Transformation of the liner of the ball mill in the gold mine selection plant, the rubber liner has significant advantages

The ball mill is widely used in gold mining plants. Its working principle is to use the rotation of the cylinder body and cooperate with the movement of the steel ball in the cylinder body to make the material fully rub against the liner to achieve the crushing of the material. Therefore, the liner of the ball mill plays a key role in the crushing of the material.This paper takes a large-scale gold mine selection plant as an example. In order to improve the production efficiency of the grinding section of the selection plant and reduce investment costs, measures have been taken to replace the ball mill liner with a rubber liner, and good results have been achieved.

Engineering background

There are currently 6 sets of grinding systems in use in the grinding and floating section of a gold mine concentrator.There are 2 sets of MQY4561 grinding systems, and 1 set of MQG3236, MQG2736, MQY3645, and MQY3245 grinding systems each, which are used to crush gold ore and have a processing capacity of 13,000t/D.

In the grinding system, the inlet and outlet end cap liners of the No. 6 billiard mill are all made of alloy steel liners in the design and initial use. Compared with the rubber liners, their quality is heavier and the installation is time-consuming and laborious.The liner of the inlet and discharge end caps adopts an equal thickness design. After use, it is found that when the liner of the inlet and discharge end caps is worn out to the point where it cannot be used, the cylinder liner has less wear and can continue to be used for a long time. At the same time, replacement is bound to cause waste of materials and increased costs; If the liner of the ball mill is replaced in batches according to the wear of the liner of the inlet and discharge end caps, compared with the overall replacement, the parking time required is longer, which affects the equipment operation rate of the ball mill.

Optimization of ball mill liner

(1) Optimization of the material and structure of the liner of the inlet and outlet end caps

The inlet and outlet end cap liners of the 6 billiard mill were changed from the initial alloy steel liners to rubber liners.The liner of the feed end cap was changed to a steel-rubber composite liner, and the liner of the discharge end cap was changed to a rubber liner.The structure was changed from an integral type to a split type, which is divided into two parts: the end cap liner and the lifting strip.Due to the continuous lifting of steel balls and materials by the lifting strips, the wear is relatively fast, while the end cap liner wears lightly, so 1 set of end cap liner can be used with 2 sets of lifting strips, saving production costs.

According to experience, the liner of the feed end cap wears out faster and more severely than the liner of the discharge end cap. Therefore, the liner of the feed end cap adopts steel-rubber composite lifting strips, while the liner of the discharge end cap adopts pure rubber lifting strips, which effectively reduces the total quality of the liner.The difference in the service life of the end cap liner at the inlet and outlet ends is reduced.

After the transformation, the quality of the new end cap liner has been greatly reduced. The total mass of the original alloy steel liner is 21,996 kg. The total mass of the steel-rubber composite liner now used is 7,827 kg. The total mass of the liner is reduced by 14,169 kg, which reduces the quality by about 2/3. It greatly reduces the labor intensity when replacing the liner, improves the maintenance efficiency, and saves electrical energy.

(2) Optimization of related parameters of cylinder liner

Combined with the process requirements, the corresponding technical requirements are put forward for each mill liner：

First, according to the different working conditions of each mill, clear requirements are put forward for the dimensions and materials of the cylinder liner to extend the service life of the cylinder liner.;

The second is that under the premise of ensuring the service life, the maximum peak and trough size of each liner of the ball mill is clearly limited, thereby limiting the total quality of the liner to improve the processing capacity of the ball mill.;

Third, because the liner manufacturers are different from the manufacturers of supporting accessories (bowl-shaped pads, rubber gaskets), they often cause trouble due to their mismatched sizes and shapes. It is now required that the manufacturers who make the liners provide them uniformly, which is conducive to the supporting installation and use of the liners, reducing installation time and failure and parking time.

Transformation effect of ball mill liner

Through the optimization and transformation of the liner of the ball mill, electrical energy can be effectively saved, and the processing capacity can be increased by 0.78t/h, and the annual processing capacity can be increased by 6739.2T.Due to the reduced quality of the end cap liners at the inlet and discharge ends, the cylinder liners are thin near the inlet and discharge ends. The liners are replaced on average twice a year for each mill, which can save at least 6h each time, and the maintenance time of the grinding system can be reduced by 12h per year.