Technically pure magnesium cpds. and sulphur di:oxide prodn. - from magnesite, dolomite and waste gas by reaction in suspension and settling before sepn.

摘要

In the prodn. of technically pure Mg cpds., e.g. Mg(HSO3)2, MgSO3, MgSO4, MgO, and esp. the prodn. of technically pure SO2 from MgCO3 contaminated mainly with CaCO3, e.g. crude magnesite, dolomite and/or waste gas, the impure MgCO3 is made into a suspension and this is reacted with a SO2 carrier, e.g. waste gas and/or Mg salt, pref. Mg(HSO3)2, in one or more stages. It is then transferred to a settler, from which a clear soln. of Mg(HSO3)2, MgSO3 or MgSO4 is discharged and the impurities are removed in the form of a slurry. Impurities (e.g. Ca and Fe cpds.) can be removed from natural Mg cpds., giving a high grade prod.