What Should I Do If The Discharge Of The Ball Mill “Runs Rough” And The Discharge Port Throws Stones?

Ball mills are widely used in mining, metallurgy, cement and other industries and are an important part of the grinding system. This article mainly introduces the causes and solutions of the “rough” discharge of the ball mill and the stone thrown at the discharge port.

Reasons And Solutions For The “Rough” Discharge Of The Ball Mill

The “roughness” of the ball mill refers to the abnormal phenomenon that the fineness of the mill product is significantly coarser and difficult to control. It generally appears in the double-chamber open-circuit tube mill with a relatively small length and diameter. The roughness of the ball mill will increase the energy consumption of the ball mill and cause waste, and the large particle size will also affect the subsequent sorting. Therefore, in actual production, try to avoid the phenomenon of roughness of the ball mill.

The main reason for the “rough running” of the ball mill is that the capacity of the coarse grinding chamber is too strong and the capacity of the fine grinding chamber is insufficient. The reasons why the grinding capacity of the coarse grinding chamber is significantly higher than that of the fine grinding chamber are:

  1. If the loading volume of the grinding body in the rough grinding chamber is too small, the diameter of the steel ball is too small, or the filling rate of the grinding body in the fine grinding chamber is too much lower than that of the rough grinding chamber, increase the grinding body load and adjust the grinding body gradation. Increase the ratio of large balls, or appropriately increase the filling rate of the grinding body in the fine grinding chamber.
  2. If the feeding amount is too large or the feeding amount in a short period of time increases sharply, in the operation, the feeding amount should be ensured to be compatible with the crushing capacity of the bin, and the feeding amount should be prevented from suddenly increasing.
  3. If the grate gap of the partition board is too large, electric welding can be used to weld the steel bar to the place where the gap is too large.

  1. If the compartment plate is damaged or dropped, and the grinding body moves into the warehouse, the compartment plate should be replaced or installed, and the mixed grinding body should be sorted.
  1. If the size of the limestone to be milled is too large, the size of the limestone should be reduced. Before the problem of the size of the limestone is solved, the diameter of a steel ball in a warehouse should be appropriately increased, or the feeding amount should be temporarily reduced.
  2. If the crushing capacity of one warehouse is greatly reduced due to the phenomenon of “saturation” in one warehouse, the problem of “saturation” should be eliminated and prevented.

Ball Mill

Reasons And Solutions For The Stones Thrown At The Discharge Port Of The Ball Mill

When the feeding amount exceeds a certain limit value, the ball mill will throw out unground broken stones from the outlet, and the amount of stones thrown out is still large, which not only increases the power consumption of the ball mill, but also increases the labor of the personnel. strength.

  1. The Particle Size Of Imported Materials Is Too Large, Causing Insufficient Output Of The Ball Mill To Throw Stones

Excessively large particles will bring additional burden to the ball mill, and individual oversized particles are not easily crushed by the steel ball, which will cause the output of the ball mill to decrease and the power consumption to increase. Under the condition that new feedstock is continuously added, the stones that are not crushed will be thrown out of the mill along the exit of the mill. Therefore, during operation, the particle size of the material on the feeder should be closely monitored. When the particle size exceeds the designed large particle size, the feeding should be reduced or stopped immediately, and corresponding measures should be taken to ensure that the particle size of the feed is qualified.

  1. Insufficient Replenishment Of Steel Balls

Due to the long-term operation of the mill, the steel ball wears severely, the diameter is reduced, and the impact force is correspondingly weakened. When the steel balls in the ball mill are not replenished in time, the output of the ball mill is insufficient. Therefore, in order to maintain a certain ball-filling coefficient and steel ball diameter, qualified steel balls should be added to the ball mill regularly according to the current of the ball mill and the accumulated amount of grinding materials.

  1. The Size Of the Steel Ball Added Is Not Suitable

The ratio of steel balls refers to the proportion of large, medium and small diameter steel balls in the mill. Each type of ball mill has an optimal steel ball ratio, which is set by the manufacturer when the mill leaves the factory. The large-diameter steel ball mainly plays the role of crushing, and the small-diameter steel ball mainly plays the role of grinding. There are many large-diameter steel balls and small-diameter steel balls, and the small surface area is not conducive to grinding, which affects the efficiency; the small balls are too large to be broken and the efficiency is also affected. When the mill is initially installed with steel balls, the ratio of steel balls should be determined according to the value given by the manufacturer. When replacing the lining of the mill, the steel balls should be screened, and the broken steel balls and small diameter steel balls should be cleaned up. The diameter of the steel balls to be cleaned during the selection of steel balls should be determined based on experience, and the small diameter steel balls should not be cleaned too much. Generally, the diameter of the steel balls to be cleaned is 15-20mm or less.

  1. Lining Wear

After the lining of the mill is worn to a certain extent, the volume of the mill will increase due to the reduction of the thickness of the lining. In order to maintain the best filling rate, increasing the load of steel balls can effectively increase the output of the mill and prevent the mill from producing stones. The increase of steel balls is generally 5%-15%. When the inner liner of the ball mill is damaged or falls off, an obvious impact sound can be heard on the spot. If such a situation occurs, the ball mill should be stopped as soon as possible and the damaged liner should be dealt with immediately to avoid large-scale damage to the ball mill liner.

During the normal operation of the ball mill, due to the influence of external factors, there will be many failures. If these failures are not solved in time, it will directly lead to the difficulty of smooth production. When solving these failures, strict analysis is required. The reason for the failure is to adopt correct and reasonable key technologies to ensure the normal performance of the ball mill

Eternal Bliss Alloy Casting & Forging Co, Ltd.

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