Production of potassium carbonate

Claim 1

IN A PROCESS FOR SEPARATING A MIXTURE OF MAGNESIUM OXIDE, POTASSIUM SULFATE, AND POTASSIUM SULFIDE, THE STEPS WHICH COMPRISE LEACHING SAID MIXTURE WITH AN AQUEOUS SOLUTION OF POTASSIUM CARBONATE SATURATED WITH POTASSIUM SULFATE, SAID POTASSIUM CARBONATE BEING IN SUFFICIENT AMOUNT TO INHIBIT SOLUTION OF SOLID PHASE POTASSIUM SULFATE WHEREBY POTASSIUM SULFIDE IS SELECTIVELY DISSOLVED FROM SAID MIXTURE, SEPARATING THE LEACH LIQUOR FROM THE UNDISSOLVED SOLIDS, TREATING SAID LEACH LIQUOR WITH CARBON DIOXIDE TO A PH BETWEEN ABOUT 7.9 AND ABOUT 8.5, WHEREBY THE POTASSIUM SULFIDE THEREIN IS CONVERTED INTO POTASSIUM CARBONATE AND BICARBONATE AND POTASSIUM BICARBONATE IS PRECIPITATED THEREFROM, SEPARATING THE PRECIPITATES POTASSIUM BICARBONATE, PREPARING FROM THE POTASSIUM BICARBONATE MOTHER LIQUOR AN AQUEOUS SOLUTION OF POTASSIUM CARBONATE SATURATED WITH POTASSIUM SULFATE BY CONCENTRATING THE SOLUTION TO PRECIPITATE SOLID PHASE POTASSIUM SULFATE, AND RECYCLING SAID AQUEOUS SOLUTION FOR LEACHING A FURTHER QUANTITY OF SAID MIXTURE OF MAGNESIUM OXIDE, POTASSIUM SULFATE, AND POTASSIUM SULFIDE.