Ball mill is a grinding machine that widely used in many industries. Therefore, we will have a comprehensive briefing from the side of classification and structure.

I. Classification of the ball mill.

1. Classify by the grinding medium.

Usually, the grinding mediums are included steel balls, grinding cylpebs, grinding rod, etc. Mills loaded with the steel balls and the grinding cylpebs are named ball mills. And the mills that load with the steel rod are called rod mill, or cylinder mill. Most of rod mills are used for the wet-type application. In the first of its chamber, cylinder shaped steel rod are installed. While the steel balls and the grinding cylpebs are loaded in the other chambers.

2. Classify by the discharging ways.

They are mainly typed in grate ball mills and the overflow ball mills. The grate ball mills are installed with a grid plate in the end of its discharging side, through which the ground materials are compelled out of the mill by force. This mainly goes for the first stage grinding; oppositely, the overflow ball mills are discharged in self-acting. The production capacity is smaller than the grate ball mill. But it is good at the grinding fineness and more applicable for the second and third stage grindings.

3. Classify by the length-diameter.

Ball mill, the draw ratio is ≤2.

Cylinder mill, the draw ratio is 2~3.

Long mill, the draw ratio is >4.

II. Structure.

A ball mill is composed of feeding device, cylinder device, discharging device, transmission device, bearing device, lubricating system.

The feeding device is used for conveying the raw ore to the inner cylinder and returning sand from the classifier. There are two fashions to feed in the raw ores. The common method is feed in with a tilting chute. The other way is to install a screw feeder at the empty shaft neck.

The cylinder device is soldering by the thick steel plate with flange plate at the both ends. Man-hole is designed for the maintenance when the machine is halt. The liners can be made by several materials. Usually, by high manganese steel, high-chromium iron, medium manganese ductile cast iron and rubber, etc. Presently, high manganese steel is the most widely used textures of materials.

A conic shape of casting steel, bush is installed in the discharge end of the hollow shaft. You can see the helical blade on them. The decrescent steel balls and grinding cylpebs will be sifted out with the slurries by the fixed screen outside the bush.

The base bearing of the ball mill is a hollow shaft device. It is supported by a half-round sliding bearing with a pipeline on the top. Lubrication oil is sprayed from the pipeline to the bearings, which can also keep the machine working in a low temperature

Transmission devices are both available in the edge drive and centre drive.

Our company-Great Wall Machinery has been in the ball mill making area for almost 56 years. The first set of the ball mill was produced in 1968. And we will be committed to offer more quality grinding machines to the markets and strive for it in the new coming year of 2014.