Abstract: The invention relates to a method for improving the performance of nickel electrodes in alkali chloride electrolysis by adding water-soluble platinum compounds to the catolyte.

Abstract: Processes comprising: (a) reacting phosgene and a monohydroxyl aryl compound in the presence of a suitable catalyst to form a diaryl carbonate and a solution comprising an alkali chloride; (b) separating the diaryl carbonate from the solution; (c) adjusting the pH of the solution to a value of less than or equal to 8 to form a pH-adjusted solution; (d) treating the pH-adjusted solution with an adsorbent to form a treated solution; (e) subjecting at least a portion of the treated solution to electrochemical oxidation to form chlorine and an alkali hydroxide solution; and (f) recycling at least a portion of one or both of the chlorine and the alkali hydroxide solution.

Abstract: Processes for the production of chlorine by multi-stage oxidation, for example, by thermal reaction of hydrogen chloride with oxygen using catalysts or by non-thermal activated reaction of hydrogen chloride with oxygen, in which the gas mixture formed in the reaction, comprising the target products chlorine and water, unreacted hydrogen chloride and oxygen, and possibly other secondary constituents, such as carbon dioxide and nitrogen, (a) is cooled to condense hydrochloric acid as an aqueous solution of hydrogen chloride and (b) the aqueous solution of hydrogen chloride formed is separated from the gas mixture, characterised in that (c) the separated aqueous solution of hydrogen chloride is fed at least partially to an electrochemical oxidation in which at least part of the hydrogen chloride is oxidised to chlorine, (d) the chlorine gas occurring in step d) is optionally added to the gas mixture occurring in step c), (e) the residues of water present in the gas mixture from steps c) and e), in particular by

Abstract: A process is disclosed comprising: (a) reacting hydrogen chloride and oxygen to form a gas mixture comprising chlorine, water, unreacted hydrogen chloride, and unreacted oxygen; (b) cooling the gas mixture to form an aqueous solution of hydrogen chloride; (c) separating at least a portion of the aqueous solution of hydrogen chloride from the gas mixture; (d) removing at least a portion of the water from the gas mixture; and (e) subjecting the gas mixture to a gas permeation such that at least a portion of the unreacted oxygen in the gas mixture is separated to form a chlorine-rich gas stream and an oxygen-containing partial stream.

Abstract: A process is disclosed comprising: (a) reacting hydrogen chloride and an oxygen-containing gas to form a gas mixture comprising chlorine, water, unreacted hydrogen chloride, and unreacted oxygen, wherein the oxygen-containing gas reacted with the hydrogen chloride has an oxygen content of not more than 99 vol. %; (b) cooling the gas mixture to form an aqueous solution of hydrogen chloride; (c) separating at least a portion of the aqueous solution of hydrogen chloride from the gas mixture; and (d) subjecting the gas mixture to a gas permeation to form a chlorine-rich gas stream and an oxygen-containing partial stream.

Abstract: Processes comprising: (a) providing an initial gas mixture comprising chlorine, water, hydrogen chloride and oxygen; (b) cooling the initial gas mixture to form condensed hydrochloric acid and an intermediate chlorine-containing gas mixture; (c) contacting the intermediate gas mixture with a water-containing phase under a set of conditions selected from a pressure, a temperature and combinations thereof to form a chlorine hydrate-containing phase and a remaining gas mixture; (d) separating the chlorine hydrate-containing phase from the remaining gas mixture; (e) subjecting the chlorine hydrate-containing phase to a set of conditions selected from heat, pressure relief and combinations thereof to release chlorine and form a residual chlorine hydrate/water-containing phase; and (f) separating the released chlorine from the residual chlorine hydrate/water-containing phase.

Abstract: Processes are described which comprise: (a) reacting chlorine with carbon monoxide to form phosgene; (b) reacting the phosgene with at least one organic amine to form at least one isocyanate and hydrogen chloride; (c) separating the hydrogen chloride; (d) oxidizing the hydrogen chloride with oxygen in a gas phase to form additional chlorine; and (e) recycling at least a portion of the additional chlorine to the reaction of the chlorine and the carbon monoxide; wherein the oxidation of the hydrogen chloride is initiated via a high energy source which may be selected from electron-exciting radiation, ionizing radiation, a gas discharge, a plasma, and combinations thereof.

Abstract: A shelf for electronic plug-in units is provided. The shelf includes at least one support plate that has at least one shaped opening. At least one guide rail is arranged for being mounted on the support plate, which includes a guide groove for receiving the electronic plug-in unit. There is also provided at least one positioning unit arranged on the guide rail, which includes a trunnion insertable form-fittingly into the shaped opening in the support plate to fix a position of the positioning unit relative to the support plate, and a locking element to lock in place an electronic plug-in unit fully inserted into the guide rail.

Abstract: An isocyanate is produced by: (a) reacting chlorine with carbon monoxide to form phosgene, (b) reacting the phosgene with an organic amine to form an isocyanate and hydrogen chloride, (c) separating the isocyanate and hydrogen chloride, (d) optionally, purifying the hydrogen chloride, (e) preparing an aqueous solution of the hydrogen chloride, (f) optionally, purifying the aqueous solution of hydrogen chloride, (g) subjecting the aqueous hydrogen chloride solution to electrochemical oxidation to form chlorine, and (h) returning at least a portion of the chlorine produced in (g) to (a).

Abstract: Process wherein the vanadium present in the chromium ore chromite is recovered as vanadium pentoxide during the course of the fusion of the chromium ore with alkali and its work-up to produce sodium chromate solution and sodium dichromate.

