Methods of recovering chemicals in

Claim 1

IN A PROCESS FOR THE RECOVERY OF THE ALKALI SALTS FROM THE WASTE LIQUORS FROM THE PRODUCTION OF CELLULOSE BY THE DIGESTION OF THE WOOD WITH AN ALKALI SALT SELECTED FROM THE GROUP CONSISTING OF ALKALI SULPHITES AND ALKALI BISULPHITES, THE STEPS WHICH COMPRISE EVAPORATING AND BURNING SAID WASTE LIQUOR TO FORM A MOLTEN MASS CONTAINING ALKALI AND SULPHUR COMPOUNDS, DISSOLVING SAID MOLTEN MASS IN A SOLVENT, INTRODUCING CARBON DIOXIDE INTO THE SOLUTION THUS FORMED AND THEREBY FORMING ALKALI BICARBONATE, THE ADDITION OF CARBON DIOXIDE BEING CONTINUED UNTIL THE BICARBONATE FORMED IS NEAR ITS LIMIT OF SOLUBILITY, HEATING SAID SOLUTION TO ELIMINATE HYDROGEN SULPHIDE FORMED THEREIN, INTRODUCING ADDITIONAL CARBON DIOXIDE INTO SAID SOLUTION WHEREBY ALKALI BICARBONATE IS CRYSTALLIZED THEREFROM, AND SUBSEQUENTLY SEPARATING THE CRYSTALLIZED ALKALI BICARBONATE FROM SAID SOLUTION.