprogramall grinding parametersthroughPC software to achieve the desired effect on the sample. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Mortar Grinder Pulverisette 2 $1.00 Mortar Grinder Pulverisette 2 $1.00 The Automatic Mortar Grinder Pulverisette 2 is ideal for universal grinding of medium-hard-brittle to soft-brittle materials (dry or in suspension) to analytical fineness, as well as for formulation and homogenisation of pastes and creams at laboratory scale. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Jaw Crusher Pulverisette 1 $1.00 Laboratory Jaw Crusher Pulverisette 1 $1.00 This Laboratory Jaw Crusher is designed for fast and effective pre-crushing of very hard, hard, medium-hard, and brittle materials, even ferrous alloys. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Disc Pulverizer Pulverisette 13 $1.00 Laboratory Disc Pulverizer Pulverisette 13 $1.00 The Laboratory Disc Pulverizer Pulverisette 13 is designed for batch or continuous fine grinding of hard-brittle to medium-hard solids. Quantity Add to Quote request Quick View [yith_wcwl_add_to_wishlist] Quick View Crushers, Pulverizers, Grinders Laboratory Cutting Mill Pulverisette 15 $1.00 Laboratory Cutting Mill Pulverisette 15 $1.00 This Laboratory Cutting Mill is recommended for size reduction of dry sample material with soft to medium-hard consistency, for fibrous materials or cellulose materials. Quantity Add to Quote request Quick View
The High Energy Planetary Ball Mill Pulverisette 5 PREMIUM with 2 working stations is the ideal mill for fast, wet or dry, grinding of larger sample quantities down to the nanometer range, with the highest safety standards.
The Ring & Puck Mill Pulverisette 9 is designed for extremely fast pulverizing (speed up to 1500 rpm) of hard, brittle and fibrous laboratory samples, dry or in suspension, down to analytical fineness.
The Planetary Mono Mill Pulverisette 6 is recommended for extremely rapid, batch grinding of hard to soft material, dry or in suspension, down to colloidal fineness. It is also an ideal laboratory instrument for mixing and homogenising of emulsions.
The Planetary Micro Mill Pulverisette 7 is designed for uniform, and extremely fine size reduction of very small samples of hard to soft material, dry or in suspension, down to colloidal fineness. Also designed for mixing and homogenising of emulsions or pastes.
The Planetary Ball Mill Pulverisette 5 allows fast and very fine grinding of hard to soft material, dry or in suspension, down to colloidal fineness. It can also be used for mixing and homogenising of emulsions and pastes. Grinding capacity of up to 8 samples per operation.
The Vario Planetary Mill Pulverisette 4 is ideal for mechanical activation and alloying.It offers thefreedom toprogramall grinding parametersthroughPC software to achieve the desired effect on the sample.
The Automatic Mortar Grinder Pulverisette 2 is ideal for universal grinding of medium-hard-brittle to soft-brittle materials (dry or in suspension) to analytical fineness, as well as for formulation and homogenisation of pastes and creams at laboratory scale.
Cone crushers were originally designed and developed by Symons around 1920 and therefore are often described as Symons cone crushers. As the mechanisms of crushing in these crushers are similar to gyratory crushers their designs are similar, but in this case the spindle is supported at the bottom of the gyrating cone instead of being suspended as in larger gyratory crushers. Figure5.3 is a schematic diagram of a cone crusher.
The breaking head gyrates inside an inverted truncated cone. These crushers are designed so that the head-to-depth ratio is larger than the standard gyratory crusher and the cone angles are much flatter and the slope of the mantle and the concaves are parallel to each other. The flatter cone angles help to retain the particles longer between the crushing surfaces and therefore produce much finer particles. To prevent damage to the crushing surfaces, the concave or shell of the crushers is held in place by strong springs or hydraulics which yield to permit uncrushable tramp material to pass through.
The secondary crushers are designated as Standard cone crushers having stepped liners and tertiary Short Head cone crushers, which have smoother crushing faces and steeper cone angles of the breaking head. The approximate distance of the annular space at the discharge end designates the size of the cone crushers. A brief summary of the design characteristics is given in Table5.4 for crusher operation in open-circuit and closed-circuit situations.
