Process for the recovery of metal chlorides from jarosite sludges resulting from the sulphuric acid processing of ores

A process for use in recovering valuable metal chlorides from sludges of jarosite type resulting from the sulphuric acid processing of zinc ores, comprising

• a. contacting the sludge at a temperature close to the boiling point with an aqueous solution of alkaline earth metal chloride which contains free hydrochloric acid and is in excess stoichiometric ratio to the sulphate content of said sludge, so as to dissolve said contained metals in chloride form and precipitate sulphate ions in the form of an alkaline earth metal sulphate;
• b. separating insoluble products including said alkaline earth metal sulphate from metallic chloride solution resulting from step (a) by hot filtration;
• c. stripping said insoluble products of metallic chlorides by hot washing and filtration;
• and
• d. recovering the metallic chloride solution resulting from steps (b) and (c).