Abstract: A method for controlling the direct process to vary the concentrations of trialkylhalosilanes and alkyltrihalosilanes in the product. The method comprises contacting an alkyl chloride with silicon metalloid in the presence of a catalytic amount of a catalyst comprising 0.5 to 10 weight percent copper, 5 to 200 ppm tin, 25 to 2,500 ppm phosphorous, and greater than zero to less than 50 ppm zinc, where the concentration of each of the catalyst components is based on the weight of the silicon, at a temperature within a range of about 250.degree. C. to 400.degree. C. The present inventors have found that by controlling the zinc concentration the concentrations of trialkylhalosilanes and alkyltrihalosilanes in the product can be varied.

Abstract: A process for separating dimethyldichlorosilane from methyltrichlorosilane in a mixture. The process comprises contacting a mixture comprising methyltrichlorosilane and dimethyldichlorosilane with silica gel, where the dimethyldichlorosilane is selectively retained by the silica gel. The process provides for the recovery of a methyltrichlorosilane fraction reduced in dimethyldichlorosilane concentration. The present process is especially useful for removing low levels of dimethyldichlorosilane present as a contaminate in methyltrichlorosilane.

Abstract: A process for separating methyltrichlorosilane from dimethyldichlorosilane in a mixture. The process comprises contacting a mixture comprising methyltrichlorosilane and dimethyldichlorosilane with activated carbon, where the methyltrichlorosilane is selectively adsorbed by the activated carbon. The process allows for the recovery of a dimethyldichlorosilane fraction reduced in methyltrichlorosilane concentration. The methyltrichlorosilane can be recovered by desorption from the activated carbon. The present process is especially useful for removing low levels of methyltrichlorosilane present as a contaminate in dimethyldichlorosilane.

Abstract: A process for purifying halosilanes consisting of contacting a mixture comprising a halosilane and a hydrocarbon with an adsorbent selective for the hydrocarbon, thereby reducing the hydrocarbon content of the mixture. The present process is particularly useful for removing hydrocarbon contaminates from chlorosilanes, where the hydrocarbon contaminates have a boiling point similar to that of the chlorosilanes.

Abstract: The present invention is a method for analyzing silicon for nonmetallic contaminants. The method comprises: (A) forming an alloy comprising silicon and a metal which promotes separation of nonmetallic contaminants present in the alloy, (B) separating the nonmetallic contaminants from the alloy, and (C) analyzing the separated nonmetallic contaminants for chemical content. The present invention is particularly useful for analyzing metallurgical grade silicon intended for use in the direct process for the production of organohalosilanes for the presence of oxides and carbides of calcium, aluminum, and silicon.

Abstract: The present invention is an improved process for preparing a portland cement composition where the process comprises heat calcining a mixture comprising a source of calcium and a source of silicon to form clinker. The improvement comprises providing to the process a silicon containing product resulting from the hydrolysis of chlorosilicon by-product as at least a portion of the source of silicon.

Abstract: A process for the hydrogenation of chlorosilanes. The process comprises contacting a chlorosilane with aluminum and a hydrogen source selected from a group consisting of hydrogen gas and gaseous hydrogen chloride in the presence of a catalyst. The catalyst is selected from a group consisting of copper and copper compounds, tin and tin compounds, zinc and zinc compounds, and mixtures thereof.

Abstract: The present invention is a process for converting a high-boiling component resulting from the reaction of an organochloride with silicon into commercially more desirable monosilanes. The process comprises contacting the high-boiling component with hydrogen gas at a temperature within a range having a lower limit greater than 250.degree. C. and an upper limit of 1000.degree. C. Yield of the present process may be improved by use of a catalyst selected from a group consisting of activated carbon, platinum metal, platinum supported on alumina, palladium supported on carbon, SbCl.sub.5, H.sub.2 PtCl.sub.6, BCl.sub.3, AlCl.sub.3, and AlCl.sub.3 supported on a support material selected from a group consisting of carbon, alumina, and silica. In a preferred embodiment of the present process the process is run at a pressure within a range of about 250-1000 psig. The present process is preferential for the production of diorganodichlorosilane in relation to organotrichlorosilane in the monosilane product.

Abstract: The present invention is a process for converting a high-boiling component resulting from the reaction of an organochloride with silicon into commercially more desirable monosilanes. The process comprises contacting the high-boiling component with chlorine at a temperature within a range of about 250.degree. C. to 1000.degree. C. Improved yield of monosilanes can be obtained in the process by the use of a catalyst selected from a group consisting of alumina, silica. activated carbon, AlCl.sub.3, and AlCl.sub.3 supported on a support selected from a group consisting of alumina, silica, and carbon.

Abstract: The present invention is an improved process for the reaction of an alkyl halide with particulate silicon in a fluidized-bed process. The improvement comprises controlling the particle size of the silicon within a range of one micron to 85 microns. Preferred is when the particle size of the silicon has a mass distribution characterized by a 10th percentile of 2.1 to 6 microns, a 50th percentile of 10 to 25 microns, and a 90th percentile of 30 to 60 microns. Most preferred is when the particle size mass distribution of the silicon is characterized by a 10th percentile of 2.5 to 4.5 microns, a 50th percentile of 12 to 25 microns, and a 90th percentile of 35 to 45 microns. The process is run in the presence of a catalyst composition comprising copper and other catalysts.