The Standard cone crushers are for normal use. The Short Head cone crushers are designed for tertiary or quaternary crushing where finer product is required. These crushers are invariably operated in closed circuit. The final product sizes are fine, medium or coarse depending on the closed set spacing, the configuration of the crushing chamber and classifier performance, which is always installed in parallel.
For finer product sizes, i.e., less than 6mm, special cone crushers known as Gyradisc crushers are available. The operation is similar to the standard cone crushers, except that the size reduction is caused more by attrition than by impact . The reduction ratio is around 8:1 and as the product size is relatively small the feed size is limited to less than 50mm with a nip angle between 25 and 30. The Gyradisc crushers have head diameters from around 900 to 2100mm. These crushers are always operated under choke feed conditions. The feed size is less than 50mm and therefore the product size is usually less than 69mm.
Maintenance of the wear components in both gyratory and cone crushers is one of the major operating costs. Wear monitoring is possible using a Faro Arm (Figure 6.10), which is a portable coordinate measurement machine. Ultrasonic profiling is also used. A more advanced system using a laser scanner tool to profile the mantle and concave produces a 3D image of the crushing chamber (Erikson, 2014). Some of the benefits of the liner profiling systems include: improved prediction of mantle and concave liner replacement; identifying asymmetric and high wear areas; measurement of open and closed side settings; and quantifying wear life with competing liner alloys.
Various types of rock fracture occur at different loading rates. For example, rock destruction by a boring machine, a jaw or cone crusher, and a grinding roll machine are within the extent of low loading rates, often called quasistatic loading condition. On the contrary, rock fracture in percussive drilling and blasting happens under high loading rates, usually named dynamic loading condition. This chapter presents loading rate effects on rock strengths, rock fracture toughness, rock fragmentation, energy partitioning, and energy efficiency. Finally, some of engineering applications of loading rate effects are discussed.
In Chapter4, we have already seen the mechanism of crushing in a jaw crusher. Considering it further we can see that when a single particle, marked 1 in Figure11.5a, is nipped between the jaws of a jaw crusher the particle breaks producing fragments, marked 2 and 3 in Figure11.5b. Particles marked 2 are larger than the open set on the crusher and are retained for crushing on the next cycle. Particles of size 3, smaller than the open set of the crusher, can travel down faster and occupy or pass through the lower portion of the crusher while the jaw swings away. In the next cycle the probability of the larger particles (size 2) breaking is greater than the smaller sized particle 3. In the following cycle, therefore, particle size 2 is likely to disappear preferentially and the progeny joins the rest of thesmaller size particles indicated as 3 in Figure11.5c. In the figures, the position of the crushed particles that do not exist after comminution is shaded white (merely to indicate the positions they had occupied before comminution). Particles that have been crushed and travelled down are shown in grey. The figure clearly illustrates the mechanism of crushing and the classification that takes place within the breaking zone during the process, as also illustrated in Figure11.4. This type of breakage process occurs within a jaw crusher, gyratory crusher, roll crusher and rod mills. Equation (11.19) then is a description of the crusher model.
In practice however, instead of a single particle, the feed consists of a combination of particles present in several size fractions. The probability of breakage of some relatively larger sized particles in preference to smaller particles has already been mentioned. For completeness, the curve for the probability of breakage of different particle sizes is again shown in Figure11.6. It can be seen that for particle sizes ranging between 0 K1, the probability of breakage is zero as the particles are too small. Sizes between K1 and K2 are assumed to break according a parabolic curve. Particle sizes greater than K2 would always be broken. According to Whiten , this classification function Ci, representing the probability of a particle of size di entering the breakage stage of the crusher, may be expressed as
The classification function can be readily expressed as a lower triangular matrix [1,16] where the elements represent the proportion of particles in each size interval that would break. To construct a mathematical model to relate product and feed sizes where the crusher feed contains a proportion of particles which are smaller than the closed set and hence will pass through the crusher with little or no breakage, Whiten  advocated a crusher model as shown in Figure11.7.