Abstract: The invention describes an electrochemical cell for the electrolysis of an aqueous solution of hydrogen chloride, comprising at least an anode half-cell with an anode, a cathode half-cell with a gas diffusion electrode as cathode and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the membrane consisting of at least a perfluorosulfonic acid polymer, wherein the gas diffusion electrode and the ion exchange membrane are adjacent to each other, characterised in that the gas diffusion electrode and the ion exchange membrane, under a pressure of 250 g/cm2 and at a temperature of 60° C., have a contact area of at least 50%, with respect to the geometric area.

Abstract: To create an orthodontic device with a base having a base surface for fixing the device to a tooth, and a slot for receiving an archwire, which is defined by a bottom surface and two side surfaces arranged on either side of the bottom surface and aligned in substantially parallel spaced relation to each other, and which extends in a substantially straight line through the base in the longitudinal direction of the base on a side thereof facing away from the base surface, and with a cover element for at least partially covering the open side of the slot facing the bottom surface, which is convertible and is easier to handle during the conversion, and which offers the wearer an increased degree of security, it is proposed that the side surfaces of the slot have a positively locking guide, which is aligned substantially parallel in relation to the longitudinal direction of the slot, and in which the cover element is slidably and detachably held on the base.

Abstract: The invention relates to a method for producing trichlorosilane by reacting silicon with hydrogen, silicon tetrachloride and, optionally, hydrogen chloride, whereby the silicon is provided in comminuted form, and the silicon is mixed with a catalyst during comminution.

Abstract: The invention relates to a method for the production of high purity silicon, characterized by the following steps: a) reaction of metallic silicon with silicon tetrachloride (SiCl4), hydrogen (H2) and hydrochloric acid (HCl) at a temperature of 500 to 800° C. and a pressure of 25 to 40 bar to give a trichlorosilane-containing (SiHCl3) feed gas stream, b) removal of impurities from the resultant trichlorosilane-containing feed gas stream by scrubbing with condensed chlorosilanes at a pressure of 25 to 40 bar and a temperature of 160 to 200° C.

Abstract: The invention relates to a method for producing chlorosilanes using silicon containing homogeneously distributed copper silicide. The invention especially relates to a method for producing trichlorosilane by reacting said silicon with water, silicon tetrachloride and optionally hydrogen chloride.

Abstract: The present invention describes an electrochemical cell, comprising at least an anode half-cell with an anode, a cathode half-cell with a cathode, and an ion exchange membrane arranged between the anode half-cell and the cathode half-cell, the anode and/or the cathode is a gas diffusion electrode. And a gap is provided between the gas diffusion electrode and the ion exchange membrane, and the half-cell with the gas diffusion electrode has an electrolyte feed and an electrolyte discharge as well as a gas inlet and a gas outlet. The electrochemical cell preferably has an electrolyte feed that is hermetically connected to the gap.

Abstract: The invention relates to a method for producing silane (SiH4) by a) reacting metallurgical silicon with silicon tetrachloride (SiCl4) and hydrogen (H2), to form a crude gas stream containing trichlorosilane (SiHCl3) and silicon tetrachloride (SiCl4), b) removing impurities from the resulting crude gas stream by washing with condensed chlorosilanes, c) condensing and subsequently, separating the purified crude gas stream by distillation, d) returning the partial stream consisting essentially of SiCl4 to the reaction of metallurgical silicon with SiCl4 and H2, e) disproportionating the partial stream containing SiHCl3, to form SiCl4 and SiH4 and f) returning the SiH4 formed by disproportionation to the reaction of metallurgical silicon with SiCl4 and H2, the crude gas stream containing trichlorosilane and silicon tetrachloride being liberated from solids as far as possible by gas filtration before being washed with the condensed chlorosilanes.

Abstract: The invention relates to a method for producing trichlorosilane, whereby silicon is reacted with hydrogen, silicon tetrachloride and optionally hydrogen chloride, said silicon containing iron in the form of homogeneously distributed iron silicide.

Abstract: The invention relates to a method for producing silane (SiH4) by a) reacting metallurgical silicon with silicon tetrachloride (SiCl4) and hydrogen (H2), to form a crude gas stream containing trichlorosilane (SiHCl3) and silicon tetrachloride (SiCl4), b) removing impurities from the resulting crude gas stream by washing with condensed chlorosilanes, c) condensing and subsequently, separating the purified crude gas stream by distillation, d) returning the partial stream consisting essentially of SiCl4 to the reaction of metallurgical silicon with SiCl4 and H2, e) disproportionating the partial stream containing SiHCl3, to form SiCl4 and SiH4 and f) returning the SiH4 formed by disproportionation to the reaction of metallurgical silicon with SiCl4 and H2, the crude gas stream containing trichlorosilane and silicon tetrachloride being liberated from solids as far as possible by gas filtration before being washed with the condensed chlorosilanes.

Abstract: The invention relates to a fluidized-bed reactor for the production of trichlorosilane by reacting silicon with silicon tetrachloride, hydrogen and optionally hydrogen chloride at a high pressure and high temperature. According to the invention, the fluidized-bed reactor, at least on the surface facing towards the reaction chamber, is made of a nickel-chrome-molybdenum-(NiCrMo)-alloy with a chrome proportion of at least 5 weight percent, an iron proportion of less than 4 weight percent and an additional proportion of 0-10 weight percent consisting of other alloy elements. The invention also relates to a method for producing trichlorosilane in said fluidized-bed reactor and to the use of said trichlorosilane.