The Recovery of Copper from Smelting Slag by Flotation Process

Aiming at the recovery of copper from smelting slag, a flotation approach was studied. It was found that this slag composed of fine particles with complex association and distribution, in which bornite was the main copper-bearing mineral after a detailed mineralogy analysis via polarizing microscope, SEM and XRD. Consequently, flotation was attempted to recycle Cu in slag containing copper sulphide components. Three key factors affecting flotation were ascertained, namely, grinding fineness, the collector and the pH value, while the recovery of Cu estimated by ICP and XRF. Copper concentrate grading at 14.47 with 79.66% Cu recovery was obtained, in the condition of the grinding fineness of −0.074 mm and the proportion of 80%, reagent dosages of 50 g/t for butyl xanthate and a pH value of 10 adjusted using Na2CO3.