Patent ID: 6827837
Filing Date: 2004-12-07
Classification: C22B,Y02P

Abstract:
A method for recovering trace elements from coal including the steps of:mixing a charge including an ash formed by the combustion of a pre-selected coal, the ash including gold and one or more platinum group elements, an inquart including gold and one or more platinum group elements and a fluxing agent; charging a furnace with the charge; heating the charge in the furnace to a pre-selected temperature forming a molten charge including a molten inquart; absorbing a portion of the gold and one or more platinum group elements of the ash into the molten inquart; discharging a molten slag from the furnace; casting a dare bar by discharging the molten inquart including an absorbed portion of the gold and one or more platinum group elements of the ash to a mold; digesting the dore bar in an electrowinning process wherein the dore bar is introduced into an acidic bath as an anode and an electrical potential is maintained between the anode and a metallic plate cathode: reducing silver ions from the dore bar onto the metallic plate cathode; and precipitating and dissolving trace elements in the electrolytic solution producing an anode slime.