Recovery of values in naturally occurring alkali metal sulfate minerals

Claim 1

A PROCESS FOR SEPARATING AND RECOVERING THE ALKALI METAL SULFATE CONTENT OF A SULFATE MINERAL CONSISTING OF AT LEAST ONE ALKALI METAL SULFATE FROM THE GROUP CONSISTING OF SODIUM SULFATE AND POTASSIUM SULFATE AND AT LEAST ONE OTHER SULFATE FROM THE GROUP CONSISTING OF THE SULFATES OF CALCIUM, MAGNESIUM, ALUMINUM, COPPER, LEAD AND MANGANESE WHICH COMPRISES: FREEING THE SULFATE MINERAL FROM ANY CHLORIDE ASSOCIATED THEREWITH BY RAPIDLY WASHING THE SULFATE MINERAL WITH COLD WATER; FORMING AN INTIMATE MIXTURE OF THE WASHED SULFATE MINERAL AND AT LEAST ONE SOLID OXIDE SELECTED FROM THE GROUP CONSISTING OF SILICA, TITANIA, ZIRCONIA, ALUMINA, AND IRON OXIDE, WHICH OXIDES FORM RELATIVELY INSOLUBLE COMPOUNDS WITH THE OXIDES OF THE METALS OF THE SECOND GROUP ENUMERATED ABOVE; MAINTAINING THE MIXTURE AT A TEMPERATURE BETWEEN ABOUT 500*C. AND 1500*C. FOR A TIME SUFFICIENT TO EFFECT CONVERSION OF A SUBSTANTIAL PORTION OF THE SULFATE MINERAL TO THE RELATIVELY INSOLUBLE COMPOUND OF THE ADDED OXIDE; LEACHING THE REACTION MIXTURE WITH WATER AT ABOUT 100*C. TO EXTRACT THE ALKALI METAL SULFATE FROM THE INSOLUBLE REACTION PRODUCT; COOLING THE AQUEOUS EXTRACTION LIQUOR SUFFICIENTLY TO CRYSTALLIZE THE ALKALI METAL SULFATE THEREFROM AND RECOVERING THE SAID SULFATE.