Manufacture of ammonium sulfate from gypsum

Abstract

Abstract AMMONIUM SULFATE IS MANUFACTURED FROM GYPSUM BY A CONTINUOUS PROCESS IN WHICH AN AQUEOUS FLOW OF MATERIAL IS CONTINOUSLY RECYCLED ALONG A PREDETERMINED CLOSED CIRCUIT DEFINED BY A CONDUIT AND A WIDER VALLEL CONNECTED IN SERIES. A FRESH AQUEOUS GYPSUM SLURRY COMPRISING A DISPERSION OF FINELY DIVIDED GYPSUM IN AN AMMONIUM SULFATE SOLUTION IS CONTINUOUSLY INTRODUCED INTO THE FLOWING MATERIAL AND FOLLOWED BY CONTINUOUS INFECTION OF CARBON DIOXIDE GAS AND GASEOUS AMMONIA WHICH REACT WITH THE GYPSUM TO FORM CALCIUM CARBONATE AND AMMONIUM SULFATE. ANY REACTION HEAT IS ABSORBED BY A COOLER TO MAINTAIN THE TEMPERATURE BETWEEN DESIRED LIMITS. THEN, A RETARDATION OF MATERIAL FLOW IS CAUSED BY PASSING THE MATERIAL THROUGH THE VESSEL OF THE CIRCUIT AND SO ALLOWING CRYSTALS OF CALCIUM CARBONATE TO GROW UNDE*R CONTROLLED CONDITIONS. AFTER COMPLETION OF CRYSTAL GROWTH, A PORTION OF THE FLOWING MATERIAL IS CONTINUOUSLY WITHDRAWN FROM ITS CIRCUIT AND THE SOLID CALCIUM CARBONATE IS REMOVED FROM THIS PORTION IN ORDER TO OBTAIN AN AMMONIUM SULFATE SOLUTION WHICH MAY BE USED AS SUCH OR WORKED UP TO SOLID AMMONIUM CARBONATE.

Inventors

• 👤 Johan F Witte
• 👤 Jacobus J De Wit

Bibliographic Details