wear parts of ball mill new york

ball mill liner design

ball mill liner design

There are many different designs and styles of ball mill liners. As with grinding balls local economics and ultimately operating costs determine the best design and material to use. The initial set of liners is rarely the final design selected. Based upon individual experience, mill superintendents develop preferences for liner designs. The following is given as a guideline for the initial set of liners.

For 60 mm (2.5) and smaller top size balls for cast metal liners use double wave liners with the number of lifters to the circle approximately 13.1 D in meters (for D in feet, divide 13.1 D by 3.3). Wave height above the liners from1.5 to 2 times the liner thickness. Rubber liners of the integral molded design follow the cast metal design. If using the replaceable lifter bar design in either metal or rubber the number of lifters should be about 3.3 D in meters (for D in feet* divide 3.3 D by 3.3) with the lifter height above the liners about twice the liner thickness. The use of double wave liners, particularly when using 50 mm (2) or larger balls, may show a loss of 5% or so in the mill power draw until the waves wear in and the balls cannest between the lifters.

When liners, and double wave liners in particular, wear with circumferential grooves, slipping of the charge is indicated, and this warns of accelerated wear. When the top size ball is smaller than 50mm (2.5) and mill speed is less than 72% of critical wear resistant cast irons can be used. For other conditions alloyed cast steel is recommended.Rubber liners are well suited to this same area and not onlyreduce operating costs but can reduce noise levels.

Single wave liners are recommended for larger size balls (50mm/2.5 and larger). The number of the lifters to the circle equals approximately 6.6 D in meters (for D in feet, divide 6.6 D by 3.3). The liners are from 50 to 65 mm thick (2 to 2.5) with the waves from 60 to 75 mm (2.5 to 3) above the liners. The replaceable lifter bar design madeof either metal or rubber in about the same design proportions can be used. There could be a loss in power with rubber particularly if the mill speed is faster than about 72% of critical speed, and the ball size is larger than 75 mm. Because of the impacting from the large balls, single wave liners for ball mills are usually made from alloyed steels or special wear-resistant alloyed cast irons. Because of the difficulty of balancing growth and wear with work hardening manganese steel is used infrequently and then with extreme care to allow for growth.

When a grate discharge is used the grates and wear platesare normally perpendicular to the mill axis while the discharge pans conform to the slope of the mill head. The grates and wear plates are normally made from alloy wear resistant cast steel or rubber. They are ribbed to prevent racing and excessive wear. The dischargers and pans are generally made from either wear resistant cast ironor rubber, or wear resistant fabricated steel.Slot plugging can be a problem in grate discharge mills. Whether the grates are made of metal or rubber the slots should have ample relief tapered toward the discharge side. Total angles 7 to 10 degrees (3.5 to 5 degrees per side) are commonly used. Metal grates often havea small lead-in pocket or recess which can fill in with peened metal rather than have the slot peen shut. With the proper combination of metal internals and rubber surfaces, rubber grates have flexibility that tend to make them self cleaning and yet not fail due to flexing.

Except when using rubber liners, the mill surfaces are covered with a protective rubber or plastic material toprotect the surfaces from pulp racing and corrosion. This is done in wet grinding mills. Since dry grinding mills get hot due to heat from grinding generally rubber liners and rubber materials cannot be used.

Shell liners may be furnished of various materials and of several designs. In each case the material used is the best obtainable, resulting in the lowest cost per ton of ore ground. The liner contours are selected for the specific grinding application and take into consideration liner wear, scrap loss, and mill capacity.

Liners cast of Manganese Steel, Ni-Hard, Chrome-moly, or other similar materials may be of the step type, block type, wave type, or the two-piece plate and lifter construction. These are illustrated on the right. During the past years of building ball Mills various other shapes of liners have been tried, such as the pocket type, spiral liners, etc.; in most cases it is found that these special shapes and designs are not justifiable from the standpoint of economics. They involve additional costs which are not generally recovered from an increased efficiency in milling operation.

Lorain Shell Liners consist of high carbon rolled steel plates accurately formed to the mill shell radius. These are held in place by rolled alloy steel heat treated lift bars. This type liner is carefully engineered for the specific grinding application. Variations in lift bar design and liner plate thickness provide this flexibility of design for application.

All shell liners designed for ball mill operations are of such size and shape that they will easily pass through the manhole opening to facilitate relining operations. In rod mill work the design is such that they will easily pass through the large ball open end discharge trunnion.

Where cast liners are used, and especially in rod mill applications, we furnish rubber shell liner backing to help cushion the impact effect of the media within the mill and prevent pulp racing. With the Lorain type of liner such shell liner backing is not required. For special applications where severe corrosive conditions exist a shell liner of special alloys can be furnished and also the interior surface of the shell can be treated to protect such parts from the corrosive conditions.

