Ball mill is the necessary grinding equipment for mineral processing plant. It is mainly used as grinding operation before sorting. is a pulverizer consisting of a rotating drum containing cobblestones or metal balls as the grinding media that can grind ores and other materials to 20 mesh or finer in a variety of applications, open or closed circuit.
The composition of the ball mill
The internal structure of the ball mill is relatively complex, with many components. The main components include the cylinder body, the lining plate, the partition plate (only available in multi-silo mills), the main bearing, the feeding and discharging device, and the transmission system. Among them, the transmission parts of the ball mill include V-belt, motor, reducer and pulley.
It is one of the important parts of the ball mill. In addition to bearing the static load of the grinding body, the cylinder also bears the impact of the grinding body, and the cylinder is revolving, so the cylinder is alternating stress. In order to ensure the grinding efficiency of the cylinder, a lining plate will be installed in the cylinder.
The ball mill bearing is mainly the part that supports the rotation of the ball mill. Commonly used bearings include sliding bearings and rolling bearings. No matter which kind of bearing is very important for its lubrication requirements, generally thin oil is used for centralized circulating lubrication, and some small machines also use it. Oil ring lubrication, oil ring drip lubrication or wool lubrication.
It is located at both ends of the cylinder and is connected with the flange at the bottom of the cylinder by screws. There is a small hole in the middle to ensure the smooth discharge of exhaust gas.
The working principle of ball mill
The working principle of the ball mill is that the whole frame supports the ball mill barrel, and the motor of the tail device drives the ball mill bearing to make the ball mill rotate clockwise. The rotation is not the main purpose. Balls and materials make the steel balls and materials realize parabolic motion, and during the movement, forces such as impact, impact and self-grinding occur, and then the grinding is completed.
During the grinding process, because the feeding port of the ball mill is continuously feeding, the ground material will be forced to move to the discharge port to realize the discharge. Some ball mills rely on feeding materials to discharge ore by gravity, and some ball mills are equipped with a grid plate at the discharge place, which will forcefully discharge the ground material, and the material is directly scraped out by the grid plate.
Ball mill performance advantages
1. High wear resistance and impact resistance (lining plate)
After the advanced double-medium quenching process, the lining plate can withstand huge impact force during production, and can maintain the surface shape of the lining plate for a long time during operation, reducing the lining plate. deformation and wear.
2. The lining plate has strong habituation
Compared with the high manganese steel lining plate on the market, the ball mill lining plate produced by Henan ball mill manufacturers is made of medium alloy double medium quenched medium alloy steel, which shows high cost performance and can be used to various mine rocks. Wet grinding, dry grinding, mixed grinding, etc.
3. High flexural strength of gears (gears)
The use of displacement gears for ball mill accessories can eliminate the phenomenon of undercutting, so that the gears with weak flexural strength can be greatly strengthened, and the flexural strength of the gear teeth can be more than doubled.
4. Excellent lubrication and reliable operation
The displacement gear can reduce the sliding speed of the meshing and reduce the sliding ratio, thereby improving the wear resistance and anti-glue performance of the gear, and also improving the hydrodynamic performance and lubrication condition of the gear transmission. The reliability of the ball mill operation is improved.
5. Heat insulation and cooling, long life (bearing)
The diameter of the hollow shaft of the rolling bearing part of the ball mill is thickened, so that the radial interval between the rolling bearing and the feeding and discharging screw cylinder is enlarged, which has a certain heat insulation and cooling effect and prolongs the bearing. service life.
6. Energy saving and consumption reduction, less wear and tear
Use thin oil lubrication instead of grease lubrication to avoid poor lubrication due to lack of oil, so that the friction coefficient of bearings and other components is reduced, and the loss rate of components is greatly reduced.
Classification of ball mills
Classification according to the different discharge methods of the ball mill
Generally, ball mills are divided into two categories, one is the center discharge ball mill (overflow ball mill). The other type is the peripheral discharge ball mill (lattice ball mill). The structure of the two types of ball mills is basically the same, the difference is that there is no ore discharge grid in the barrel of the overflow type ball mill. Due to the different discharge characteristics, the two types of ball mills also have their own uses, and each has its own advantages and disadvantages. Generally, the overflow type ball mill has a finer grinding fineness and is more suitable for the regrinding of materials. The working performance and production capacity of the grid ball mill are better than that of the overflow type ball mill, but its structure is slightly more complicated, and the particle size of its grinding products is also larger than that of the overflow type ball mill, so it is more suitable for the rough grinding of materials.
Classification according to different working methods of ball mills
Ball mills can also be divided into continuous ball mills and batch ball mills. As the name implies, the different working methods of the two determine their different working characteristics. The ball mills used in mineral processing plants and coal-water slurry plants end with continuous ball mills. When processing chemical products such as ceramic raw materials, glazes, etc., due to the characteristics of materials, intermittent ball mills are required for grinding. The batch ball mill can control the particle size of the material by adjusting the grinding time, but its grinding efficiency is not high and the operation is not very convenient.
Classification according to the way the ball mill barrel is placed
Ball mills can also be divided into vertical ball mills and horizontal ball mills. Vertical ball mill is a new type of ball mill with the cylinder fixed. After a lot of experiments, it is found that the vertical ball mill has the advantages of high grinding efficiency, low energy consumption and low noise. This also makes the vertical ball mill favored by more and more users.