Abstract: A process for the separation of a mineral acid from a common ion salt comprises a step of flowing a quantity of the mineral acid and salt in aqueous solution onto a strong base common ion form anion exchange resin bed whereon the mineral acid is retarded with respect to the salt. The salt is removed from the anion exchange resin. An interface cut of the mineral acid and the salt is recirculated from a bottom portion to a top portion of the anion exchange resin for further separation. A quantity of water is flowed through the anion exchange resin bed to elute the mineral acid therefrom. A portion of the elutant fluid is recycled to the top of the anion exchange resin bed.

Abstract: The present invention is directed to a process for continuously producing aqueous hydrochloric acid having a concentration of at least 3.5% by weight comprising:(a) continuously introducing water to the top of an absorption unit,(b) continuously introducing a gas stream containing anhydrous hydrogen chloride to the bottom of said absorption unit,(c) removing an overhead gaseous stream from said unit, said gaseous stream containing no more than 3% by weight, and preferably no more than 1% by weight hydrogen chloride, and(d) removing a bottom liquid stream from said unit, said bottom stream containing at least 35.5% by weight hydrogen chloride, and(e) returning a portion of said bottom stream to said unit.

Abstract: An improved process for the removal of acetylene from a hydrogen chloride stream in which the acetylene is converted to vinyl chloride by contact with a hydrochlorination catalyst, the improvement comprising, prior to contacting the stream with the hydrochlorination catalyst, contacting said stream with a catalyst comprising a noble metal, preferably of the platinum group, or salt or oxide thereof, supported or unsupported, at a temperature of between about 50.degree. and about 200.degree. C. and a pressure between about 8 and about 20 bar absolute.

Abstract: A process for the thermal destruction of heavy halogenated wastes in a hydrogen/oxygen flame which process comprises passing a mixture of heavy halogenated wastes in the vapor phase and a carrier gas of hydrogen or hydrogen-rich hydrocarbon through burning means provided with gaseous oxygen. Destruction efficiencies of better than 99.999% can be achieved with typical industrial wastes comprising hexachlorobenzene, polychlorinated biphenyls and related compounds.

Abstract: Treatment of waste water containing chlorides comprising treatment with Ca (OH).sub.2 or CaCO.sub.3 to convert the chlorides to CaCl.sub.2, adding sulfuric acid to said water in a reaction vessel to produce hydrochloric acid and gypsum, circulating the mixture in a closed cycle between the reaction vessel and a distillation column for the extractive distillation of the resulting hydrochloric acid, and filtering out the accumulating gypsum sludge from the treated waste water, wherein the added amount of waste water amount of hydrochloric acid correspond to the amount of sludge exiting the reaction vessel or the amount of distillate removed from the distilling column and the amount of gypsum separated, and the hydrochloric acid concentration in the liquid is less than the maximum azeotropic concentration for a mixture of H.sub.2 O and HCl.

Abstract: The present invention provides a process for the recovery of rhodium, lithium, and iodine values from tar which is generated during carbonylation reactions. The process comprises sequentially extracting the tar with water and then leaching the remaining tar with acetic acid, burning the resulting residue, and recycling the resulting rhodium-enriched residue to the reaction process. Preferably, the process further comprises the recovery of iodine values by the incineration of the acetic acid leachate and treatment of the off-gas with aqueous alkali hydroxide. Lithium values are recovered by evaporating water from the aqueous phase of the water extraction step and recycling the resulting residue to the reaction process.

Abstract: A method of extraction of HI from an aqueous solution of HI and I.sub.2. HBr is added to create a two-phase liquid mixture wherein a dry phase consists essentially of HBr, I and HI and is in equilibrium with a wet phase having a far greater HBr:HI ratio. Using a countercurrent extractor, two solutions can be obtained: a dry HBr--HI--I.sub.2 solution and a wet essentially HBr solution. The dry and wet phases are easily separable, and HI is recovered from the dry phase, after first separating I.sub.2, as by distillation. Alternatively, the HI-HBr liquid mixture is treated to catalytically decompose the HI. HBr is recovered from the wet phase by suitable treatment, including high-pressure distillation, to produce an H.sub.2 O--HBr azeotrope that is not more than 25 mole percent HBr. The azeotrope may be returned for use in an earlier step in the overall process which results in the production of the aqueous solution of HI and I.sub.2 without major detriment because of the presence of HBr.

