COPPER SULPHATE RECOVERY FROM MINE WATERS

The main aim of this work is to study the recovery of copper sulfate from mine waters at the Mining Company Bor. For the copper sulfate recovery was treated 91 m(3) Underground mine water, containing 0.3 g/l copper, 2.2 g/l iron at pH 3.2 and 37 m(3) Cerovo mine water, containing 0.5 g/l copper, 0.61 g/l iron at pH 4.5. The mine waters were mixed and prepared 128 m(3) mine solution (copper content 0.35 g/l, iron 1.74 g/l, pH 3.8), then are pre-treated chemically and physically for recovery pregnant solution. The first neutralization and hydroxide precipitation of two mine solutions yielded 141 kg wet sludge contained of copper iron and impurities hydroxides. The hydroxide sludge was dissolved in sulphuric acid. The resulting solution 4.3 m(3) contained 2.5 g/l copper, 11.3 g/l iron and soluble impurities at pH 1.5. The obtained solution, containing copper, iron and impurities was further treated to oxidize ferrous to ferric iron, followed by neutralization at pH 3.0 and precipitation. The resulting filtrate contained 2.5 g/l copper and 1.5 g/l iron at pH 1.8. The pregnant electrolyte was produced from pregnant leach solution by solvent extraction in three extraction and two stripping stages. The reach copper solution was further evaporated up to 450 g/l H2SO4, 10 g/l Cu, where main quantity of copper sulphate was separated. This process is possible to apply for treatment 3000 m(3)/day, two mine waters, to produce 1390 t/year copper sulphate technical quality.