METHOD FOR OBTAINING CERAMIC BLOCK-CELLULAR FILTERS-SORBENTS FOR TRAPPING GASEOUS RADIOACTIVE CAESIUM Russian patent published in 2015 - IPC C04B38/06 C04B35/111 C04B35/18 

FIELD: chemistry.

SUBSTANCE: method for obtaining ceramic block-cellular filters-sorbents for trapping gaseous radioactive caesium includes soaking of polyurethane matrix of cellular structure with dross, consisting of inert filling agent - electrofused corundum, disperse aluminium oxide powder and polyvinyl alcohol solution, drying and burning. Sorption-active composition of alumo-sol and silica sol, taken with ratio of aluminium and silicon oxides 30-35:70-65 wt %, with addition of 0.3-0.8 wt % of polyvinyl alcohol relative to dry composition substance, is applied on obtained corundum matrix with average size of cell 0.5-1.5 mm by method of repeated soaking and thermal processing in the interval of temperatures 600-700°C. Amount of composition constitutes 21-45 wt % of matrix weight. Ceramic block-cellular filter-sorbent of radioactive caesium has open porosity 85-90 vol %, compression strength 2.5-4.0 MPa, specific surface of sorption-active layer 300-360 m²/g. Chemisorption process on obtained filters-sorbents results in formation of stable crystalline caesium alumosilicates: CsAlSiO₄ (calsilite) and CsAlSi₂O₆ (pollucite), sorption capacity constitutes 0.16-0.32 g of Cs₂O/g of filter-sorbent.

EFFECT: increased sorption capacity of filter.

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