Starting from the base working principle that compression is the forcing of two surfaces towards one another to crush the material caught between them. Impact crushing can be of two variations: gravity and dynamic. An example of gravity impact would be dropping a rock onto a steel plate (similar to what goes on into an Autogenous Mill). Dynamic impact could be described as material dropping into a rapidly turning rotor where it receives a smashing blow from a hammer or impeller. Attrition crushing is the reduction of materials by rubbing; primarily a grinding method. Shear crushing is accomplished by breaking along or across lines of cleavage. It is possible, when required, for a crusherto use a combination of two or three of these principles.
Rapidly increasing operating costs for minerals beneficiating plants continue to be the biggest single problem in maximizing profitability from these operations. The average world inflation rate has been increasing over the last decade and shows little sign of easing. The threat of continued increases in the price of fuel oil will eventually increase the cost of electrical power, in direct proportion for most users. This will undoubtedly cause closure of some lower grade ore bodies unless energy utilization efficiencies, particularly in comminution, can be improved.
Most of the recent literature concerning comminution performance improvement has been directed at grinding mill performance. It can be expected that more refined control systems will improve the overall milling energy efficiency, which is normally the largest single cost component of production. However, published gains by such methods to date appear to be limited to something less than 10%.
The second largest cost for comminution processes is normally that for wear metal consumed in grinding operations. Allis-Chalmers has continuing -research programs into all forms of comminution processes involving crushing and grinding. Improved crushing technology shows the way to reducing both energy and wear metal consumption mainly by producing finer feed which will improve downstream grinding mill performance.
A new testing procedure for studying crushing phenomena, presently being perfected by Allis-Chalmers, is described for the first time. These bench scale laboratory tests will give more accurate prediction of both energy requirements and size distribution produced in commercial crushing processes. As a direct result, this machine will allow more accurate comparisons to be made in capital and operating cost expenditures for various combinations of crushing and milling processes.
These new testing procedures can be run on small samples including pieces of drill core material. They could be part of testing and feasibility studies for most new concentrators. The same methods can be used to determine likely yield of various sized crushed products and, therefore, benefit crushed stone producers.
The theoretical and practical phenomena concerning comminution processes have received considerable attention in the literature and are not discussed here in any detail. Instead, the breakage studies in this paper are based on an empirical treatment of the fundamental relationships between energy and the size distributions of processed particles that have been observed both in the laboratory and in large-scale, commercial cone-crushing operations.
Because of the bewildering number of variables encountered when studying comminution processes, most investigators have preferred to assume that the size distribution generated in milling and crushing processes bears some relatively fixed relationship such as those described by Gates-Gaudin-Schuhmann1 or Rosin-Rammler.
Fred Bond, in his Third Theory of Comminution, used the former, essentially assuming that size versus cumulative percent passing that size was represented by a straight line of assumed slope 0.5 below the 80% passing size. Based on this assumption, Bond derived his well-known relationship:
The Work Index for rod and ball mills can be determined from laboratory tests and, as demonstrated by Rowland, the relationship gives us a reasonably accurate tool for the design of rotary grinding mill circuits.
Bonds methods have been less successful in predicting fine crushing performance, however, primarily because the typical crusher feed and product distributions do not meet the assumed conditions necessary for the satisfactory application of his equation (see Fig. (1)).
It is most evident that the curved lines appearing on Fig. (1) do not represent a Gates-Gaudin-Schuhmann size distribution. It is therefore not surprising that Bonds procedures do not work well in this situation. The Rosin- Rammler distribution has also been found inadequate to generally describe crusher products.
Work during the early 60s led to the concept of comminution as a repetitive process, with each step consisting of two basic operations the selection of a particle for breakage and the subsequent breakage of this particle by the machine. In this approach, the process under investigation is modelled by combining the particle selection/breakage event with information on material flow in and out of the comminution device.
Most workers who have used this approach have considered size reduction to be the result of the mechanical operation of the comminution device. This mechanical operation consumes the energy, and size reduction is merely a result of this energy consumption. This viewpoint is reasonably valid for tumbling mills where energy input tends to be constant and the proportion of the energy that is usefully consumed in particle breakage is low (<10%). It does not appear to be valid in compression crushers, however, since breakage energy is a significant proportion (>50%) of the total energy input to the crusher and markedly different power rates (energy input per unit of crusher feed) can be obtained by varying ore feedrates and/or crusher parameters such as closed side setting. It will therefore be necessary to include energy information in any model of the crushing process before it will be possible to accurately predict crusher performance. The inclusion of this energy-size information will significantly increase the complexity of these models.
The single-particle breakage event has been the subject of several studies. Most of these have utilized only sufficient energy to break the particle and do not simulate commercial crushing operations where energy levels are such that catastrophic repetitive breakage usually takes place. This approach to the study of comminution processes does yield valuable information, however, and it is unfortunate that it has not received greater attention.
