Mining Legislation in Zambia

Ball mill is widely used in the grinding operation of electric power, chemical industry, mineral processing, cement industry, especially in the mineral processing industry. At present, there are various kinds of ball mill types on the market with different functions and prices. It is difficult to select a suitable ball mail machine when choosing it. Next, Xinhai ball mill machine manufacturers take you to learn about the ball mill and then select the suitable ball mill types for your mineral processing plant.

One. Learn about the ball mill types

According to the shape of the grinding medium, the ball mill can be divided into ball mill, rod mill, rod-ball mill, gravel mill.

According to the unloading way, the ball mill can be divided into tail unloading ball mill, middle unloading ball mill.

According to the transmission mode, the ball mill can be divided into center drive ball mill, edge drive ball mill.

According to different process operations, the ball mill can be divided into dry ball mill, wet ball mill, intermittent ball mill, continuous ball mill.

According to the different applications, the ball mill can be divided into ore ball mill, cement ball mill, coal mill, ceramic ball mill, laboratory ball mill.

Two. How to select the ball mill machine?

Generally, there are many factors when choosing ball mill machines, such as mineral properties, grinding requirements, production environment, energy consumption. It is suggested to choose the appropriate ball mill types after the scientific analysis.

1. Select the ball mill machine according to the ore characteristics

Ball mill can be divided into dry ball mill and wet ball mill according to dry and wet conditions. In general, the dry ball mill is suitable for all kinds of metal ores, non-metal ores, the materials react with water (cement, marble) and the products stored and sale in the powder form. In addition, if the mineral processing plant is located in a dry area, and the water resources are scarce, the dry ball mill can be used for the purpose of water conservation.

The wet ball mill has a wide application, which can deal with a variety of metallic ores, non-metallic ores, such as gold, silver, copper, iron ore, molybdenum, phosphate, feldspar, fluorite. The wet ball mill can be used as long as the water does not affect the quality of the final product. Besides, the ores need special processing usually adopt the wet ball mill.

2. Select ball mill machine according to the characteristics of grinding medium

According to the characteristics of grinding medium, the ball mill types mainly include ball mill, autogenous mill and rod mill.

As the name implies, the autogenous mill does not need steel ball, steel bar or grinding medium, it only takes the mineral itself as the grinding medium to realize self-grinding. Therefore, the autogenous mill is suitable for the coarse material, and has a wide application, such as iron ore, gold ore, manganese ore, asbestos shingle, copper ore and limestone.

Ball mills are to finish the grinding operation relying on a steel ball, which has strong adaptability to materials. And because of it, the ball mill has a serious sliming phenomenon, it is suitable for the fine minerals, such as aluminum ash, lime, slag, molybdenum ore.

The Rod mills are generally suitable for ore whsoe Mohs hardness is 5.5-12 (brittle material). The rod mill is commonly used in gravity separation or magnetic separation of rare metals, such as tungsten and tin.

3. Select the ball mill according to the grinding sizes

Because the overall operation cost of the ball mill is high, so the ball mill is generally used for the regrinding of two-stage grinding, and the particle size of the material is relatively fine. Usually, the feeding particle size range is 20-30mm, and the particle size of the product is 0-3mm.

The autogenous mill has a large crushing ratio, which can handle the raw ore from the quarry and raw material after coarse crushing. It can grind the material to a relatively fine particle size once, whose crushing ratio is between 3000-4000 and the upper limit up to 5000.

The medium inside the rod mill adopts the high carbon steel rod with a carbon content of 0.8%-1% and a diameter of 50-100mm. Because the inner surface of the end cover lining plate is a vertical plane, the regular movement of the steel rod is guaranteed. In the grinding operation, the steel bar is thrown up by the centrifugal force, and it is in contact with the ore material in a plane line after falling horizontally. Most of the coarse grains are ground first, while less of the fine grains are ground. Therefore, the products of the rod mill are rough, uniform. It is not easy to be over-crushed, and the qualified rate of the finished products is high.

4. Select the ball mill according to the grinding condition

Generally, the ball mill machine can be divided into grid ball mill and overflow ball mill. The overflow ball mill can be used for the one-stage grinding, two-stage grinding and regrinding operation in the middle of the two-stage grinding. In the concentrator application, the overflow ball mill is mostly used for the material regrinding with the hydrocyclone for the two-stage grinding. The overflow ball mill mostly consists of a grinding circuit with hydrocyclone when the material diameter is greater than 4000mm. the grid ball mill is mostly used for rough grinding, often used in a single-stage grinding or one stage grinding of two-stage grinding. In the closed-circuit grinding, the -0.074mm of grinding fineness is 50%-70%, and it generally matches the spiral classifier to achieve the grinding and classification operation.

The autogenous mill mainly depends on the material itself; it can be used in crushing and one stage grinding. Compared with the ball mill, the grinding range of autogenous mill is between 300-400mm, the upper limit can reach 500mm.

The rod mill is suitable for fine and coarse grinding in one stage open circuit grinding.