COMPOSITION CONTAINING MODIFIED RED MUD WITH LOW CONTENT OF CHROMATES, AND A METHOD FOR PRODUCTION THEREOF Russian patent published in 2020 - IPC C04B18/04 C04B20/10 C05F7/00 C09K8/03 

FIELD: chemistry.

SUBSTANCE: group of inventions relates to a composition containing modified red mud with low content of chromates, methods for production and use thereof. Composition containing modified red mud with low content of chromates with following mineral composition: from 10 to 50 % by weight of iron compounds; from 12 to 35 % by weight of aluminum compounds; from 5 to 17 % by weight of silicon compounds; from 2 to 10 % by weight of titanium dioxide; from 0.5 to 6 % by weight of calcium compounds; not more than 1 ppm of chromium (VI) compounds; and in some cases other inevitable impurities, wherein composition of composition, in particular, modified red sludge with low content of chromates, contains a slightly soluble reducer for Cr (VI), wherein the composition also contains a buffer system of pH, configured to stabilize the pH range from 5 to 10, in which a slightly soluble reducer for Cr (VI) and Cr (III) obtained therefrom have low solubility, particularly solubility in water at 25 °C of less than 1 g/l. Method of producing said composition involves the following steps: a) preparing neutralized red mud; b) adding a slightly soluble reducer for Cr (VI) to the red mud and mixing the slightly soluble reducer for Cr (VI) with the red mud; c) reduction of chromium (VI) compounds contained in red slime by a slightly soluble reducer for Cr (VI) into chromium (III) compounds in aqueous systems to obtain modified red slime with low chromate content, wherein the method further comprises adding a pH buffer system configured to stabilize the pH range, in which a slightly soluble reducer for Cr (VI) and Cr (III) obtained therefrom have low solubility, particularly solubility in water at 25 °C of less than 1 g/l. Group of inventions is developed in dependent claims.

EFFECT: technical result is creation of a composition suitable for use as a reusable adsorbent for durability for contaminants in liquid, gaseous and solid medium, recycling wastes.

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