SU459253A1 - Lining for ball mills - Google Patents

Description

I

The known lining for ball mills is made up of a set of lining plates with stepped working surface and elevation of steps at an angle of 12-20 °.

The lack of linings of this type is that they, in a number of cases, reduce the productivity of the mills. The decrease in the productivity of the mill is a consequence of throwing balls of the outer row onto the opposite wall of the mill, which means that they do not fall on the ore and do not participate in grinding. In addition, productivity is reduced due to the loose packing of the outer layers of balls on the surface of this lining, which reduces the effective volume of the mill.

The aim of the invention is to increase the productivity of mills and the wear resistance of the lining.

This is achieved by the fact that the side surface of each step is inclined to the radius drawn from the center of the mill to the middle of the plate by an angle of 20-30 ° and has a height 10-30 mm higher than the radius of the largest ball, the lower plane of the step being from the side dihedral the angle is 90 ° ± ± 10 ° and has a width equal to (0.7-1) the diameter of the largest ball.

FIG. 1 and 2 depict the described lining.

The lining contains lining plate 1, step 2, side plane of step 3.

FIG. 1 letters marked:

/ - width of the lining plate, mm;

d is the diameter. the largest ball, mm;

a 12-20 ° angle of the steps;

a (0,7-l) d - width of steps, mm;

Р 20-30 ° - the angle of inclination of the side planes of the steps to the radius drawn from the center of the mill to the middle of the plate;

Y 90 ± 10 ° - the angle between the lower and side planes of the step;

() - height

steps, mm.

The arrow indicates the direction of movement of the lining. The dimensions of the lining plate are specified when constructing the profile within the limits indicated above.

FIG. 2 shows the operation of the mill with this lining.

The fallen balls of the outer layers roll onto the surface of the lining in the direction indicated by arrow A almost to meet its movement (arrow B) and enter the angle formed by step 2 and its lateral plane 3. In this case, the possible path of the ball to slide along the step will be minimal and equal to ball of maximum diameter to its radius. Upon further movement, the ball abuts against the side plane of stage 3 and is securely gripped by it. Reducing the slip path to a minimum ensures high wear resistance of the lining, and reliable adhesion of the balls to the lining provides a rise to the maximum height. Due to the slope of the side surfaces of the steps and the same height of the protrusions, the throwing of the balls is eliminated, all of them fall on the fifth ball loading together with the ore and are involved in the grinding process. Compact placement of balls on the surface of the lining increases the net volume of the mill. The high lift of the balls, their fall together with the ore on the ball loading bar and the increase in the net volume provide an increase in productivity

mill, and the same wear conditions of each stage - the preservation of the shape and properties of the lining until the end of its work.

Subject invention

The lining for ball mills, composed of a set of lining plates with a stepped working surface and a step height of 12-20 °, characterized in that, in order to improve the mill performance and lining resistance, the side surface of each step is inclined to the radius, drawn from the center of the mill to the middle of the slab, at an angle of 20-30 ° and has a height 10-30-30 mm greater than the radius of the largest ball, with the lower plane of the step being 90 ° ± 10 ° from the lateral dihedral angle and having a width equal to 0, 7-1 diameter most of the world.