Abstract: In the generation of hydrogen fluoride gas for the production of AlF.sub.3 by the reaction of fluorspar with concentrated sulphuric acid a small amount of aluminium sulphate is introduced into the reactive mix to assist in the retention of phosphorous compounds in the solid residues of the reaction and thus reduce the phosphorous content of the gaseous HF. Aluminium sulphate may be added as alum or may be generated in situ in the sulphuric acid by addition of an alumina hydrate, preferably before the acid is brought into contact with fluorspar. The addition of a small amount of calcium carbonate to the fluorspar also improves retention of phosphorous compounds in the solid residues in some instances.

Abstract: The invention is a process for the purification of hydrogen chloride formed during the thermal cracking of 1,2-dichloroethane, by hydrogenating the acetylene impurities with excess hydrogen, at pressures of from 8 to 20 bar absolute and at temperatures of from 120.degree. to 180.degree. C., using platinum or palladium supported catalysts, wherein, according to the invention, carrier materials having a specific surface area of not more than 5 m.sup.2 /g are used, the hydrogen excess used is a function of the acetylene content, the gas mixture, after reaching a temperature of approximately 70.degree. C., is permitted a dwell time of not more than 0.8 second before it enters the catalyst, and the temperature, pressure and volume flow rates are dependent on one another within narrow limits.The purified hydrogen chloride is used for oxychlorination.

Abstract: A method of recovering a wide range of hydrochloric acid concentrations and high quality ferrous sulfate by-product in several hydrate forms from waste pickle liquor containing ferrous chloride. The waste pickle liquor is concentrated in a concentrator crystallizer by boiling off water and free hydrogen chloride until ferrous chloride precipitates as a crystalline hydrate. Water and hydrogen chloride vapors from the concentrator crystallizer are directed to an acid vapor fractionator which produces an overhead line of substantially pure water that is condensed and discharged into a storage tank for subsequent use. Relatively weak hydrochloric acid from the bottom liquor in the fractionator is bled off and stored or mixed with stronger acid product formed at another stage of the process. The hydrate crystals of ferrous chloride are fed to a reactor where sulfuric acid is added to react with the ferrous chloride crystals thereby forming hydrogen chloride and ferrous sulfate monohydrate.

Abstract: In an integrated process for oxychlorination and combustion of chlorinated hydrocarbons, chlorinated hydrocarbon is burned to recover chlorine values essentially as hydrogen chloride. Hydrogen chloride is recovered from the effluent from the combustion by absorption with aqueous hydrogen chloride. Hydrogen chloride recovered by the absorption is subsequently recovered and employed in an oxychlorination reaction. A gas containing hydrogen chloride, water vapor and some oxygen recovered from the oxychlorination is cooled to condense aqueous hydrogen chloride which is employed in the absorption for recovering hydrogen chloride. The remaining gas is employed in the combustion of chlorinated hydrocarbons.

Abstract: A process for producing a purified hydrochloric acid from hydrogen chloride gas generated by reacting an alkali chloride with sulfuric acid is provided, which process comprises washing the hydrogen chloride gas with a hydrochloric acid having a saturation concentration and having the resulting gas absorbed in water.This process does not require such a particular purification step as redistillation or reabsorption.

Abstract: Hydrochloric acid produced by reacting an alkali chloride with sulfuric acid to prepare hydrogen chloride gas, followed by having the gas absorbed in water, contains a slightest amount of Br.sub.2 and other coloring materials as volatile impurities, but such amounts of impurities can be removed according to a purifying process in which the resulting hydrochloric acid is treated with an inert gas or a mixture of an inert gas with oxygen.

Abstract: In an integrated process for oxychlorination and combustion of chlorinated hydrocarbons, chlorinated hydrocarbons is burned to recover chlorine values essentially as hydrogen chloride. Combustion effluent and off-gas from an oxychlorination reaction are simultaneously treated to recover anhydrous hydrogen chloride for use in the oxychlorination reaction. In accordance with one embodiment, off-gas from the oxychlorination is employed in the combustion, prior to hydrogen chloride recovery in order to utilize any oxygen values therein. The process has particular applicability to an oxychlorination reaction of the type wherein a molten salt containing the higher and lower valent chlorides of a multivalent metal is contacted with hydrogen chloride and oxygen to recover hydrogen chloride by enriching the higher valent metal chloride content of the molten salt.

