How To Extend The Service Life of Ball Mill Liner?

The liner is one of the key components of the ball mill, which can protect the barrel of the ball mill, effectively increase the load, and improve the grinding efficiency. The long-term impact and grinding action make the ball mill liner easy to wear, deform and break, resulting in a decrease in grinding efficiency, and even shut down for replacement. So how to extend the service life of the ball mill liner?

1. Ball mill liner material and shape

The material and shape of the ball mill liner largely determine the service life of the liner itself. In terms of material, ball mill linings include metal linings, rubber linings, and magnetic linings. High manganese steel liner is a relatively common wet ball mill liner with a service life of about 8 months. The service life of the rubber lining is longer than that of the manganese steel lining, which is about three times that of the high manganese steel lining. Magnetic backing plates last longer.

In terms of shape, ball mill liners include smooth and non-smooth types. Subdivision can also be divided into waveforms, strips, trapezoids, flats, etc., among which waveforms are the most widely used liner types. When the ball mill is running, it is impacted by irregular motion, and no matter which shape it is, it will be subject to a certain degree of uneven wear.

In order to prolong the service life of the lining plate, the lining plate of wear-resistant alloy technology can be used. In view of the uneven wear of the lining plate, the method of replacing the lining plate in parts or optimizing the thickness of the lining plate of the cylinder can be used to improve the service life of the lining plate of the ball mill.

2. Filling rate and ratio of steel balls

Steel ball is an important grinding medium for a ball mill, which will affect the service life of the liner and the grinding efficiency of the ball mill. When the filling rate of the steel balls is low, the wear of the steel balls on the lining plate is relatively large, and the grinding efficiency is also relatively low at this time. The medium ratio refers to the proportion of each size of the steel ball. The larger steel ball itself has a greater impact on the lining plate. When the impact force is too large, the lining plate will easily break.

In actual production, the filling rate of the ball mill can be determined with reference to the thickness of the liner and the diameter of the steel ball. The suitable filling rate of small and medium ball mills is generally between 35 and 45%, and the filling rate of large ball mills is generally between 30 and 35%. In terms of medium ratio, you can refer to the theoretical formula of sphere diameter and a half to calculate the appropriate steel ball ratio under different ore hardness and feeding particle size.

3. Pulp concentration

Most of the grinding pulp of the wet ball mill is neutral or weakly acidic. After being immersed in the pulp for a long time, the liner of the ball mill is susceptible to the impact and corrosion of the pulp. In addition, pulp concentration is also related to pulp fluidity and viscosity. When the slurry concentration decreases, the fluidity is strong, and the impact on the lining plate is strong, which is easy to damage the lining plate.

Generally, ore with high hardness and coarse particle size will have a slightly higher slurry concentration. In actual production, generally, one-stage grinding pulp should be controlled between 72 and 82%.

4. Ball mill throughput

Ball mill throughput is an important indicator of its operating efficiency. When the processing capacity of the ball mill is too low, the amount of slurry in the cylinder is insufficient, and the probability of the steel balls hitting the lining plate directly increases, which is easy to damage the lining plate of the ball mill. However, when the processing capacity of the ball mill is too high, the pulp will accumulate in the cylinder, reducing the grinding efficiency.

Ball mills of different sizes should operate within their own reasonable processing capacity. Movement under lower load can effectively reduce the possibility of ball mill liner damage.