Pure magnesium oxide prodn - by decomposition of magnesium chloride soln prepd from starting materials contg magnesium oxide, hydroxide or carbonate

摘要

Pure MgO is prepd. from minerals, ores or ind. residues contng. Mg oxide, hydroxide and/or carbonate by (a) mixing the solid starting materials with fresh or wash-water together with recycled HCl-contng. gases, (b) adjusting the resulting suspension to pH 3-6 e.g. by further addn. of starting materials and then opt. oxidising the mixture e.g. by introduction of Cl2, (c) sepg. solids from the aq. soln., (d) decomposing the soln. at >300 degrees C., and (e) separating and recycling the HCl-contng. gases and recovering pure MgO as decomposition product.