The considerations in Figure11.7 are similar to the general model for size reduction illustrated in Figure11.4 except in this case the feed is initially directed to a classifier, which eliminates particle sizes less than K1. The coarse classifier product then enters the crushing zone. Thus, only the crushable larger size material enters the crusher zone. The crusher product iscombined with the main feed and the process repeated. The undersize from the classifier is the product.
While considering the above aspects of a model of crushers, it is important to remember that the size reduction process in commercial operations is continuous over long periods of time. In actual practice, therefore, the same operation is repeated over long periods, so the general expression for product size must take this factor into account. Hence, a parameter v is introduced to represent the number of cycles of operation. As all cycles are assumed identical the general model given in Equation (11.31) should, therefore, be modified as
Multiple vectors B C written in matrix form:BC=0.580000.200.60000.120.180.6100.040.090.20.571.000000.700000.4500000=0581+00+00+000.580+00.7+00+000580+00+00.45+000.580+00+00+000.21+0.60+00+000.20+0.60.7+00+000.20+0.60+00.45+000.20+0.60+00+000.121+0.180+0.610+000.120+0.180.7+0.610+000.120+0.180+0.610.45+000.120+0.180+0.610+000.041+0.090+0.20+0.5700.040+0.090.7+0.20+0.5700.040+0.090+0.20.45+0.5700.040+0.090+0.20+0.570=0.580000.20.42000.120.1260.274500.040.0630.090
Now determine (I B C) and (I C)(IBC)=10.5800000000.210.42000000.1200.12610.27450000.0400.06300.0910=0.420000.20.58000.120.1260.725500.040.0630.091and(IC)=000000.300000.5500001
Now find the values of x1, x2, x3 and x4 as(0.42x1)+(0x2)+(0x3)+(0x4)=10,thereforex1=23.8(0.2x1)+(0.58x2)+(0x3)+(0x4)=33,thereforex2=65.1(0.12x1)+(0.126x2)+(0.7255x3)+(0x4)=32,thereforex3=59.4(0.04x1)+(0.063x2)+(0.09x3)+(1x4)=20,thereforex4=30.4
In this process, mined quartz is crushed into pieces using crushing/smashing equipment. Generally, the quartz smashing plant comprises a jaw smasher, a cone crusher, an impact smasher, a vibrating feeder, a vibrating screen, and a belt conveyor. The vibrating feeder feeds materials to the jaw crusher for essential crushing. At that point, the yielding material from the jaw crusher is moved to a cone crusher for optional crushing, and afterward to effect for the third time crushing. As part of next process, the squashed quartz is moved to a vibrating screen for sieving to various sizes.
Crushers are widely used as a primary stage to produce the particulate product finer than about 50100mm. They are classified as jaw, gyratory, and cone crushers based on compression, cutter mill based on shear, and hammer crusher based on impact.
A jaw crusher consists essentially of two crushing plates, inclined to each other forming a horizontal opening by their lower borders. Material is crushed between a fixed and a movable plate by reciprocating pressure until the crushed product becomes small enough to pass through the gap between the crushing plates. Jaw crushers find a wide application for brittle materials. For example, they are used for comminution of porous copper cake. A Fritsch jaw crusher with maximal feed size 95mm, final fineness (depends on gap setting) 0.315mm, and maximal continuous throughput 250Kg/h is shown in Fig. 2.8.
A gyratory crusher includes a solid cone set on a revolving shaft and placed within a hollow body, which has conical or vertical sloping sides. Material is crushed when the crushing surfaces approach each other and the crushed products fall through the discharging opening.
Hammer crushers are used either as a one-step primary crusher or as a secondary crusher for products from a primary crusher. They are widely used for crushing hard metal scrap for different hard metal recycling processes. Pivoted hammers are pendulous, mounted on the horizontal axes symmetrically located along the perimeter of a rotor. Crushing takes place by the impact of material pieces with the high speed moving hammers and by contact with breaker plates. A cylindrical grating or screen is placed beneath the rotor. Materials are reduced to a size small enough to pass through the openings of the grating or screen. The size of the product can be regulated by changing the spacing of the grate bars or the opening of the screen.
