6Singh M. Role of PG impurities on strength and microstruc- ture of selenite plaster[ J]. Construction and Building Mate- rials ,2005,19 (6) :480 - 486.
7Singh M. Effect of phosphatic and fluoride impurities of phosphogypsum on the properties of selenite plaster[ J]. Ce- ment and Concrete Research, 2003,33 ( 9 ) : 1363 - 1369.
8Tabikh A, Miller F M. The nature of phosphogypsum impu- rities and their influence on cement hydration [ J ]. Cement and Concrete Research, 1971,1 (2) : 663 - 678.
9Taher M A. Influence of thermally treated phosphogypsum on the properties of portland slag cement [ J ]. Resources, Conservation and Recycling,2007,52( 1 ) :28 - 38.
10Olmez H, Yilmaz V T. Infrared study on the refinement of phosphogypsum for cements [ J ]. Cement and Concrete Re- search, 1988,18 (3) :449 - 454.
