PROCESS FOR OBTAINING SULFUR DIOXIDE AND PURE MAGNESIUM OXIDE FROM GASES WITH A LOW CONTENT OF SULFUR DIOXIDE AND SORBENTS CONTAINING MAGNESIUM OXIDE

摘要

In a process for producing SO2-rich gases and pure MgO from gases low in SO2, as are obtained, for example, in furnace units of a steam generator fired with brown coal, the gases low in SO2 are prepurified to remove fly ash and scrubbed in two stages by means of a slurried sorbent for SO2, where, in the first scrub, the gases low in SO2 are saturated with contaminated MgO at a pH of about 7 and the gaseous impurities which are soluble in the scrubbing water, for example halides, mainly chlorides and fluorides, are separated from the gases low in SO2. In the second stage, the gases are scrubbed by means of a sorbent suspension at a basic pH at which the sulphur oxides are bound and the sulphates are obtained as solution and the sulphites are obtained as solid. The solids are split by heating into SO2-rich gases and the purified sorbent which can be reused or can sometimes also be sold on as pure sorbent. IMAGE