Abstract:Copper was leached from waste copper smelting slag flotation tailings by ammonia leaching. The results show that copper leaching rate is 53.20% and copper grade in leaching residue is 0.39% under the conditions including NH3?H2O concentration of 2 mol/L, L/S of 7 mL/g, temperature of 30 ℃, agitation speed of 400 r/min, and reaction time of 60 min. The size and shape of ore particles do not change greatly before and after leaching, but numbers of fine particles in surface of coarse particles of ores reduce after leaching.