Abstract: The present invention is a process for converting a high-boiling component resulting from the reaction of an organochloride with silicon into commercially more desirable monosilanes. The process comprises contacting the high-boiling component with hydrogen chloride at a temperature within a range of about 250.degree. C. to 1000.degree. C. in the presence of a catalyst selected from a group consisting of activated carbon, platinum supported on alumina, zeolite, AlCl.sub.3, and AlCl.sub.3 supported on a support selected from a group consisting of carbon, alumina, and silica.

Abstract: The present invention is a process for converting a high-boiling component resulting from the reaction of an organochloride with silicon into commercially more desirable monosilanes. The process comprises contacting the high-boiling component with hydrogen chloride and hydrogen gas at a temperature within a range of about 250.degree. C. to 1000.degree. C. in the presence of a catalyst selected from a group consisting of activated carbon, alumina, silica, zeolite, AlCl.sub.3, AlCl.sub.3 supported on a support selected from a group consisting of carbon, silica, and alumina; platinum supported on a support selected from a group consisting of carbon, silica, and alumina; and palladium supported on a support selected from a group consisting of carbon, silica, and alumina.

Abstract: The present invention is an improvement of the Direct Process for the manufacture of alkylhalosilanes by the contact of powdered metallurgical grade silicon with an alkyl halide in the presence of a copper catalyst. The improvement reduces lot-to-lot variations in silicon conversion to desired dialkyldihalosilanes. The improvement comprises alloying 0.01 to nine weight percent copper with the silicon to be used in the process and separating slag. In a preferred embodiment of the present process, silicon-copper alloy is pulverized to a powder and mixed with additional copper and other catalysts to form a contact mass reactive with alkylhalides.

Abstract: The present invention is a process for the production of silanes from the contact of silicon metal or a silicon containing material with hydrogen chloride. The described process employs a metal or metal compound on a solid support as a catalyst which increases the production of tetrachlorosilane. The metal or metal compound is selected from a group consisting of palladium and palladium compounds, rhodium and rhodium compounds, platinum and platinum compounds, iridium and iridium compounds, tin and tin compounds, nickel and nickel compounds, and aluminum and aluminum compounds. The process is run at a temperature of about 250.degree. C. to 500.degree. C.

Abstract: The present invention is a process for the production of silanes from the contact of hydrogen chloride with silicon. The silicon may be in the form of silicon metal or a silicon containing material. The described process employs a catalyst which increases the yield of tetrachlorosilane. The catalyst is selected from a group consisting of tin and tin compounds, nickel and nickel compounds, arsenic and arsenic compounds, palladium and palladium compounds, and mixtures thereof. The process is run at a temperature of about 250.degree. C. to 500.degree. C.

Abstract: The instant invention is a catalyzed process for the redistribution of linear, chloride or hydroxy end-terminated polyorganosiloxanes or cyclic polyorganosiloxanes. Effective catalysts for the described process are alumina, silica-alumina, activated carbon, zeolite, and acid clay. The catalyzed redistribution process can be incorporated as an element of a three-stage process. The three-stage process allows control of the yield of cyclic polyorganosiloxanes.

Abstract: This invention discloses a method of treating silicon with non-volatile, phosphorous compounds to allow the silicon to be used in the direct process for the manufacture of alkylhalosilanes. The treatment of the silicon is carried out by feeding phosphorous compounds to the silicon during or after refining.

Abstract: The instant invention is a process for the addition of alkyl groups to non-halogen containing silanes. Non-halogen containing silanes are reacted with an alkyl halide in presence of a halogen-accepting metal. The process is run with or without a catalyst, which is effective in improving exchange of alkyl groups from the alkyl halide with hydrogen atoms of the silane.

Abstract: The present invention provides a method for increasing the yield of methyldichlorosilane obtained from the reaction of silicon metal with methyl chloride without substantially decreasing the combined yield of methyldichlorosilane and dimethyldichlorosilane. This is achieved by blending the methyl chloride with an amount of hydrogen chloride sufficient to accomplish this without forming significant amounts of undesirable SiCl.sub.4 and/or HSiCl.sub.3. In accordance with a preferred embodiment of the present method the concentration of hydrogen chloride is from 0.1 to about 3 weight percent, based on methyl chloride. Most preferably the hydrogen chloride is present only from the first 50% to about 90% of the methyl chloride addition.

Abstract: The present invention provides a method for reducing the concentration of methyltrichlorosilane obtained during the reaction of silicon metal with methyl chloride without substantially decreasing the combined yield of methyldichlorosilane, dimethylchlorosilane and dimethyldichlorosilane. The methyl chloride is blended with from 0.05 up to about 44 mole percent of hydrogen, based on combination of methyl chloride and hydrogen. At hydrogen concentrations above about 12 mole percent there is a substantial increase in the methyldichlorosilane content of the reaction product while the concentration of methyltrichlorosilane in the reaction product is maintained below about 4 percent by weight.