Grinding Effect Of Surface Hardness Of Steel Balls On Ores With Different Hardness

The particle size distribution of products after comminution of minerals has always been an important subject of great concern to mineral processing workers.For a long time,there has been no interruption in finding a suitable method to analyze the fineness characteristics of crushed products from the mechanism.Among them,JK particle size crushing model is a widely used method.With the help of this model,the grinding experiments under different conditions were carried out with steel balls with different surface hardness,using pure magnetite minerals,pure quartz minerals and actual iron ores as grinding minerals representing different hardness.The characteristics of energy consumption and fineness of grinding products of steel balls with different surface hardness were investigated when the hardness of grinded minerals was different.The results show that:(1)The fineness characteristics of grinding products of three kinds of grinded minerals are similar under different surface hardness of steel balls.The specific performance is as follows:with the increase of the surface hardness of the steel ball,the fineness of the grinded minerals gradually increases.Comparing the fineness of grinding products with the t_n family curve,the fineness of grinding products increases with the increase of surface hardness of steel balls.(2)Under the same surface hardness of steel balls,the fineness of grinding products of three kinds of grinded minerals is different.The performance rules are as follows:the results show that the higher the hardness of the grinded minerals,the smaller the fineness of the grinding products.Taking the t_n family curve as a comparison index,the overall fineness of grinding products decreases with the increase of the hardness of the grinded minerals.Comparing the fineness of grinding products with the t_n family curve,the fineness of grinding products decreases with the increase of the hardness of grinded minerals under the same surface hardness of steel balls.(3)Comparing the characteristics of energy consumption in grinding under different conditions.The grinding energy consumption decreases with the increase of the surface hardness of steel balls when the fineness of three kinds of grinded minerals reaches the same grinding product under different surface hardness of steel balls.Under the same surface hardness of steel balls,for three kinds of grinded minerals,the grinding energy consumption increases with the increase of the hardness of the grinded ore itself when the grinding product fineness reaches the same level.(4)Mathematical models of grinding product size distribution of magnetite,quartz and actual iron ore under different surface hardness of steel balls are established.The results show that the data from actual grinding tests are well matched with the JK particle size crushing model curve.When the surface hardness of steel balls is different,the model fitting parameter M increases with the increase of the surface hardness of steel balls,which indicates that the expected maximum fineness of grinding products increases with the increase of the surface hardness of steel balls.Under the same steel ball surface,the model fitting parameter M increases with the decrease of the hardness of the grinded minerals,which indicates that the expected maximum fineness of the grinded minerals increases with the decrease of the hardness of the grinded minerals.