Improvements relating to the production of magnesium basic carbonate, or magnesia

摘要

544,907. Magnesium carbonates and oxide. OCEAN SALTS (PRODUCTS), Ltd., PRYTHERCH, W. E., ANDERSON, J. H., and ADAMS, B. A. Feb. 24, 1941, No. 2485. [Class 1 (iii)] Basic magnesium carbonate, from which magnesia is obtained by calcination, is prepared from dolomite or dolomite limestone with the aid of seawater or other solution containing magnesium salts. An aqueous suspension of calcined dolomite is carbonated to yield a solution of magnesium bicarbonate which is filtered to separate calcium carbonate &c. A further portion of the suspension is treated with seawater to yield a precipitate of magnesium hydroxide which is added to the bicarbonate solution to form a basic magnesium carbonate. The dolomite is preferably calcined at a temperature which decomposes only the magnesium carbonate. Specification 543,665, is referred to.