Prague, Czech Republic

M. A. Meretukov, Independent Expert, Professor, Doctor of Technical Sciences, e-mail: mamerat@gmail.com

UGC The Gold Mining Copmany, Plast, Russia

K. I. Strukov, Company President, Doctor of Technical Sciences, e-mail: ugold@ugold.ru

A number of hydrometallurgical processes was tested for processing of secondary copper-bearing materials, which include copper- and copper alloy-based metallic waste with the concentration of noble metals reaching 5%, as well as copper alloys serving as the base for noble metal plating. To selectively remove the layer of noble metals from the copper base, one could rely on cyanic solution electrolysis, whereas to selectively dissolve copper – on the treatment with ammonia, solutions of inorganic acids and iron(III) and copper(II) chlorides. The method of liquid extraction was tested for copper recovery from leaching solutions. E-scrap serves as a constant renewable source of secondary raw materials. The reason for it is that the military, production, office and household equipment quickly becomes outdated and is to be dismounted and recycled on a regular basis. From 20 to 50 million tons of electronic scrap are generated annually in the world; copper is the most growing part of the electronic waste market. The physical and mechanical treatment used to prepare e-scrap (mostly, printed circuit boards) for further processing includes such operations as cutting; crushing/grinding; air, magnetic and electrostatic separation; and gravity concentration. The paper shows that a variety of hydrome tallurgical processes, which involve the use of acidic solutions (H₂SO₄, HNO₃, HCl + HNO₃) in the presence of oxidizing agents (H₂O₂, O₂, Fe³⁺ и Cl₂), can also be used for copper dissolution. The author demonstrates the possibility of using such processes as chlorination with electrolytically produced gas, treatment in ammonia medium followed by liquid extraction, pressure oxidation, ionic liquid treatment, use of supercritical water, electrokinetic electrolysis and bioleaching.

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