摘要
以微波辐照代替常规热源,以磷石膏为原料,采用醇水法制备α-半水硫酸钙(α-HH)晶须。通过分析固相产物结晶水含量、物相组成和晶体微观形貌变化,探究醇液比、固液比及pH值等因素对α-HH晶须的影响规律。结果表明,随着醇液比增大,磷石膏主要成分二水硫酸钙(DH)向α-HH脱水转化速率加快,反应时间缩短,但过高的醇液比会造成α-HH晶须成核速率过快,晶核数量增多,晶粒尺寸减小;随着固液比减小,DH向α-HH晶须的转化速率放慢,反应时间延长,但晶须长径比增大;随着pH值增大,α-HH晶须长径比增大,但pH值过高会抑制α-HH晶须生长。当醇液比为70%,固液比为1∶7,pH值为9,在常压微波体系中反应30 min,可制备出长径比为31的α-HH晶须。
Microwave radiation heating is used instead of conventional heat source, and phosphogypsum is used as raw material to prepare α-HH whiskers. The effects of glycerol-liquid ratio, solid-liquid ratio and pH value on α-HH whiskers were studied according to the change of the solid phase crystal water content, crystal phase composition and crystal microscopic morphology. The results show that with the increase of glycerol-liquid ratio,the dehydration rate of phosphogypsum is accelerated, but too high glycerol-liquid ratio will make the nucleation rate of α-calcium sulfate hemihydrate crystals too fast, the number of crystal nucleus increases, and the whisker size decreases. With the decrease of the solid-liquid ratio, the conversion rate of phosphogypsum to α-calcium sulfate hemihydrate crystals is reduced, and the reaction time is prolonged, but the length of the whiskers gradually increases, the diameter decreases, and the aspect ratio gradually increases. With the increase of pH value, the whisker aspect ratio increases, but too high pH value will inhibit the growth of the whiskers. When the glycerol-liquid ratio is 70%, solid-to-liquid ratio is 1∶7, initial pH value is 9, and reaction time is 30 min, calcium sulfate hemihydrate whiskers with a length-to-diameter ratio of 31 can be prepared in an atmospheric microwave system.
作者
李德星
郭荣鑫
林志伟
张绍奇
Li Dexing;Guo Rongxin;Lin Zhiwei;Zhang Shaoqi(Yunnan Key Laboratory of Disaster Reduction in Civil Engineering,Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming,Yunnan 650500)
出处
《非金属矿》
CSCD
北大核心
2022年第1期46-50,55,共6页
Non-Metallic Mines
基金
国家自然科学基金(11962009)。
关键词
微波辐照
磷石膏
醇水法
α-HH晶须
microwave irradiation
phosphogypsum
glycerol-water method
α-HH whiskers
