华东理工大学学报（自然科学版）2018，Vol.44Issue(1)：9-14,6.DOI:10.14135/j.cnki.1006-3080.20170305002
水化时间和温度对半水硫酸钙晶须水化过程的影响
Effects of Hydration Time and Temperature on Hydration Process of Calcium Sulfate Hemihydrate Whiskers
摘要
Abstract
The hydration process of calcium sulfate hemihydrate (HH) whiskers by hydrothermal method was studied.Investigation mainly focused on the influence of hydration time and temperature on the hydration process of HH whiskers,and the determination of the hydration time and temperature on which HH whiskers could be relatively stable.The results showed that HH whiskers eventually transferred to flake,sheet,or lump calcium sulfate dihydrate (DH) with the time increasing at the hydration temperature within 25-90 ℃.With the increase of hydration temperature,the hydration induction period extended.Especially at 90 ℃,the hydration induction period of HH whiskers increased significantly from 3 min at 60 ℃ to 60 min at 90 ℃.Therefore,the hydration of whiskers could be suppressed by rapid dehydration above 90 ℃.According to the observation results of hydration products and phase composition analysis,the hydration mechanism is mainly divided into three processes,the hydration induction period,the dissolution of HH whiskers,and the recrystallization of the calcium sulfate dehydrate.That is to say that there is a period of the hydration induction during the process of the hydration process of HH whiskers.When the whiskers contact with water,the active Ca2+ ions on its surface perform hydroxylation reaction with water.Then the hydroxyl groups on the whisker surface contact with water molecules by hydrogen bonding,and the water molecules are adsorbed on the surface of the whiskers.With the increase of hydration time,the water molecules will intrude into the lattice body and destroy the crystal structure,resulting in the break of the whiskers.With the fracture of HH whisker crystal structure,the Ca2+ and SO42-ions spread to the solution which accelerates the dissolution of HH whiskers.With the continuous precipitation and growth of DH,the further dissolution of HH whiskers is accelerated,until all HH whiskers are transferred to flake or thin plate DH crystals.关键词
半水硫酸钙晶须/水化时间/水化温度/水化机理Key words
calcium sulfate hemihydrate whiskers/hydration time/hydration temperature/hydration mechanism分类
通用工业技术引用本文复制引用
刘天杰,范浩,许妍霞,宋兴福,于建国..水化时间和温度对半水硫酸钙晶须水化过程的影响[J].华东理工大学学报（自然科学版）,2018,44(1):9-14,6.基金项目
国家高技术研究发展(“863”)计划(2011AA06A107) （“863”）
青海省科技项目(2015-GX-Q19A) （2015-GX-Q19A）
