SULFATE CELLULOSE PRODUCTION PROCESS Russian patent published in 2001 - IPC

FIELD: paper-and-pulp industry. SUBSTANCE: wood material is digested at elevated temperature and pressure in white sulfate lye, to which products formed in sulfate cellulose production process are added, in particular tall pitch together with elementary sulfur or elementary sulfur-modified tall pitch together with elementary sulfur or without it, preferably in amounts 3-4% of the weight of absolutely dry wood (on conversion to solids contained in additive). EFFECT: increased yield of cellulose at the same delignification degree and cellulose quality. 2 cl, 2 tbl, 22 ex