Study on the Grinding Law of Ball Media for Cassiterite–Polymetallic Sulfide Ore

Abstract

To solve the problem involved in the grinding of cassiterite–polymetallic sulfide ore in which fine grinding causes the cassiterite to be overground or coarse grinding leads to inadequate liberation of sulfide minerals, the influences of the ball grinding medium on the size distribution of the grinding product were investigated. Two types of ball filling patterns, namely, single-sized and multi-sized ball grinding media, were adopted in wet batch grinding tests. The results show that increasing the grinding time resulted in a rapid increase in minus 0.038 mm particles and a slight increase in the Sn grade in this fine size fraction. The smaller the ball filling fraction was, the more obviously the ball size affected the size distribution of the grinding product, the variation of which with the ball size became complicated with the increase in the ball filling fraction. Obvious jumping phenomena in the plotting of the percentages of the discussed size fractions against the ball size were observed when the balling filling fraction was larger than 30%; the most obvious jumping phenomena took place at a 35% ball filling fraction. The results of the grinding tests with the multi-sized media show that the size distribution of the grinding product was closely related to that of the mixed ball sizes and their composition percentages.

A Review of the Grinding Media in Ball Mills for Mineral Processing

“…This was confirmed by Nava et al [88], who found that the liberation degree decreased with increasing ball size. Yang et al [89] found that the liberation of the locked minerals is dependent on both the mill filling rate and ball size. The liberation of the desired product in the range from 0.038 to 0.154 mm increased with ball size at a mill filling rate of 30%.…”

Grinding Media in Ball Mills-A Review

“…In the experiment 22mm was found to give better liberation and qualified product size. In another study done by Yang et al [99] using steel balls of varying diameters from 16-40mm where batch grinding tests were done using mono-sized balls and multi-sized balls. At 30% ball filling using 40mm balls, was the optimum for single-sized balls because it reduced overgrinding significantly though it produced coarser particles.…”