IMPROVED METHOD OF BROWN STOCK WASHING

摘要

A nonionic surfactant, i.e. alkylene oxide adducts of alkylphenois or higher aliphatic alcohols or acids, in combination with 2) a water soluble low molecular weight organic polyelectrolyte like polyacrylates, and preferable 3) a solvent like tetrahydrofurfuryl alcohol and ethoxylated derivatives thereof, are used to wash pulps of virgin cellulose fibres to remove and recover spent cooking chemicals and pitch.