Ball mills are widely used in the production of cement, silicate products, new building materials, refractory materials, fertilizers, black and non-ferrous metal dressings and glass ceramics, dry or wet grinding of various ores and other grindable materials. In the ball mill, the main function is to grind the ball, then how to choose the grinding ball?
1. Determine the total amount of steel balls allowed to be loaded according to the power of the main motor of the ball mill. The load rate of the steel ball filling space is generally 25% - 35%, the lower steel ball load rate, power consumption is also reduced, but the productivity is also low. Therefore, the first prerequisite for verifying the total amount of steel balls added is that the sum of the weight of the steel ball and the weight of the material in the mill is less than and close to the allowable value of the motor power of the ball mill.
2. Determine the ball diameter of the largest ball mill.
3. The reasonableness of the steel ball ratio is measured by the specific surface area of the steel ball. The specific surface area of the steel ball in a warehouse should be 9.5-10.5 m2 per ton of steel ball. For a closed ball mill with a roller press, this value can be adjusted to 12-14 m2/t steel ball. The liner used is of continuous lift type. The specific surface area of the steel ball loaded in the second bin should be 35-38 m2/t steel ball, and it can be 38-40 m2/t steel ball with the roller press. The ratio between the ball diameters of various ball mills is still calculated according to the maximum bulk density.
4. in line with the main function of the ball in each warehouse, and combined with the type of liner used. The clinker particles fed in a warehouse are up to 30 mm, and all of its main function is to break, therefore. The diameter of the loaded steel ball should be between 50-90mm. The clinker entering the second chamber of the ball mill is less than 2-3 mm, so its role is fine grinding. The range of the steel ball should be 15-50 mm. Because the fine grinding is inter-grinding, the highest efficiency can be achieved by inserting a single corrugated liner with a single-size ball (20-25mm). If a steel ball of a certain range diameter is still selected in the second bin, a grading lining plate may be used, so that the larger ball is close to the sump plate, and the smaller ball is located at the discharge end.
5. Calculate the unit steel ball output to verify the rationality of the ball.