The ratio of ball mill steel ball size addition should be determined according to the ball mill diameter size, ore hardness, ore size into the ball mill, steel ball hardness, ball mill speed and other factors. When the model of ball mill is determined, the speed of ball mill is set. The hardness of the ore can be measured, and the size of the ore into the ball mill can be determined by changing the size of the grizzly screen. Usually, the newly installed ball mill has a grinding process, during the grinding process, the amount of steel balls is added at one time, accounting for 80% of the ball mill loading, and the proportion of steel balls added can be added according to the size of steel balls (Φ120㎜, Φ100㎜, Φ80㎜, Φ60㎜, Φ40㎜). The weight of steel balls added is based on the quality of steel balls, and the quality of steel balls determines the tonnage of ore consumption added. With the new ball mill steel balls, the steel ball addition is calculated according to the amount of ore processed per ton (i.e. 0.8㎏ per ton of ore), while the general steel balls are needed to process one ton of ore (1㎏-1.2㎏). Ball mill steel ball proportioning is based on the effective length of the ball mill, whether with roller press, how big the feed size is, what liner and structure is used, the expected sieve fineness and ratio table, how much rotating speed and other factors. General steel ball grading is 120mm, 100mm, 80mm, 40mm, if high chrome ball must ask the manufacturer to add rare earth in the production. Ball mill in the grinding process ball mill steel ball add amount steel ball amount only add 80%, because after the ball mill is installed, the ball mill size gear needs to mesh, processing volume is also to gradually increase, to be normal continuous operation of the ball mill after two or three days, pick up the size gear meshing situation, to be all normal, open the ball mill manhole cover for the second time to add the remaining 20% steel ball. The addition of small steel balls is only one time to add balls for use. Because the reasonable friction between steel ball and steel ball, steel ball and ore, steel ball and ball mill liner during normal operation of the ball mill will increase the abrasion and make the big ball grinding small and medium ball grinding to small ball. So normally under normal circumstances, there is no need to add small balls. Adding small balls is in the case of useful mineral size without monomer dissociation, when the mill fineness can not reach the flotation requirements, you can add the right amount of small balls. The steel balls in the ball mill are constantly worn out during the operation, in order to maintain the ball charge filling rate and the reasonable ratio of balls, and to keep the stable operation of the ball mill, it is necessary to make reasonable ball replenishment and low compensation wear.