Study on Hydration of Calcium Sulfate Hemihydrate Whiskers
Calcium sulfate whiskers are considered to be a prosperous reinforced material in application due to their high mechanical properties.But the hydration occurs easily at moist atmosphere or in aqueous solution.The surface topographies of the calcium sulfate hemihydrate whiskers and the hydrates were analyzed by on-line observation and using XRD.The results indicated the transformation of the crystal type and shape of calcium sulfate hemihydrate whiskers and the reduction of whiskersaspect ratio.The hydration process of the calcium sulfate hemihydrate whiskers and the effective parameters were further discussed based on FT-IR measurements.The conclusions were obtained that the hydration of calcium sulfate hemihydrate whiskers can be divided into the three phases,namely,initial hemihydration phase,dehydration phase,and coarsening,dissolving and the re-formation of calcium sulfate dehydrate crystal phase.In addition,it was found that in the hydration process of calcium sulfate hemihydrate whiskers the calcium sulfate dihydrate whiskers are formed at first and then converted into the calcium sulfate dihydrate with different crystal shapes,but in the hydration of gypsum hemihydrate the gypsum dihydrate is formed without transition products.The surface active site-calcium ion which has strong trend to react with H2O,the surface -OH and the inner channels are considered to play important roles in the hydration process of calcium sulfate hemihydrate whiskers.
Hemihydrate calcium sulfate Whisker Hydration process
Y.X.Han Y.B.Wang Z.T.Yun W.Z.Yin L.X.Li
School of Resources & Civil Engineering,Northeastern University,Shenyang,China
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
3318-3323
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）