Chlorosilane-containing process streams are treated by vaporizing the process stream, contacting the vaporized process stream with an alkaline medium in a scrubber, the scrubbing liquid being maintained at a pH of 9-13 by introduction of alkaline medium, and feeding the scrubbing medium to a waste treatment plant containing at least one mixing tank in which the pH is adjusted to the range of 7-9 by addition of mineral acid, separating solids by means of a centrifuge, and isolating separated solids.

Chlorosilane-containing process streams are treated by vaporizing the process stream, contacting the vaporized process stream with an alkaline medium in a scrubber, the scrubbing liquid being maintained at a pH of 9-13 by introduction of alkaline medium, and feeding the scrubbing medium to a waste treatment plant containing at least one mixing tank in which the pH is adjusted to the range of 7-9 by addition of mineral acid, separating solids by means of a centrifuge, and isolating separated solids.

The invention relates to an improved process to manufacture TCS in a polysilicon plant based upon combining a high temperature FBR process reacting metallurgical grade silicon, hydrogen, and silicon tetrachloride (STC) to make trichlorosilane (TCS) and a high temperature thermal converter to hydrogenate STC to TCS and hydrogen chloride.

Separation of chlorosilane mixtures containing boron, arsenic, and/or phosphorus impurities is facilitated by a distillative separation using at least one divided column, with recycle streams to a first column being passed through an external absorbent for the impurities.

By incorporating an additional TCS and/or DCS redistribution reactor in the TCS recycle loop and/or DCS recycle loop, respectively, of a process and system for silane manufacture, efficiencies in the production of silane are realized. Further improvements in efficiencies may be realized by directing a portion of the product from a redistribution reactor into a distillation column, and specifically into the distillation column that formed the feedstock that went into the redistribution reactor.

By incorporating an additional TCS and/or DCS redistribution reactor in the TCS recycle loop and/or DCS recycle loop, respectively, of a process and system for silane manufacture, efficiencies in the production of silane are realized. Further improvements in efficiencies may be realized by directing a portion of the product from a redistribution reactor into a distillation column, and specifically into the distillation column that formed the feedstock that went into the redistribution reactor.

[Problem] To provide a novel production method for pentachlorodisilane and to obtain pentachlorodisilane having a purity of 90 mass % or more by carrying out this production method.

[Solution] A production method provided with: a high-temperature reaction step in which a raw material gas containing vaporized tetrachlorosilane and hydrogen is reacted at a high temperature in order to obtain a reaction product gas containing trichlorosilane; a pentachlorodisilane generation step in which the reaction product gas obtained in the high-temperature reaction step is brought into contact with a cooling liquid obtained by circulative cooling of a condensate that is generated by cooling the reaction product gas, the reaction product gas is quickly cooled, and pentachlorodisilane is generated within the condensate; and a recovery step in which the generated pentachlorodisilane is recovered.

[Problem] To provide a novel production method for pentachlorodisilane and to obtain pentachlorodisilane having a purity of 90 mass % or more by carrying out this production method.

[Solution] A production method provided with: a high-temperature reaction step in which a raw material gas containing vaporized tetrachlorosilane and hydrogen is reacted at a high temperature in order to obtain a reaction product gas containing trichlorosilane; a pentachlorodisilane generation step in which the reaction product gas obtained in the high-temperature reaction step is brought into contact with a cooling liquid obtained by circulative cooling of a condensate that is generated by cooling the reaction product gas, the reaction product gas is quickly cooled, and pentachlorodisilane is generated within the condensate; and a recovery step in which the generated pentachlorodisilane is recovered.

A novel process provides for the preparation of the chlorinated, uncharged substance tetrakis(trichlorosilyl)germane, and for the use thereof.

A process for preparing a product including a monohydrogentrihalosilane is disclosed. The process includes the steps of: 1) initially charging a reactor with a contact mass including both fresh silicon and recycled contact mass, where the recycled contact mass is obtained from during or after a production phase of an inorganic Direct Process reaction for production of a monohydrogentrihalosilane; and thereafter 2) feeding to the reactor a hydrogen halide and additional fresh silicon, thereby forming the product.