wear parts of ball mill alternative

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 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.

low alloy steel ball mill liners design | wear parts for industry | qiming casting

The main function of the ball mill liner is to protect the mill and use the convex peak of the liner to play the ball to grind and crush the material. Therefore, the main failure mode of the liner is abrasive wear under the repeated impact of small energy. Under the condition of abrasive wear, wear resistance directly affects the service life of parts, so the research on wear resistance is also an important technical problem. This project is put forward for the failure of liner under abrasive wear conditions, and the purpose is to improve the comprehensive performance of low alloy steel wear-resistant material under this condition.

Wear-resistant low alloy steel materials usually contain alloying elements such as silicon, manganese, chromium, molybdenum, nickel, etc. The strong influence of these alloying elements on the matrix structure and hardenability of the material can be brought into full play, which can make the material have better wear resistance.

Carbon: Carbon is an important element that affects the strength, hardness, toughness, hardenability, and wear resistance of cast steel. If the carbon content is too high, the hardness of the high carbon martensite formed after heat treatment is high, but the toughness is low, and cracks are easy to form during heat treatment; if the carbon content is too low, the hardenability and hardness of the casting are poor, and the wear resistance is poor. Considering the combination of hardness and toughness, two different carbon contents (mass fraction, the same below) were adopted in this material, which was 0.30% 0.35% and 0.40% 0.45%, respectively. The effects of two carbon contents on the microstructure and properties of low alloy steel were studied.

Chromium: Chromium is one of the basic elements of wear-resistant materials. Its main function is to improve the hardenability of steel, strengthen the matrix by solution, improve the oxidation resistance of steel and increase its corrosion resistance. Chromium and iron form continuous solid solution and form a variety of compounds with carbon. The complex carbide of chromium has a significant effect on the properties of steel, especially the improvement of wear resistance. Cr and Fe form intermetallic compound FeCr. Chromium can significantly increase the hardenability of steel, but it also tends to increase the temper brittleness of steel. Chromium improves the temper brittleness of the steel and reduces the martensite point ms of the steel. When chromium is added into pure iron and steel, the strength and hardness can be improved at a certain chromium content. Considering the effect of chromium on Microstructure and properties of steel, the content of chromium is 1.0% ~ 1.4%. The effect of chromium on Microstructure and properties of steel is observed by experiment.

Nickel: Nickel and carbon do not form carbides. They are the main alloying elements for forming and stabilizing austenite. In this respect, the role is second only to carbon and nitrogen. Nickel and iron exist in the phase and phase of steel in the form of mutual solubility, which makes them strengthen. By refining the grain size of the phase, the low-temperature properties, especially the toughness of steel are improved. Nickel can improve the hardenability of steel by reducing the critical transformation temperature and the diffusion rate of elements in steel. Some physical properties of steel and alloy can be significantly improved when nickel content is high. The effect of nickel on toughness, plasticity, and other process properties of steel is less than that of other alloy elements. In addition, as nickel is a rare element and an important strategic material, the nickel content is set at 0.4% based on the above factors.

Molybdenum: Molybdenum belongs to the element of the closed phase region. Molybdenum exists in the solid solution phase and carbide phase in steel. In the carbide phase, when the content of Mo is low, it forms composite cementite with iron and carbon; when the content is high, it forms its own special carbide. The effect of molybdenum in steel can be summarized as improving hardenability, improving thermal strength, preventing temper brittleness, increasing remanence and coercivity, improving the corrosion resistance of alloy in some media and preventing pitting corrosion tendency. Molybdenum has a solid solution strengthening effect on ferrite and improves the stability of carbides, so it has a favorable effect on the strength of steel. The effect of molybdenum on the Temper Embrittlement of steel is quite complicated. As a single alloy element, Mo increases the temper brittleness of steel, but when it coexists with other elements, such as chromium and manganese, molybdenum reduces or suppresses the temper brittleness caused by other elements. Because the different content of molybdenum may have different effects on the properties of steel, we decided to select the content of molybdenum in the experiment as 0.25% 0.35% and 0.45% 0.60%.

Manganese: Manganese is a good deoxidizer and desulfurized. Manganese and iron form solid solution, which improves the hardness and strength of ferrite and austenite in steel; at the same time, it is a carbide forming element, which enters cementite to replace some iron atoms. Manganese can refine pearlite and improve the strength of pearlite steel indirectly by reducing the critical transformation temperature. Manganese can also significantly reduce the AR1 temperature and the austenite decomposition rate of steel. Manganese has a significant effect on improving the strength of low and medium carbon pearlite steels. However, as an alloying element, manganese has its disadvantages. When the content of Mn is higher, the grain size of the steel tends to be coarsened and the sensitivity of temper brittleness is increased. It is easy to produce white spots in steel due to improper cooling after smelting, casting, and forging. Considering the effects of manganese on the microstructure and properties of steel, the content of manganese is 1.1% 1.4%.

