METHOD FOR SEPARATING A MIXTURE OF ALKYLCHLOROSILANES AND ALKYL CHLORIDE Russian patent published in 2022 - IPC C07F7/16 C07C17/38 C07C19/03 

FIELD: silicon dust mixture separating.

SUBSTANCE: invention relates to a method for separating a mixture of silicon dust, process off-gases, alkyl chloride and alkylchlorosilanes. The method is characterized by the fact that the mixture of variable composition to be separated enters the bottom part of the distillation column operating with full reflux, and four streams are simultaneously released on the column, namely, the gaseous flow along the top of the column (process off-gases), the "wet cleaning" sludge as bottom liquid , liquid alkyl chloride as a top side draw, and liquid alkylchlorosilanes having a stabilized alkyl chloride content as a bottom side draw. At the same time, the lower side extraction in the form of a mixture of alkylchlorosilanes and alkyl chloride with a stable content of alkyl chloride enters as irrigation to an external stripping column equipped with a bottom liquid evaporator, on which raw alkylchlorosilanes are obtained as bottom liquid, and alkyl chloride with a part of alkylchlorosilanes in the form of vapors from the upper part of the stripping section is returned for re-separation to the distillation column together with the separated mixture of silicon dust, process off-gases, alkyl chloride and alkylchlorosilanes, and the stripping section does not have a dephlegmator.

EFFECT: use of the proposed scheme makes it possible to reduce the total energy costs by more than 2 times compared to the known methods for separating the dust-gas mixture, and the number of pieces of equipment is reduced, which leads to a reduction in equipment costs and to a decrease in the required area of building structures.

9 cl, 3 dwg, 4 ex