Abstract: A process for preparing sodium bicarbonate and hydrogen chloride by reacting an aqueous sodium chloride solution with carbon dioxide under pressure in the presence of an amine and of an organic solvent.1. Carbon dioxide is introduced under a pressure of5-80 bars into a mixture essentially containing1.1 an aqueous sodium chloride solution,1.2 a tertiary amine,1.3 a non-polar, organic solvent, and1.4 a polar, organic solvent having a boiling point above 140.degree. C.,2. the aqueous and organic phases obtained are separated under the same pressure as step 1,3. the aqueous phase is rid of the precipitated sodium bicarbonate and following reconcentration with sodium chloride is fed back into process stage 1 (carbonization),4. the organic phase(s) containing the polar and non-polar organic solvents is (are) heated and the hydrogen chloride released is evacuated, and5. the tertiary amine, polar and non-polar organic solvents from step 4 are recirculated to step 1.

Abstract: Relatively dry hydrogen iodide can be recovered from a mixture of HI, I.sub.2 and H.sub.2 O. After the composition of the mixture is adjusted so that the amounts of H.sub.2 O and I.sub.2 do not exceed certain maximum limits, subjection of the mixture to superatmospheric pressure in an amount equal to about the vapor pressure of HI at the temperature in question causes distinct liquid phases to appear. One of the liquid phases contains HI and not more than about 1 weight percent water. Often the adjustment in the composition will include the step of vaporization, and the distinct layers appear following the increase in pressure of the vapor mixture. Adjustment in the composition may also include the addition of an extraction agent, such as H.sub.3 PO.sub.4, and even though the adjusted composition mixture contains a significant amount of such an agent, the creation of the distinct liquid phases is not adversely affected.

Abstract: A process for removing ethylene and vinyl chloride from a gas stream containing them by passing a mixed gas containing ethylene, vinyl chloride and a necessary amount of chlorine through a fixed-bed reactor charged with as a catalyst an activated alumina supporting at least 4% by weight of ferric chloride in terms of iron, said catalyst having an outer surface area per unit packed catalyst volume of not less than 7.8 cm..sup.2 /ml. Ethylene and vinyl chloride are converted into and removed as 1,2-dichloroethane and 1,1,2-trichloroethane. The concentrations of ethylene and vinyl chloride can be decreased to not more than 10 p.p.m. and not more than 20 p.p.m., respectively.

Abstract: A process for producing sodium bicarbonate and hydrogen chloride by reacting an aqueous sodium chloride solution with carbon dioxide in the presence of an amine and an organic solvent. The steps of the process are carried out, wherein:(1) carbon dioxide is introduced into a mixture containing essentially(1.1) an aqueous sodium chloride solution,(1.2) a tertiary amine, and(1.3) a polar, organic solvent;(2) the aqueous and organic phases so obtained are separated;(3) the aqueous phase freed from the separated sodium bicarbonate following reconcentration with sodium chloride is fed back into process stage 1 (carbonization stage);(4) the organic phase (s) (is) are separated from the polar organic solvent and possibly of water to the widest possible extent and/or required; and(5) the residue containing a non-polar solvent is heated and the hydrogen chloride is removed.

Abstract: A process for preparing sodium bicarbonate and hydrogen chloride by reacting an aqueous sodium chloride solution with carbon dioxide under pressure in the presence of an amine and of an organic solvent.1. Carbon dioxide is introduced under a pressure of8-80 bars into a mixture essentially containing1.1 an aqueous sodium chloride solution,1.2 a tertiary amine,1.3 a non-polar organic solvent, and1.4 a polar, organic solvent having a boiling point above 140.degree. C.,2. the aqueous and organic phases obtained are separated under the same pressure as step 1,3. the aqueous phase is rid of the precipitated sodium bicarbonate and following reconcentration with sodium chloride is fed back into process stage 1 (carbonization),4. the organic phase(s) containing the polar and non-polar organic solvents is (are) heated and the hydrogen chloride released is evacuated, and5. the tertiary amine, polar and non-polar organic solvents from step 4 are recirculated in step 1.

