Method for treating arsenic containing materials

A method for selectively removing arsenic from a sulphide material containing arsenic, the method comprising the steps of conducting a leaching step comprising contacting the material with a leaching solution that leaches arsenic from the material to form a leach solution containing dissolved arsenic and a solid comprising a sulphide material of reduced arsenic content, the leaching solution that is provided to the leaching step comprising an alkaline solution having a sulphide-containing compound present in an amount that is less than the stoichiometric amount of sulphur containing compound required to react with the arsenic present in the material, separating the solid from the pregnant liquor, and recycling at least part of the leach solution to the leaching step.

A method for selectively removing antimony from a sulphide material containing antimony, the method comprising the steps of conducting a leaching step comprising contacting the material with a leaching solution that leaches antimony from the material to form a pregnant liquor containing dissolved antimony and a solid comprising a sulphide material of reduced antimony content, and subsequently separating the solid from the pregnant liquor, wherein a leaching solution that is provided to the leaching step comprises an alkaline solution having a sulphide-containing compound present in an amount less than the stoichiometric amount of sulphur containing compound required to react with the antimony present in the material.