The feature of the hammer crushers is the appearance of elevated pressure of air in the discharging unit of the crusher and underpressure in the zone around the shaft close to the inside surface of the body side walls. Thus, the hammer crushers also act as high-pressure, forced-draught fans. This may lead to environmental pollution and product losses in fine powder fractions. A design for a hammer crusher (Fig. 2.9) essentially allows a decrease of the elevated pressure of air in the crusher discharging unit . The A-zone beneath the screen is communicated through the hollow ribs and openings in the body side walls with the B-zone around the shaft close to the inside surface of body side walls. As a result, the circulation of suspended matter in the gas between A and B zones is established and the high pressure of air in the discharging unit of crusher is reduced.
Crushers are widely used as a primary stage to produce the particulate product finer than about 50100 mm in size. They are classified as jaw, gyratory and cone crushers based on compression, cutter mill based on shear and hammer crusher based on impact.
A jaw crusher consists essentially of two crushing plates, inclined to each other forming a horizontal opening by their lower borders. Material is crushed between a fixed and a movable plate by reciprocating pressure until the crushed product becomes small enough to pass through the gap between the crushing plates. Jaw crushers find a wide application for brittle materials. For example, they are used for comminution of porous copper cake.
A gyratory crusher includes a solid cone set on a revolving shaft and placed within a hollow body, which has conical or vertical sloping sides. Material is crushed when the crushing surfaces approach each other and the crushed products fall through the discharging opening.
Hammer crushers are used either as a one-step primary crusher or as a secondary crusher for products from a primary crusher. They are widely used for crushing of hard metal scrap for different hard metal recycling processes.
Pivoted hammers are pendulous, mounted on the horizontal axes symmetrically located along the perimeter of a rotor and crushing takes place by the impact of material pieces with the high speed moving hammers and by contact with breaker plates. A cylindrical grating or screen is placed beneath the rotor. Materials are reduced to a size small enough pass through the openings of the grating or screen. The size of product can be regulated by changing the spacing of the grate bars or the opening of the screen.
The feature of the hammer crushers is the appearance of elevated pressure of air in the discharging unit of the crusher and underpressure in the zone around of the shaft close to the inside surface of the body side walls. Thus, the hammer crushers also act as high-pressure forced-draught fans. This may lead to environmental pollution and product losses in fine powder fractions.
A design for a hammer crusher (Figure 2.6) allows essentially a decrease of the elevated pressure of air in the crusher discharging unit . The A-zone beneath the screen is communicated through the hollow ribs and openings in the body side walls with the B-zone around the shaft close to the inside surface of body side walls. As a result, circulation of suspended matter in the gas between A- and B-zones is established and high pressure of air in the discharging unit of crusher is reduced.
For a particular operation where the ore size is known, it is necessary to estimate the diameter of rolls required for a specific degree of size reduction. To estimate the roll diameter, it is convenient to assume that the particle to be crushed is spherical and roll surfaces are smooth. Figure6.2 shows a spherical particle about to enter the crushing zone of a roll crusher and is about to be nipped. For rolls that have equal radius and length, tangents drawn at the point of contact of the particle and the two rolls meet to form the nip angle (2). From simple geometry it can be seen that for a particle of size d, nipped between two rolls of radius R:
Equation (6.2) indicates that to estimate the radius R of the roll, the nip angle is required. The nip angle on its part will depend on the coefficient of friction, , between the roll surface and the particle surface. To estimate the coefficient of friction, consider a compressive force, F, exerted by the rolls on the particle just prior to crushing, operating normal to the roll surface, at the point of contact, and the frictional force between the roll and particle acting along a tangent to the roll surface at the point of contact. The frictional force is a function of the compressive force F and is given by the expression, F. If we consider the vertical components of these forces, and neglect the force due to gravity, then it can be seen that at the point of contact (Figure6.2) for the particle to be just nipped by the rolls, the equilibrium conditions apply where
As the friction coefficient is roughly between 0.20 and 0.30, the nip angle has a value of about 1117. However, when the rolls are in motion the friction characteristics between the ore particle will depend on the speed of the rolls. According to Wills , the speed is related to the kinetic coefficient of friction of the revolving rolls, K, by the relation
Equation (6.4) shows that the K values decrease slightly with increasing speed. For speed changes between 150 and 200rpm and ranging from 0.2 to 0.3, the value of K changes between 0.037 and 0.056. Equation (6.2) can be used to select the size of roll crushers for specific requirements. For nip angles between 11 and 17, Figure6.3 indicates the roll sizes calculated for different maximum feed sizes for a set of 12.5mm.
