Abstract: The invention relates to a process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon and copper catalyst, wherein the concentration of oxygen in the chloromethane used is reduced by mixing a) chloromethane which contains oxygen, and b) chloromethane which contains a gaseous boron compound.

Abstract: Aluminum chloride is removed effectively from compound mixtures containing organochlorosilanes such as are produced in the direct synthesis, by adding a diluent containing organochlorosilanes and optionally chloromethane to a solids content <15% and a concentration of compounds having a boiling point >71° C. of less than 25%, and evaporating this diluted mixture into a volatile product stream and an AlCl3-containing solid.

Abstract: The invention relates to a process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon and copper catalyst, wherein the concentration of oxygen in the chloromethane used is reduced by mixing a) chloromethane which contains oxygen, and b) chloromethane which contains a gaseous boron compound.

Abstract: Aluminum chloride is removed effectively from compound mixtures containing organochlorosilanes such as are produced in the direct synthesis, by adding a diluent containing organochlorosilanes and optionally chloromethane to a solids content <15% and a concentration of compounds having a boiling point >71° C. of less than 25%, and evaporating this diluted mixture into a volatile product stream and an AlCl3— containing solid.

Abstract: A process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon, copper catalyst and from 10 to 90 ppm of strontium leads to increased selectivity and higher production rate.

Abstract: The invention relates to a process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon, copper catalyst and a total proportion of sodium and potassium of from 10 to 400 ppm.

Abstract: The invention relates to a process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon, copper catalyst and a total proportion of sodium and potassium of from 10 to 400 ppm.

Abstract: A process for the direct synthesis of methylchlorosilanes by reaction of chloromethane with a contact composition comprising silicon, copper catalyst and from 10 to 90 ppm of strontium leads to increased selectivity and higher production rate.

Abstract: A process for preparing silanes of the formula 1: RaSiHbCl4-a-b  (1) where R is methyl or ethyl, a is 0, 1, 2 or 3 and b is 0 or 1, from hydrogen chloride gas and reactants selected from among a) silicon metal, b) disilanes and oligosilanes whose radicals are selected from among H, R and Cl,  and mixtures thereof, wherein the hydrogen chloride gas is prepared from H2 and Cl2 in a concerted process.

Abstract: A process for preparing silanes of the formula 1:

Abstract: A continuous process for the direct synthesis of silanes of the formula

Abstract: A continuous process for the direct synthesis of silanes of the formula 1 RaSiCl4−a  (1) involves reacting finely divided silicon metal with R—Cl in a fluidized bed, where R is hydrogen, methyl or ethyl and a is 0, 1, 2, 3 or 4, where a product stream comprising gaseous silanes of the formula 1, further gaseous reaction products, unreacted RCl and silicon-containing dust is discharged from the fluidized bed, wherein at least part of the dust is introduced in the form of a suspension in a liquid selected from among liquid silanes of the formula 1, further liquid reaction products and mixtures thereof, into the fluidized bed.

Abstract: The invention relates to a process for treating filter dusts which are produced during the melting of inorganic compounds, especially those containing fluorides and/or oxides, in which process the filter dusts are fused. The disposal of the fused filter dusts is simple.

Abstract: A process for the direct synthesis of organochlorosilanes using CuCl prepared from the copper-containing residues from the direct synthesis of organochlorosilanes, where, in the preparation of the CuCl, in a first step, copper from an aqueous suspension of the copper-containing residues is oxidized to CuCl2 using mineral acid and oxidant, where mineral acid or oxidant or mineral acid and oxidant contain chlorine, giving an aqueous CuCl2 solution, and in a second step, the aqueous CuCl2 solution is reduced to CuCl using elemental iron.

Abstract: A process for the direct synthesis of organochlorosilanes using CuCl prepared from the copper-containing residues from the direct synthesis of organochlorosilanes, where, in the preparation of the CuCl, in a first step, copper from an aqueous suspension of the copper-containing residues is oxidized to CuCl2 using mineral acid and oxidant, where mineral acid or oxidant or mineral acid and oxidant contain chlorine, giving an aqueous CuCl2 solution, and in a second step, the aqueous CuCl2 solution is reduced to CuCl using elemental iron.

Abstract: In the process for the direct synthesis of methylchlorosilanes from chloromethane and silicon in the presence of a copper catalyst and promoter, the reaction mixture comprising chloromethane, methylchlorosilanes, and dust-like components comprising copper, promoter and silicon are removed continuously. The dust-like components are separated from the reaction mixture and cooled with liquid chloromethane.

Abstract: The invention relates to a continuous process for the direct synthesis of methylchlorosilanes by reacting chloromethane with a catalyst composition comprising silicon, zinc promoter and copper catalyst which is selected from a) copper oxide, b) mixtures of at least 80% by weight of copper oxide and copper(I) chloride, c) copper(I) chloride and d) mixtures of at least 80% by weight of copper(I) chloride and copper oxide, where copper catalysts a), b), c) or d) are employed alternately in such a way that copper catalyst a) or b) is followed by c) or d), or copper catalyst c) or d) is followed by copper catalyst a) or b).

Abstract: In a process for the direct synthesis of methylchlorosilanes, chloromethane is reacted with a catalyst composition comprising silicon, copper catalyst, zinc promoter and pyrogenic silicic acid.

Abstract: Methylchlorosilanes are prepared by reacting methyl chloride with a contact catalyst which comprises silicon, copper catalyst, zinc promoters and tin promoters and/or antimony promoters, in which hydrogen chloride is added in the course of from 1% to 45% of the duration of the production campaign.

Abstract: In the direct synthesis of methylchlorosilanes by reacting methyl chloride with a catalyst composition which comprises silicon, copper catalyst, zinc promoters and tin promoters and/or antimony promoters, a catalyst composition is used which was activated in advance by treatment with HCl under specific activation conditions.