Hydrometallurgical process for the recovery of copper, lead or zinc

A hydrometallurgical process for treatment of polymetallic ores and sulfide concentrates of copper and zinc, by-products of lead and zinc from smelting plants, or mixtures thereof having a content of lead, copper, zinc, iron, arsenic, gold and silver, wherein the hydrometallurgical process comprises:

• grinding a raw material to a particle size of less than 44 microns;
• leaching the ground raw material by feeding to a solid-gas-liquid (SGL) reactor with oxygen of less than 30 psia and an acid solution so as to obtain a residue containing lead sulfate, silver and gold with elementary sulfur (PbSO4—Ag/Au+So) and a solution containing copper, zinc, arsenic and iron in a sulfuric acid medium;
• purifying the leaching solution by neutralizing residual acidity in the leaching solution;
• recovering gold and silver from the leaching residue by eliminating So in the residue;
• precipitating copper or zinc basic salts from the purified solution with a neutralizing agent so as to obtain a solution containing magnesium sulfate and/or sodium sulfate with heavy metals, and basic salts of copper or zinc;
• purifying the precipitated solution containing magnesium sulfate and/or sodium sulfate so as to produce a diluted solution of sodium sulfate and/or magnesium sulfate and removing heavy metals therefrom;
• concentrating the diluted solution of sodium sulfate and/or magnesium sulfate so as to recover water and to obtain a saturated solution of magnesium sulfate and/or sodium sulfate;
• and
• crystallizing magnesium sulfate and/or sodium sulfate salts from the saturated solution of magnesium sulfate and/or sodium sulfate so as to obtain hydrated salts of magnesium sulfate and/or sodium sulfate respectively.