Process of purifying caustic aluminate liquors

Claim 1

IN THE PRODUCTION OF ALUMINA FROM ALUMINOUS ORES BY THE WET ALKALI ALUMINATE METHOD, WHEREIN SOLUBILIZED ORGANIC COMPOUNDS ARE INTRODUCED INTO THE CIRCULATING CAUSING ALUMINATE LIQUID FROM THE ORE AND FROM STARCH UNTILIZED AS A FLOCCULATING AGENT FOR THE INSOLUBLE ORE RESIDUE SETTLED FROM THE CAUSTIC ALUMINATE LIQUOR, AT LEAST A PORTION OF WHICH ORGANIC COMPOUNDS INHIBIT SETTLING OF THE INSOLUBLE ORE RESIDUE, THE IMPROVEMENT OF INCREASING THE EFFECTIVENESS OF STARCH IN FLOCCULATION THE INSOLUBLE ORE RESIDUE, WHICH COMPRISES CONCENTTRATING THE RESIDUE-FREE LIQUOR TO OBTAIN A PRECIPITATED GELATINOUS SLUDGE OF ORGANIC COMPOUNDS, HEATING THE SLUDGE-CONTAINING LIQUID AT ABOVE ATMOSPHERIC PRESSURE TO FROM ABOUT 150 TO 250* C. WITHOUT EVAPORATION TO FURTHER DECONTAMINATE THE LIQUOR IN RESPECT TO SETTLING INHIBITING ORGANIC SUBSTANCES, AND THEREAFTER SEPERATING THE PRECIPITATED SLUDGE FROM THE LIQUOR.