Abstract: Aqueous hydrochloric acid of very high purity can be obtained in a process for purifying crude aqueous 5 to 20 wt. % hydrochloric acid. In the purification, process water or a water/HCl mixture is evaporated from the crude aqueous hydrochloric acid at a pressure of from 0.01 to 1.0 bar and a temperature of from 10.degree. to 100.degree. C. until a crude, azeotropic mixture of water and HCl is obtained. The crude, azeotropic mixture of water and HCl is distilled in a distillation apparatus at a pressure of from 0.1 to 1.5 bar and a temperature of from 50.degree. to 110.degree. C. A purified gaseous, azeotropic mixture of water and HCl is recovered from the head of the distillation apparatus and a liquid mixture is left at the bottom of the distillation apparatus. The liquid mixture which is left at the bottom of the distillation apparatus is distilled at a pressure of from 0.5 to 2.5 bar and a temperature of from 80.degree. to 130.degree. C.

Abstract: The present invention relates to a process for the pretreatment of activated carbon, capable of being employed especially for the purification of concentrated solutions of hydrochloric acid.

Abstract: A process for producing a chlorine-free hydrochloric acid low in AOX from crude gases containing hydrogen chloride and organic impurities has been found. The crude gases wer subjected to a thermal treatment at 800.degree. to 1600.degree. in a reducing atmosphere. The hydrochloric acid obtained after absorption of the hydrogen chloride is chlorine-free and contains virtually no organic impurities. The waste gas is also chlorine-free.

Abstract: A process for purification of hydrochloric acid containing hydrogen fluoride, which process comprises steps of:contacting the hydrochloric acid containing hydrogen fluoride with at least one silicon compound of the formula:R.sup.1 R.sup.2 R.sup.3 SiX (1)wherein X is chlorine, hydroxyl or OSiR.sup.4 R.sup.5 R.sup.6, and R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and alkyl groups having 1 to 4 of carbon atoms, andrecovering a trialkylfluorosilane compound produced in said contacting step of the formula:R.sup.1 R.sup.2 R.sup.3 SiF (2)wherein R.sup.1, R.sup.2 and R.sup.3 are the same as defined above,said recovering step comprising sub-steps of: hydrolyzing the produced trialkylfluorosilane compound (2) after the recovery thereof to convert to a trialkylsilanol compound of the formula:R.sup.1 R.sup.2 R.sup.3 SiOH (3)wherein R.sup.1, R.sup.2 and R.sup.

Abstract: A spent pickling solution containing a relatively small percentage of hydrofluoric acid and used for pickling zirconium or hafnium so as to be saturated with zirconium or hafnium fluoride, is treated by the addition thereto of sodium sulfate, Na.sub.2 SO.sub.4, to precipitate sodium zirconium or hafnium fluoride. The remaining solution is recycled for further pickling use, and may have fluoride concentration increased by the addition of calcium fluoride thereto resulting in the precipitation of calcium sulfate.

Abstract: Disclosed is a method for the processing of the residues that occur in the production of chlorosilane. The processing is performed by the separation of the residual chlorosilanes, followed by hydrolysis of these residues with water vapor. The water vapor used has a temperature between 100.degree. and 300.degree. C. and additionally contains hydrogen chloride. The hydrolysis residues occurring in the present method have an extremely small chloride content and can be transported, if desired, directly to a dump. The hydrogen chloride that is released can be absorbed in water and removed as hydrochloric acid or can be desorbed for further technical use. Preferably it is reused for chlorosilane production.

Abstract: Processes and apparatus for the closed-loop regeneration of spent hydrochloric acid pickle liquors that have been used to pickle ferrous metals by recovering ferrous chloride from the spent pickle liquors at very low temperatures. The process includes maintaining the hydrochloric acid and iron concentrations within the spent pickle liquor at levels that will prevent the liquor from freezing when cooled to about -10 degrees Fahrenheit and that will permit the formation of ferrous chloride crystals within the spent pickle liquor when the liquor is cooled below about +18 to 20 degrees Fahrenheit and to about -10 degrees Fahrenheit. The ferrous chloride crystals formed at such low temperatures are then removed from the pickle liquor, which then permits reuse of the free hydrochloric acid remaining within the thus regenerated pickle liquor in normal pickling operations.