Abstract: A method of removing hydrogen fluoride from gaseous mixtures of hydrogen fluoride and hydrogen chloride, which contain up to about 5 percent by weight of hydrogen fluoride, is described. The method comprises initially contacting the gaseous mixture with a particulate, substantially anhydrous, bed of alkaline earth metal chloride material, for example, calcium chloride, to produce an effluent gas mixture having a substantially reduced hydrogen fluoride content. The effluent gas is then contacted with a secondary treatment bed of particulate, substantially anhydrous, alkaline earth metal chloride material, for example, calcium chloride, to produce a product gas containing less than 20 ppm of hydrogen fluoride. The temperature of the secondary treatment bed is maintained in the range from about -20.degree. to about +20.degree. C., and, more preferably, in the range from about 0.degree. to about 5.degree. C.

Abstract: A method is disclosed for separating hydrogen chloride from a gaseous mixture containing hydrogen chloride and carbon dioxide in admixture with other gaseous impurities comprising contacting said gaseous mixture with a cross-linked, water-soluble polymer of N-glycidylpiperazine at a temperature between about -10.degree. and 100.degree. C.

Abstract: The invention provides a process for the separation of a strong mineral acid from other species present in an aqueous solution and the recovery thereof. The process comprises the steps of: (a) bringing an aqueous solution containing the mineral acid to be separated into contact with a substantially immiscible extractant phase, whereupon the mineral acid to be separated selectively and reversibly transfers to the extractant phase; (b) separating the two phases; and (c) backwashing the extractant phase with an aqueous system to recover substantially all the mineral acid contained in the extractant phase. The special extractant phase used comprises a strong organic acid which acid is oil soluble and substantially water immiscible both in free and in salt form, an oil soluble amine which amine is substantially water insoluble both in free and in salt form and a carrier solvent for the organic acid and amine, the molar ratio of the organic acid to amine in the extractant phase being between about 0.5:2 and 2:0.5.

Abstract: A process is provided for preparing alkanesulfonyl chlorides having 1-12 carbon atoms, in which the reaction of the corresponding alkanethiols and/or dialkyl disulfides with chlorine and water at a temperature of between -10.RTM. and +50.degree. C. is carried out in the desired alkanesulfonyl chloride as the reaction medium. The reaction can be carried out batchwise or continuously in a circulatory reactor, mixing of the reactants being effected by the hydrogen chloride formed in the reaction.

Abstract: A process for the preparation of optionally substituted benzoyl chloride from optionally substituted benzotrichloride at elevated temperature in the presence of a catalyst is described wherein optionally substituted benzotrichloride or a mixture thereof with optionally substituted benzoyl chloride is reacted with an excess of 1 to 20 mol percent of optionally substituted benzoic acid and/or water and the hydrogen chloride-containing off-gases formed during the reaction are washed with optionally substituted benzotrichloride or the mixture of optionally substituted benzotrichloride and optionally substituted benzoyl chloride.

Abstract: Gaseous hydrogen chloride is extracted from dilute aqueous hydrochloric acid using amines, by:(a) extracting the aqueous hydrochloric acid with an amine or with a mixture of an amine and an inert, water-immiscible solvent having a boiling point of at least 120.degree. C., tertiary alkylamines being used containing 14 to 36 carbon atoms in the nitrogen-bound side chains, the side chains having at most one nitrogen-bound methyl group and at least one nitrogen-bound aliphatic group containing at least 6 carbon atoms, where the amine acid constant is less than 10.sup.-3 ;(b) adding an inert, water-immiscible solvent having a boiling point of at least 120.degree. C.

Abstract: Method of removing organic contaminants from aqueous hydrochloric acid comprising countercurrently contacting the aqueous acid containing the contaminants and steam at superatmospheric pressures, and recovering said aqueous acid substantially free from organic contaminants. The invention is particularly adapted for the removal of chloral from aqueous hydrochloric acid.

Abstract: An improvement in the process for obtaining gaseous hydrogen chloride by extracting dilute aqueous hydrochloric acid with amines wherein:(a) the aqueous hydrochloric acid is extracted with an amine or a mixture of an amine and an inert, water-immiscible solvent boiling at not less than 120.degree. C., using tertiary alkylamines which contain 14 to 36 carbon atoms in the nitrogen-bonded side chains, which side chains include at most one nitrogen-bonded methyl group and at least one nitrogen-bonded aliphatic radical containing at least 6 carbon atoms, the acid constant K.sub.a of the amine being less than 10.sup.-3 ;(b) an inert, water-immiscible solvent boiling at not less than 120.degree. C.

