Abstract:A heavy metal industrial sludge is mainly composed of calcium hydrophosphate, gypsum and amorphous hydroxide, and silica gel. Copper and nickel are dispersed in various physical phases, and the mixture with calcium hydrogen phosphate as main body is the main carrier of valuable metals of nickel and copper, which are difficult to be extracted and recycled by physical methods. Mineralization test results show that concentrate with Cu and Ni contents of 6.96% and 6.15% can be obtained after flotation of sintering material under the conditions including bituminous dosage of 15%, sodium sulfate dosage of 20%, quartz dosage of 20%, borax dosage of 2%, sintering temperature of 1 150 ℃, and sintering time of 60 min. Recovery of copper and nickel in concentrate is 87.63% and 88.64% respectively, and Cu and Ni grades in tailing can be reduced to 0.54% and 0.44% respectively.