Abstract: A method of detoxifying a component of contaminated soil containing a halogenated organic compound including contacting the contaminated soil with atomic hydrogen in an amount effective to react with halogen contained in the compound and substituting the hydrogen for the halogen.

Abstract: A continuous process for the recovery of anhydrous hydrogen fluoride gas by contacting an aqueous solution of an alkali metal fluoride in hydrofluoric acid with a sulfur-containing dehydrating stream. The dehydrating stream preferably consists of sulfur trioxide dissolved in sulfuric acid. The desired product is obtained in high yield and purity.

Abstract: The preferred invention describes a process for the hydrogenation of organochlorine compounds and a neutralizing agent for hydrochloric acid which is obtained from organochlorine compounds.

Abstract: The present invention relates to neutralization of liquid waste products containing different organohalides. A method of combustion neutralization of liquid waste products resides in that a mixture of the liquid waste products with an alkali reagent is prepared and introduced in the form of a sprayed flow into a high-temperature stream of the fuel combustion products, sprayed water being introduced between the stream of fuel combustion products and the path of the sprayed mixture. The consumption during combustion neutralization is no less than 1.2 kg per kg of the above mixture of waste products with the alkali reagent and no more than 2.5 kg per kg of the fuel being used.

Abstract: A method for recovering hydrobromic acid and methanol from a filtrate obtained by brominating bisphenol A in a methanol solvent and filtering off the resulting brominated bisphenol A, which comprises adding water to the filtrate, followed by distillation for purification.

Abstract: A process is disclosed for the separation of halogenated hydrocarbons from concentrated hydrochloric acid, which contains 10 to 37% by weight of hydrogen chloride. The hydrochloric acid is freed from the halogenated hydrocarbons in an extraction with paraffins having more than 7 carbon atoms, or with paraffin waxes having dropping points from 70.degree. to 160.degree. C. or with paraffin/paraffin wax mixtures, preferably in a continuous counterflow extraction or cross-flow extraction.

Abstract: The invention is a multi-stage process for purifying hydrogen chloride containing acetylene and ethylene, from pyrolysis of 1,2-dichloroethane to provide highly pure hydrogen chloride for use in the preparation of silicon compounds. In the first stage, unsaturated by-products are chlorinated by reaction with an excess of chlorine gas. In the second stage, the unreacted chlorine gas remaining in the hydrogen chloride is reacted with an excess of defined olefins or chloroolefins and the hydrogen chloride is separated from the chlorination products and the excess olefins or chloroolefins by low-temperature rectification under pressure.

Abstract: A process for the dehydrohalogenation of a feed comprised of an admixture of primary, secondary and tertiary alkylhalides to selectively convert the secondary and tertiary alkylhalides of the admixture to olefins by dehydrohalogenation, with minimal conversion, if any, of the primary alkylhalides. The reaction, which is particularly applicable to the selective dehydrobromination of an admixture of primary, secondary and tertiary alkylbromides, is carried out in a distillation-reaction zone, column, or distillation-reactor, to simultaneously (i) convert the secondary and tertiary alkylbromides to olefins and hydrogen bromide, and (ii) separate the olefins and hydrogen bromide, (iii) and the primary alkyl bromides, from the reaction mixture.

Abstract: 1,1-Dichloro-1-fluoroethane, 1-chloro-1,1-difluoroethane and hydrogen fluoride are separated from their liquid mixtures, such as liquid mixtures resulting from the hydrofluorination, of 1,1,1-trichloroethane or vinylidene chloride. 1,1-Dichloro-1-fluoroethane and 1-chloro-1,1-difluoroethane are first separated by distillation into their respective mixtures with hydrogen fluoride, which are thereafter subjected to parallel phase separations resulting in two hydrogen fluoride-enriched liquid phases, a 1-chloro-1,1-difluoroethane-enriched liquid phase and a 1,1-dichloro-1-fluoroethane-enriched liquid phase. 1-Chloro-1,1-difluoroethane and 1,1-dichloro-1-fluoroethane are purified from the respective halohydrocarbon-enriched liquid phases by distillation. The hydrogen fluoride-enriched stream generated from the phase separation of the hydrogen fluoride/1,1-dichloro-1-fluoroethane mixture is recycled to the hydrofluorination reaction mixture.

