METHOD OF IMMOBILISATION OF ISOTOPES OF RADIOACTIVE WASTES OF TRANSURANIC ELEMENTS (VERSIONS) Russian patent published in 2009 - IPC G21F9/00 

FIELD: chemistry.

SUBSTANCE: invention relates to field of ecologically safe geoconservation of radioactive elements, in particular to creation of alumosilicate matrices for conservation of transuranic elements (TUE) basing on the theory of geochemical barriers. Technical result is achieved by the following: method of immobilisation of isotopes of transuranic elements of radioactive wastes in alumosilicate glass ceramics in accordance with the first version includes precipitation of radioactive elements on iron (III) hydroxide obtained by galvano-chemical method, according to the second version - on peat, preparation of matrix from mixture of dried precipitated radioactive elements and bentonite (montmorillonite) clay with introduction into mixture of neutron absorber -cadmium oxide ensuring component ratio in terms of oxides, wt %: transuranic elements - 15-17; SiO₂ - 65-73; Al₂O₃ - 8-12; oxide sum (Na₂O, K₂O, MgO, CaO, FeO and other) - 6-10; neutron absorber CdO - 0.5; formation by percussion pressing of granules consisting of envelope and core, envelope being made from pressed homogeneous mixture of bentonite clay and 10-30 wt % SiO₂, core - from pressed mixture of radioactive elements and bentonite (montmorillonite) clay, with ratio envelope/core equal from 1/20 to 1/10 wt %, further drying of formed granules, sintering by heating from room or temperature 180°C at rate of temperature increase from 1 to 25°C per minute to temperature of final exposure from 1000 to 1200°C ( in accordance with the first version) or from 1100 to 1200°C (in accordance with the second version) during from 2 to 8 hours in order to obtain rhyolite-like glass-ceramic blocks and cooling.

EFFECT: method insures creation for conservation of isotopes of transuranic elements rhyolite-like glass-ceramic blocks, characterised as natural materials - high-temperature metamorphic rocks (contact hornfels) and volcanic glass.

2 cl