COPPER SULPHATE RECOVERY FROM MINE WATERS

11th International Multidisciplinary Scientific GeoConference SGEM2011, www.sgem.org, SGEM2011 Conference Proceedings/ ISSN 1314-2704, June 20-25, 2011, Vol. 3, 239-244 pp

ABSTRACT

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 m3
Underground mine water, containing 0.3 g/l copper, 2.2 g/l iron at pH 3.2 and 37 m3
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 m3 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 m3 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 m3/day, two mine waters, to produce 1390 t/year copper sulphate
technical quality.

Keywords: mine waters, solvent extraction, copper sulphate