The Bond Impact Work Index method has been an industry standard for the determination of crusher power requirements but was originally developed to ensure, that sufficient power was connected to primary gyratory crushers. In this method, pieces of rock are fractured by trial and error in the test device shown in Fig. (2), until sufficient impact energy has been applied to break the rock.
Normally, the rock breaks in halves, and in most tests only two and seldom more than three large pieces are observed after fracture. No size distribution information is used in calculating the Bond Impact Work Index from the formula:
KWH/tonne). The procedure works quite well for this type of crusher but tends to understate power requirements in fine crushers where power rates are typically much higher (upwards from 0.25 KWH/tonne).
Because of this, a research program was instituted by Allis-Chalmers Comminution Task Force Committee to break rock in a manner more analogous to that observed within commercial fine crushers. A pendulum type test device similar in most respects to that developed by the United States Bureau of Mines and shown diagrammatically in Fig. (3), was built and has been used in an extensive test program to determine whether it would be possible to predict cone crusher performance.
The rock samples selected for crushing in this device are usually minus 38mm (1-), plus 19mm () in size. The sample rock is weighed and then placed between the platens. The end of the rebound platen is placed in contact with the rebound pendulum and the crushing pendulum is raised to a predetermined vertical height which depends on the size of the sample. The crushing pendulum is then released after striking the crushing platen and breaking the rock, the remaining energy is transferred via the rebound platen to the rebound pendulum. The horizontal distance that the rebound pendulum travels is recorded by displacement of a marker and is subsequently converted to a vertical height.
where Ec = crushing energy E1 = crushing pendulum potential energy (before release) KE = kinetic energy of the two platens E2 = rebound pendulum maximum potential energy (after crushing) EL = system energy loss (sound, heat, vibration)
The system energy loss, EL, is determined by plotting EL as a function of the initial height of the crushing pendulum with no rock present. The major portion of this loss is by vibration. It is felt that the difference between system energy losses with and without rock present in the system is minimal as long as enough initial energy is supplied to result in a small elevation of the rebound pendulum.
The fragments from several rock samples broken under identical conditions were combined for each of the size analyses reported in this paper. Bond Work Indices were also backcalculated from the data using the standard formula, i.e.
Confirmation of the ability of the procedure to provide information suitable for the prediction of crusher performance was obtained by taking feed samples from 31 commercial operations treating a wide range of rocks and ores. At the time of taking a feed sample for laboratory testing in the pendulum device, relevant performance data such as power, feed rate and size distributions for feed and product were taken on the operating crusher. Several thousand rocks have been broken during tests with the device over the past 3 years.
The first thing to notice from these graphs is that there is an extremely good family relationship within each set of size distribution curves. This is somewhat coincidental, since the pendulum curve is the product of a single particle-single impact breakage event and the typical crusher product curve results from multiple particle-multiple impact breakage, but is probably due to two facts:
In order to show that the pendulum product size distribution is sensitive to power rate, several tests have been run on the same feed material at different levels of pendulum input energy. Typical results are shown in Fig. (7) as Schuhmann size distribution (log-log) plots. It can be seen that increasing amounts of fine material are produced with increasing energy input. The same effect was previously demonstrated for an operating crusher in Fig. (1). We can, therefore, conclude from this
that net power rates will be the same in the pendulum and the crusher when the two distributions coincide (as they do in Figs. (4) thru (6). This permits us to determine the efficiency of power utilization in crushers and to predict the product size distribution which will arise from operating crushers at different power rates.
The Bond Work Index figures obtained by backcalculation from the pendulum data are compared with the Net Work Index values obtained from the plants in Fig. (8). The agreement is surprisingly good especially in view of the fact that the 80% passing values do not completely describe the total feed arid product size distributions. This agreement is probably due to the fact that the use of comparable energy levels in both machines gives rise to similar reduction ratios and product size distributions. Because of this, the pendulum test provides a good estimate of the Net Work Index when this is required for current design procedures.
The pendulum product distribution is a breakage function and can be used in models of the process to predict crusher product distributions for different operating conditions. As an example of this approach, Whitens model of the cone crusher, Fig. (9), has been used to simulate the situation given in Fig. (4). The result of this simulation is given in Fig. (10) where it can be seen that very good approximations of crusher performance can be obtained.
The writers are firmly of the opinion that results to date prove that the use of this pendulum device can give more energy-size reduction information in a form readily useable for crusher application. The data can be generated in less time and from a much smaller sample than is required for pilot plant testing. Our present pendulum tester is a research tool and is currently being modified for use in commercial testing of minerals and rocks. More details of this device will be given at a later date.
