Abstract: The invention relates to a process for producing hydrogen-containing chlorosilanes by reducing Si-based deposits of solid material during the operation of a pressurised reactor comprising one or more reaction spaces, wherein at least one organochlorosilane is reacted with hydrogen in at least one of these reaction spaces for at least some of the time, characterized in that at least one of the optionally two or more reaction spaces in which this reaction takes place is supplied with additional HCl for at least some of the time. The additional HCl is preferably produced by hydrodehalogenation of silicon tetrachloride with hydrogen in at least one of the optionally two or more reaction spaces of the reactor.

Abstract: The invention relates to a process for producing a product gas mixture containing hydrogen-containing chlorosilanes within an integrated process by hydrogenating integrated process by-product silicon tetrachloride and organochlorosilane, more particularly methyltrichlorosilane, with hydrogen in a pressurized hydrogenation reactor comprising one or more reaction spaces each consisting of a reactor tube of gastight ceramic material, wherein the product gas mixture is worked up and at least a portion of at least one product of the product gas mixture is used as starting material for the hydrogenation or as starting material for some other process within the integrated process. The invention further relates to an integrated system useful for practising the integrated process.

Abstract: The invention relates to a process for preparing trichlorosilane, characterized in that hydrogen and at least one organic chlorosilane are reacted in a reactor which is operated under superatmospheric pressure and comprises one or more reactor tubes which consist of a gastight ceramic material.

Abstract: The invention relates to the use of a ceramic tube composed of silicon carbide variants in processes for converting chlorosilanes, wherein the tube has a flange or a flare at one end and is closed at the other end.

Abstract: The invention provides for the use of a particular burner design to heat reactors for conversion of chlorosilanes, wherein the burner has a jet tube and the jet tube surrounds the flame and the flame tube in a gastight manner, as a result of which the combustion air, the gaseous and/or liquid fuels, and also the flue gases cannot get into the reaction furnace space. The advantage is the complete separation of the flue gas from the actual interior of the reaction furnace, which prevents critical interactions between flue gas moisture and chlorosilanes in the case of fracture of the arrangement accommodating the chlorosilanes. This in turn makes it possible to use gaseous or liquid fuels to heat such a reaction furnace. Excessive local input of heat as a result of direct flame contact is prevented; the heat input is homogenized.

Abstract: The invention provides a process and apparatus for preparing chlorosilane from the reaction of very finely divided ultra-pure silicon with hydrogen chloride, the very finely divided ultra-pure silicon being fed into a solid bed of metallurgical silicon, the feed line for ultra-pure silicon and the fixed bed having a certain minimum temperature.

Abstract: The invention relates to a method for converting silicon tetrachloride by means of hydrogen to form trichlorosilane in a modified hydrodechlorination reactor. The invention further relates to a the use of such a modified hydrodechlorination reactor as an integrated component of a system for producing trichlorosilane from metallurgical silicon.

Abstract: The invention relates to an improved method for converting silicon tetrachloride having hydrogen in a hydrodechlorination reactor comprising a catalyst. The invention further relates to a catalytic system for such a hydrodechlorination reactor.

Abstract: The invention relates to the use of a ceramic heat exchanger as an integral part of a process for catalytic dehalogenation of silicon tetrachloride to trichlorosilane in the presence of hydrogen, wherein the product gas and the reactant gases are conducted as pressurized streams through the heat exchanger, and the heat exchanger comprises heat exchanger elements made from ceramic material.

Abstract: The present invention relates to a multistage process for preparing trichlorosilane and silicon tetrachloride from metallurgical silicon, in which trichlorosilane and silicon tetrachloride are prepared from metallurgical silicon in a first step, and the silicon tetrachloride is processed further to the trichlorosilane end product in a second step. The present invention further relates to a plant in which such processes can be performed in an integrated manner.

Abstract: The invention relates to a method for converting silicon tetrachloride having hydrogen to trichlorosilane in a hydrodechlorination reactor, wherein the hydrodechlorination reactor is operated under pressure and comprises one or more reactor tubes which are made of a ceramic material. The invention further relates to the use of such a hydrodechlorination reactor as an integral component of a system for producing trichlorosilane from metallurgical silicon.

Abstract: The invention relates to a method for yielding boron-depleted chlorosilanes from a chlorosilane mixture containing boron by means of separation by distillation of a boron-enriched distillation flow. The invention further relate to a device for yielding boron-depleted chlorosilanes from a chlorosilane mixture containing boron.

