Method of recovering chemicals from spent pulping liquors

Claim 1

A PROCESS FOR RECOVERING METAL AND SULFUR VALUES FROM A SPENT COOKING LIQUOR CONTAINING THE SAME, SAID METAL BEING SELECTED FROM THE GROUP CONSISTING OF ALKALI AND ALKALINE EARTH METALS, COMPRISING: (A) INTRODUCING SAID LIQUOR IN A FINELY DIVIDED STATE AND AN OXYGEN CONTAINING GAS INTO A COMBUSTION ZONE TO EFFECT COMBUSTION OF THE LIQUOR AT A TEMPERATURE GREATER THAT 1700*F., THE QUANTITY OF OXYGEN CONTAINING GAS BEING SUFFICIENT TO MAINTAIN COMBUSTION IN A REDUCING ATMOSPHERE, SAID COMBUSTION PRODUCING FROM THE LIQUOR AN INORGANIC SMELT RESIDUE CONTAINING THE METAL AND A COMBUSTION GAS CONTAINING HYDROGEN SULFIDE; (B) REMOVING THE INORGANIC RESIDUE SMELT AND THE COMBUSTION GAS FROM THE COMBUSTION ZONE; (C) SEPARATING THE COMBUSTION GAS FROM THE SMELT; (D) REACTING THE COMBUSTION GAS WITH AN OXYGEN CONTAINING GAS TO CONVERT THE HYDROGEN SULFIDE TO SULFUR DIOXIDE.