Abstract: A two-step distillation process provides semiconductor purity, concentrated hydrofluoric acid. Further, the distillation process, occurring under reduced pressures eliminates essentially pure water after the first distillation step. The product output of the second distillation process provides an acid of weight percent greater than 27 weight percent. The product acid is carefully diluted to the required concentrations during the dilution step.

Abstract: The invention relates to a process for purifyng crude gaseous hydrogen chloride originating from plants producing silane or siloxane and containing as impurities silanes which contain chlorine and/or organic radicals, water, alkanols, hydrocarbons, chlorinated hydrocarbons, organic acids and derivatives thereof, by condensation, compression and fractional distillation. In this process, the crude gas is at least partially freed from condensable products by cooling to -35.degree. C., then compressed in a screw compressor with oil injection to 1.5 MPa, the oil is separated off, freed from gel-containing residues through a filter web and again recycled into the compressor. The compressed hydrogen chloride gas is fractionated in a distillation column under pressure and hydrogen chloride having a purity of 99.999 percent is recovered.

Abstract: The invention concerns a process for ultra-drying of a gas or gas mixture by bringing this into contact with a silicate containing material.In order to obtain a residual water level of 5 ppb or less, the invention is characterized in that the gas or gas mixture is brought into contact with a silcate containing material, preferably a zeolite or silicagel, that has been modified with silane, borane, and/or the alkyl and/or halogen substituted compounds thereof.The invention is further concerned with the separation of tritium oxide from gas mixtures preferably with water.

Abstract: A method to purify impure gaseous hydrogen chloride containing an unsaturated chlorinated hydrocarbon contaminant in an amount less than that necessary to inhibit purification, comprising exposing the impure hydrogen chloride to an ultraviolet light source in the presence of gaseous chloride for a sufficient time for the gaseous chloride to react with organic impurities in the hydrogen chloride to form heavier organic compounds and thereafter separating the heavier compounds from the hydrogen chloride.

Abstract: A process for drying a gaseous hydrogen halide of the formula HX, wherein X is bromine, Chlorine, FLuorine, or iodine, to remove water impurity therefrom, in which a scavenger precursor composition is provided, including a support having associated therewith partially or fully alkylated metal alkyl compounds or pendant groups. The precursor composition is reacted with gaseous hydrogen halide to convert the metal alkyl compounds and/or pendant functional groups to the corresponding metal halide compounds and/or pendant functional groups, which in turn react with the water impurity to produce an essentially completely water-free (below 0.1 ppm) gaseous hydrogen halide effluent. The process of the invention has utility for producing high purity, anhydrous gaseous hydrogen halides for semiconductor manufacturing operations.

Abstract: A distillable liquid containing non-volatile impurities is freed of those impurities by boiling the liquid to form vapors of the liquid, passing the vapors through a packed column heated to a temperature such that liquid entrained in the vapors is completely vaporized and the non-volatile impurities remain in the packed column, and condensing the vapors from the column.

Abstract: The water content of an HCl gas stream is reduced to less than 1 ppm by contacting the gas stream with a chloride of silicon or a chloride of a metal having a valence of at least four that is immobilized on a solid support.

Abstract: In a process for the purification of hydrogen chloride from the pyrolysis of 1,2-dichloroethane, optionally after a preceding step of acetylene removal by selective hydrogenation under specific conditions followed by rectification of the resulting mixture to obtain hydrogen chloride containing at most 5 ppm of unsaturated hydrocarbons and at most 5 ppm of chlorinated hydrocarbons.

Abstract: A method for controlling the water present in hydrogen fluoride is described which effectively removes all the water contained in the hydrogen fluoride solution to form other compounds that either have extremely low vapor pressure or are acceptable in a process such as chemical vapor purification. The method involves as one of the steps the contacting of a reactive metal halide with a hydrogen fluoride containing water. The metal halide reacts with the water contained in the hydrogen fluoride solution yielding a metal oxide, hydrogen halide, and anhydrous hydrogen fluoride. The metal oxide is a solid, with low vapor pressure, thereby effectively removing oxygen-bearing species from the hydrogen fluoride.

