Abstract: The invention relates to a water-soluble receptacle which is suitable for accommodating an additive or an additive composition and is filled with an additive or an additive composition comprising at least one dye or at least one dye composition, wherein the water-soluble receptacle has a wall thickness in the range from 5 to 50 µm, and wherein the water-soluble receptacle comprises a water-soluble polymer composition or consists of a water-soluble polymer composition, wherein the polymer composition comprises: a) at least one polyvinyl alcohol copolymer P1 having a degree of hydrolysis in the range from 75 to 95 mol%, wherein the polyvinyl alcohol copolymer P1 is a copolymer which comprises vinyl alcohol repeating units, vinyl ester repeating units and repeating units of at least one comonomer, wherein the at least one comonomer is selected from pentaerythritol acrylate and pentaerythritol acrylate derivatives and also optionally acrylic acid; and/or b) at least one polyvinyl alcohol P2 having a degree

Abstract: Method for producing silicon which is suitable as a starting material for producing a silicon melt for the fabrication of silicon blocks or silicon crystals, comprising the following steps: introducing a gaseous mixture of monosilane and hydrogen into a reactor, thermal degrading the gaseous mixture for forming silicon powder, separating the formed silicon powder produced from the gaseous mixture, and mechanical compacting the separated silicon powder with compacting rollers which having a roller jacket consisting of a ceramic material selected from graphite, glass and silicon nitride.

Abstract: In a reactor for the decomposition of a silicon-containing gas, provision is made, to avoid silicon deposition on an inner wall of a reactor vessel, for at least one catalytically active mesh to be provided within a reaction chamber between at least one gas feed line and the inner wall (4). The mesh accelerates the thermal decomposition of the gas and reduces the deposition of silicon on the inner wall. Also described is a process for the preparation of silicon using the reactor according to the invention and the use in photovoltaics of the silicon prepared.

Abstract: Compacting device for the low-metal compaction of a powder with a casing which at least in part surrounds a working chamber, with a feed arrangement arranged on the casing and feeding a powder, which is to be compacted, into the working chamber, with at least a compacting roller which is rotatably arranged in the working chamber, comprises a roller jacket and, together with an opposing wall, forms a compacting gap for compacting the powder therein, characterised in that the at least one compacting roller consists of ceramic, at least on the roller jacket.

Abstract: Method for producing silicon which is suitable as a starting material for producing a silicon melt for the fabrication of silicon blocks or silicon crystals, comprising the following steps: introduction of a gaseous mixture of monosilane and hydrogen into a reactor, thermal degradation of the gaseous mixture with formation of silicon powder, separation of the silicon powder obtained from the gaseous mixture, and mechanical compacting of the separated silicon powder.

Abstract: In a reactor for the decomposition of a silicon-containing gas, provision is made, to avoid silicon deposition on an inner wall of a reactor vessel, for at least one catalytically active mesh to be provided within a reaction chamber between at least one gas feed line and the inner wall (4). The mesh accelerates the thermal decomposition of the gas and reduces the deposition of silicon on the inner wall. Also described is a process for the preparation of silicon using the reactor according to the invention and the use in photovoltaics of the silicon prepared.

Abstract: A reactor for separating a gas containing silicon is provided with at least one electrically heatable deposition element of silicon to save costs, which element has a doping with at least one impurity to improve its electrical conductivity, the doping having a concentration in an initial state, such that the deposition element with the silicon deposited thereon in the final state is suitable for the manufacture of silicon melt for the production of polycrystalline silicon blocks or single silicon crystals for photovoltaics. A method for manufacturing silicon with the reactor according to the invention and the use of the manufactured silicon in photovoltaics are also described.

Abstract: Compacting device for the low-metal compaction of a powder with a casing which at least in part surrounds a working chamber, with a feed arrangement arranged on the casing and feeding a powder, which is to be compacted, into the working chamber, with at least a compacting roller which is rotatably arranged in the working chamber, comprises a roller jacket and, together with an opposing wall, forms a compacting gap for compacting the powder therein, characterised in that the at least one compacting roller consists of ceramic, at least on the roller jacket.

Abstract: The invention relates to a method for producing silane (SiH4) by a) reacting metallurgical silicon with silicon tetrachloride (SiCl4) and hydrogen (H2), to form a crude gas stream containing trichlorosilane (SiHCl3) and silicon tetrachloride (SiCl4), b) removing impurities from the resulting crude gas stream by washing with condensed chlorosilanes, c) condensing and subsequently, separating the purified crude gas stream by distillation, d) returning the partial stream consisting essentially of SiCl4 to the reaction of metallurgical silicon with SiCl4 and H2, e) disproportionating the partial stream containing SiHCl3, to form SiCl4 and SiH4 and f) returning the SiH4 formed by disproportionation to the reaction of metallurgical silicon with SiCl4 and H2, the crude gas stream containing trichlorosilane and silicon tetrachloride being liberated from solids as far as possible by gas filtration before being washed with the condensed chlorosilanes.

Abstract: The invention relates to a method for producing silane (SiH4) by a) reacting metallurgical silicon with silicon tetrachloride (SiCl4) and hydrogen (H2), to form a crude gas stream containing trichlorosilane (SiHCl3) and silicon tetrachloride (SiCl4), b) removing impurities from the resulting crude gas stream by washing with condensed chlorosilanes, c) condensing and subsequently, separating the purified crude gas stream by distillation, d) returning the partial stream consisting essentially of SiCl4 to the reaction of metallurgical silicon with SiCl4 and H2, e) disproportionating the partial stream containing SiHCl3, to form SiCl4 and SiH4 and f) returning the SiH4 formed by disproportionation to the reaction of metallurgical silicon with SiCl4 and H2, the crude gas stream containing trichlorosilane and silicon tetrachloride being liberated from solids as far as possible by gas filtration before being washed with the condensed chlorosilanes.

Abstract: The invention relates to a method for producing trichlorosilane by reacting silicon with silicon tetrachloride and hydrogen while adding hydrogen chloride, the residence time of the hydrogen chloride in the reaction chamber being less than the residence time of the silicon tetrachloride.