The most effective and therefore common equipment for crushing and grinding is drum mills. The mill drum is made welded or riveted from sheet steel, and the end caps are cast from cast iron or steel. They are connected to each other by bolts. The electric motor is connected to the drive shaft through a gearbox or in large mills (slow-speed) through a coupling. To prevent wear, the drum and end caps are lined with manganese steel armor plates with a thickness of 50 to 150 mm, and the inner part of the hollow trunnions with removable collars. Hatches are used to unload worn balls and insert the lining inside the mill.
Depending on the type of grinding medium , drum mills are divided into:
- ball - grinding medium in the form of steel or cast iron (less often porcelain) balls with a diameter from 25 to 150 mm;
-rod - grinding medium steel rods with a maximum length of 6 m;
Rod mills are used for fine crushing and coarse grinding of rocks and ores of low and medium strength. Ball mills, which are most widely used, are used for grinding a variety of products, primarily ores of various minerals, both metallic and non-metallic, as well as clinker in the production of cement.
In production conditions, the mill is loaded with balls and ore up to 40-45% of its volume. During the rotation of the mill drum, the balls rolling, sliding and falling, grind the ore grains.
Rod mills are similar in their design to cylindrical ball mills with central unloading. Their length is 1.5-2 times larger than the diameter. The grinding medium is the rods. The mill is filled with rods 100-200 mm below the mill axis, i.e. the rods occupy 35-45% of the internal volume of the mill. The volume weight of the rods is 6-7 t/m3. When grinding ore in a rod mill, the contact between the rods is carried out along the entire length of the rod, and not at individual points, as when grinding balls. With the free fall of the rod, the impact force at each point is less than the impact of the ball, because this blow is perceived by a larger area. Therefore, rod mills give a coarser and uniform coarseness of the crushed product than ball mills.
The crushing and grinding equipment presented by our company has proven itself to be of high quality and reliable design with maximum performance.
Our equipment is used in many domestic and foreign enterprises, time-tested and constantly being improved.
We take into account all the wishes of the customer and design the equipment taking into account the working conditions and the type of processed raw materials.