The treatment of full grinding of ball mill is briefly introduced

1, generally reduce or stop feeding, and strengthen the ventilation in the mill, so that the ball mill operates under less material or no material to produce more heat. The drying mill should increase the heat into the mill, promote the water to evaporate quickly, and be carried away by the hot gas flow; At the same time, the material adhered to on the steel ball, on the lining plate and in the grate gap of the compartment plate will crack under the thermal expansion of its adhesive body and flake off under the repeated impact of the grinding body.

2, after the above method is ineffective, you can stop feeding, add grinding materials to the mill (raw material mill with dry coal or quicklime, cement mill with dry slag or dry slag), when the grinding sound is close to normal, feed a small amount of materials; After the grinding sound is normal, gradually increase the feeding amount until the normal feeding.

3, when the grinding is particularly serious, it is necessary to use the method of reverse grinding to deal with, the method is to pour out the ball and material in the warehouse, thoroughly chisel the crust on the lining plate and the steel ball, remove the blockage of the grate on the compartment plate, and then rematch the ball or load the poured ball. When the ball mill needs to be cleared, it is appropriate to use the reverse grinding method.

Since the mechanical essence of the ball mill grinding process is a functional transformation process, it shows that the basic fact of the two wood, grinding is to increase the surface energy of the material, when the conversion efficiency of each energy is unchanged, to increase the productivity must increase the input energy; The fact that improving the energy conversion efficiency of each time can also increase the surface energy of the material, that is, the yield of the soil, is the basis for energy saving. And the potential of saving energy consumption is very great. Only with a clear understanding of the mechanical principle of the grinding process, can the ball mill scientifically determine the technical parameters of the grinding process, so that the grinding process is high efficiency and low consumption. In the grinding process of the ball mill, the ball mill can be fully closed, so it can be dry grinding and wet grinding; It can also be filled with different gases in the grinding tank to achieve powder processing under different atmospheres. The study of the motion law of the grinding ball is helpful to understand the grinding mechanism of the planetary ball mill, and is of great significance to the optimization of operating parameters in scientific experiments and actual production.

Analysis of the ball mill mechanics principle, ball mill from the ore crushing and grinding process of physical phenomenon and geometric characteristics analysis, ball mill grinding is a continuation of crushing ore, but from the thermodynamic point of view, when the planetary mill ball by the inertia force of the radial component of the ball pointing to the outside of the tank, the ball will be subjected to the supporting force of the ball mill tank without leaving the inner wall of the ball mill tank; When the resultant force of the inertia force on the ball is pointed in the radial direction of the ball mill tank, the ball will break away from the inner wall of the ball mill tank and impact on the opposite side. At the same time, increasing the revolution speed and rotation speed of the ball mill tank or using a large diameter ball can significantly increase the inertia force of the ball, so that the ball energy is significantly increased, and the grinding effect is significantly enhanced. However, changing the inside diameter of the ball grinding tank will not significantly change the grinding effect. When the angular velocity of the ball mill is much higher than the angular velocity of the revolution, the ball will not leave the ball mill and lose the impact on the material.

Grinding is a process of increasing internal energy, and the mill does work on the ore block. Fracture by overcoming the cohesion of the ore block. Therefore, grinding is the two functions of the mutual transformation of the grid input electrical energy by the motor into mechanical energy. Mechanical energy does work on the mill and medium through the drive system. The mechanical energy that becomes the grinding medium. When the grinding medium falls or rolls down, it does work on the ore, and the work of the medium becomes the internal energy of the ore to deform and break the ore. After the ore is broken, it becomes the new surface energy of the ore. The work that deforms and breaks the ore is called active work, which includes the work of deformation and the work of separation. Most of the work done by the medium to the ore is lost in the surrounding medium space as heat energy during the crushing process, which is called the quasi-lost work of crushing. It includes the cold friction work between ores and machinery and between ores, the loss of heat energy reported by the repeated action of crushing force, and the loss of sound energy, light energy and radiation energy. Every time an energy conversion occurs, a certain loss of energy occurs.

What is the full grinding of the ball mill? From the phenomenon to the essence, we gradually discuss and analyze the ball mill grinding: How is the ball mill grinding phenomenon?
1, the full grinding phenomenon is light: the grinding sound is changed from clear to low, the output of the grinding tail is reduced, and the inlet and outlet wind pressure of the mill is increased;
2, the phenomenon of full grinding is serious: the grinding sound disappears, the main motor current is greatly reduced, and the material output of the grinding tail is greatly reduced.

Ball mill full grinding inducement:
1, may be due to excessive feeding amount, resulting in the grinding capacity of the grinding body can not adapt, resulting in full grinding phenomenon;
2, the particle size of the grinding material becomes larger or the grainability becomes worse, and in these two cases, the feeding amount is not reduced in time;
3, the water content of the grinding material is too high, and the ventilation is poor, the wind can not bring the water vapor and fine materials generated during the grinding process out of the mill in time, causing the material to adhere to the surface of the steel ball and the liner due to high humidity, increasing the buffering effect and reducing the grinding efficiency; At the same time, the wet material also blocks the gap between the compartment plate and the discharge grate plate, which causes the discharging difficulty. This reason caused by "full grinding" is more common.
4, the grate in the compartment plate is blocked by broken iron filings and debris.
5, in the closed circuit system, the powder selection efficiency of the separator decreases, the amount of return is too much, the feeding amount is not reduced, and the grinding capacity of the ball mill can not be adapted.
6, the average ball diameter of a bin steel ball is too small, or the filling rate is too low, or the filling rate of a bin abrasive body is too low than the second bin.
7. One or two compartments between one and two silos are partially broken or perforated, causing the grinding body to slip into the silo and the grinding capacity to decrease.