Silicon: Silicon is one of the common elements of steel. As an alloying element, the content of silicon in steel should not be less than 0.40%. Silicon does not form carbide in steel, but exists in ferrite or austenite in the form of solid solution. It improves the strength of the solid solution in steel, and its cold work deformation hardening rate is very strong, second only to phosphorus, but also reduces the toughness and plasticity of steel to a certain extent. If the content of silicon is more than 3%, the plasticity, toughness, and ductility of the steel will be significantly reduced. Silicon can improve the elastic limit, yield limit, yield ratio, fatigue strength, and fatigue ratio of steel. Silicon can increase the annealing, normalizing, and quenching temperatures of steel, reduce the diffusion rate of carbon in ferrite, and increase the tempering stability of steel. Considering the effects of silicon on properties and microstructure of steel, the content range of silicon is 1.1% 1.4%.

Rare earth: There are two main functions of rare earth in steel, one is purification and the other is alloying. Re can improve as-cast microstructure, refine grain size, purify molten steel, modify non-metallic inclusions, improve their morphology and distribution, and play a role in microalloying. Improve toughness and casting properties (hot cracking resistance and fluidity), improve strength. However, due to the uncertainty of adding method and amount, if the rare earth content is too much, it may have an adverse effect on the properties of steel. Therefore, the content of rare earth in this material is determined to be 0.04% 0.06%.

Boron: The outstanding function of boron in steel is that the hardenability of steel can be increased by a small amount of boron (0.001%). When the content of boron is more than 0.007%, it will lead to hot embrittlement of steel. Therefore, the boron content in this material is determined to be 0.003%.

The main elements of the experimental materials were selected according to the above analysis. The carbon content of sample #1 and #2 is 0.30% 0.35%, and the content of molybdenum is 0.25% 0.35%; the carbon content of sample #3 and #4 is 0.40% 0.45%, and the molybdenum content is 0.45% 0.60%.

In this experiment, a 50 kW medium frequency induction furnace is used for smelting. In order to reduce the oxidation of the furnace charge, the stirring of molten metal should be avoided as far as possible. In the later stage of smelting, the feeding block should not be too large and should be dried to a certain temperature to prevent splashing at the furnaces mouth. The feeding sequence is scrap steel, pig iron nickel plate, ferrochrome, ferromolybdenum ferrosilicon, ferromanganese rare earth ferrosilicon, and finally adding aluminum for deoxidation.

After dry mixing for 2-3 min, the molding sand was mixed with water and glass for 4-6 min. After the mold is made, the mold is hardened by blowing carbon dioxide (blowing pressure is 0.15-0.25 MPa, blowing time is 1-2 min). Before pouring, the sand mold and alloy are preheated in the furnace and kept dry. The preheating temperature is about 100 .

The properties of as-cast materials must be properly heat treated. In the actual working condition, the martensite structure with high hardness, high strength, and good toughness should be obtained, and the heat treatment process of quenching and tempering is adopted. The undercooled austenite of low alloy wear-resistant steel is relatively stable, and the cooling rate of oil in the low-temperature zone is much smaller than that of water, so oil is the most suitable quenching medium. Tempering is to reduce or eliminate the residual stress caused by quenching, improve the plasticity and toughness of the material, reduce its brittleness, and obtain the appropriate combination of plasticity, toughness, and hardness. Therefore, the quenching temperatures of 850, 880, 910, and 930 are selected for 1 h. The tempering temperature is 200, 230, 260, and 290 , and the holding time is 2 h.

It can be seen from Fig. 1 that, on each quenching temperature curve, with the increase of tempering temperature, the hardness value of #1 sample basically shows a downward trend, but the decrease range is not very large, and the downward trend is relatively gentle; on the impact toughness curve, with the increase of quenching temperature, the value decreases, but with the increase of tempering temperature, its value increases. With the increase of tempering temperature, the carbon content, alloying element content, dislocation density, and twinning number in the martensite matrix decrease, so the amount of strengthening also decreases, so the hardness decreases. With the increase of tempering temperature, the matrix recrystallization and carbide point coarsening and spheroidizing. Because the carbide spheroidization reduces the dislocation slip distance and makes the slip distance shorter, the dislocation can not cut them, so the toughness shows an upward trend.

Figure 3 shows the metallographic structure of the sample after quenching at 910 and tempering at 230 . It can be seen that the microstructure and matrix of the two kinds of samples are lath martensite. The microstructure of the sample is uniform and the grain size is fine.

It can be seen from Table 2 that with the increase of hardness, the wear resistance of #1 #4 samples increases in turn. Therefore, it can be concluded that the wear loss of materials is directly related to the hardness of materials. The higher the hardness is, the smaller the weight loss is, the better the wear resistance of materials is. In addition, the dispersed carbides in the matrix also contribute to the wear resistance of the materials, but the effect is less than that of the hardness because of the few carbides precipitated.

China Mill liners manufacturer, Qiming Machinery is a leader in the design, manufacture, and supply of mill liners for mineral processing and quarrying industries. It offers customers complete wear liner solutions for mills that increase performance, equipment availability, and lower maintenance costs. Its mill liners are also tested to withstand the acidity level of different elements that may be present in the milling process. Longer milling life to your machine means fewer expenses and more profit or income to your company.

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.