Ball Mill Working Principle

Specification of Ball Mill

Ball mill is key equipment for grinding in mineral processing plant, it is widely used in cement, silicate, new-type building material, refractory material, fertilizer, ore dressing of ferrous metal and non-ferrous metal, glass ceramics etc.  There are dry grinding and wet grinding, ball mill can be divided into tabular type and flowing type according to different forms of discharging materials.

Ball Mill Working Principle:

The ball mill is a horizontal rotating device transmitted by the outer gear. The materials are transferred to the grinding chamber through the quill shaft. There are ladder liners and ripple liners and different specifications of steel balls in the chamber. The centrifugal force caused by rotation of barrel brings the steel balls to a certain height and impact and grind the materials. The ground materials are discharged through the discharging board thus the grinding process is finished.

What is Rod Mill?

Rod mills are long cylinders filled with steel rods that grind by compressive forces and abrasion. The length of the cylinder is typically 1.5 to 2.5 times longer than the diameter. As the mill turns, the rods cascade over each other in relatively parallel fashion. One of the primary advantages of a rod mill is that it prevents over-grinding of softer particles because coarser particles act as bridges and preferentially take the compressive forces. Rod mills can take particles as coarse as 5 cm. Many of the newer operations tend to install ball mills in combination with SAG mills and avoid rod mills due the cost of the media, the cost of replacing rods and general maintenance costs. Many older operations have rod mills in combination with ball mills.

What is grinding?

Grinding, the final stage used in the comminution process, is usually conducted in cylindrical tumbling mills where the particle size is reduced through a combination of impact and abrasion. The primary differences between these mills are in the ratio of diameter to the length of the cylinder and the type of grinding media employed. Grinding media can be steel rods, steel balls, hard pebbles or the ore itself.