Abstract: The present invention relates to a method of purifying strong acids or strongly acidic media to remove di- and higher valent metal ions, which can be used within the context of the production of high-purity silica. The invention further relates to the use of special ion exchangers for carrying out the method according to the invention and the resultant high-purity silicas.

Abstract: The present invention relates to a process for preparing aqueous colloidal silica sols of high purity from silicate solutions, to aqueous colloidal silica sols with a specific profile of impurities, and to the use thereof. The invention further encompasses high-purity aqueous silica obtained as an intermediate in the course of the purification process, high-purity silicon dioxide obtainable by dewatering, and the use thereof.

Abstract: A controlled preparation of octachlorotrisilane and higher polychlorosilane such as DCTS and DCPS from monomeric chlorosilane, proceeds by exposing the chlorosilane to a nonthermal plasma and recycling chlorosilane that has not been converted to octachlorotrisilane into the plasma.

Abstract: The invention relates to a process and an apparatus for preparation of polychlorosilanes from monomeric chlorosilanes, by subjecting the chlorosilanes to a thermal plasma.

Abstract: The invention relates to a process for preparing polysilanes by converting monosilane in the presence of hydrogen in a plasma, and to a plant for performing the process.

Abstract: The invention relates to a process for dismutating at least one halosilane and reducing the content of extraneous metal and/or a compound containing extraneous metal in the at least one halosilane and in the at least one silane obtained, by contacting at least one halosilane of the general formula I, HnSiClm (I), where n and m are integers and n=1, 2 or 3 and m=1, 2 or 3 and n+m=4, with a particulate, organic, amino-functional resin to obtain at least one silane of the general formula II, HaSiClb (II), where a and b are integers and a=0, 2, 3 or 4 and b=0, 1, 2 or 4 where a+b=4, in one step, in which the content of extraneous metal and/or compounds containing extraneous metal has been reduced compared to the halosilane of the formula I. The invention further provides for the use of this resin for dismutating halosilanes and as an absorbent of extraneous metals or compounds containing extraneous metal in a process for preparing monosilane.

Abstract: The invention relates to a process for preparing dimeric and/or trimeric silanes by conversion of monosilane in a plasma and to a plant for performance of the process.

Abstract: The invention relates to a process and an apparatus for controlled preparation of octachlorotrisilane from monomeric chlorosilanes, by subjecting the chlorosilanes to a thermal plasma.

Abstract: Hollow bodies having a silicon-comprising shell, are produced by, in a gas comprising at least one silane of the general formula SinH2n+2?mXm with n=1 to 4, m=0 to 2n+2 and X=halogen, (a) generating a non-thermal plasma by an AC voltage of frequency f, or operating a light arc, or introducing electromagnetic energy in the infrared region into the gas, giving a resulting phase which (b) is dispersed in a wetting agent and distilled, and then (c) the distillate is contacted at least once with a mixture of at least two of the substances hydrofluoric acid, nitric acid, water, giving a solid residue comprising hollow bodies having a silicon-comprising shell after the conversion reaction of the distillate with the mixture has abated or ended.

Abstract: The invention relates to a process for converting polychlorosilanes into hexachlorodisilane, by one or more trimeric polychlorosilanes or a trimeric polychlorosilane in a mixture with higher molecular weight polychlorosilanes being exposed to a gas discharge and hexachlorodisilane being formed and isolated.

Abstract: The invention relates to a process for preparing dimeric and/or trimeric silanes by conversion of monosilane in a plasma and to a plant for performance of the process.

Abstract: The invention relates to a process for preparing dimeric and/or trimeric silanes by conversion of monosilane in a plasma and to a plant for performance of the process.

Abstract: The present invention relates to a specific process for producing trisilylamine from monochlorosilane and ammonia in the liquid phase. The invention further relates to a plant in which such a process can be carried out with advantage.

Abstract: The invention relates to a process for producing trimeric and/or quaternary silicon compounds or trimeric and/or quaternary germanium compounds, where a mixture of silicon compounds or a mixture of germanium compounds is exposed to a nonthermal plasma, and the resulting phase is subjected at least once to a vacuum rectification and filtration.

Abstract: The present invention relates to a specific process for producing trisilylamine from monochlorosilane and ammonia in the liquid phase. The invention further relates to a plant wherein such a process can be carried out with advantage.

Abstract: The invention relates to a method for indirectly determining the purity of silanes and germanes using a device for measuring specific resistance. The invention further relates to a system for industrially producing and/or filling containers with silanes or germanes, including a quality control in which a device is used for measuring specific resistance.

Abstract: The invention provides a method for the processing of finely divided solids during the production of chlorosilanes, which is characterized in that the finely divided solids are hydraulically pressed to give bodies of increased density. Moreover, also provided is the compact obtained by the process according to the invention which is characterized by a filling factor of the finely divided solids to be hydraulically pressed of 3.9 to 4.5.

Abstract: It has been found that conventional cheap waterglass qualities in a strongly acidic medium react to give high-purity silica grades, the treatment of which with a base leads to products which can be processed further to give glass bodies with low silanol group contents.

Abstract: An apparatus for preparing dimeric and trimeric silicon compounds is provided. The apparatus includes a reactor for generating a nonthermal plasma; a collecting vessel in product flow communication with the nonthermal plasma reactor; and a series of at least three rectification columns in flow communication with the collecting vessel.

Abstract: The invention relates to a process for preparing dimeric and/or trimeric silanes by reaction of monosilane in noble gas in a non-thermal plasma, and also to a plant for performance of this process.