Rod mill is widely used to grind various ores and rocks in metal and nonmetal mines and building materials industries. The rod mill grinds ores by the pressure and grinding and stripping force of steel bars, which has the advantages of mature production technology and simple and scientific process. Therefore, its position is the same as that of ball mill. The steel bar and lining board of the bar mill are the main components, and their material quality affects the production capacity and service life of the rod mill. The following is an introduction on how to choose the material of the steel bar and lining board of the bar mill for ore dressing?
1. Steel bar material-high hardness and wear resistance
The steel bar material of the rod mill adopted by various mining machine manufacturers in our country is mainly round steel, which is produced by the steel factory. If it is not handled, there will be malfunction phenomena such as broken bars and broken bars, therefore, in order to avoid the occurrence of this phenomenon, it is very important to choose the steel bar material with high hardness, abrasion resistance, and the phenomenon of broken and disordered bars is not easy to occur. Practice shows that the round steel is strictly processed by heat treatment technology, it can improve the hardness and abrasion resistance of the steel bar of the rod mill, ensure the operation rate of the rod mill, prolong the service life and time of the equipment, and provide the possibility for users to increase production. Therefore, for the steel bar material of the bar mill for ore dressing, the round steel after heat treatment should be selected.
The diameter of the steel bar should be chosen appropriately, which can not only break large pieces of material, but also have enough surface area. The steel bar with small diameter has larger surface area and less abrasion to the lining plate. However, the price of the small diameter steel bar per unit weight is relatively high, and the service life is short, because the small diameter steel bar will soon be worn out to the abandoned size of 25~40mm. The steel bar is easy to break and bend after being worn to this size. When the maximum diameter of the steel bar is 100~115mm, when the diameter of the steel bar is worn to 38mm, it is often broken, and the broken steel bar can be discharged out of the machine during operation. When the maximum diameter of the steel bar is only 50~65mm, the worn steel bar is easy to bend, and the steel bar smaller than the abandoned diameter should be taken out regularly during operation. The diameter of commonly used steel bars is 50~100mm.
The length of the steel bar is the effective cylinder length (namely the net length after the simplified length minus the thickness of the end cap liner) minus 150mm, or minus 300-400mm from the nominal cylinder length. The proportion of steel bar load size of rod mill the size proportion method of steel bar load initially installed is similar to the proportion method of steel ball size in ball mill.
2. Lining material-light weight, corrosion resistance
In mineral grinding, the lining board of the bar mill is constantly subjected to the rubbing and impact of ores and steel bars, so the wear resistance is also necessary. Generally, the lining board of the bar mill in our country is made of stone, alloy steel, high manganese steel, wear-resistant rubber and so on. Comparing these materials separately, we will find that stone materials are cheap and have a wide range of sources, but the wear resistance is low and the service life is worried; High manganese steel and alloy steel have good wear-resistant properties, but its disadvantage is that the quality is large, which increases the load on the rod mill, and it is not convenient for manufacturers or users to install it, so it is not very suitable; But the wear-resistant rubber lining board has light weight, low noise, low energy consumption, corrosion resistance, wear resistance and other advantages, but its high temperature resistance effect is not very good, can only be used in wet grinding, wear-resistant rubber liner has received more and more recognition and praise. As for the material of the lining plate of the rod mill, it is also necessary to make a choice suitable for the working conditions according to the grinding process.