Abstract
Various types of the extractive technologies for the treatment of the separated electrotechnic gold scrap in the laboratory scale were tested and verified. Separated electrotechnic scrap is mainly represented by various types of contacts from the electric and electronic devices and apparatuses. As a basic material of the body of these contacts is most frequently used copper alloys for example different types of brasses and bronzes. Contact layer is presented by galvanically coated gold surface. Gold content in such separated contacts is usually up to 1 wt. %, copper content approximately 75 - 80 wt. %.
Three leaching solutions were tested on the extraction efficiency of gold in the first part of this work. As leaching solution were mixture of inorganic acids, aqueous solution of thiourea and aqua regia used and obtained results were discused. A treatment of separated electric gold-coated contacts by electrochemical process is suggested, described and verified in the second part of this paper. This methode is based on the two - steps electrolysis, the first step is copper electrolysis and the second step is gold electrolysis.
There were verified, that it is possible Cu - electrolyses the metallic copper with 98,12 % purity with 85 % recovery. During Cu-electrolyses the gold is concentrated in anode slime. The anode slime is smelting and casting the Au/anodes from which is possible, by Au - electrolysis, to obtain gold with 99,99 % purity and 99,74 % recovery. Presented technology is possible to use also for another types of separated electric and electronic scrap with gold and copper content.