著者
松田 伸一 池上 隆康 小浜 弘之
出版者
無機マテリアル学会
雑誌
石膏と石灰 (ISSN:21854351)
巻号頁・発行日
vol.1986, no.202, pp.142-151, 1986-05-01 (Released:2011-03-07)
参考文献数
20

Magnesium basic carbonate was synthesized by using so called “the sodium carbonate method”. The process composed of following steps such as precipitation and dissolution of the amorphous basic carbonate, crystallization and dissolution of the carbonate (nesquehonite), and the formation of the basic carbonate.The results obtained are summarized as follows : 1) The crystallinity of nesquehonite depends on the concentration ratio of [CO32-] / [OH-] 2.2) The formation rate of the basic carbonate depends on the dissolution rate of nesquehonite and the concentration ratio of [OH-] / [HCO3-].3) The composition of basic carbonate depends on aging conditions, that is 4MgCO3·Mg (OH) 2·8H2O is stable at high concentration of [OH-] and low temperature, 4MgCO3·Mg (OH) 2·5H2O (dypingite) is stable at low concentration of [OH-] and high tempbrature.4) Ultimate composition of basic carbonate depends on the drying temperature. 4MgCO3·Mg (OH) 2· 5H2O (giorgiosite) is stable at room temperature, on tne other hand, 4MgCO3·Mg (OH) 2·4H2O (hydromagnesite) is stable at about 110 °C.Above results indicate that the concentration of initial solution, the aging temperature, and the pH of mother's solution play the important role on the synthesis of magnesium basic carbonate.