When the ball mill is grinding, due to the small number of coarse-grained ore in the grinding ore, it is easy to form a grinding medium in the ball mill that is too clear, and as a ball mill grinding product, the 30-50mm particle size cannot be obtained through the grid control. nugget. These nuggets or stubborn stones are gradually heated in the grinding machine, occupying the volume of the grinding machine, and the output of the grinding machine decreases, the unit power consumption increases and decreases, and excessive crushing occurs.

To eliminate or prevent the accumulation of stubborn stones in the ball mill, the common methods are:

1. Open the "gravel window" to draw critical particles out of the body, which can be used as a gravel medium for a gravel mill or treated separately.
1. Use ball mill semi-autogenous grinding, that is, add large steel balls (ball diameter 100-150mm) with a filling rate of 5% to 8% into the autogenous mill to supplement the energy shortage and grinding of the bulk as the medium. critical particle".
2. The self-grinding-ball mill-crusher crushing process is adopted, that is, the self-grinding open-circuit grinding, the material on the discharge cylinder sieve is drawn out, and after fine crushing and ball mill crushing, it is combined with the product under the sieve, which is the so-called A-B-C grinding process.

Ball mills are used to grind and pulverize materials, which are widely used for powders, such as cement, silicate, refractory materials, fertilizers, glass ceramics, etc. As well as non-ferrous metals of non-ferrous metal mines and stone dressing production lines of both parties. Ball mills grind various ores and other materials whether wet or dry.

The color of the finished product is important, and the color and material of the grinding body must be considered.

Low pollution is very important. Grinding media can be selected for easy separation of finished products (ie: magnetically separate non-ferrous metal products from steel and stainless steel media). Another method of separation is to use the same material as the product being ground media.