Misconceptions and influences of ball quality judgment of ball mill

The quality of the ball mill ball not only affects productivity, but also the consumption of the ball, and thus the cost of the grinding medium. It is wrong to pursue high hardness and low unit consumption. High hardness and low unit consumption do not equal low cost. Balls with high hardness and low unit consumption are often very expensive. High hardness does not necessarily increase or even reduce productivity.

The quality of the ball mill ball not only affects productivity, but also the consumption of the ball, and thus the cost of the grinding medium. It is wrong to pursue high hardness and low unit consumption. High hardness and low cost are different from high hardness and low cost. High hardness does not necessarily increase productivity or even reduce productivity. Only high productivity can reduce unit consumption indicators. Therefore, the main criteria for steel balls should be high mill productivity and low grinding media costs. Only high productivity and low grinding media costs can achieve good economic benefits. Economic benefits are a necessary condition for the survival and development of an enterprise.

When choosing a steel ball, two problems are often overlooked: the harder the steel ball, the better, but the hardness value is appropriate; the density of the steel ball is also a problem that cannot be ignored. Generally speaking, as the hardness increases, the unit consumption of the steel ball will decrease as long as no crushing occurs; and, ball deformation can be reduced, ball deformation during crushing can be reduced, and more energy can be used to crush ore particles, which can improve the productivity of the mill. However, the increase in the hardness of the steel ball can only be moderate, with an appropriate range, rather than the harder the better. If only ball loss is considered, the higher the hardness, the less consumption. However, in order to improve the productivity of the factory, the productivity increases with the increase of ball hardness within a certain range. However, when the hardness exceeds a certain range, the productivity of the mill will be adversely affected and the productivity of the mill will be reduced. When the steel ball is too hard, there are two reasons

① The steel ball bounces severely, causing some energy loss during rebound, so the energy of the ball is no longer used for breaking, affecting breaking;

② When the hardness of the steel ball is too high, the steel ball and the steel ball come into contact with each other and slide violently, which cannot effectively make the mineral particles between the steel balls mesh with each other, weakening the grinding effect of the ore particles.

As for the effect of ball density on grinding, generally speaking, the productivity of balls of the same size and high density is higher than that of balls with low density.

The density of steel balls is affected by three factors

①The density of different materials such as steel, cast iron, alloy steel is different. The density of steel is higher than that of cast iron. Alloy steel varies according to the density and content of the main alloy elements.

② Due to the influence of steel ball manufacturing methods, the rolled and forged steel balls are dense and have high density. The structure of cast steel balls, cast iron balls or cast alloy balls is not very dense and even has pores, so the density is small.

③The density of different crystal structures such as martensite, austenite, bainite and ferrite is also different, which will also affect the crystallinity.