Abstract: A hydrophilic polymer with improved biodegradability and particular usefulness in detergent compositions contains units derived by polymerization from at least one monomers A bearing a carboxylic acid function or an equivalent function, units derived by polymerization from at least one monomers B bearing an electron-rich group or a function capable of introducing an electron-rich group into the main chain, and, optionally, units derived by polymerization from at least one monomers C which is copolymerizable with A and B, but is different from A and B. Examples of suitable monomers as monomers A include maleic anhydride, acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid, and the salts thereof. Examples of suitable monomers as monomers B include butadiene, isoprene, chloroprene, dimethylbutadiene, cyclohexadiene, butadienecarboxylic acid, butadienedicarboxylic acid, acetylene, acetylenecarboxylic acid and acetylenedicarboxylic acid.

Abstract: Novel biodegradable polymers consisting of a biodegradable core bound to at least two carboxylic polyacid-based branches via a bond capable of being broken by hydrolysis or by oxidation are described. Biodegradable detergent compositions containing such polymers are also described.

Abstract: A hydrophilic polymer with improved biodegradability and particular usefulness in detergent compositions contains units derived by polymerization from at least one monomers A bearing a carboxylic acid function or an equivalent function, units derived by polymerization from at least one monomers B bearing an electron-rich group or a function capable of introducing an electron-rich group into the main chain, and, optionally, units derived by polymerization from at least one monomers C which is copolymerizable with A and B, but is different from A and B. Examples of suitable monomers as monomers A include maleic anhydride, acrylic acid, methacrylic acid, itaconic acid, fumaric acid and maleic acid, and the salts thereof. Examples of suitable monomers as monomers B include butadiene, isoprene, chloroprene, dimethylbutadiene, cyclohexadiene, butadienecarboxylic acid, butadienedicarboxylic acid, acetylene, acetylenecarboxylic acid and acetylenedicarboxylic acid.

Abstract: Process for the low-temperature treatment according to the Bayer cycle of gibbsite-bearing bauxite of low reative silica content, involving desilication of the said bauxite before leaching, by a liquor of low caustic soda concentration and characterized in that this sodium liquor consists of one or more washing waters originating from the Bayer cycle, mixed or otherwise with leaching liquor, wherein the weighted reactive silica content is preferably lower than 5% of the alumina content of the bauxite and the concentration of the sodium liquor used for desilication ranges from 50 to 120 g/liter of Na.sub.2 O caustic.

Abstract: A process for the continuous production of alumina by means of the Bayer process by alkaline attack in reactors on bauxites which primarily consist of aluminum monohydrates and contain silica in a free state or combined in the form of aluminum silicate, the essential aim of which is to delay scaling of the reactors by deposits of sodium silico-aluminate on the reactor walls. The process comprises the following steps: (1) the bauxite is put into suspension by crushing in a sodic liquor (aqueous solution of caustic soda); (2) the suspension is raised to a temperature of from 90.degree. to 108.degree. C. and held at that temperature for a period of time sufficient to convert at least 75% of the aluminum silicate contained in the bauxite into insoluble sodium silico-aluminate; (3) The suspension is then subjected to steam heating by passing through a tube-type heat exchanger under pressure at a temperature which is at least equal to 160.degree. C. and preferably is from 160.degree. to 230.degree. C.