Abstract: In order to solve the problem of low copper recovery rate and high water content of copper concentrate in Yinshan Mining Company，the grinding effects of steel ball，pebble and ceramic ball for VTM-800 vertical mill were investigated. The results showed that with pebble and ceramic ball as grinding medium，the content of iron ions in grinding products is low，which is conducive to the flotation recovery of copper minerals. Compared with the use of steel ball，the medium consumption of ceramic ball decreased by nearly 90%，and the power consumption decreased by 33% and 15% respectively compared with steel ball and pebble. The use of ceramic ball and pebble as grinding medium can reduce the over-grinding of grinding products and improve the grade and recovery rate of copper concentrate. Using ceramic ball as grinding medium can prolong the service life of spiral lining of vertical grinding machine.

Key words: vertical grinding machine, steel ball, pebble, ceramic ball, grinding medium