摘要
研究了用气液法制备文石型ＣａＣＯ２ 晶须时，温度、初始ｐＨ 值、结晶促进剂等工艺因素对晶须生长的影响，利用Ｘ 射线衍射分析了试样中文石型ＣａＣＯ３ 的质量分数．通过实验发现，在Ｈ３ＰＯ４或可溶性磷酸盐的作用下，Ｃａ（ＯＨ）２ 悬浊液具有类似的碳酸化过程，但采用Ｈ３ＰＯ４ 或酸性磷酸盐时，反应的渗流效应比采用碱性磷酸盐显著，所得产物中文石质量分数也较高．适宜于文石型ＣａＣＯ３ 生长的温度范围为２５ ～７５ ℃；初始酸度值范围为８－６ ～１２－４ ．通过对比Ｃａ３（ＰＯ４）２ 和ＣａＨＰＯ４对晶须生长的影响，发现可以作为文石型ＣａＣＯ３ 晶核的成份为ＣａＨＰＯ４ 而非Ｃａ３（ＰＯ４）２ ．
Aragonite whiskers were synthesized by using the CO 2?Ca(OH) 2 suspension system. Studied are the influences of accelerating agents, temperature and initial pH value of the react solution on the growth of aragonite whisker. X ray diffraction analysis was used to determine the content of aragonite of the final product. Experiments show that carbonate processes of Ca(OH) 2 are similar when using phosphoric acid or soluble phosphates as accelerating agents. However, when phosphoric acid or acidic agents were selected, the osmotic effect of the carbonate process was more evident than that of using alkalinous agents. In addition, the contents of aragonite of the final products were increased when using phosphoric acid or acidic agents as accelerating agent.The suitable temperature for growing of aragonite crystal is from 25 ℃ to 75 ℃,and the adequate initial pH value range is 8 6～12 4. It has been known that the nucleus of aragonite is calcium phosphate. However. the present work reveals that the real nucleus of aragonite is calcium hydrogen phosphate instead of calcium phosphate.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
1999年第10期10-13,共4页
Journal of Xi'an Jiaotong University
基金
西安交通大学博士点论文基金
关键词
晶须
气液法
合成
碳酸钙
文石型
calcium carbonate
aragonite
whisker
phosphoric acid
