Recovery of valuable metals from copper blast furnace slag

Recovery of valuable metals such as copper and nickel from copper blast furnace slag by carbon was studied. The optimum conditions necessary for maximum recovery of these metals with minimum reduction of iron oxide were derived. The effect of several experimental parameters, such as temperature, carbon addition and CaO addition to the slag, on the efficient recovery of copper and nickel was studied. A two-stage reduction process was also employed to study the improvement in copper and nickel recoveries over single-stage reduction. Based on the results obtained in this investigation, a carbon addition of 5%, a CaO addition of 5% and a reducing temperature of 1,573 K were found to be the optimum conditions for maximum recovery of both copper and nickel. Alloy phase of higher grade with respect to copper and nickel was obtained by employing a two-stage reduction process.