Process for the production of high strength low consistency calcined gypsum

Claim 1

A PROCESS OF PRODUCING CALCINED, GYPSUM CHARACTERIZED BY A VERY LOW CONSISTENBY WHEN GAUGED WITH WATER WHICH COMPRISES HEATING PARTICLES OF GYPSUM, OF SUCH A SIZE THAT THEY WILL NOT PASS THROUGH A 20 MESH SCREEN, IN AN AQUEOUS SOLUTION CONTAINING AT LEAST ABOUT 0.05% BY WEIGHT OF A WATER-SOLUBLE, POLY-CARBOXYLIC ORGANIC COMPOUND FROM THE GROUP CONSISTING OF SUCCINIC ACID AND ITS WATER-SOLUBLE ALKALI SALTS, AND A MIXTURE OF SUCCINIC AND FURMARIC ACIDS AND THEIR WATER-SOLUBLE ALKALI SALTS, UNDER SUPERATMOSPHRIC STEAM PRESSURE WITHIN A RANGE OF FROM ABOUT 15 TO 25 POUNDS PER SQUARE INCH GAUGE PRESSURE AN IN A STATE OF QUIESCENCE, FOR A PERIOD OF FROM ABOUT THREE TO SEVEN HOURS, REMOVING THE SOLUTION FROM CONTACT WITH THE GYPSUM PARTICLES, AND THEN HEATING THE LATER IN AN ATMOSPHERE OF STEAM AT A PRESSURE OF FROM ABOUT 15 TO ABOUT 35 POUNDS PER SQUARE INCH AND AT A TEMPERATURE OF FROM ABOUT 250 TO ABOUT 290*F. FOR A TIME SUFFICIENT TO COMPLETE FORMATION OF SMALL STUBBY CRYSTALS OF CALCINED GYPSUM, REMOVING THE FORMED CRYSTALS FROM THE STEAM ESNVIRONMENT AND DRYING THEM AT A TEMPERATURE ABOVE THAT AT WHICH RECONVRSION TO GYPSUM WOULD TAKE PLACE, AND GRINDING THE RESULTING PRODUCT.