廃ホタテ貝殻焼成物を原料とするaragonite型軽質炭酸カルシウムの合成 -非晶質炭酸カルシウムを中間体とする方法- [in Japanese] Synthesis of Aragonite-Type of Calcium Carbonate from Calcined Scallop Shell -With amorphous calcium carbonate as an intermediate- [in Japanese]
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Aragonite type of calcium carbonate was synthesized via amorphous calcium carbonate from calcined scallop shell. The effect of aging and Mg<SUP>2+</SUP> ion addition on polymorphism of the product was determined, and the mechanism of formation of aragonite is discussed. Aging of amorphous calcium carbonate first led to the formation of calcite and unstable vaterite, and the vaterite was then converted to aragonite with the longer aging. The addition of Mg<SUP>2+</SUP> ions further enhanced the formation of aragonite. The elemental analysis by atomic absorption spectrometry and the characterization of the products by EPMA and XRD showed that Mg<SUP>2+</SUP> ions were preferentially adsorbed on the calcite nucleus, then involved in the growing calcite (not needlelike crystal like aragonite). This adsorption inhibited the growth of calcite, leading to aragonite formation.
- Journal of MMIJ
Journal of MMIJ 113(12), 1055-1058, 1997-12-25
The Mining and Materials Processing Institute of Japan