Study on Inprovement of the Crystals of By-produced Gypsum of the Ammonia-Soda Process by Addition of Organic Substances

Abstract

When we Synthesize CaSO₄⋅2H₂O and recover the brine by utilizing by-product CaCl₂ of Ammonia-Soda process and by-product Na₂SO₄⋅10H₂O of rayon industry, glanular and dense crystals of CaSO₄⋅2H₂O and the concentrated NaCl solution are obtained by means of addition of a little amount of certain organic substances—partecularly Na-citrate—to the reactive solution, resolving Na₂SO₄⋅10H₂O into NaCl solution, and holding the reactive solution slightly basic.