Study on Sparingly-Soluble Carbonete Crystallization as Technology for CO_2 Fixation

分批进行反应结晶试验，以检查l-天冬氨酸和l-甘氨酸对结晶速率的影响。从结果来看，与结晶操作因素的影响相比，它们的影响并不显著。在此基础上，研究了反应结晶过程中过饱和度、过饱和度形成速率、温度、搅拌等因素对碳酸钙晶体形状的影响。在此基础上，将钙盐与碳酸盐溶液直接混合，在常温常压下进行碳酸钙结晶，发现固体氯化钠的加入有利于方解石的选择性生成，而不加固体氯化钠时，球文石的结晶效果较好。加入方式、反应物浓度对晶体形状和粒度分布也有影响。由此发现了不稳定的微细粒通过氯化钠表面溶解选择性地转化为方解石的新现象，并得到了方解石的生长速率。本研究可定位为一种微生物研究，不仅有助于碳酸钙结晶法生产二氧化碳新工艺的开发，

Reactive crystallization tests were done batch-wisely, to examine the effect of l-aspartic acid and l-glycine on the crystallization rate. From the results, effect of them was recognized not to be significant in comparison to the effect of crystallization operation factors. Then studies on reactive crystallization were carried out to obtain the effect of supersaturation, the rate of its formation, temperature and mixing on the shape of calcium carbonate crystals. Based on the results of above studies, direct mixing of calcium salt and carbonate sollution was applied to calcium carbonate crystallization under normal temperature and pressure, to recognize that solid sodium chloride addition was effective to form calciteselectively, althogh vaterite crystallized much without its addition. And also method of addition, reactant concentration affected crystal shape and size distribution. Consequently new phenomena that unstale microfines were transformed selectively to calcite by dissolution of sodium chloride surface, was found, and growth rate of calcite was obtained. This study could be located as a germic reserach, and it will contribute not only to the new process development of carbon dioxide flxation by calcium carbonate crystallization,