Process for purifying alumina and recovering a gallium concentrate

Claim 1

A PROCESS FOR SIMULTANEOUSLY EFFECTING PURIFICATION OF ALUMINA AND RECOVERY OF G ALLIUM, WHICH COMPRISES DECOMPOSING ALUMINUM HYDROXIDE WITH HYDROCHLORIC ACID, SAID ALUMINUM HYDROXIDE BEING FORMED BY HYDROLYZING ALKALI ALUMINATE SOLUTION OBTAINED FROM THE ALKALI DECOMPOSITION OF AN ALUMINUM CONTAINING ORE, PASSING THE RESULTING SOLUTION THROUGH A STRONGLY BASIC ANION EXCHANGE RESIN LAYER HAVING AN AFFINITY FOR GALLIUM TO ADSOSRB GALLIUM, IRON AND OTHE METALLIC IMPURITIES, INTRODUCING INTO THE THUSLY TREATED SOLUTION AN AMOUNT OF HYDROGEN CHLORIDE GAS SUFFICIENT TO FORM ALUMINUM TRICHLORIDE AS A PRECIPITATE AND FIRING THE PRECIPITATE TO FORM PURIFIED ALUMINA, WASHING THE RESIN LAYER WITH AQUEOUS HYDROCHLORIC ACID AND THEN ELUTING THE ADSORBED GALLIUM, IRON AND OTHER IMPURITIES WITH WATER, NEUTRALIZING THE RESULTING ELUTION WITH AMMONIA TO FORM A PRECIPITATE OF GALLIUM, IRON AND OTHER METALLIC IMPURITIES AS THEIR HYDROXIDES, AND FIRING THE HYDROXIDES TO FORM MIXED OXIDES CONTAINING A SUBSTANTIAL AMOUNT OF GALLIUM OXIDE.