Abstract: The invention relates to a method of producing silane or hydrochlorosilanes by disproportionation of a higher chlorinated hydrochlorosilane or a mixture of said hydrochlorosilanes in the presence of a catalyst. Before the catalyst is used, it is a) washed with hyper-pure water in one or several steps; b) transferred in the water-moist state to the reactor in which the disproportionation is to proceed; c) treated in the reactor with boiling methanol or rinsed with anhydrous methanol; and d) the methanol is removed from the catalyst by evacuation and/or stripping with inert gas. The invention further relates to a method for treating disproportionation catalysts.

Abstract: Process wherein the vanadium present in the chromium ore chromite is recovered as vanadium pentoxide during the course of the fusion of the chromium ore with alkali and its work-up to produce sodium chromate solution and sodium dichromate.

Abstract: The invention relates to a method and a device for producing globular grains of high-purity silicon by atomising a silicon melt (6) in an ultrasonic field (10). Globular grains having a grain size of 50 ?m can be produced by means of said method and device and can be used to separate high-purity silicon from silane in the fluid bed. The silicon melt (6) is fed into the ultrasonic field (10) at a distance of <50 mm in relation to a field node, and the atomised silicon leaves the ultrasonic field (10) at a temperature close to the liquidus point. The invention also relates to a use of the product produced according to the inventive method or using the inventive device, as particles for producing high-purity silicon from silane in a fluid bed.

Abstract: Silane is produced in a continuous process by disproportionating trichlorsilane in at least 2 recreation areas for reaction/distillation, which are run through by a countercurrent of steam and liquid in the presence of catalytically active solid under a pressure which ranges between 500 mbar and 50 bar.

Abstract: This invention relates to a continuous process for the preparation of silane by catalytic disproportionation of trichlorosilane in a reactive/distillative reaction zone having a catalyst bed of catalytically active solid.

Abstract: The invention relates to a method for the production of high purity silicon, characterized by the following steps: a) reaction of metallic silicon with silicon tetrachloride (SiCl4), hydrogen (H2) and hydrochloric acid (HCl) at a temperature of 500 to 800° C. and a pressure of 25 to 40 bar to give a trichlorosilane-containing (SiHCl3) feed gas stream, b) removal of impurities from the resultant trichlorosilane-containing feed gas stream by scrubbing with condensed chlorosilanes at a pressure of 25 to 40 bar and a temperature of 160 to 200° C.

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 removing anhydrous acids and hydrohalogens from trichlorosilane by contacting the trichlorosilane with solid bases. The invention further relates to the use of the trichlorosilane so purified in the production of silane and/or super-pure silicon.

Abstract: The invention relates to a method for producing trichlorosilane, whereby silicon is reacted with hydrogen, silicon tetrachloride and optionally hydrogen chloride, said silicon containing iron in the form of homogeneously distributed iron silicide.

Abstract: Silane is produced in a continuous process by disproportionating trichlorsilane in at least 2 recreation areas for reaction/distillation, which are run through by a countercurrent of steam and liquid in the presence of catalytically active solid under a pressure which ranges between 500 mbar and 50 bar.

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: Process for recovering the vanadium present in the chromium ore chromite, as vanadium pentoxide, as a by-product from the vanadium-containing sodium chromate solution produced in the process of preparing sodium chromate and sodium dichromate from said ore, by precipitation of calcium vanadate from the sodium chromate solution, treatment of the precipitate with water and sodium carbonate, sodium bicarbonate, carbon dioxide or sodium carbonate and carbon dioxide, to precipitate calcium carbonate and electrolysis of the solution remaining after separation of the calcium carbonate precipitate, to produce vanadium pentoxide.

Abstract: The invention relates to a method for the production of high purity silicon, characterized by the following steps: a) reaction of metallic silicon with silicon tetrachloride (SiCl4), hydrogen (H2) and hydrochloric acid (HCl) at a temperature of 500 to 800° C. and a pressure of 25 to 40 bar to give a trichlorosilane-containing (SiHCl3) feed gas stream, b) removal of impurities from the resultant trichlorosilane-containing feed gas stream by scrubbing with condensed chlorosilanes at a pressure of 25 to 40 bar and a temperature of 160 to 200° C.

Abstract: The invention relates to a method and a device for separating aluminium from chlorosilanes, in particular for separating aluminium trichloride from silicon tetrachloride or trichlorosilane or from mixtures of silicon tetrachloride or trichlorosilane. According to the invention, aluminium chloride is removed from the chlorosilanes silicon tetrachloride and trichlorosilane in a continuous process, without the addition of admixtures, to obtain a residual content of aluminium that is as low as required, by separating the aluminium trichloride and the chlorosilane by distillation, at a temperature approximately greater than 160° C.

Abstract: Process wherein the vanadium present in the chromium ore chromite is recovered as vanadium pentoxide during the course of the fusion of the chromium ore with alkali and its work-up to produce sodium chromate solution and sodium dichromate.

Abstract: The invention relates to a method of producing silane or hydrochlorosilanes by disproportionation of a higher chlorinated hydrochlorosilane or a mixture of said hydrochlorosilanes in the presence of a catalyst. Before the catalyst is used, it is a) washed with hyper-pure water in one or several steps; b) transferred in the water-moist state to the reactor in which the disproportionation is to proceed; c) treated in the reactor with boiling methanol or rinsed with anhydrous methanol; and d) the methanol is removed from the catalyst by evacuation and/or stripping with inert gas. The invention further relates to a method for treating disproportionation catalysts.

Abstract: The invention relates to a method for removing anhydrous acids and hydrohalogens from trichlorosilane by contacting the trichlorosilane with solid bases. The invention further relates to the use of the trichlorosilane so purified in the production of silane and/or super-pure silicon.

Abstract: The invention relates to a method and a device for producing globular grains of high-purity silicon by atomising a silicon melt (6) in an ultrasonic field (10). Globular grains having a grain size of 50 &mgr;m can be produced by means of said method and device and can be used to separate high-purity silicon from silane in the fluid bed. The silicon melt (6) is fed into the ultrasonic field (10) at a distance of <50 mm in relation to a field node, and the atomised silicon leaves the ultrasonic field (10) at a temperature close to the liquidus point. The invention also relates to a use of the product produced according to the inventive method or using the inventive device, as particles for producing high-purity silicon from silane in a fluid bed.

Abstract: A process for recovering the vanadium present in the chromium ore chromite. as ammonium metavanadate, as a by-product of the fusion of the chromium ore with alkali and its work-up to produce sodium chromate solution and sodium dichromate.

Abstract: Process for preparing trichlorosilane by reacting silicon with silicon tetrachloride, hydrogen and optionally hydrogen chloride using catalysts, where silicon is intensively mixed with the catalyst before the reaction.