摘要 |
A process for preparing calcined gypsum (stucco) which comprises treating a mass of calcined gypsum by adding, with thorough blending, small portions of an aqueous solution of ligno sulfonate; allowing the treated stucco to heal; and optionally drying the healed stucco and further optionally grinding the healed stucco. If the treated calcined gypsum is not to be used shortly after the healing procedure, it should be dried to provide storage stability. If further strength is desired the treated stucco should be ground to expose fresh crystal faces. The process is particularly useful in gypsum board manufacture and production of bagged building and industrial plasters.
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