Abstract: A process for delignifying raw cellulose which comprises a preliminary treatment for impregnating raw cellulose with a monopersulphuric acid solution, a successive filtration without washing with recycle of the filtered liquid to the first step, and a treatment, at low temperature and in alkaline solution at a pH higher than 9, of the previously impregnated raw cellulose in order to permit the reaction of the monopersulphuric acid with the lignin contained in the raw cellulose.

Abstract: A printed waste paper de-inking composition for use in the "washing" process is disclosed containing:(A) a salt of a fatty acid present in an amount of between 15% and 32% based upon the weight of the entire composition;(B) a nonionic ethoxylated and/or propoxylated surfactant present in an amount between 5% and 25% based upon the weight of the entire composition;(C) an anionic surfactant represented by sulphonates or sulphates present in an amount of between 2% and 8% based upon the weight of the entire composition;(D) a sodium carboxylmethylcellulose in an amount of between 1% and 5% based upon the weight of the entire composition; and(E) an alkaline inorganic salt of the group comprising metasilicate, disilicate, carbonate, borate and polyphosphates, the alkaline inorganic salt present in an amount of between 30% and 80% based upon the weight of the entire composition; the percentages of the components (A), (B), (C), (D), and (E) totaling essentially 100%An improved "washing" process for de-inking printed

Abstract: A de-inking composition is disclosed consisting substantially of:(A) a salt of a fatty acid of the formula: R--COO--M wherein R represents one or more hydrocarbon chains selected from the class consisting of saturated and/or unsaturated hydrocarbons; and M represents a metal selected from the class consisting of Na and K; said fatty acid salt being present in an amount between 5% and 32% with respect to the weight of the entire composition;(B) a non-ionic ethoxylated and/or propoxylated surfactant of the formula: ##STR1## wherein: Y is either H or CH.sub.3 ;R.sup.1 O represents the hydrophobic moiety of the molecule and is derived from a compound selected from the class consisting of alkylphenols of formula ##STR2## saturated primary fatty alcohols of formula R"--CH.sub.2 OH; saturated secondary fatty alcohols of formula R"' ##STR3## fatty acids of the formula R.sup.v --COOH; and mixtures thereof, wherein R', R", R"', R.sup.iv and R.sup.