Recovery of Copper from Arsenic-Containing Process Feed

Process to recover copper from a process feed including one or more feed components containing a base metal sulphidic feed, iron, copper and arsenic. Process feed and aqueous quench solution are introduced to a pressure oxidative leaching step with a partial pressure of oxygen above 200 kPa to form free sulphuric acid, to solubilize copper and other metal in the feed as aqueous sulphate compounds and to precipitate arsenic as solid iron arsenic compounds. A treated slurry comprising a liquid phase containing sulphuric acid and copper sulphate, and solids containing the iron arsenic compounds is withdrawn and the liquid phase is separated from the solids. To lessen arsenic re-dissolution and to maintain stability of the solid iron arsenic compounds, one or more of temperature, free acid level and residence time of the treated slurry is controlled. Copper metal is recovered from the separated liquid phase.