METHOD OF PREPARING MAGNESIUM-BASED BISULFITE COOKING LIQUOR FOR COOKING CELLULOSE USING REGENERATED CHEMICALS Russian patent published in 2007 - IPC D21C3/10 D21C11/02 

FIELD: paper-and-pulp industry.

SUBSTANCE: method is intended for use in production of cellulose fabricated from fibrous intermediate products via treatment with magnesium-based bisulfite cooking liquor using regenerated chemicals. Method is accomplished as follows. Solution containing magnesium bisulfite and magnesium monosulfite is prepared in system of regeneration of chemicals and heat from exhausted lyes at 60-70°C. Resulting solution is then saturated with sulfur dioxide in the form of gas emissions and/or condensates formed during cooking cellulose and concentrating exhausted lyes to form magnesium bisulfite and sulfurous acid solution. Preparation of the solution is effected at pH 4.5-5.0 and bound sulfur dioxide content 51.0-55.0%, while saturation of resulting solution with sulfur dioxide is effected to pH 2.8-4.5 and bound sulfur dioxide content 47.0-51.0%.

EFFECT: increased feasibility of method due to simplified technology and reduced operational expenses.

1 tbl, 2 ex