Study of the enrichment of refractory oxidized lead ores from tailings from mining plants via combined electrochemical polarization

Abstract Man-made oxidized nonferrous metal ores accumulate in large quantities in mining plants, causing environmental problems and polluting the soil, groundwater, and atmosphere with toxic heavy metals. Traditional flotation is often ineffective and fails to yield acceptable levels of nonferrous metal recovery. This study aims to use refractory oxidized lead ore electrochemical enrichment to increase lead recovery into flotation concentrates to 93–95% from mine plant tailings. Cerussite is the primary lead mineral in the ore. Cathodic voltammetry revealed that cerussite reduction occurs partially through decomposition into Pb 2+ ions and through direct solid-phase discharge of mineral particles to elemental lead. To convert the mineral cerussite to an easily floatable sulfide form, the traditional flotation reagent sodium sulfide was used. Under microelectrolysis conditions in a weakly alkaline solution of sodium sulfide, lead cations formed during the solid-phase decomposition of cerussite interact with sulfide ions and form lead sulfides. The electrode mechanisms of cerussite mineral sulfidation were used for the electrochemical enrichment of oxidized lead ore. Sulfidization of ore from the Alaigyr deposit in the Republic of Kazakhstan was carried out in a special electrolyzer with a pulp preparation apparatus. A multifactorial model of lead recovery into sulfide concentrate was obtained, indicating that a high degree of recovery of 98.56% was achieved under the experimentally determined optimal conditions.