Lignin prodn. from black lyes from paper mfr.

摘要

Lignins are obtd. from black lyes from alkaline pulp, sulphate or kraft paper mfr. by (a) acidification of the lye, previously diluted with water or recycled lye in a basic pH range to ppte. the lignin; (b) sepn. of the flocculated lignin; (c) washing and purifying the pptd. prod. in one or two stages with an acid soln.; and (d) drying under conditions which maintain its chemical and thermal stability.