Process for preparing aluminum sulfate

Claim 1

A PROCESS OF MAKING ALUMINUM SULFATE COMPRISING: (A) PROVIDING IN A FIRST VESSEL A FIRST SUSPENSION, COMPRISED OF SUBSTANTIALLY PURE CRYSTALLINE AND ALUMINUM SULFATE SUSPENDED IN A SUPERSATURATED FIRST SOLUTION OF ALUMINUM SULFATE ACIDIFIED WITH SULFURIC ACID IN THE RANGE OF ABOUT 3% TO ABOUT 40%; (B) FURTHER SUPERSATURATING SAID FIRST SOLUTION BY CONCENTRATION TO INDUCE CRYSTALLIZATION OF ALUMINUM SULFATE THEREFROM; (C) SEGREGATING BY HYDRAULIC ELUTRIATION FROM SAID FIST SUSPENSION IN SAID FIRST VESSEL A FIRST ZONE OF A SECOND SUSPENSION OF A FIRST SYSTEM OF FINE CRYSTALS OF ALUMINUM SULFATE SUSPENDED IN SAID FIRST SOLUTION AND A SECOND ZONE OF A FIRST SYSTEM OF RELATIVELY LARGER CRYSTALS OF ALUMINUM SULFATE IN SAID FIRST SOLUTION; (D) WITHDRAWING SAID SECOND SUSPENSION IN AN ACCOMPANYING PORTION OF SAID FIRST SOLUTION FROM SAID FIRST VESSEL; (E) DISSOLVING SAID FIRST FINE CRYSTALS OF SAID WITHDRAWN SECOND SUSPENSION INTO THE SAID ACCOMPANYING PORTION OF SAID FIRST SOLUTION TO FORM A SECOND SOLUTION OF ALUMINUM SULFATE;