Abstract: The invention relates to a process for treating elemental silicon and ferrosilicon with slag having the following analytical composition:______________________________________ K.sub.2 O from 2 to 13% by weight Na.sub.2 O from 0 to 2% by weight .SIGMA. K.sub.2 O + Na.sub.2 O from 2 to 13% by weight SiO.sub.2 from 45 to 72% by weight Al.sub.2 O.sub.3 from 0 to 30% by weight .SIGMA. SiO.sub.2 + Al.sub.2 O.sub.3 from 60 to 78% by weight CaO from 0 to 30% by weight MgO from 0 to 30% by weight .SIGMA. CaO + MgO from 15 to 30% by weight CaF.sub.2 from 0 to 10% by weight MgF.sub.2 from 0 to 10% by weight .SIGMA. CaF.sub.2 + MgF.sub.2 from 0 to 10% by weight .SIGMA. CaO + MgO + CaF.sub.2 + MgF.sub.2 from 15 to 30 % by weight ______________________________________and impurities resulting from the raw materials.

Abstract: This invention relates to a process for preparing tetrafluoroethyloxyalkyl silanes by the addition of silanes containing Si-bonded hydrogen to tetrafluoroethyl-alkenylether in a tubular reactor in which the reaction mixture containing an excess of silanes is recycled at a rate of at least 10 meters per minute.

Abstract: A continuous process for preparing silanes and siloxanes having SiOC groups which comprises (a) introducing in a liquid phase a chlorosilane and a hydroxyl-containing aliphatic compound in parallel flow into a first stage of a first reactor in an amount such that from 0.5 to 0.

Abstract: A process for the addition of Si-bonded hydrogen to an aliphatic multiple bond in the presence of a platinum catalyst which is obtained by dissolving a platinum halide in at least 20 parts by weight of olefin for each part by weight of the platinum halide, and subsequently heating and mixing the solution obtained with from 0.5 to 1 mole of a primary and/or secondary amine for each gram atom of platinum.

Abstract: This invention relates to the preparation of organosilicon compounds by the addition of a silicon compound containing Si-bonded hydrogen to a compound having an aliphatic multiple bond in the presence of a catalyst which promotes the addition of Si-bonded hydrogen to compounds containing an aliphatic multiple bond. In this process the reactants and the catalyst are continuously introduced into a pipe-shaped reactor while the contents of the reactor, which are maintained in a liquid phase by the application of pressure are circulated in the reactor at a rate of at least 1,000 cm per minute and while the reaction mixture is continuously being removed from the reactor.

Abstract: A method for utilizing a residue containing elemental silicon in the form of particles having a maximum diameter of 50 microns which comprises heating the residue for at least 15 hours at a temperature of from 100.degree. to 350.degree. C. in the presence of atmospheric air and/or an inert gas and thereafter recycling the treated residue into a process for preparing halosilanes.

Abstract: A process of melting down and purifying silicon, which comprises melting silicon in at least half of the amount up to double of the amount of a silicate melt heated by resistance heating up to a temperature of at least 1,420.degree. C., said melt consisting of 2-30% by weight of calcium oxide, 5-35% by weight of magnesium oxide, wherein the sum of calcium oxide and magnesium oxide will be 15-38% by weight, 0.5-28% by weight of aluminum oxide and 45-70% by weight of silicon dioxide, and wherein, to the melt are added at least 0.29% by weight of elementary and/or chemically bound copper, preferably 0.50-3% by weight, calculated on the silicon amount.

Abstract: Disiloxanes of the general formula (CH.sub.2 .dbd.CHR.sub.2 Si).sub.2 O, where R represents the same or different, monovalent hydrocarbon radicals, are obtained by reacting a compound of the formula (CH.sub.2 .dbd.CHRClSi).sub.2 O with a Grignard compound of the formula RMgX, where R is the same as above and X represents chlorine, bromine or iodine.

Abstract: A process for preparing oxime containing silicon compounds which comprises reacting an oxime with a silicon compound having at least three nitrogen atoms linked to the same silicon atom through Si--N bonding per molecule.

Abstract: An improved process for converting organopolysiloxane polymers which comprises reacting halosilanes which organopolysiloxanes in the presence of activated charcoal and if desired, an inorganic acid.

Abstract: An improved process for preparing methylchlorosilanes which comprises reacting tetramethylsilane and hydrogen chloride in the gaseous state with a solid Friedel-Crafts catalyst.

Abstract: An improved process for preparing organosiloxanes and alkyl halides by passing organohalosilanes and alkanols having 1 and/or 2 carbon atoms through at least one layer of packing material which is maintained at a temperature of from 60.degree. to 150.degree. C, the improvement which comprises (1) recycling from 1 to 6 liters of an aqueous phase separated from the organosiloxanes emerging from the layer or layers of packing material for each mol of organohalosilane introduced into the layer or layers of packing material and (2) reacting the organosiloxane separated from the aqueous phase with from 2 to 10 percent by weight based on the weight of the organosiloxane with the same organohalosilane which is passed through the layer or layers of packing material.

Abstract: An improved process for preparing bis-(trimethylsilyl-)urea which comprises reacting urea with hexamethyldisilazane in the presence of a catalytic amount of salts selected from the class consisting of ammonia, basic amine comounds and quaternary ammonium hydroxides.