Regeneration process of the elements so2 and na2o contained in the residual lyes from the cooking of the cellulose materials, and in particular with a solution of sodium sulphite

摘要

269,909. Barbou, P. A., and Delvaille, R., (trading as Soc. Barbou et Cie.). April 21, 1926, [Convention date]. Waste products, treatment and utilization of.- The lye obtained in the manufacture of cellulose for making paper, artificial silk, &c. by boiling cellulosic material with sodium sulphite is treated to regenerate sodium sulphite for use again. The lye is treated with an alkaline earth base such as lime to precipitate calcium sulphite. The residual liquid is treated with calcium bisulphite, which may be formed by solution of the precipitated calcium sulphite in sulphur dioxide solution or with bisulphites of other alkaline-earth metals or of magnesium, aluminium, or manganese to precipitate an organic metal compound, and to yield a liquid containing sodium bisulphite which is neutralized with caustic soda to form a solution of sodium sulphite.