Calcining gypsum in suspension - in medium e.g. sulphuric acid or saline soln. and at varying rate of flow

摘要

Method of calcination under ordinary pressure of gypsum obtd. as by-product and/or mineral, in dispersion in a calcining medium such as sulphuric acid and/or appropriate saline solns., comprises preparing the dispersion continuously and causing it to advance in an uninterrupted flow along the calcination path. The rate of flow is increased and diminished alternately and the temp. altered along the calcination path. The variation of the rate of flow gives rise to a mixing effect which makes unnecessary supplementary stirring of the dispersion along the calcination path.