Abstract: The invention relates to a method for reducing the content of boron-containing compounds in compositions I comprising at least one silicon halide, especially of chlorosilanes of the type HnSiCI4-n with n being equal to 0, 1, 2 or 3, by introducing a small amount of moisture into the composition I in a first step and separating the hydrolyzed boron- and/or silicon-containing compounds in a second step in such a way that a pre-purified composition II having a reduced boron content is obtained, wherein, in particular, the first and second steps can be run in at least one or more cycles. Also claimed is an apparatus for performing the method and an overall system into which this apparatus is integrated.

Abstract: The invention relates to a method for yielding boron-depleted chlorosilanes from a chlorosilane mixture containing boron by means of separation by distillation of a boron-enriched distillation flow. The invention further relate to a device for yielding boron-depleted chlorosilanes from a chlorosilane mixture containing boron.

Abstract: A process for producing anti-allergic surfaces, and articles which comprise these anti-allergic surfaces. The process of the invention produces anti-allergic surfaces. The basis of the anti-allergic action is that self-cleaning properties make it impossible or very difficult for allergenic substances to deposit on these surfaces, and make it possible for them to be cleaned from the surface by a simple cleaning procedure using water set in motion. The surfaces may be either textile surfaces or polymer surfaces. Structures composed of elevations and depressions, as have been described on many previous occasions, are applied to these surfaces. The coatings of the invention can be applied very simply by applying a dispersion of suitable particles in a solvent to the relevant surface and then removing the solvent. Textiles, mattresses, or covers, for example, can be provided with the anti-allergic surfaces of the invention.

Abstract: A process for producing anti-allergic surfaces, and articles which comprise these anti-allergic surfaces. The process of the invention produces anti-allergic surfaces. The basis of the anti-allergic action is that self-cleaning properties make it impossible or very difficult for allergenic substances to deposit on these surfaces, and make it possible for them to be cleaned from the surface by a simple cleaning procedure using water set in motion. The surfaces may be either textile surfaces or polymer surfaces. Structures composed of elevations and depressions, as have been described on many previous occasions, are applied to these surfaces. The coatings of the invention can be applied very simply by applying a dispersion of suitable particles in a solvent to the relevant surface and then removing the solvent. Textiles, mattresses, or covers, for example, can be provided with the anti-allergic surfaces of the invention.

Abstract: A process for producing anti-allergic surfaces, and articles which comprise these anti-allergic surfaces. The process of the invention produces anti-allergic surfaces. The basis of the anti-allergic action is that self-cleaning properties make it impossible or very difficult for allergenic substances to deposit on these surfaces, and make it possible for them to be cleaned from the surface by a simple cleaning procedure using water set in motion. The surfaces may be either textile surfaces or polymer surfaces. Structures composed of elevations and depressions, as have been described on many previous occasions, are applied to these surfaces. The coatings of the invention can be applied very simply by applying a dispersion of suitable particles in a solvent to the relevant surface and then removing the solvent. Textiles, mattresses, or covers, for example, can be provided with the anti-allergic surfaces of the invention.

Abstract: Pyrogenic oxides having a BET surface area of between 30 and 150 m.sup.2 /g have a viscosity of less than 2,500 mPas in an aqueous suspension. They are prepared by setting the hydrogen ratio gamma and the oxygen ratio lambda to less than one in a high-temperature flame hydrolysis. The pyrogenic oxides are employed in the CMP application in the electronics industry.

Abstract: X-ray amorphous, aluminum oxide which exhibits a specific surface area (BET) according to DIN 66 131 of >10 m.sup.2 /g, an average particle size of .gtoreq.0.1 .mu.m and a water content of >10%. The X-ray amorphous aluminum oxide can be produced by reacting water vapor and vaporous aluminum trichloride in a molar ratio of 1.5 to 10:1, preferably 7.+-.1:1=H.sub.2 O:alCl.sub.3 at a temperature of 200.degree. to 1000.degree. C., preferably 600.degree..+-.50.degree. C. and at a dwell time of >1 sec., preferably 3.5.+-.1 sec. and a partial vacuum of 100.+-.10 mm H.sub.2 O column. By means of calcination thereof an aluminum oxide can be obtained which consists of .gtoreq.90% by weight of .alpha.-aluminum oxide and exhibits a specific surface area (BET) according to DIN 66 131 of >5 m.sup.2 /g and an average particle size of .gtoreq.0.1 .mu.m.

Abstract: A spherical, hydrophilic silica consisting of compact, massive, non-crystalline particles without inner pores with a particle size of 0.5 to 10 .mu.m, preferably 0.5 to 4 .mu.m and especially 1 to 3 .mu.m with a BET surface of <50 m.sup.2 /g, preferably of 1 to 10 m.sup.2 /g is prepared by heating water vapor and gaseous silicon tetrachloride separately to a temperature of 300.degree. to 400.degree. C., mixing them with each other in a molar ratio of 2:1 to 6.7:1 and reacting the mixture at a temperature of 600.degree. to 1200.degree. C.