With the prosperity and development of the crushing industry, rock crusher is becoming more and more important. We often use it to crush limestone, river pebble, granite, basalt, and quartz stone and other materials. Moreover, itis widely used to crush ore and large pieces of material in mining smelting, building material, road, railway, water conservancy chemical industry and other fields.
The crusher has a bright prospect. With the development of the mining industry, more and more rocks appear. In order to save energy and generate economic benefits, people will pay more and more attention to the industrial rock crusher. As a result, itsdemand will increase significantly.
There are many types of rock crushers. Generally, itmainly consists of jaw crusher, cone crusher, hammer crusher, vertical shaft impact crusher, impact crusher and so on. According to the requirements of materials size, different types of crushers are used in different crushing stages. Here, Aimix will introduce detailed informations to you.
Firstly, You should consider the size of raw materials you want to process. If the materials are very big particles, you can choose the primary crushing machine(jaw rock crusher). Because jaw crusher is suitable for crushing large stone materials. On the contrary, you should choose Aimixs other kind of crusher machines(cone crusher orimpact crusher) in order to crush smaller stone materials.
Secondly, you should consider the performance of cheap rock crusher. Aimix, a reliable crusher supplier, adopts advanced technology to manufacture all kinds of crushers. Therefore, our crushers have simple structure, easy maintenance, stable performance and low operation cost. So you can choose our small rock crusher for sale without any hesitation.
Lastly, price is a very important factor you should think about. We willrecommend suitable crusher to different customers according to their budgets and requirements. We ensure that all customers will get best crusher with the most reasonable price.
Aimixs impact crusher is one important type of rock crusher machine for sale. It adopts the latest technology, absorbs the advantages of many domestic and foreign impact crushers, and has very superior performance. Its excellent features are as follows:
Lastly, the crushing ratio is large, and it can reach to 40%. So it can simplify the crushing process, can make the three section crushing into two or one section crushing, and reduce the equipment cost of the mineral processing factory.
This kind of portable rock crusher designed and manufactured by Aimix Group is a superior product. And it uses the most advanced technology and conception. Therefore, it has so many unparalleled advantages.
Firstly, the maintenance of the mini rock crusher machine is simple. The discharge port of cone crushers hydraulic motor can be adjusted. And cone crusher allows the fixed cone to be fully removed to adjust the collar nut to replace the liner, thus it can greatly simplify the replacement work of the liner. And all parts can be maintained or repaired from the top or side, so equipment maintenance is very convenient. And you can find more informations on Aimxs crusher maintenance manual.
Secondly, the rock crushing equipment has large productioncapacity. The cone crusher has higher speed stroke, so the rated power of the cone crusher is increased, and the processing capacity of the equipment is greatly improved.
Thirdly, this rock crusher machine has a two-way iron release hydraulic cylinder, which allows the iron to go through the crushing chamber, and reduces the shutdown due to debris in the crushing chamber.
Fourthly, large diameter spindle and heavy main frame ensure that the equipment has durable and reliable working condition. The independent thin oil lubrication system can ensure the bearing lubrication has double protection.
The type of rock crusher for sale is mainly composed of frame, rock crusher transmission shaft, eccentric sleeve, spherical bearing, crushing cone, adjusting device, adjusting sleeve, spring and discharging port. In order to give customers a better understanding of the crusher, Aimix will describe the detailed informations of the following parts .
Firstly, the main frame of the rock crushing plant. The main frame consists of the upper frame part and the lower frame part. The two parts are connected by hydraulic cylinder. The upper shelf is a welding piece, and the upper side of the shelf is welded with a wear-resistant copper plate. And the lower frame is a whole cast steel.
Secondly, the adjusting device. Hydraulic motor drives pinion, and the pinion drives the adjusting cap on the gear, thereby the fixed cone will be driven to rotate. In this way, the gap between the fixed cone and the mobile cone will be adjusted.
Third, hydraulic control station. It mainly includes fuel tank with oil table, motor oil pump, filter device, energy storage device, control device, pressure switch, safety protection device, etc. A terminal box and a button control cabinet are also equipped beside the small portable rock crushers.
The rock crushing machine mainly used in the primary stage is jaw crusher. As everyone knows, diesel jaw crusher is a coarsely crushing machine. Besides, this kind of crusher machine is widely used to crush rock and large pieces of materials in mining smelting, building material, road, railway, water conservancy, chemical industry and so on. PE400-600-jaw-crusherModel: PE-400*600 Feed opening size(mm): 400*600 Max.Feeding size(mm):340 Adjusting range of discharge opening(mm):40-100 Processing capacity(t/h): 16-60 Rotation speed of eccentric shaft(r/min):275 Mixing power(kw): 30 Total weight(T): 7 Dimension(L*W*H)(mm): 1730*1730*1760
The working principle of jaw rock crushers for sale is: when the stone crushing equipmentworks, motor drives belt and pulley to move, and the eccentric shaft drives the mobile jaw plate. When the mobile jaw plate rises, the angle between elbow plate and mobile jaw plate becomes larger. So the mobile jaw plate will be close to the fixed jaw plate. At the same time, materials can be crushed. When the mobile jaw plate down, the angle between elbow plate and the movable jaw becomes small.In addition,under the effect of rod and spring, the mobile jaw plate will be far from the fixed jaw plate. Meanwhile, the finished products will be discharged.
