Ammonium complex system-based method for separating and purifying lead, zinc, cadmium, and copper

An ammonium complex system-based method for separating and purifying lead, zinc, cadmium and copper, comprising:

• (1) leaching a zinc-containing raw material with a leach solution, so as to obtain an extracting solution;
• (2) filtering the extracting solution obtained in step (1), so as to obtain a filtrate and a filter residue;
• (3) mixing the filtrate obtained in step (2) with metal lead to displace copper, and performing a solid-liquid separation to obtain a first separated liquid;
• mixing the first separated liquid with metal cadmium to displace lead, and performing a solid-liquid separation to obtain a second separated liquid;
• mixing the second separated liquid with metal zinc to displace cadmium, and performing a solid-liquid separation to obtain a third separated liquid;
• (4) electrolyzing the third separated liquid obtained in step (3) to obtain metal zinc, and subjecting an electrolytic solution after the electrolysis back to step (1) to leach the zinc-containing raw material;
• wherein the metal lead in step (3) is added in an amount of 0.25-0.3 times a mass of copper in the filtrate in step (2);
• the metal cadmium in step (3) is added in an amount of 0.5-0.8 times a mass of lead in the first separated liquid;
• the metal zinc in step (3) is added in an amount of 3-10 times a mass of cadmium in the second separated liquid.