Abstract: A method for the separation of anhydrous HCl and HBr from mixtures of the two acids comprising treating the mixture with a hindered pyridine to form a mixture of hindered pyridine salts of the acids, and heating the mixture of salts to a temperature at which thermal cleavage of at least the hydrochloride salt is induced. The hindered pyridines are defined as aromatic compounds having one or more nitrogen atoms in an aromatic ring, or a polymer with pendant aromatic moieties having one or more nitrogens in an aromatic ring, having an appropriate degree of steric hindrance such that the salt formed by the nitrogen atom of the aromatic compound and a strong protic base will undergo dissociation to the aromatic compound and the protic acid at a temperature below the decomposition temperature of the aromatic compound. The formation of salts and their cleavage can be done as either a one-step or two-step process.

Abstract: A chemical method of removing thiourea from spent hydrochloric acid cleaning solutions comprising the steps of: adjusting the pH to not less than 12 by addition of base to remove metal hydroxides; oxidizing thiourea to urea by the addition of at least 4 moles of hydrogen peroxide per mole of thiourea; and further oxidizing urea to nonregulated/nonhazardous compounds by the addition of at least 3 moles of a hypochlorite per mole of urea. UV analysis confirms a greater than 98% removal of thiourea from solutions containing 0.4 to 2.7 wt. % thiourea after as little as 3 hours with an exotherm, .DELTA.t, of less than 105.degree. F.

Abstract: A gaseous feed stream comprising hydrogen fluoride and 1,1-difluoroethane is contacted with liquid organic barrier material in a condensing zone to partially condense the feed stream. The gaseous phase remaining after the partial condensation comprises most of the 1,1-difluoroethane originally present in the feed stream while the liquid condensate comprises most of the hydrogen fluoride originally present in the feed stream. The gaseous phase and the liquid condensate are removed from the condensing zone as separate streams. Less than about 50 percent of the 1,1-difluoroethane originally present in the feed stream reacts with hydrogen fluoride to form 1,1,1-trifluoroethane during the partial condensation and the removal of the separate streams from the condensing zone. The preferred liquid organic barrier material is 1,1,-trifluoroethane.

Abstract: A process for removing mineral impurities such as metal oxides from coal and shale oil structures is disclosed. The process is carried out by subjecting crushed coal or shale to a hydrocarbon fluoride leaching solution, separating the HF leach liquor from the coal or shale, washing the coal or shale with water, leaching the washed coal or shale with hydrogen chloride solution, separating the HCl leach liquor from the coal or shale, washing the coal or shale with water, and removing residual impurities from the treated coal or shale by heating under a vacuum. The process allows for the recovery of carbons and hydrocarbons of high purity from coal or shale which do not require expensive emission control equipment when combusted.

Abstract: A process for the purification of hydrochloric acids contaminated with C.sub.1 -chlorinated hydrocarbons involves the controlled use of a distillator column. The contaminants are removed by stripping with HCl gas, the stripping being performed in a bubble column.

Abstract: A process for manufacturing high purity anhydrous hydrogen fluoride (HF) having low levels of arsenic impurity by contacting anhydrous hydrogen fluoride product, or an intermediate product obtained during the manufacture of HF, with hydrogen peroxide in the presence of a catalyst which comprises effective amounts of molybdenum or an inorganic molybdenum compound and a phosphate compound. The volatile trivalent arsenic impurity in the anhydrous hydrogen fluoride is oxidized to a non-volatile pentavalent arsenic compound and the resultant mixture is distilled to recover high purity anhydrous hydrogen fluoride with reduced levels of arsenic impurity. In one embodiment, an oxidizing agent such as nitric acid or a nitrate salt is added to the reaction mixture to oxidize organic contaminants.

