METHOD FOR PURIFYING WASTE PROCESS GASES FROM SULPHUR DIOXIDE

摘要

The invention relates to the purification of waste process gases from sulphur dioxide in industries using sulphur-containing raw materials and can be used for power plants, the metallurgical and chemical industries. The aim of the invention is to reduce the consumption of basic calcium compounds, use the coarse grinding thereof, increase the purity of produced gypsum and to reduce the time of the oxidation process of calcium sulphite. The inventive method consists in transferring sulphur dioxide from a gas to the pulp of the basic calcium compound in the form of a water-soluble calcium bisulphite Ca (HSO3)2 at a initial content of the basic calcium compound in said pulp equal to or less than 60 g/dm<3> and the molecular-mass ratio between SO2 and the basic calcium compound within the limits of (1-2):1. Afterwards, the calcium bisulphite is air oxidised to sulphate in the presence of the equimolar quantity of the basic calcium compound or by distilling and catching the equimolar quantity of sulphur dioxide.