The ball mill grinding is made of the friction between the steel balls and the material. Therefore, the quality of steel balls has a very important effect on the efficiency and the quality of the ball mill. The quality of steel balls affects both the production efficiency and the consumption of the ball, and it's also affects the cost of grinding medium. So it's important to choose steel balls. 

 

The most important two things when choosing a mill ball: 1. Steel balls are not the harder the better, they have the suitable hardness; 2.The density of steel balls is also a problem. 
 

 

 

It is wrong to simply pursue high hardness and low single consumption. High hardness and low single-consumption are not the same as low cost, high hardness and low single-consumption ball are often high in price. High hardness does not necessarily increase productivity, or even decrease, only high productivity can reduce the individual consumption indicators. As a result, the primary criteria for choosing a ball of steel should be high productivity and low grinding medium. 

 

About the impact of hardness, as the hardness increases, as long as there is no breakage, the ball loss decreases generally; And it can make the spheres small of the ball, energy can be used more for crushing ore grains, it increases the productivity of the mill. 

 

But the increase in steel ball hardness is modest, and must in a proper range, it is not the harder the better. If you only think about the cost of the ball, the higher the hardness, the lower the burn. But for the ball mill productivity, it's increases with steel ball hardness in a certain range, but when hardness exceeds a certain range, it has adverse effect on mill productivity which makes the productivity decrease. 

 

In regard to the impact of steel ball density on the ball mill, the same size has large productivity and low density productivity. The density of steel balls is influenced by three factors:

 

1.Material influence. The density of different materials such as steel, cast iron and alloy steel is different, steel is denser than cast iron, alloy steel density depends on the density and content of the main alloy elements. 

 

2.Impact of steel ball manufacturing methods. The steel ball of rolling and forging is well organized, so it has large density; The cast steel balls, cast-iron balls or casting alloy spheres are not very dense, and even has pores, so the density is small. 

 

3.Effect of steel sphere crystal structure. The density of the martensite, austenitic, bainite, ferrite, and other crystal structures is different, and it also has an effect on the fineness of crystallization.