Head liners are of the segmental type constructed of Manganese Steel, Chrome molybdenum, or Ni-Hard and are designed to pass easily through the manhole opening or discharge opening in the case of rod mills. For ball mill work ribs are cast with the feed head liners to deflect the ball mass and minimize wear on the headliner itself.

Where cast liners are used shell liner bolts and head liner bolts are made of forged steel with an oval head to prevent turning and loosening within the liners. These are held in place with two hex nuts and a cut washer. For wet grinding applications special waterproof washers can be furnished.

Theeffect of liner design upon mill performance appears to have received little attention. Clearly, the main function of the liner is to form a removable surface to the null body, which may be replaced when seriously worn.

It is also clear however, that the metal plates which serve this purpose may have a surface which ranges from smooth in one which carries an intricate pattern of raised bars or sunken depressions. The merits of the various types do not appear, however, to have been studied.

where smooth liners are those which have projections insufficient to give appreciable keying between the liner and the ball charge, whilst lifter liners are those which are so heavily ribbed as to give rise to appreciable interlocking between the balls and the liners.

Various common types of liners are illustrated in Fig. 6.12. Although these liners have various patterns of projections, or depressions, to give an amount of interaction between the liner and the grinding medium, it would be expected that wear would round the edges. It is doubtful whether, after some time in service, the performance of a mill with these liners differs appreciably from that of a mill with a smooth surface. Liners furnished with heavy lifter bars are also sometimes used and in such a case the locking of the ball charge to the shell must be very effective. Nevertheless, although a few vague general statements to the effect that a lifter mill gives a product with different size characteristics to that of a smooth mill have appeared, the point does not appear to have been widely investigated. It is probable, however, that, on the grounds of differences in the size characteristics of the products, there exists no sound reason for the use of lifters in preference to the normal smooth liners.

It is possible that, when a material with a low coefficient of friction is milled, the charge might slip on a smooth mill shell, with consequent loss of grinding capacity, and in such a case the use of lifter bars might well be the solution. It has also been suggested by one of the authors, Rose, that the use of lifter bars might eliminate the surging of the charge sometimes encountered in mill operation.

An entirely different conception of the duty of the mill liner underlies the design of the studded liner developed by Usines Emile Henricot of Count St. Etienne. These liners, illustrated in Fig. 6.12 and Fig. 6.13, consist of comparatively thin plate liners with uniformly spaced studs on the working surface; these studs being integral with the plate. Provided the spaces between the studs are not allowed to become choked with tramp-iron, etc., the studs furnish a good key between the shell and the charge which, it is claimed, leads to a greater power consumption and to improved grinding. Furthermore it would appear that the studs impose a definite geometrical arrangement in the outer layer of balls which, in turn, brings about a closer packing, throughout the ball mass, than obtains with conventional types of liner. This effect would also lead to improved performance. Evidence of this effect of the studs upon the packing of the charge appears in Fig. 6.13b, for the balls are clearly seen to lie in rows in the mill instead of in completely random array.

An incidental merit claimed for these liners is that the high bearing pressure between the balls and the studs of the liners leads to work hardening of the studs; with a consequential reduction of the rate of metal wear.

The Henricot liners, which have been discussed in a paper by Belwinkel, appear to be the only attempt so far made to influence the grinding characteristics of a mill by means of correctly designed liners. It would therefore appear that there is some room for development in this direction.

ball mill liner function | wear parts for industry | qiming casting

ball mill liner function | wear parts for industry | qiming casting

Ball mill is a major equipment in the production of power plants, cement plants, mines, chemical industry, metallurgy and other industries, the liner is one of the components of the mill, the main role is to protect the cylinder, the cylinder from the grinding body and Material direct impact and friction, help to improve the mill grinding efficiency, increase production and reduce metal consumption. As the liner in the harsh conditions of long-term conditions, maintenance and replacement of considerable volume, not only requires human, material and financial resources, but also a direct impact on productivity.

Ball mill liner plays a major role in protecting the inner wall of the anchor windlass. Different shapes of the ball mill lining plate can improve the grinding effect of the ball mill and improve the working efficiency of the ball mill. 1, flat ball mill liner, the surface smooth, suitable for installation in the fine grinding warehouse. 2, the pressure of the type of ball mill liner, suitable for coarse grinding warehouse, for low speed ball mill. 3, ladder-type ball mill liner, ladder liner is better than the pressure liner, suitable for installation in the coarse grinding warehouse. 4, small corrugated liner crest and pitch are small, suitable for fine grinding and coal mill. 5, end cover liner installed in the grinding head cover or cylinder cover to protect the end cover from wear and tear. 6, ring groove liner in the lining of the T surface for casting a circular groove, after installation to form a circular groove, suitable for multi-warehouse grinding of the first and second positions, dry, wet grinding Machine can be. 7, grading liner, grinding mill for the ideal state should be large particles of material with a large diameter grinding body to impact and crush, that is, in the direction of the mill feed with large diameter grinding body, with the material The direction of the material to the gradual reduction of the grinding body should be sequentially reduced.

