Extraction and separation of copper and zinc from bronze production dust and slag by electrochemical and extraction methods

The article describes an X-ray fluorescence analysis conducted to study a composition of bronze production slag from copper melting. Copper content is up to 48.742% at., zinc content is 33.405% at. The authors optimized the parameters of bronze slag leaching with a sulfuric acid concentration of 0.1 mol/l. After sulfuric leaching a copper cake underwent copper-ammonia leaching, and copper-chloride pickling (period: 20–40 minutes, copper limit concentration: 35.0–55.5 g/l, respectively). Copper extraction from leaching solutions was conducted using extraction solvents D2EGFK, DKh-510A, LIX 54-I at their concentration of 50–100%. The article compares efficiency of extraction processes for copper-ammonia and copper-chloride solutions. In both cases, the highest efficiency was attributed to extraction agents LIX-54-I with a concentration of 50% in kerosene, included into the class of β-diketones and containing 1-phenyl-decan-1,3-dione isomers with various structures of the alkyl group. Subsequent electroextraction of copper from the resulting re-extracting solutions was conducted at set optimal cathode current density (ik) of 0.6 A/dm2, maximum current copper yield achieved 65%. Thus, the article presents the determined optimal conditions for extracting copper and zinc from bronze production dust and slag by electrochemical and extraction methods and describes the opportunity to use pickling solutions, extraction solvents and sulfuric acid electrolyte as reusable solutions.