Huels Aktiengesellschaft

Huls Aktiengesellschaft

Dynamit Nobel Aktiengesellschaft

Huls Troisdorf Aktiengesellschaft

Klaus Ruff

Bernhard Falk

Klaus Schrage

Werner Gratz

Detlef Liesching

A method for processing chlorosilane distillation residues by hydrolysis with steam, in which the hydrolysis is carried out at escalating temperatures from about 130.degree. C. to at least 170.degree. C.

Method of processing chlorosilane distillation residues with steam

A process for waste liquid-free processing of residues of chlorosilane distillations, wherein the residue is allowed to react with liquid hydrochloric acid accompanied by the release of hydrogen chloride, the resulting reaction mixture is allowed to coagulate, the solid phase is separated and dried and heat-treated, and the liquid phase and the condensed gaseous constituents are recycled into the process.

Process for waste liquid-free processing of chlorosilane distillation

A residue from the production of chlorosilanes from raw silicon is treated with steam and aditionally with nitrogen-oxygen mixtures. The resulting residue has a lower chloride content.

Method for processing residues from the distillation of chlorosilanes

Residues which are obtained from the distillation of chlorosilanes prepared by reaction of raw silicon with chlorine or hydrogen chloride are processed by treatment in aqueous phase with an excess of at least 15% of calcium carbonate, and the liquid components are recycled into the process so that no liquid waste is formed.

Waste liquid-free processing of chlorosilane distillation residues with

Disclosed is a method for the processing of the residues that occur in the production of chlorosilane. The processing is performed by the separation of the residual chlorosilanes, followed by hydrolysis of these residues with water vapor. The water vapor used has a temperature between 100.degree. and 300.degree. C. and additionally contains hydrogen chloride. The hydrolysis residues occurring in the present method have an extremely small chloride content and can be transported, if desired, directly to a dump. The hydrogen chloride that is released can be absorbed in water and removed as hydrochloric acid or can be desorbed for further technical use. Preferably it is reused for chlorosilane production.

Method for processing the residues of a chlorosilane distillation

A method for increasing the trichlorosilane yield in the hydrochlorination of silicon in a fluidized bed involves chilling the gas mixture issuing from the fluidized bed in the shortest possible time immediately after leaving the fluidized bed to temperatures below 550.degree. C. When the temperature of the fluidized bed is below 550.degree. C., the gas mixture is chilled to temperature 100.degree. C. lower than the reaction temperature in the fluidized bed. The method makes it possible, at a reaction temperature of, for example, 800.degree. C. to increase the 16 to 20% trichlorosilane yields obtained formerly at this temperature to 55%, especially when gaseous silicon tetrachloride is also added to the fluidized bed.

Method for increasing the yield of trichlorosilane in the fluidized-bed

A process is described for increasing the percentage of silicon tetrachloride during the reaction of hydrogen chloride or a mixture of hydrogen chloride and chlorine with substances containing metallic silicon. In this process the chlorosilanes are exposed to a temperature ranging between 300.degree. C. and 1400.degree. C.

Process for increasing the percentage of silicon tetrachloride

Disclosed is a process for the cleavage of chlorosiloxanes in the gas phase at temperatures between 350 and 1450.degree. C. to form chlorosilanes and silicon dioxide as reaction products. The claimed process is preferably performed in the presence of metallic silicon or ferrosilicon. The procedure can be combined with the large-scale technical production of chlorosilanes by the chlorination or hydrochlorination of silicon. The inventive process makes it possible to perform the chlorination or hydrochlorination of silicon with the formation of chlorosilanes in an increased yield while reducing the formation of by-products.

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Troisdorf, Germany

Klaus Ruff