Aiming at the problem of the grade of raw copper ore and copper recovery decreasing in a mine,Anhui province,an experimental research was carried out.By adopting semi-preferential and semi-mixing floatation,and process of selective classification and regrinding of middlings,a concentrate with total copper grade of 20.71% and copper recovery of 91.53% was gained.While copper grade of 20.71% was guaranteed,the copper recovery was increased by 1.13%.