METHOD OF PRODUCING ENCAPSULATED CALCIUM PEROXIDE GRANULES Russian patent published in 2019 - IPC C01B15/43 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry, specifically to a technology of producing encapsulated calcium peroxide granules – a stabilized solid source of active oxygen. Ability to generate active forms of oxygen and hydrogen peroxide determines wide application of calcium peroxide in food, perfume industry, agriculture, medicine, household chemicals, recovery of contaminated soil and water, paper and fiber bleaching, purification of drinking water and liquid wastes, etc. Disclosed is a method of producing encapsulated calcium peroxide granules, involving reaction of lime with aqueous solution of hydrogen peroxide and subsequent granulation and encapsulation of calcium peroxide, characterized in that lime is added in form of an aqueous suspension, molar ratio of CaO:H₂O₂ is 0.8–2.0, 20–50 wt % aqueous solution of hydrogen peroxide, containing 0.5–5 wt % of sodium polyphosphate (relative to CaO) as encapsulating agent and 0.5–2 wt % (relative to CaO) of sodium metasilicate, residue after mixing solutions is separated and fed into screw mixer heated to temperature of 40–60 °C, which uniformly loads the formed granules into the chamber with a fluidised bed, where final dehydration and encapsulation of product in air current heated to temperature of 40–60°C takes place. It is advisable that mother solution after separation of sediment is used to prepare an aqueous suspension of lime.

EFFECT: disclosed method enables to obtain encapsulated calcium peroxide granules with high content of active oxygen and controlled activity required in various industries in one process cycle.

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