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公开(公告)号:US20070044687A1
公开(公告)日:2007-03-01
申请号:US11217039
申请日:2005-08-31
申请人: David Blackburn , Qingxia Liu , Michael Shake
发明人: David Blackburn , Qingxia Liu , Michael Shake
CPC分类号: C04B28/145 , C04B20/1066 , C04B20/107 , C04B2111/0062 , Y10T428/2993 , C04B14/365 , C04B24/2647
摘要: A gypsum slurry includes calcium sulfate hemihydrate, water and calcium sulfate dihydrate is coated with a hydrophilic, dispersible coating. The coating is less soluble than the calcium sulfate hemihydrate to delay exposure of the landplaster to the remainder of the slurry, preventing premature crystallization and the early stiffening that accompanies it. Another embodiment is a gypsum slurry that includes calcium sulfate hemihydrate, a polycarboxylate dispersant, water and coated calcium sulfate dihydrate. In this case, the hydrophilic, dispersible coating is selected to serve as a modifier to enhance the ability of the dispersant to fluidize the gypsum slurry.