Prodn. of magnesium sulphate-contg. metal oxide mixt. useful as fertiliser

摘要

Prodn. of a MgSO4-contg. metal oxide mixt. comprises: (a) calcining a MgSO4-contg. metal sulphate mixt. at 900-1100 deg C in a fluidised-bed reactor; (b) cooling the resulting gas/solids mixt. to 250-350 deg C in a waste-heat boiler; (c) collecting a coarse solids fraction A with a low MgSO4 content from the boiler; (d) passing the gas through a dust separator, pref. a cyclone or electrostatic precipitator, to collect a fine solids fraction B with a high MgSO4 content; (e) scrubbing the gas; (f) extracting soluble metal sulphates from fraction A to give a MgSO4 soln.; and (g) wetting fraction B with the soln. to give a prod. contg. 15-40 wt.% MgSO4.