Qiming Casting is one of the largest manganese steel, chromium steel, and alloy steel foundry in China. Products include crusher wear parts, Crusher spare parts, mill liners, shredder wear parts, apron feeder pans, and electric rope shovel parts.

ball mill liner | wear parts for industry | qiming casting

ball mill liner | wear parts for industry | qiming casting

Ball mill liners are the main replacement wear parts for ball mills. These liners are manufactured by wear-resistant material and rubble. As a wear-resistant foundry, Qiming Casting manufactures manganese steel, Cr-Mo alloy steel, and Ni-hard steel liners for all kinds of ball mills, which include: single wave liners, modified single wave liners, double wave liners, shell liners, feed head liners, and discharge end liners.

Qiming Casting is Your Foundry for Ball Mill Liners! All Qiming Casting liners are backed by ISO9001:2015 quality control system and are shipped only after meeting our rigorous quality standards. We are committed to meeting your replacement parts needs in a professional and efficient manner. Our Customer Support Department is ready to help you with a quote, to check inventory, or simply answer a technical question. Talk to your Qiming Casting professional today about your specific needs!

It is widely used in cement, silicate products, new building materials, refractories, chemical fertilizer, black and non-ferrous metal mineral processing, glass ceramics and other production industries, dry or wet grinding of various ores, and other grindable materials. Ball mill is suitable for grinding all kinds of ores and other materials. It is widely used in mineral processing, building materials, and the chemical industry. It can be divided into dry grinding and wet grinding. According to the different ways of ore discharge, it can be divided into grid type and overflow type.

The ball mill is composed of a horizontal cylinder, feeding and discharging hollow shaft, grinding head, and other parts. The cylinder is a long cylinder, which is equipped with a grinding body. The cylinder is made of steel plate, which is fixed with the cylinder by steel liners. The grinding body is generally a steel ball, which is loaded into the cylinder according to different diameters and a certain proportion. The grinding body can also be used as a steel section. The grinding material is selected according to the particle size. The material is loaded into the cylinder by the hollow shaft at the feed end of the ball mill. When the cylinder of the ball mill rotates, the grinding body is attached to the liner of the cylinder due to the action of inertia, centrifugal force, and friction, and is taken away by the cylinder. When it is brought to a certain height, it is thrown down due to its own gravity, and the falling grinding body is like a projectile The material in the cylinder will be broken.

The material enters the first bin of the mill evenly through the feeding device through the feeding hollow shaft screw. There are stepped lining plates or corrugated lining plates in the bin, which are filled with various specifications of steel balls. The rotation of the cylinder generates centrifugal force to bring the steel balls to a certain height and then fall down, which has a heavy impact and grinding effect on the material. After rough grinding in the first bin, the material enters the second bin through a single-layer partition board. The bin is inlaid with a flat lining board and steel balls to further grind the material. The powder is discharged through the discharging grate plate to complete the grinding operation.

During the rotation of the cylinder, the grinding body also has the phenomenon of sliding. In the process of sliding, the material is ground. In order to make effective use of the grinding effect, the grinding body cylinder is divided into two sections with a partition board when the material is finely ground with 20 mesh. That is to say, it becomes a double bin. When the material enters the first bin, it is broken by the steel ball. When the material enters the second bin, the steel section has no effect on the material For grinding, the qualified materials are discharged from the hollow spindle at the discharge end. When grinding the materials with small feed particles, such as sand No.2 slag and coarse fly ash, the mill cylinder can be a single bin cylinder mill without partition, and the grinding body can also be made of the steel section.

The raw material is fed into the hollow cylinder through the hollow Journal for grinding. The cylinder is filled with grinding media of various diameters (steel ball, steel bar or gravel, etc.). When the cylinder revolves around the horizontal axis at a certain speed, the medium and raw materials in the cylinder will fall or roll off the inner wall of the cylinder when the gravity is greater than the centrifugal force under the action of centrifugal force and friction, and the ore will be broken due to the impact force. At the same time, in the process of mill rotation, the sliding motion of grinding media also produces a grinding effect on raw materials. The ground material is discharged through the hollow journal.