Abstract: A method of separating HF from a mixture including HF and HCl is disclosed wherein the mixture is contacted with silica causing the HF to react with the silica to form SiF.sub.4. The concentration of HCl is increased thereby increasing the relative volatility of SiF.sub.4 /HCl. The SiF.sub.4 is then removed as an aqueous distillate. The concentration of the HCl can be increased by various methods including adding gaseous or concentrated HCl to the mixture or by distilling off a portion of the water to thereby increase the concentration of the HCl. This method provides an efficient method of removing SiF.sub.4 and HF from HCl.

Abstract: Hydrogen chloride gas obtained as a by-product in the production of chloroacetic acid by subjecting acetic acid to a catalytic chlorination reaction with chlorine gas in the presence of acetic anhydride and/or acetyl chloride is purified. The prepurified by-product still contains 0.1-3 vol % acetyl chloride and up to 0.1 vol % chloroacetyl chloride. For purification, the hydrogen chloride gas is passed through two zones series-connected together and scrubbed in countercurrent fashion. More particularly, it is scrubbed in the first zone with concentrated hydrochloric acid and in the second zone with concentrated sulfuric acid.

Abstract: Metal ions are reduced from a higher to a lower oxidation stage using ferrophosphorus as the reductant.

Abstract: A process for purifying hydrogen fluroide characterized by adding fluorine to hydrogen fluoride containing at least one element selected from the group consisting of boron, silicon, phosphorus, sulfur, chlorine and arsenic, and/or at least one compound of these elements, reacting the fluorine with said element and/or said compound and distilling the resulting mixture.

Abstract: A process for hydrogenating acetylene in hydrogen chloride gas using the catalytic palladium supported on silicon carbide carrier whose iron content is specified to be not more than 1,000 ppm. The catalyst has the advantages of enhancing the conversion of acetylene into ethylene, improving the selectivity of ethylene, and retaining catalytic activity over a long time at a large space velocity. This process can be effectively applied to the hydrogenation of acetylene in hydrogen chloride gas separated from the thermally decomposed products of 1,2-dichloroethane which occurs in the production of vinyl chloride; namely, the hydrogen chloride gas that contains thus hydrogenated acetylene (ethylene) can be recycled in such an effective way that 1,2-dichloroethane can be produced economically.

Abstract: A device for and method of working up etching and pickling liquids consisting of a vertical furnace having one or more vertical reaction spaces through which balls move at a maximum packing density.The furnace has a temperature gradient from the bottom (high) to the top (low). The reaction space and the balls consist of a material which is inert with respect to the liquid to be worked up. The liquid is introduced into the upper side of the furnace so that a film is formed in the heated surface of the balls. The salt dissolved in the liquid decomposes pyrolytically. The metal oxide is deposited on the surface of the balls and is removed therefrom after leaving the reaction space. The acid residue vapours are drained at the top and recovered in a separate absorber to the original pickling or etching acid.

Abstract: A method of recovering concentrated hydrochloric acid from the product obtained from the acid hydrolysis of a cellulose containing material such as biomass. The method involves contacting such product with an extracting solvent, of which a major portion is acetophenone, to separate the product into a hydrochloric acid enriched phase and a hydrochloric acid depleted phase and then separating and recovering the hydrochloric acid from the hydrochloric acid enriched phase.

Abstract: The invention is a process for the recovery of protic acids from a medium which comprises(a) contacting a medium containing a protic acid with a reversible base under conditions such that the protic acid and the reversible base form a salt; and(b) exposing the salt of the protic acid and the reversible base to temperatures at which the salt dissociates liberating the protic acid.

Abstract: A process for recovering hydrogen fluoride from waste stream gases containing hydrogen fluoride by contacting the waste stream with a scrubbing agent comprising a chlorinated pyridine.

Abstract: A fluorinated carbonyl compound ##STR1## where x is 2 or 3 and A represents CF.sub.3 or H, coexisting with hydrogen fluoride in a mixed gas is purified by first adjusting the temperature of the mixed gas to 100.degree.-300.degree. C. to cause decomposition of a usually coexisting complex of the fluorinated compound with HF and then bringing the hot mixed gas into contact with concentrated sulfuric acid maintained at 10.degree.-40.degree. C. Almost the entire amount of HF is absorbed in sulfuric acid and subsequently recovered, while the purified compound neither dissolves in sulfuric acid nor reacts with HF present in sulfuric acid.

