Liner is an important part of the ball mill equipment, its role is to protect the cylinder, end cover (board) from wear. The liner needs to be replaced periodically, so its construction should be easy to replace. Lining materials are: metal material (manganese steel, chrome steel, etc.) and two kinds of rubber. At present, there are many domestic metal material linings, and the rubber lining is in the stage of trial promotion.
Type of liner:
A flat lining is used for the fine grinding chamber, and the rising height of the grinding body depends on the coefficient of static friction with the tree board.
2 The bead liner is used in the first chamber to enable the grinding body to rise higher and have a larger impact energy.
The 3 rib liner is similar to the bead liner.
4 Wave liners for base ball mills.
The 5 step liner is suitable for crushing the bin. It is widely used and has the following three advantages.
a) The height of the lifting of the same sphere is uniform.
b) Uniform wear on the surface of the board.
c) The dragging ability of the liner acts on the abrasive bodies of the other layers. The sliding wear between the liner and the outermost abrasive body is reduced, and the sliding and abrasion between the different levels of the abrasive bodies are also prevented.
6 hemispherical lining, suitable for smashing bins.
7 corrugated liner, boltless liner for fine grinding, with small peaks and tightness.
8 graded lining, which can automatically grade steel balls.
The shape of the barrel liner has a great influence on the work of the ball mill. When handling coarse-grained materials, the lining of the ball mill cylinder should be undulated (such as wave shape, convex shape, lap shape and stage shape). This shape liner has the ability to raise the grinding media to a higher height, thereby enhancing the impact capability of the media and increasing the productivity of the ball mill. Often used in the first stage of grinding.
Fine grinding (often referred to as the second stage of grinding) is mainly caused by abrasion and peeling. The smooth-shaped lining is easy to slide the steel ball, and the grinding and peeling action is strong. Therefore, the fine-grinding ball mill cylinder adopts a smooth lining. The type I, II and III lining plates shown in Figure 5-6 are directly bolted. On the cylinder, the IV and V-type liners are fixed by steel wedges and bolts, which have the advantage of being easy to install at the factory. The thickness of the liner is determined by the diameter of the ball mill, typically between 50 and 150 mm.
Figure 5-7 shows the strip liner of the ball mill barrel, which is not bolted but is pressed against the end cap liner. The end cap (plate) liner is made of the same material as the ball mill liner liner, usually in the form of a fan. The hollow journal can be smooth and threaded on the inner surface of the sleeve. The thread of the hollow journal bushing of the ore end is used to transport the material to the ball mill and the reverse thread of the hollow journal bushing of the discharge end prevents the coarse material and the steel ball from being discharged. When the ore supply capacity is large, the hollow shaft bushing of the ore end can be provided without a thread, because the thread will limit the amount of ore.