1. Adjust the load of the ball mill grinding body According to the production test, it is found that increasing the load of the grinding body can not achieve the effect of increasing production. It is found that the most suitable loading capacity of grinding body should control the steel ball matching ball at 95% of the rated loading capacity.
2. Optimize the grading analysis of the ball of the ball mill sieve residual curve of the Φ3200×13000mm cement ball mill, and learn that the material end curve of a bin does not decrease significantly, indicating that the crushing capacity of the bin is not very strong; There is a long horizontal line segment in the second bin, indicating that the steel ball stage of the bin is equipped with problems, so the corresponding adjustments are made to the grinding body: (1) increase the average ball diameter of the first bin, reduce the average ball diameter of the second bin; (2) Optimize one and two bin filling materials.
3. The improvement method of the extrusion effect of the roller press Φ3200×13000mm cement ball mill is a double-bin mill, and the crushing function is transferred to the roller press, in this case, the extruded material is easier to achieve the quality index. However, due to the increase in production, the pressure of the roller press decreases, and the roll gap is still the original set range, resulting in an increase in the passing volume, poor material extrusion effect, more particles content above 10mm, increased teasing volume, easy blockage of the outlet grate, some particles deposited in the second warehouse to reduce the grinding effect, frequent subject failures of the roller press, and the operating rate is only about 40%. Influence cement ball mill output. Improvement measures: overhaul the roll press, weld the roll surface, and slightly reduce the roll gap setting.
4. Improve the efficiency of the sorting machine to adjust the reasonable cycle load, generally K=218%, the sorting efficiency reaches about 78%, the sorting machine gets the maximum play, in addition to regularly replace the sorting machine blade, improve the output of Φ3200×13000mm cement ball mill.
5. Strengthen the ventilation and system sealing of the cement ball mill, reduce air leakage and proper ventilation, which can discharge the cement ball mill inside the micro-powder, reduce over-crushing, and discharge water vapor to reduce sticky balls. In addition, the production equipment connected with the ball mill, such as the elevator and powder separator, are sealed to improve the wind lock effect.
6. Reduce the grinding temperature and strengthen the heat dissipation of the grinding system. The temperature of the grinding system is high, some gypsum dehydration affects the quality of cement, increases the electrostatic adsorption of fine powder, aggravates the paste ball in the ball mill, and makes the grinding phenomenon serious, so we should pay attention to the heat dissipation of the system surface.

7. Clear warehouse regularly and make up the ball in time. In the process of mineral processing, grinding and grading is a very critical and important part, the mill is a high energy consumption, low efficiency, failure prone equipment, the running status of the mill monitoring, not only can improve equipment efficiency and productivity, reduce energy consumption, reduce failure, and can improve economic benefits to ensure normal production.
Vibrating screen because of its compact structure, high classification dehydration efficiency, and the use of the mill can greatly improve the current efficiency, but the vibrating screen is working under high frequency vibration, its structure is under the action of alternating forces, in the long-term effect of inevitable damage, on the one hand will change the vibration screen amplitude and frequency, affecting the screening efficiency, on the other hand affect the life of the vibrating screen, Therefore, the working condition monitoring of the vibrating screen can ensure the efficient work of the equipment, reduce losses and extend life. The real-time monitoring of the working state of ball mill and vibrating screen by using double single-chip microcomputer structure not only breaks the monopoly of PC in the host of mine equipment monitoring and diagnosis system, but also shows incomparable advantages in reliability, economy and adaptability of the monitoring system. The monitoring test of the developed system shows that it is not only intelligent, stable and reliable, but also has the following characteristics:
(1) Parameter setting is flexible, and the standard value can be set at any time during the operation of the system.
(2) strong versatility, because the system first tests the equipment in the normal state when it is powered on for the first time. The reference standard value of each parameter, so that the same type of ball mill and vibrating screen can be monitored.
(3) The status display is intuitive, suitable for field needs. The following are four commonly used ball mill feeders: 1. The feed funnel enters the conical sleeve located in the hollow journal of the mill and slides into the mill along the rotating cylinder wall. The section of the feed pipe is elliptical.
2, the spiral feeder The spiral feeder has a spiral spoon, which gradually slides the material along the inner wall of the spoon to the bottom of the spoon when it is turned. There is a round hole on the side wall of the bottom of the spoon, the round hole is aligned with the hole of the hollow journal of the ball mill, and the material enters the ball mill through the round hole of the side wall and the hollow journal.
3. Screw feeder The working principle of the screw feeder is the same as that of the drum feeder, but the structure is different. The material is fed into the spoon wheel by the feeding funnel, the rotating spoon wheel lifts the material up, and then the wheel blade is directly poured into the spiral sleeve located in the hollow shaft, and the inner spiral blade transfers the material to the mill.
4. The coarse grain feed of the combined feeder can be lifted directly by the spiral partition through the hole of the cover and sent to the hollow journal, while the sand return in the trough is sent to the hollow journal through the spiral partition of the cylinder after the scoop and hook head are picked up. This method not only increases the production of the feeder, but also the coarse material does not need to be picked up by the spoon, thus reducing the wear of the spoon.