The maximum particle size of a limestone sample received from a cone crusher was 2.5cm. It was required to further crush it down to 0.5cm in a roll crusher with smooth rolls. The friction coefficient between steel and particles was 0.25, if the rolls were set at 6.3mm and both revolved to crush, estimate the diameter of the rolls.
It is generally observed that rolls can accept particles sizes larger than the calculated diameters and larger nip angles when the rate of entry of feed in crushing zone is comparable with the speed of rotation of the rolls.
Jaw crushers are mainly used as primary crushers to produce material that can be transported by belt conveyors to the next crushing stages. The crushing process takes place between a fixed jaw and a moving jaw. The moving jaw dies are mounted on a pitman that has a reciprocating motion. The jaw dies must be replaced regularly due to wear. Figure 8.1 shows two basic types of jaw crushers: single toggle and double toggle. In the single toggle jaw crusher, an eccentric shaft is installed on the top of the crusher. Shaft rotation causes, along with the toggle plate, a compressive action of the moving jaw. A double toggle crusher has, basically, two shafts and two toggle plates. The first shaft is a pivoting shaft on the top of the crusher, while the other is an eccentric shaft that drives both toggle plates. The moving jaw has a pure reciprocating motion toward the fixed jaw. The crushing force is doubled compared to single toggle crushers and it can crush very hard ores. The jaw crusher is reliable and robust and therefore quite popular in primary crushing plants. The capacity of jaw crushers is limited, so they are typically used for small or medium projects up to approximately 1600t/h. Vibrating screens are often placed ahead of the jaw crushers to remove undersize material, or scalp the feed, and thereby increase the capacity of the primary crushing operation.
Both cone and gyratory crushers, as shown in Figure 8.2, have an oscillating shaft. The material is crushed in a crushing cavity, between an external fixed element (bowl liner) and an internal moving element (mantle) mounted on the oscillating shaft assembly. An eccentric shaft rotated by a gear and pinion produces the oscillating movement of the main shaft. The eccentricity causes the cone head to oscillate between the open side setting (o.s.s.) and closed side setting (c.s.s.). In addition to c.s.s., eccentricity is one of the major factors that determine the capacity of gyratory and cone crushers. The fragmentation of the material results from the continuous compression that takes place between the mantle and bowl liners. An additional crushing effect occurs between the compressed particles, resulting in less wear of the liners. This is also called interparticle crushing. The gyratory crushers are equipped with a hydraulic setting adjustment system, which adjusts c.s.s. and thus affects product size distribution. Depending on cone type, the c.s.s. setting can be adjusted in two ways. The first way is by rotating the bowl against the threads so that the vertical position of the outer wear part (concave) is changed. One advantage of this adjustment type is that the liners wear more evenly. Another principle of setting adjustment is by lifting/lowering the main shaft. An advantage of this is that adjustment can be done continuously under load. To optimize operating costs and improve the product shape, as a rule of thumb, it is recommended that cones always be choke-fed, meaning that the cavity should be as full of rock material as possible. This can be easily achieved by using a stockpile or a silo to regulate the inevitable fluctuation of feed material flow. Level monitoring devices that detect the maximum and minimum levels of the material are used to start and stop the feed of material to the crusher as needed.
Primary gyratory crushers are used in the primary crushing stage. Compared to the cone type crusher, a gyratory crusher has a crushing chamber designed to accept feed material of a relatively large size in relation to the mantle diameter. The primary gyratory crusher offers high capacity thanks to its generously dimensioned circular discharge opening (which provides a much larger area than that of the jaw crusher) and the continuous operation principle (while the reciprocating motion of the jaw crusher produces a batch crushing action). The gyratory crusher has capacities starting from 1200 to above 5000t/h. To have a feed opening corresponding to that of a jaw crusher, the primary gyratory crusher must be much taller and heavier. Therefore, primary gyratories require quite a massive foundation.