Abstract: Tantalum (TaF.sub.5) or antimony pentafluoride (SbF.sub.5) is separated from a product mixture comprised of HF, isobutyryl fluoride and TaF.sub.5 or SbF.sub.5 by distillation below 760 mm of mercury.

Abstract: A process for treating and recovering pickling waste liquids used for the pickling of stainless steel such as nitric-hydrofluoric acid, nitric acid, hydrochloric acid and, sulfuric acid is disclosed, which comprises recovering the nitric-hydrofluoric acid and the iron oxide or metallic ion from the waste liquids of nitric-hydrofluoric acid and nitric acid by two solvent extraction processes and recovering the Cr and Ni containing ferrite from the waste liquids of sulfuric acid or hydrochloric acid by a ferrite formation process. When the waste acid is sulfuric acid, gypsum of a high purity can be obtained.

Abstract: Hydrogen chloride is recovered from a mixture with propylene by extractive distillation with an inert extraction solvent to minimize reaction between hydrogen chloride and propylene during such distillation. The temperature and pressure conditions are coordinated with the extraction solvent and amount thereof to prevent the presence of hydrogen chloride in a liquid state. The process is particularly suitable for recovering hydrogen chloride in the production of allyl chloride by thermal chlorination of propylene.

Abstract: A process for the removal of hydrogen halides including HCl and HF, and/or sulfur dioxide from silicon tetrafluoride. Contaminated gaseous silicon tetrafluoride is passed through a column of zeolite preferably in the hydrogen cation form so as to permit recovery of silicon tetrafluoride containing less than about 10% of the original contamination levels. Acid-stable zeolite materials suitable for the process of the invention are subjected to a flow of hot gases to permit regeneration of the column for use in a semicontinuous process.

Abstract: A method for conducting a chemical process in which a feed containing at least one liquid is introduced into a vessel containing a plurality of packed, vertically arranged tubes, and in which at least one liquid product and at least one gaseous product are obtained, in which the tubes and a space above them are kept flooded with liquid by controlled removal of liquid product from the lower portion of the vessel.

Abstract: A process for obtaining hydrogen and oxygen from water in a two stage process including a first electrolysis stage performed in a two chamber cell wherein the chambers are separated by a membrane. Iodine is introduced into the cathodic chamber and hydrogen iodide is formed therein. Oxygen is formed in the anodic chamber and is removed as a product. The membrane conducts hydrogen ions and prevents the passage of the products HI and oxygen. In a second phase, hydrogen iodide is separated and removed from the cathodic chamber and is thermally decomposed into hydrogen and iodine. The iodine is recycled to the cathodic chamber and the hydrogen is recovered as a product.

Abstract: A process for oxidizing hydrogen halides having substantially no sulfur impurities by means of a catalytically active molten salt is disclosed. A mixture of the subject hydrogen halide and an oxygen bearing gas is contacted with a molten salt containing an oxidizing catalyst and alkali metal normal sulfates and pyrosulfates to produce an effluent gas stream rich in the elemental halogen and substantially free of sulfur oxide gases.

Abstract: A process for the separation of volatile chlorine compounds from exhaust gases resulting from the chlorination of titanium-containing raw material by the treatment of the exhaust gases with an aqueous media in several stages and the absorption of the volatile chlorine compounds in the aqueous media. In the first stage, the exhaust gases are contacted with an aqueous solution of titanium oxide chloride and, in the subsequent second stage, the exhaust gases are contacted with water to obtain hydrochloric acid of useful concentration.

Abstract: A method for preparing hydrogen chloride resulting from chlorination reactions for use in the ethyleneoxichlorination process by reacting the chlorine contained in the hydrogen chloride with ethylene in the gaseous phase in the presence of carrier catalysts based on an iron-free transition metal chloride having an activity profile which increases in the flow direction, while maintaining the space-flow rates relatively high and the residence time of the gas in the reactor short. After discharge of the reaction product from the reactor the product is subjected to partial condensation advantageously performed in several steps.