Abstract: A method of separating HBr from a mixture of HBr/HCl using the difference in the stability to heat of the amine hydrohalides thereof. A mixture of HBr/HCl is treated with a solution of an amine and the HCl is split off, by the action of heat, from the amine hydrochlorides in the resulting mixture of amine hydrochlorides and amine hydrobromides, and the HBr is then recovered from the residual amine hydrobromides with the aid of a base and optionally recovered.

Abstract: The crude product obtained from the acid hydrolysis of cellulose, the product comprising concentrated hydrochloric acid and the various sugars obtained from the acid hydrolysis of cellulose, is separated into a first fraction comprising concentrated hydrochloric acid and a second fraction comprising the sugars by a process comprising:(1) contacting the crude product with an organic solvent consisting essentially of at least one C.sub.5 -C.sub.9 alcohol such that the organic solvent is enriched with the concentrated hydrochloric acid,(2) separating the enriched organic solvent from the concentrated hydrochloric acid depleted crude product, and(3) recovering the concentrated hydrochloric acid from the enriched organic solvent.

Abstract: This invention is a simple and effective method for removing uranium from aqueous HF solutions containing trace quantities of the same. The method comprises contacting the solution with particulate calcium fluoride to form uranium-bearing particulates, permitting the particulates to settle, and separting the solution from the settled particulates. The CaF.sub.2 is selected to have a nitrogen surface area in a selected range and is employed in an amount providing a calcium fluoride/uranium weight ratio in a selected range. As applied to dilute HF solutions containing 120 ppm uranium, the method removes at least 92% of the uranium, without introducing contaminants to the product solution.

Abstract: Anhydrous hydrogen fluoride of high purity can be recovered from metallic fluoride salts containing phosphate values by digesting the metallic salts in an aqueous solution in a humid atmosphere at a sufficiently high temperature to release a gas containing hydrogen fluoride and negligible amount of P.sub.2 O.sub.5. The released gas is rectified in a rectification operation which includes a rectification zone in which the rectification occurs in the presence of sulfuric acid.

Abstract: A process for obtaining anhydrous hydrogen chloride from chlorine-containing organic residues by combusting these in an oxygen-containing atmosphere and separating the hydrogen chloride from the water formed during combustion. The residues are combusted in an oxygen-containing atmosphere under superatmospheric pressure and at above 2,000.degree. C., the combustion products are then cooled and passed into a first cooling zone which contains a saturated solution of hydrogen chloride in water, the mixture of water, hydrogen chloride and the other combustion products is cooled in this zone and the mixture of gaseous hydrogen chloride and carbon dioxide is discharged from the cooling zone, cooled to a lower temperature in a second cooling zone, and separated from the aqueous hydrochloric acid.

Abstract: A method of manufacturing hydrogen chloride by splitting off hydrogen chloride from solutions of amine hydrochlorides. The hydrogen chloride is split off by heating the amine hydrochlorides at 100.degree. to 250.degree. C. in an inert, organic, essentially non-polar solvent having a boiling point at least 20.degree. C. above the temperature of heating while an inert gas stream is passed therethrough. The hydrogen chloride is then separated from the exiting mixture of inert gas and hydrogen chloride. The amine components of the amine hydrochlorides are tertiary alkylamines, tertiary aryldialkylamines, secondary arylalkylamines, primary alkylarylamines or mixtures thereof which contain 14 to 36 carbon atoms in the side chains bonded to nitrogen. Not more than one of the side chains of the amine component is a methyl group bonded to nitrogen and at least one of the side chains is an aliphatic radical, bonded to nitrogen, containing at least 6 carbon atoms. The inert solvents boil above 120.degree. C.

Abstract: A method of recovering hydrochloric acid from spent hydrochloric acid pickle liquor is used to increase the amount of hydrochloric acid recovered and to improve the form of the waste products for better handling and reduced energy costs. The waste pickle liquor from the pickle line is first concentrated before the liquor is reacted in a double exchange process with strong sulphuric acid. The concentrator separates the weak pickle into two streams consisting of an overhead vapor stream and an underflow of strong pickle liquor. The overhead vapor stream separates out hydrochloric acid by means of a fractionator with the underflow of strong pickle liquor being fed to the double exchanger reactor to be mixed with the sulphuric acid. The overhead from the reaction process which consists of hydrogen chloride and water vapor is condensed and made available for addition to the fractionated hydrogen chloride.

