How to use the steel ball to maximize the effect
The steel ball of the ball mill, as the grinding medium of the ball mill, constantly collides and rubs against the material and the barrel of the ball mill during the grinding process. Therefore, the consumption of ball mill steel balls is particularly large among all the wearing parts of the ball mill. Compared with another consumable ball mill liner, the consumption of steel balls is almost ten times that of the liner. Although the large consumption of steel balls is an inevitable phenomenon in the grinding operation, under the condition of ensuring the normal operation of the ball mill, properly controlling the consumption of steel balls to avoid excessive ball consumption is also one of the effective ways to control the grinding cost.
1. Regularly clean the invalid balls and add new steel balls
Too many invalid balls will increase the rate of broken balls, which will lead to an increase in the load capacity of the ball mill and increase power consumption. This is one of the reasons for the high ball consumption. Therefore, it is very important to regularly clean out the invalid balls and add new steel balls according to the grade.
2. Reasonable steel ball filling rate
The steel balls added in the cylinder of the ball mill account for 30~40% of the volume of the cylinder. When the speed of the ball mill reaches a certain level, the greater the filling rate, the more times the steel balls strike the material. Large grinding area and fast wear. In addition, if the filling rate is too high, it will also change the motion state of the steel balls of the ball mill and reduce the impact on large particle materials. On the contrary, the filling rate is too small and the grinding effect is weak.
3. Reasonable ratio of steel balls
The steel balls in the mill are of different sizes and proportions. Among them, large balls account for 30-40%, medium balls account for 40%-30%, and small balls account for 30%. In the later period, as the large ball continued to wear, the diameter became smaller and smaller. So add big balls regularly. But pay attention to the reasonable ratio. If the proportion of large balls in the mill exceeds 70%, the effect area of the balls will be reduced. Not only will the ball consumption increase, but it will also affect the grinding efficiency. If the proportion of large-diameter steel balls in the mill exceeds 70%, it will result in a reduction in the area of action of the balls. We know that the grinding efficiency of the ball mill is obtained by adding the sum of the work done by each steel ball. There are too many large balls, resulting in many grinding balls not playing their effectiveness. It is also an inevitable result that the grinding efficiency of the ball mill will decrease.
4. Grinding aids or heat treatment can be added to difficult-to-grind materials
The grindability of materials is also an important factor affecting the consumption of steel balls in ball mills. In actual production, if you encounter difficult-to-grind materials, you can add some grinding aids or heat the ore to reduce the hardness of the materials. Improving the grindability is also an effective way to reduce ball consumption.
5. Reduce the feed particle size
The larger the grain size of the ball mill, the greater the work done by the ball mill on the material. If you want to achieve the specified grinding fineness, the workload of the ball mill will inevitably increase. Subsequently, the energy consumption of the steel ball will also increase.
In order to reduce the power consumption of the ball mill, the feed particle size of the grinding can be reduced. Therefore, it is required that the particle size of the crushed ore should be small, that is, "more crushing and less grinding".
6. Reasonable grinding concentration
The size of the grinding concentration will affect the specific gravity of the pulp, the degree of adhesion of the material around the steel ball and the fluidity of the pulp. If the grinding concentration is high, the adhesion of the material around the steel ball is good. The impact and grinding effect of the steel ball on the material is also great, and the wear of the steel ball is faster. In actual production, the grinding concentration can be controlled by controlling the amount of ore feeding, water supply or adjusting the grading effect.
7. Control the speed of the ball mill
On the premise that the proportion of steel balls in the ball mill is reasonable and the speed of the ball mill increases, the steel balls in the cylinder will be in a state of falling and become a thrown pile. When the rotation rate increases to a certain value, the useful power reaches the maximum value. At this time, the grinding effect is better, and the ball wear of the ball mill is more reasonable. The theoretical critical speed of the ball mill is generally 78-84%. Due to the nature of the material and other factors, it is necessary to determine the speed of the ball mill according to the actual situation.
