가스법에 의한 염기성 탄산마그네슘의 제조 : 4 . 염기성 탄산마그네슘의 생성 4 . Formation Process of Basic Magnesium Carbonate = Preparation of Basic Magnesium Carbonate by Gas Method

다국어 초록 (Multilingual Abstract)

The following results have been obtained through the studies on the preparation of basic magnesium carbonate by gas method.
The basic magnesium carbonate could be identified by means of the pH measurement, chemical analysis, refractive index, X-ray diffraction and microscopic studies.
The formation of basic magnesium carbonate from Mg (OH)₂ suspension and CO₂ depended on the concentration of Mg (OH)₂ in the suspension and the flow rate of CO₂ as well as on temperature.
The basic magnesium carbonate formation with 0.24 mole/ℓ of Mg (OH)₂ suspension and CO₂ flow rate of 33 ㎖/min. at 70-90℃ did not give MgCO₃ · 3H₂O, but gave a compound with mole ratio of CO₂/MgO of 0.75-0.84, which corresponds approximately to (3-5) MgCO₃ · Mg(OH)₂ · (3-5) H₂O. The refractive index was about 1.531.
When Mg(HCO₃)₂ solution was heated, a metastable compound was formed initially, which then transformed into MgCO₃ · 3H₂O, and this in turn gave basic magnesium carbonate by decomposition (into CO₂ and H₂O).
In order to obtain the best quality basic salt, it is therefore important to assure that Mg(OH)₂ neutral Mg-salt and amorphous compound do not coexists in the finished product.