METHOD FOR SEPARATING SILICON ISOTOPES Russian patent published in 2022 - IPC B01D59/28 C01B33/107 

FIELD: chemical processes.

SUBSTANCE: invention can be used in chemical engineering. Separation of stable silicon isotopes by the method for chemical isotope exchange between gaseous halogen-containing silicon compounds by the general formula SiH_nX_4-n, wherein X is a halogen atom, and liquid molecular complex compounds therein in the form SiH_nX_4-n-D, wherein D is a molecule of a complexing agent, is implemented in counter-flow mass transfer columns with lower and upper flow reversal assemblies. Phosphorus-containing compounds by the general formula R₁R₂R₃(O)_mPO_q are used as a complexing agent, where R₁, R₂, R₃ are hydrocarbon radicals, wherein R₁=R₂=R₃≠CH₃; R₁=C_n1H_2n1+1, the number of carbon atoms n₁=2-5, or R₁=C₆H₅; R₂=C_n2H_2n2+1, the number of carbon atoms n₂=2-5, or R₂=C₆H₅; R₃=C_n3H_2n3+1, the number of carbon atoms n₃=2-5, or R₃=C₆H₅; m is the number of oxygen atoms linked with a hydrocarbon radical on one side and with a phosphorus atom on the other side, m=0, 2, 3; q is the number of oxygen atoms connected by a double bond with a phosphorus atom, q=0, 1, wherein m≠q.

EFFECT: possibility of increasing the sorption capacity of the complexing agent, reducing the amount of the complexing agent circulating in the unit, increasing the concentration of the ²⁸Si isotope and the productivity of the unit for separating silicon isotopes when ²⁸Si is concentrated.

1 cl, 6 tbl, 5 ex