Highly pure magnesium carbonate prodn. - by carbonating aq. suspension of calcium and magnesium carbonate(s) to dissolve magnesium, filtration and pptn.

摘要

Prodn. of high purity Mg carbonate comprises treating an aq. suspension of a mixt. of Ca carbonate and hydrated Mg carbonate with CO2 at is not >40 degrees C until a considerable concn of Mg cations is present in the water and the introduction of CO2 is stopped while most of the Ca is present as Ca carbonate. The solids are sepd. from the aq. soln. then CO2 is removed from the soln. to ppte. Mg carbonate which is sepd. from the aq. phase. Highly pure Mg carbonate or for certain refractory applications, Mg carbonate contg. the desired amt. of Ca cpd. is obtd.