Abstract: The copper grade in copper smelting slag is 5.23%, which has good recycling value. Copper minerals in the raw slag are mainly matte and metallic copper. The gangue minerals are mainly ferrite and iron olivine. There are a large number of glass phases. The existence of glass phase has an adverse impact on beneficiation. Asynchronous flotation process is adopted for the smelting slag to preferentially recover coarse-grained copper minerals with good floatability under coarse grinding fineness. The copper concentrate with copper content of 45.36% and copper recovery of 81.65% was obtained. Fine grained copper minerals are recovered after regrinding of flotation tailings. The comprehensive copper concentrate with copper content of 13.65% and copper recovery of 13.74% was obtained. The concentrate contains 33.99% copper, 3.42 g/t gold and 79.17 g/t silver. The recovery rate gold and silver are 95.40%, 85.94% and 81.17% respectively. The copper, gold and silver in the smelting slag are all well recovered.