Removal of Pyrrhotite from High-Sulphur Tailings Utilising Non-Oxidative H2SO4 Leaching

Tailings are a residual material stream produced in the mineral processing of ores. They may contain major sulphide content that increases risk acid rock drainage (ARD) but also host valuable metals. Tank bioleaching is technically viable method to treat tailings. However, significant pyrrhotite cause increased and oxidant consumption result longer retention times process. In this work, non-oxidative H2SO4 leaching studied for high-sulphur tailings, both as pre-treatment consider recovery possibilities Fe S. Continuous mode validation tests, conducted at 90 °C, pH 1.0 106 min time, resulted complete dissolution with 427 kg/t (as 95% H2SO4). Unwanted Ni Zn was taking place yield 21.5% 13.5%, respectively, while Co Cu negligible. The continuous tests signalled by shortening could be dramatically decreased. H2S-rich gas stream, which utilised later metals’ processes after precipitate (CoNi)S, ZnS CuS products. FeSO4 solution, approximately 20 g/L Fe.