FIELD: chemistry of polymers. SUBSTANCE: described is method of preparing hydroxadull polymer. Method comprises esterification of water-soluble polymer of acrylic acid or salt thereof, average molecular weight of which polymer exceeds 1,000,000 in aqueous solution with alkylating additive selected from dialkyl sulfate, alkyl halide, halohydrin and alkylene oxide and addition of hydroxamate groups using hydroxyamine salts selected from phosphates, perchlorates, sulfates, sulfites, hydrochlorides, acetates and propionates to the resulting esterified polymer; water-soluble polymer is in dispersed phase of water- in-oil emulsion. Also described are water-soluble polymers and method of removing suspended solid particles. Desired polymers are useful for flocculation of flows in Bayer process. EFFECT: simplified process. 10 cl, 81 ex, 7 tbl _
