Matching relationship between hardness and hardness of steel ball
Steel ball grinding mine production in large consumption of materials, accounts for about 20% of the cost of production, the wear lies not only in material itself, and working conditions, ore hardness is directly related, among the factors match properly is beneficial to improving mill output of a single machine.
Ore hardness is an objective existence, is unable to change. The only way in production is to adjust the steel ball hardness to meet the needs of grinding production. Usually steel ball high hardness, wear resistance is high, the material loss is low. But the steel ball wear not only its hardness, and ball mill lining board and ore hardness related, according to references: wear coefficient is function of ball hardness and hardness ore ratio, namely: e = f (Hm/Ha)
When the ratio of K=0.8-1.3, the wear resistance increases with the increase of the steel ball hardness. But when the ratio of K>1.3, the hardness of steel ball is increased, the wear resistance coefficient is not significant, while the impact toughness of the steel ball is decreased, which leads to the decrease of ball mill grinding efficiency. This is because the larger ball hardness and high brittleness, the impact toughness is smaller, in ball mill operation, steel balls, a steel ball and a mill lining plate after impact, high brittleness of the steel ball is the most prone to large spalling phenomena, to form a round ball, ball is not round force than ball by force is larger, easily lead to cracking or chipping. Second, directly generating crack broken (broken ball), ball grinding in grinding ore production process in the most prone to sliding, rather than round uniformity of steel ball rolls as and produce considerable impact to grind and smash ore.
For different ore deposit, the optimum value of steel ball hardness is different. Must pass the test, the selection of suitable metal material, hardness, impact toughness of the steel ball.