Method of removing iron, zirconium and titanium from aluminum sulfate

Claim 1

A PROCESS FOR THE PURIFICATION OF AQUEOUS ALUMINUM SULFATE CONTAINING AS IMPURITIES IRON, TITANIUM AND ZIRCONIUM TO PRODUCE SUBSTANTIALLY IRON FREE ALUMINUM SULFATE WHICH COMPRISES (1) ADDING AN OXIDIZING AGENT TO THE IMPURE AQUEOUS ALUMINUM SULFATE AT A TEMPERATURE OF 115 TO 140*F. TO CONVERT FERROUS IRON IN THE AQUEOUA ALUMINUM SULFATE TO FERRIC IRON (2) ADMIXING THE OXIDIZED AQUEOUS ALUMINUM SULFATE WITH A WATER-INSOLUBLE AMINE ANION EXCHANGER TO EXTRACT THE IRON, TITANIUM AND ZIRCONIUM IMPURITIES FROM THE AQUEOUS ALUMINUM SULFATE (3) SEPARATING AND RECOVERING THE PURIFIED AQUEOUS ALUMINUM SULFATE (4) REACTIVATING THE AMINE ANION EXCHANGER CONTAINING THE IMPURITIES EXTRACTED FROM THE AQUEOUS ALUMINUM SULFATE BY INTIMATE CONTACT WITH AN AQUEOUS SOLUTION OF SULFURIC ACID HAVING A CONCENTRATION OF FROM 6% TO 30% H2SO4 AT A TEMPERATURE OF 90 TO 130*F. TO REMOVE THE IRON, ZIRCONIUM AND TITANIUM FROM THE AMINE ANION ANION EXCHANGER (5) TREATING THE RESULTANT REACTIVATED EXCHANGER TO REDUCE THE SULFATE CONTENT TO A VALUE OF LESS THAN 25% SULFATE BASED ON THE WEIGHT OF AMINE ANION EXCHANGER AND (6) RETURNING THE THUS TREATED ACTIVATED AMINE FOR FURTHER CONTACT WITH IMPURE AQUEOUS ALUMINUM SULFATE FOR REMOVAL OF IRON IMPURITIES FROM THE AQUEOUS ALUMINUM SULFATE.