The invention relates to the technical field of
precious metal recovery, in particular to a process for separating
precious metal from
copper-
nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a
sulfuric acid solution containing
etidronic acid, leaching, and washing,
drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a
sodium peroxide-
sodium carbonate composite flux,
roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing
hydrochloric acid,
sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an
ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain
sponge palladium; adding
ammonium chloride into the filtrate D, precipitating and calcining to obtain
sponge platinum; and leaching the filter residue C by using a
hydrochloric acid-
chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining
zinc powder to obtain crude gold. According to the process, the leaching rates of
platinum,
palladium and gold and the product purity are greatly improved; flux and
reagent systems are optimized, consumption and
energy consumption are reduced, waste liquid treatment is matched for up-to-standard
discharge, and efficient
resource recovery and environment-friendly cooperation are achieved.