Wearing and grinding of SAG pebble as media in lab scale vertical mill

With the rising popularity of Semi Autogenous Grinding (SAG) in domestic large mines, there are different ways to dispose the pebble from SAG. The pebble grinding effect tests were carried out using pebble as a kind of grinding media in the vertical mill to deal with the pebble, which included conditional experiments of grinding time, filling ratio, grinding concentration and grinding handling capacity, as well as media contrast experiments of pebble and steel ball grinding. The results show that the SAG pebble can be used as a kind of grinding media in the vertical mill. But the wastage of pebble is larger than the steel ball (about 0.05 %), typically 1 %~2 %. When the grinding time is 3min, filling rate is 60 %, grinding concentration is 65 %, grinding weight is 5 kg, grinding effect can satisfy the requirement of flotation in practice. The contrast experiment of steel ball and pebble in the same conditions was studied under the grinding time of 3 min, the speed of 210 r/min, grinding concentration of 65 %, grinding quantity of 5 kg, medium diameter of 10~20 mm and filling rate of 60 %. The result shows that the fineness of steel ball is higher 16.72 % than the pebble, overcrush is higher by 2.35 %, but the 0.045~0.038 mm yield of pebble is higher than steel ball, indicating that pebble medium can easily make the size of mineral grinding to fine disseminated extent which makes the particle size distribution more reasonable.