Abstract: A method of de-inking cellulosic fibrous materials comprising: 1) admixing an alkaline reagent with hydrogen peroxide and an aqueous suspension of inked cellulosic fibrous material in amounts whereby the alkaline reagent and hydrogen peroxide react at the ink particle/cellulosic fiber interfaces to dislodge the ink particles from the cellulosic materials; and, 2) removing the dislodged ink particles from the aqueous suspension, wherein the alkaline reagent comprises sodium carbonate or a mixture of sodium carbonate and a) ammonium hydroxide, b) sodium bicarbonate or c) mixtures of sodium carbonate and ammonium hydroxide.

Abstract: A water soluble, surface active, polymeric agent is mixed with digestion liquor, preferably with an additional surface active defoamer coagulant agent prior to or during acidification of the alkaline digestive liquor. This results in an easily separable, non-gelatinous, non-gummy, coagulated lignin as a solids, particulate fraction that tends to float on a clarified liquid fraction containing recoverable salts. The solids fraction and the liquid frictions are easily separated, one from the other, by a gravity separation step.

Abstract: A method of de-inking cellulosic fibrous materials comprising: a. admixing an alkaline reagent selected from the group consisting of ammonium hydroxide and hydrogen peroxide and mixtures thereof with an aqueous suspension of inked cellulosic fibrous material such that they react at the ink particle/cellulosic fiber interfaces to dislodge ink particles from the cellulosic materials; and b. removing the dislodged ink particles from the aqueous suspension.