Abstract: A gold mine of Zhaojin Mining Industry is challenged by high cost of cyanidation fine grinding and high consumption of steel balls.So pilot and industrial test on Isa mill replacing ball mill is carried out.The results show that Isa mill is advantageous when it comes to fine grinding of cyanidation gold leaching.Compared to conventional ball mills,given the same treatment quantity,Isa mill could increase the fineness of grinding products by 5.16 percentage points,lower grinding cost by 20.15 %.It not only saves energy,but also improves gold leaching rate;the grinding media are nano ceramic balls,eliminating the influence of iron scrap pollution of steel media on gold recovery,reducing reagent consumption of reagent indirectly.The environmental and economic benefits are good.