Beneficiation method for improving recovery rate of copper metal in quenching slag by using slow cooling slag

The invention relates to a beneficiation method for improving the recovery rate of quenching slag copper metal by using slow cooling slag, which comprises the following steps: (1) crushing the slow cooling slag, wet-grinding until the fineness is 60-65-325 meshes, and carrying out copper flotation to obtain slow cooling slag flotation copper concentrate; (2) crushing the quenching slag, performing wet grinding, performing size mixing, sequentially adding sodium sulfide, butyl xanthate and 2 # oil, and performing flotation on relatively coarse-fraction copper ore to respectively obtain copper rough concentrate I and primary roughing tailings; (3) the primary roughing tailings are subjected to ore grinding after concentration and size mixing, sodium sulfide is added firstly, then slow cooling slag flotation copper concentrates are added, secondary roughing is conducted, and fine-fraction copper rough concentrates II and secondary roughing tailings are obtained; (4) after the copper rough concentrate I and the c