The ore discharge mechanism of an overflow ball mill is that the material is continuously fed into the feed end, and the pressure in the cylinder is constantly rising. When the slurry is higher than the lower edge of the hollow shaft at the discharge end, the material will overflow by itself.Therefore, the overflow type ball mill does not have a mechanism for forced ore discharge, which is very suitable for the second stage of grinding and fine grinding operations in the two-stage grinding.

Overflow type ball mill ore discharge concentration

1. The relationship between concentration and grinding efficiency

The ore discharge concentration of overflow ball mill is closely related to the grinding efficiency, and appropriately increasing the ore discharge concentration is conducive to improving the grinding efficiency.This is because when the ore discharge concentration is high, it means that the viscosity of the slurry is higher, which can increase the friction between the steel ball and the material, thereby improving the grinding efficiency.；

In addition, due to the high viscosity of the slurry, the steel ball is more likely to be brought to a higher position during the rotation of the cylinder, and a greater impact force is generated when it falls, which also increases the grinding effect.；

Also, the high viscosity of the slurry can also extend the time of the material in the cylinder, thereby increasing the number of grinds and making the discharge finer.

However, if the ore discharge concentration is too high, it will be counterproductive and reduce the grinding efficiency.This is because the viscosity is too high, which will lead to greater resistance during the movement of the steel ball, and its lifting height and falling force will be affected. In addition, the concentration is too high, which will cause the material to be unevenly distributed in the mill, resulting in poor grinding effect.

2. The effect of concentration on subsequent production

Mastering the concentration of ore discharge also plays a great role in subsequent production.However, it should be noted that the rationality of the ore discharge concentration, too high or too low, will have adverse effects on subsequent production.

First of all, if the ore discharge concentration of the overflow ball mill is too high, then the slurry concentration entering the flotation stage must also be very high, which may lead to insufficient contact between the material and the flotation agent, thereby affecting the flotation effect.

Secondly, if the ore discharge concentration of the overflow ball mill is too low, although the problem of insufficient contact between the above-mentioned materials and the flotation agent is avoided, the volume of the slurry will inevitably increase due to the low concentration, resulting in heavy burden on flotation operations and high energy consumption.