A method for producing hexagonal board-shaped workpieces made from an extremely chemically pure aluminum sulfate crystals

摘要

Hexagonal plate crystals of aluminum sulfate are produced in chemically pure form by a process which comprises cooling a heated saturated solution of chemically impure aluminum sulfate acidified with sulfuric acid to precipitate crystals of aluminum sulfate, heating the slurry of the cooled solution containing the precipitated aluminum sulfate crystals to a predetermined temperature wherein the temperature is maintained for a time sufficient to dissolve a portion of the crystals in the solution, cooling the heated slurry to precipitate aluminum sulfate crystals, and separating the precipitated crystals from the slurry.