The maintenance and overhaul of the ball mill is a regular work, the quality of the maintenance work directly affects the operation rate and service life of the ball mill, so how to correctly maintain and overhaul in the process of use is introduced as follows:

The maintenance of the ball mill is regular work, and the quality of maintenance directly affects the operating rate and service life of the ball mill. In order to find out the defects and eliminate the hidden dangers in time to ensure the normal operation of the mill, in addition to daily maintenance, it is necessary to stop grinding regularly (it is recommended to check the important parts such as hollow shaft, main bearing, cylinder, reducer, big and small gear, etc.) carefully and make detailed records. According to the defect situation, the appropriate treatment and arrangement of medium repair and overhaul plan shall be made according to the priority.

Solution 1: It is that some of the liner bolts are not tightened. When the ball mill rotates, the mill liner hits the ball mill barrel. Judge the parts of the mill liner of the ball mill according to the sound, find out the loose bolts and fasten them separately.

The above problems should be dealt with according to their causes. Only if the side clearance of the bearing bush is too small or the bottom contact angle is too large, the grinding cylinder must be jacked up with an oil jack, and the bearing bush should be pulled out from one side of the shaft and scraped separately.

Problem 4: Vibration occurs when the motor speed reducer of the ball mill is started. Solution 4: Adjust the clearance between the two wheels to make the two shafts concentric. Fasten the coupling bolts symmetrically with the same torque. When the rotor is unbalanced, the rotor of the ball mill shall be pulled out for static balance.

Problem 5: Huge vibration occurs when the ball mill reducer drives the mill. Solution 5: When the mill is installed with ball mill liners, there is no secondary grouting or the anchor bolt after the secondary grouting is not fastened properly. The winch is used to rotate the mill barrel, resulting in one end of the mill barrel displacement, and the two axes are not in a straight line, which causes vibration after the reducer drives the mill.

Treatment method: to readjust, so that the ball mill axis and reducer axis in the same plane axis line. The large-scale ball mill has a large volume and heavy weight, which makes the foundation sink and displace. Set monitoring settlement points beside the foundation; conduct observation, and adjust when settlement is found.

Solution 6: The sound of the normal operation of the ball mill reducer should be uniform and stable. If there is a slight knocking sound or hoarse friction sound on the gear and there is no obvious change during the operation, you can continue to observe and find out the cause, and stop the ball mill for treatment. If the sound is getting louder and louder, stop the ball mill immediately for an inspection.

It is worth noting that the balance wheel and intermediate wheel of the ball mill reducer are not installed according to the specified meshing tooth elevation, which will cause the high-speed shaft pinion of the ball mill to drive the large gear of the intermediate shaft on one side, while the pinion of the intermediate shaft of the ball mill drives the balance wheel, and the balance wheel of the ball mill turns to drive the intermediate shaft on the other side so that the reducer of the ball mill does not form both sides of the load sharing rotation, which occurs Its dangerous to make a noise.

The selection of the material of construction is a function of the application, abrasivity of ore, size of mill, corrosion environment, size of balls, mill speed, etc. liner design and material of construction are integral and cannot be chosen in isolation. A list of the primary material of construction is given, with the particular uses and strengths of each.

1. Before installing the liner, the dust in the cylinder should be removed. When the ball mill installs the liner, a layer of 1:2 cement mortar should be applied between the inner wall of the cylinder and the liner, and the liner bolts should be tightened while wet. The gaps between the liners are also smoothed with sand and grout.

2. Before installing the liner of the ball mill, the liner should be inspected and trimmed. The back and the periphery of the liner should be smooth and flat. The bolt holes should be thoroughly sanded and cast flash removed so that the bolts can penetrate smoothly.

4. Note that the direction of the liner should not be reversed. The long grinding machine generally divides the grinding cylinder into front and rear bins by the partition board. The feed end is the first bin, and the first bin is the step liner. When installing, the thin end of the step liner should be in the same direction as the arrow of the turning direction when the mill is working. The grate hole of the compartment board is tapered, and the large end of the cone mouth should be consistent with the discharge direction of the ball mill during installation. The cylinder liner cannot form an annular gap.

5. When installing the partition board, wear all the bolts, and then tighten the bolts gradually in three times. At the same time, note that the connecting bolts on the central disc in the cylinder body should be tightened first, and then the bolts on the cylinder body should be tightened. After all the bolts are tightened, the nut of the bolt on the central disk of the cylinder is spot welded to prevent loosening.

Qiming Casting is one of the largest manganese steel, chromium steel, and alloy steel foundry in China. Products include crusher wear parts, Crusher spare parts, mill liners, shredder wear parts, apron feeder pans, and electric rope shovel parts.

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