NaCl盐溶液制备半水石膏的工艺条件研究
|
摘要
采用常压盐溶液法制备半水石膏。研究在不加转晶剂时盐溶液浓度、反应温度、pH、固液比以及搅拌速度等因素对脱水速率、晶体形貌的影响规律。结果表明:盐浓度越高,二水石膏脱水速率越快,生成的晶体越细小;温度越高,二水石膏脱水速率越快,晶体直径越大;随着pH由小逐渐增大,二水石膏脱水速率呈现先增后减趋势,晶体长度先减小后增加,但总体影响较小;随着固液比增加,二水石膏脱水速率呈现先增后减趋势,晶体直径先增加后减小;随着搅拌速度增强,二水石膏脱水速率呈现先增后减趋势,晶体直径先减小后增加。常压NaCl溶液中制备半水石膏适宜工艺条件为:NaCl溶液浓度15%,pH5～pH7,反应温度95℃,反应时间2～3 h,固液比1∶6,搅拌速度150 r/min。
Preparation of hemi hydrate gypsum by aqueous salt solution method under atmospheric pressure was conducted.The influences of salt solution concentration,reaction temperature,pH,slurry concentration and stirring rate on dehydration rate and crystal morphology were investigated without crystal modifier.The results showed that the higher the salt solution concentration,the faster the dehydration rate of dihydrate gypsum and smaller crystal size;the higher the reaction temperature,the faster the dehydration rate of dihydrate gypsum and bigger crystal diameter.With the increase of pH,the dehydration rate of dihydrate gypsum appears first increases and then decreases trend,and crystal length decreases first and then increases trend,With the increase of slurry concentration,the dehydration rate of dihydrate gypsum appears first increases and then decreases trend,crystal diameter increases first and then decreases.With the increase of stirring rate,the dehydration rate of dihydrate gypsum appears first increased and then decreased trend,crystal diameter decreases first and then increases.The optimal technological conditions were determined as follows:the concentration of sodium chloride solution 15%,pH value 5～7,reaction temperature 95 ℃,reaction time 2～3 h,slurry concentration 1∶ 6,stirring rate 150 r/min.
Preparation of hemi hydrate gypsum by aqueous salt solution method under atmospheric pressure was conducted.The influences of salt solution concentration,reaction temperature,pH,slurry concentration and stirring rate on dehydration rate and crystal morphology were investigated without crystal modifier.The results showed that the higher the salt solution concentration,the faster the dehydration rate of dihydrate gypsum and smaller crystal size;the higher the reaction temperature,the faster the dehydration rate of dihydrate gypsum and bigger crystal diameter.With the increase of pH,the dehydration rate of dihydrate gypsum appears first increases and then decreases trend,and crystal length decreases first and then increases trend,With the increase of slurry concentration,the dehydration rate of dihydrate gypsum appears first increases and then decreases trend,crystal diameter increases first and then decreases.With the increase of stirring rate,the dehydration rate of dihydrate gypsum appears first increased and then decreased trend,crystal diameter decreases first and then increases.The optimal technological conditions were determined as follows:the concentration of sodium chloride solution 15%,pH value 5～7,reaction temperature 95 ℃,reaction time 2～3 h,slurry concentration 1∶ 6,stirring rate 150 r/min.
引文
[1]钟世云,陈维灯,贺鸿珠.脱硫石膏应用技术现状及其发展趋势[J].粉煤灰,2009(6):35-38.
[2]王方群,原永涛.脱硫石膏性能及其综合利用[J].粉煤灰综合利用,2004(1):41-43.
[3]丛钢,邢世健.脱硫石膏性能研究[J].新型建筑材料,1997(12):10-12.
[4]陈志山.α-型半水石膏的生产工艺[J].非金属矿,1995,18(1):23-25.
[5]李天文,姜四海.α-半水高强度石膏生产新工艺[J].现代化工,1998,18(2):22-24.
[6]孙宝歧.石膏化工百科全书:十四卷[M].北京:化学工业出版社,1993:567.
[7]李林,李琳,孙元喜.常压盐溶液法制备α-半水石膏的工艺参数研究[J].湖南文理学院学报:自然科学版,2005,17(1):31-33.
[8]林敏,方体智,彭家惠,等.盐溶液水热法制备α-半水脱硫石膏工艺条件研究[J].新型建筑材料,2009(6):1-3.
[9]刘红霞,彭家惠,瞿金东.常压盐溶液法制备α-半水石膏转晶剂的研究[J].新型建筑材料,2010(4):5-8.
[2]王方群,原永涛.脱硫石膏性能及其综合利用[J].粉煤灰综合利用,2004(1):41-43.
[3]丛钢,邢世健.脱硫石膏性能研究[J].新型建筑材料,1997(12):10-12.
[4]陈志山.α-型半水石膏的生产工艺[J].非金属矿,1995,18(1):23-25.
[5]李天文,姜四海.α-半水高强度石膏生产新工艺[J].现代化工,1998,18(2):22-24.
[6]孙宝歧.石膏化工百科全书:十四卷[M].北京:化学工业出版社,1993:567.
[7]李林,李琳,孙元喜.常压盐溶液法制备α-半水石膏的工艺参数研究[J].湖南文理学院学报:自然科学版,2005,17(1):31-33.
[8]林敏,方体智,彭家惠,等.盐溶液水热法制备α-半水脱硫石膏工艺条件研究[J].新型建筑材料,2009(6):1-3.
[9]刘红霞,彭家惠,瞿金东.常压盐溶液法制备α-半水石膏转晶剂的研究[J].新型建筑材料,2010(4):5-8.