Crushing chamber of the gold rock crusher is composedof a fixed jaw plate and a mobile jaw plate. The latterplate is periodically reciprocated against the fixed jaw plate, sometimes separated, and sometimes closed. When they are separated, the material enters the crushing chamber and the finished product is discharged from the discharge port. When they are closed, the material between the two jaw plates is crushed by crushing, bending and splitting.
In short, this is how acrusher works. If you still have questions about the working principle ofthecrusher, you can contact us online or send us an e-mail. Aimix will provide you more detailed informations (such as: rock crusher youtube).
Impact crusher has wide applications. This kind of rock crushing equipment for sale has become the crucial equipment to crush stone materials in highway, high-speed railway, water conservancy project and other fields. The crusher for sale can processall kinds of coarse, medium and fine materials, such as: limestone, feldspar, calcite, granite, talc, barite, fluorite, rare earth, coke, coal gangue, gypsum, etc. Besides, this type of small rock crusher can be used inmetal and non-metallic mineral, metallurgy, cement, chemical, refractory, ceramic and other industrial sectors.
The mini rock crusher for saleis a crushing machine that uses impact energy to crushmaterials.Then, how does an small portable rock crusher for salework?When impact crusher is working, the rotordrivenby the motor has high-speed rotation.When the materials gointo the plate hammer area, they could be crushed byplate hammer on the rotor. Then materials are thrown to the counterattack device to be crushed again,and they are re-brokenbyhammer.The process is repeated, and the materialscan be repeatedlycrushed bythree counterattack cavitiesuntil the materialsare crushedto the required size. And then they are discharged from the discharge port.
In order to design and develop the perfect rock crusher plant, Aimxs experts have made great efforts. And this kind of crushercombineshigh crushing chamber and high crushing frequency. Moreover, Aimxs will introduce the working principle of rock crushing plant for sale.
When the mobile rock crusher for sale works, the V-belt, pulley, drive shaft, small bevel gear, and large bevel gear driven by the motor drive the eccentric sleeve to rotate. The axis of the rock crusher cone driven by the eccentric shaft sleeve swing rotationally, so that the surface of the crushing wall sometimes approaches and sometimes leaves the surface of the mortar wall. Therefore, materials in the the ring crushing chamber composed of fixed cone and mobile cone can be crushed by impacting, squeezing and bending constantly. After repeated squeezing, impacting and bending, materials can be crushed to the required particle size and discharged from the lower part.
In the case of unbreakable materials go into the crushing chamber or the machine is overloaded due to some reasons, the spring insurance system will work. The discharge port will be enlarged, and the unbreakable materials are discharged from the crushing chamber. If the impurities can not be dischargedwe can use cavity cleaning system. So that the discharge port will continue to increase. And the impurities can be discharged from the crushing chamber. Under the effect of the spring, the discharge port will automatically reset, and the gold crusher machine will back to normal work.
A stone crusher vibrating screen is needed in this crushing stage. In order to meet the requirements of the rock crushing industry, Aimix Group has been committed to the development and research of this kind of small scale rock crusher for several years. So far, our technology has reached world advanced level. Therefore, Aimixs vibratory screen has many superior advantages compared with ordinary vibratory sieve:
3. Itcan savemore energy than ordinary screens. 3YK1225-vibrating-screenModel: 3YK1225 Number of screen: 3 Screen area(): 9 Maximum feed size(mm): 400 Capacity(m3/h): 10-70 Vibration power(r/min):800-970 Double amplitude(mm):8 Motor power(kw): 5.5 Sieve angle(): 20 Total weight(kg): 3850 Long * wide * high(mm): 3070*1860*1210
Aimix, one of the most professional rock crusher manufacturers, has manufactured and designed all kinds of crusher machines and crusher plantsfor several years. So far, our products have been exported to more than 60 countries, such as: India, Iran, Indonesia, Kazakhstan, Malaysia, New Zealand, Oman, Pakistan, etc. In addition, we can customize all kinds of crusher machines and all the spare parts, such as: rock crusher screen, rock crusher cone for saleand so on. In addition, we have the best quality and the most reasonable price. Due to the reliable quality and professional service, our rock type crusher machines are popular with all the customers.
We suggest that you buy crushers from professional crusher machine suppliers! If you need to purchase a crusher equipment, you can contact us online. We will show you detailed rock crusher videos and give you products photos! Dont hesitate to choose us!