Abstract: The processing of liquid chlorinated hydrocarbon residues, which may contain solids and which form viscous to solid deposits during the separation of readily boiling components, into(1) distillable organic components,(2) hydrogen chloride, and(3) solid matter with a low chlorine content,is improved by gently concentrating the residues in a first step and, in a second step, decomposing the residues at temperatures of about 200.degree.-400.degree. C., preferably 270.degree.-330.degree. C., with a continuous separation of the vapor phase components from the solid components.

Abstract: Bivalent or multivalent metal chloride in aqueous solution is decomposed in the presence of oxygen to produce HCl and the corresponding metal oxide. Hydrochloric acid recovered by adiabatic absorption from the decomoposition gas is concentrated by extractive distillation in contact with concentrated metal chloride solution. The resulting solution is concentrated by heat exchange with the hot decomposition gas. At least part of the solution of high concentration is supplied to the thermal decomposition stage at a metal chloride rate corresponding to the metal chloride content of the incoming aqueous liquor.

Abstract: Molecular chlorine level in flue gases from incineration of chlorinated organic materials is reduced by injecting into the incinerator's quench zone an amount of a C.sub.1 -C.sub.4 hydrocarbon which depends on the amount of air fed into the combustion zone, the amount of air being such that there is a 1-40 % excess of oxygen. When the wall temperature of the combustion zone is about 800.degree.-1500.degree. C., the temperature at which the hydrocarbon is added to the quench zone is about 450.degree.-1000.degree. C. Hydrogen chloride, which is formed from molecular chlorine and hydrocarbon, is more readily water-scrubbed than chlorine, so that less polluting flue gases are obtained.

Abstract: Method of reducing the amount of acetylene impurity present in hydrogen chloride gas comprising contacting said gas with an oxidation catalyst in the presence of an oxygen-containing gas to form carbon monoxide and/or carbon dioxide and water. The method of the present invention is particularly adapted to remove acetylene impurities from hydrogen chloride streams used in the oxychlorination of ethylene in the presence of a catalyst.

Abstract: The method resides in that silicon tetrafluoride is subjected to water hydrolysis in the presence of sulphuric acid, the reactants being in an aerosol state.Hydrolysis is performed at a volume ratio of silicon tetrafluoride to sulphuric acid equal to 40:1-80:1, concentration of sulphuric acid within the range of 45-73 wt. %, and the rate of silicon tetrafluoride flow in the reaction zone of 0.2-4.0 m/sec. The process is run at room temperature and atmospheric pressure.As a result of hydrolysis, silicon dioxide and fluorine-containing sulphuric acid solution are obtained, hydrogen fluoride being extracted from the solution upon heating.The proposed invention makes possible an effective use of silicon tetrafluoride with maximum conversion of the components thereof into end products, separation of the end products taking place simultaneously with the formation thereof. The yield of the products reaches 92-95 wt. % of their content in the initial raw material.

Abstract: The invention relates to the re-extraction of a metal from an organic extraction solution in which the metal is present as a metal chloride complex bonded to an extractant. The organic extraction solution is contacted with an aqueous solution, to transfer metal ions and chloride ions to the aqueous solution. Sulphuric acid is added to the aqueous solution, which is subsequently heated to drive off hydrogen chloride and water. Metal sulphate is removed from the acidified aqueous solution.

Abstract: A method and apparatus for disposing of waste material by means of a multi-stage reaction favoring desired reaction products. The rate at which different reactions reach equilibrium at different temperatures and the effects of reaction stoichiometry are controlled by the process to promote desired reactions and discriminate against undesired ones.

Abstract: The components of a liquid mixture consisting essentially of HI, water and at least about 50 w/o iodine are separated in a countercurrent extraction zone by treating with phosphoric acid containing at least about 90 w/o H.sub.3 PO.sub.4. The bottom stream from the extraction zone is substantially completely molten iodine, and the overhead stream contains water, HI, H.sub.3 PO.sub.4 and a small fraction of the amount of original iodine.When the water and HI are present in near-azeotropic proportions, there is particular advantage in feeding the overhead stream to an extractive distillation zone wherein it is treated with additional concentrated phosphoric acid to create an anhydrous HI vapor stream and bottoms which contain at least about 85 w/o H.sub.3 PO.sub.4. Concentration of these bottoms provides phosphoric acid infeed for both the countercurrent extraction zone and for the extractive distillation zone.

