Ball Mill - Super Star of Grinding Process

The ball mill is the most common and important equipment in the grinding operation. The ball mill has high applicability, strong processing capacity and many selectivity, so it is widely used and can adapt to most use situations. The most commonly used equipment for the grinding process of general materials is the ball mill.

Working Principle of Ball Mill

The working principle of the ball mill is that the cylinder is rotated by the external force of the engine, and the grinding medium steel balls in the cylinder move with the cylinder due to centrifugal force and frictional force. When the grinding medium moves to a certain height, the centrifugal force and friction force are less than the gravity of the steel ball, and the steel ball will be thrown down, causing impact on the material and breaking it, and the purpose of grinding is achieved through continuous impact and friction.

Advantages and Disadvantages of Ball Mill

(1) Advantages

1) Strong applicability: ball mills can be used for grinding of most materials, except for a few materials with special physical properties, ball mills can generally be used;

2) Strong processing capacity: The ball mill has low requirements on the hardness of the material, and can also achieve a good crushing and grinding effect for some materials with high hardness;

3) Fine particle size of the product: The grinding medium of the ball mill has a large impact force on the material, strong destructiveness, good dissociation degree of the material, and finer particle size of the obtained product.

(2) Disadvantages

Serious overgrinding phenomenon: the crushing and grinding force of the ball mill is large, although it can dissociate the material better, but it is also easy to cause the particle size of the material to be too small.

Type of Ball Mill 

(1) According to the classification of operating conditions, it can be divided into wet ball mill and dry ball mill. Wet ball mills add water to the ball mill at the same time as feeding materials, the materials are ground in a wet environment, and finally discharged with a certain concentration of ore slurry; dry ball mills are ground under dry conditions, and qualified materials are pumped out by the air flow. 

(2) According to the size of the cylinder, it can be divided into short cylinder ball mill, medium cylinder ball mill and long cylinder ball mill. The barrel length of the short barrel ball mill is less than twice the barrel diameter; the barrel length of the medium barrel ball mill is equal to three times the barrel diameter; the barrel length of the long barrel ball mill is equal to or greater than four times the barrel diameter.

(3) According to the ore discharge method, it can be divided into overflow type ball mill, grid type ball mill and peripheral type ball mill. The overflow type ball mill discharges the ore through the hollow shaft; the grid type ball mill discharges the ore through the grid plate; the peripheral ball mill discharges the ore through the periphery of the cylinder.

(4) According to the classification of transmission mode, it can be divided into center transmission ball mill and edge transmission ball mill. The drive power end of the center drive ball mill is in the center of the ball mill; the edge drive ball mill is a motor driven by the gear on the edge of the cylinder through the reducer to drive the cylinder to move.