The cone crusher is a modified gyratory crusher. The essential difference is that the shorter spindle of the cone crusher is not suspended, as in the gyratory, but is supported in a curved, universal bearing below the gyratory head or cone (Figure 8.2). Power is transmitted from the source to the countershaft to a V-belt or direct drive. The countershaft has a bevel pinion pressed and keyed to it and drives the gear on the eccentric assembly. The eccentric assembly has a tapered, offset bore and provides the means whereby the head and main shaft follow an eccentric path during each cycle of rotation. Cone crushers are used for intermediate and fine crushing after primary crushing. The key factor for the performance of a cone type secondary crusher is the profile of the crushing chamber or cavity. Therefore, there is normally a range of standard cavities available for each crusher, to allow selection of the appropriate cavity for the feed material in question.
The main task of renovation construction waste handling is the separation of lightweight impurities and construction waste. The rolling crusher with opposite rollers is capable of crushing the brittle debris and compressing the lightweight materials by the low-speed and high-pressure extrusion of the two opposite rollers. As the gap between the opposite rollers, rotation speed, and pressure are all adjustable, materials of different scales in renovation construction waste can be handled.
The concrete C&D waste recycling process of impact crusher+cone crusher+hoop-roller grinder is also capable of handling brick waste. In general, the secondary crushing using the cone crusher in this process with an enclosed crusher is a process of multicrushing, and the water content of waste will become an important affecting factor. The wet waste will be adhered on the wall of the grinding chamber, and the crushing efficiency and waste discharging will be affected. When the climate is humid, only coarse impact crushing is performed and in this case the crushed materials are used for roadbase materials. Otherwise, three consecutive crushings are performed and the recycled coarse aggregate, fine aggregate, and powder materials are collected, respectively.
The brick and concrete C&D waste recycling process of impact crusher+rolling crusher+hoop-roller grinder is also capable of handling the concrete waste. In this case, the water content of waste will not be an important affecting factor. This process is suitable in the regions with wet climates.
The renovation C&D waste recycling process of rolling crusher (coarse/primary crushing)+rolling crusher (intermediate/secondary crushing)+rolling crusher (fine/tertiary crushing) is also capable of handling the two kinds of waste discussed earlier. The particle size of debris is crushed less than 20mm and the lightweight materials are compressed, and they are separated using the drum sieve. The energy consumption is low in this process; however, the shape of products is not good (usually flat and with cracks). There is no problem in roadbase material and raw materials of prefabricated product production. But molders (the rotation of rotors in crusher is used to polish the edge and corner) should be used for premixed concrete and mortar production.
We have compared the pros and cons of many rock crushing equipment, and have received feedback from many users. So, we made this post to help you understand the difference between cone crusher and hammer crusher.
Indeed, the hammer crusher can break materials at one time without secondary crushing, but it is more common in small and medium-sized production lines and the requirements for the final particle size are not high.
You should properly note that hammer crusher can not and should not use to handle materials with high hardness, otherwise, the hammerhead will wear out quickly and you may need frequent repair and change the wearing parts, this will increase your costs a lot.
Although the process is simple, it has many shortages, for example, the yield is low, and the final aggregate product may easily be crushed or product micro cracks. This poor quality will affect sales and prices, so the hammer crusher now is often used as an auxiliary sand making equipment.
Although the initial purchase cost is not high, the replacement of the wearing parts such as hammerheads in the later stage is also a large cost, especially for crushing medium-hard and above materials.
Hammer crusher and cone crusher are both classic equipment in aggregate crushing and are both widely used. This article briefly analyzes the difference between those two types of crushing machines in 6 factors, and we hope it can help you.
In addition, it should be noted that what we call hammer crusher is a product in the traditional sense, because in many regions, small and medium-sized production lines still use this type of equipment because the crushing ratio is large and the price is low.