Abstract: A method for reducing losses due to reactions between hydrogen halides and olefinically unsaturated organic compounds in the presence of transition metals which act as catalysts for hydrohalogenation in mixtures containing same by adding to said mixtures a compound selected from the class consisting of alkyl diketones. The present invention is of particular value in the separation of components of said mixtures by distillation, but may also be usefully employed in any operation in which these mixtures are maintained in the presence of said catalytic materials. The present method offers advantages over the prior art because of the relative low toxicity and flammability of diketones and the fact that no undesirable solids are formed to foul process equipment as with some known methods.

Abstract: A process for producing hydrogen fluoride from an aqueous solution of hydrogen fluoride and sulfuric acid by distillation at an elevated temperature, in order to evaporate hydrogen fluoride of a desired concentration, in which the aqueous solution of hydrogen fluoride and sulfuric acid is stripped by steam in a separation zone, the released hydrogen fluoride is passed through a drying zone, where it is contacted with a batch of strong sulfuric acid in order to produce hydrogen fluoride of a desired concentration, and the sulfuric acid from the drying zone is fed to the separation zone.

Abstract: This invention relates to a process of removing chlorine (Cl.sub.2) and hydrogen chloride (HCl) from a combustion gas, such as a combustion gas formed from incinerating chlorine-containing organic materials, which comprises:(1) Lowering the temperature of the combustion gas below the melting point of cupric chloride or mixture thereof with other salts;(2) Contacting the cooled combustion gas of step (1), in the presence of oxygen, with copper of lower than a divalent oxidation state, such as a cuprous compound or its equivalent in a quantity sufficient to absorb chlorine and hydrogen chloride present in gas, thereby converting the cuprous compound to cupric chloride (in order to absorb substantially all HCl and Cl.sub.

Abstract: A process for the removal of hydrogen fluoride and/or hydrogen chloride from gases comprising passing the gas to be purified through anion-exchange sorbent composed of a textured chemisorption fiber based on carbo-chain polymers with vinylpyridine groups or aliphatic amino groups. On exhaustion the sorbent is regenerated with water.The process of the present invention makes it possible to purify gases substantially completely irrespective of the initial concentrations of impurities in the gas being treated and ensures practically unlimited number of sorption-regeneration cycles with the same sorbent.

Abstract: In accordance with the process of the present invention, substantially complete removal of hydrogen fluoride values from a hydrogen chloride gas stream containing the same is effected by a process wherein the gas stream is contacted with an aqueous medium containing calcium chloride and hydrogen chloride under conditions sufficient to precipitate calcium fluoride, thereby producing a hydrogen chloride acid gas substantially free of hydrogen fluoride. The aqueous solution containing the calcium fluoride solids may be treated as by filtration to remove the solids and the recovered liquor may be recycled to the absorption stage, with optional addition of make-up calcium chloride, for removal of additional hydrogen fluoride.

Abstract: A process for the production of highly pure concentrated hydrofluoric acid by purifying crude HF gas containing H.sub.2 O, SO.sub.2, SiF.sub.4, S,CaF.sub.2, H.sub.2 SO.sub.4 and CaSO.sub.4 and obtained in the reaction of fluorite and sulphuric acid, whereby the resultant HF has an H.sub.2 SO.sub.4 content of the order of a few ppm, there are substantially no deposits of CaSO.sub.4 in the first H.sub.2 SO.sub.4 washing circuit and the service life of the system is considerably lengthened.

Abstract: A gaseous mixture of hydrogen chloride containing a minor proportion of hydrogen fluoride is contacted with solid, particulate, substantially anhydrous calcium chloride to remove said HF contamination.

Abstract: A method for purifying a spent hydrofluoric acid etching solution containing siliceous by-products which comprises treating the solution with a weak anion exchange resin of the polyamine type to remove SiF.sub.6.sup.= ions therefrom is described. The anion exchange resin may be regenerated with aqueous NaOH.