Conversion of potassium sulphate to potassium carbonate

Claim 1

IN A THERMOCHEMICAL REACTION PROCESS FOR THE CONVERSION OF POTASSIUM SULPHATE TO POTASSIUM CARBONATE THE STEPS COMPRISING INCINERATING POTASSIUM SULPHATE IN THE PRESENCE OF CARBON AND UNDER REDUCING CONDITIONS TO OBTAIN A MOLTEN SMELT INCLUDING POTASSIUM SULPHIDE AND A HOT GASEOUS PRODUCT INCLUDING CARBON DIOXIDE AND SULPHUR DIOXIDE, DISCHARGING THE SMELT INTO AN AQUEOUS SOLUTION CONTAINING ZINC OXIDE TO FROM INSOLUBLE ZINC SULPHIDE AND A SOLUTION OF POTASSIUM HYDROXIDE AND POTASSIUM CARBONATE, SEPARATING THE INSOLUBLE ZINC SULPHIDE FROM SAID SOLUTION, PASSING THE HOT GASEOUS PRODUCTS OF SAID INCINERATING STEP THROUGH A FIRST LIQUID-GAS CONTACT ZONE TO REMOVE THE ENTRAINED SOLID MATTER THEREFROM AND TO ABSORB THE SULPHUR DIOXIDE IN SAID GASES, RETURNING THE REMOVED MATTER AND ABSORBED SO2 TO SAID INCINERATING STEP, DIRECTING SAID GASEOUS PRODUCTS OF INCINERATION FROM SAID FIRST CONTACT ZONE THROUGH A SECOND LIQUID-GAS CONTACT ZONE, PASSING SAID SOLUTION OF POTASSIUM HYDROXIDE AND POTASSIUM CARBONATE IN CONTACT WITH SAID GASEOUS MIXTURE CONTAINING CARBON DIOXIDE IN SAID SECOND CONTACT ZONE TO CARBONATE SAID POTASSIUM HYDROXIDE TO POTASSIUM CARBONATE, AND SEPARATING SAID POTASSIUM CARBONATE FROM THE GASES LEAVING SAID SECOND CONTACT ZONE.