Abstract: Methods of converting a variety of fluorinated materials into anhydrous hydrogen fluoride are described. The methods include thermally decomposing the fluorinated materials into a gaseous effluent comprising hydrogen fluoride and carbon dioxide. This gaseous effluent is then treated with carbon at a temperature of at least 830° C., converting the carbon dioxide to carbon monoxide (CO) and producing a gaseous product comprising the hydrogen fluoride, which can be condensed to generate anhydrous hydrogen fluoride. These methods can also be used to convert water contained in the gaseous effluent into hydrogen.

Abstract: A method and plant for hydrolysis of a liquid substrate, having a dry solids content of between 2 and 30%, to be used in an anaerobic fermentation, digestion or another process aimed at producing or extracting methane or other valuable substances, which method and plant relies on the use of vacuum and several pulpers and one or several flashtanks in series for step-wise pre-heating and pressure reduction, respectively.

Abstract: The invention relates to a process for converting a plastic feedstock and for converting used tyres to obtain carbon black, comprising the following steps: a) a solid feedstock (100) based on used tyres is sent into a reaction zone (10) in the presence of a liquid solvent (340) comprising aromatic compounds to at least partly dissolve said solid feedstock and to thermally decompose said dissolved solid feedstock so as to obtain carbon black (160) and a first hydrocarbon-based liquid fraction (120); b) a molten plastic feedstock (200) is sent together with at least a portion of the first hydrocarbon-based liquid fraction (120) obtained on conclusion of step a) into a conversion zone (20) to dissolve said molten plastic feedstock (200) and to thermally decompose said dissolved plastic feedstock so as to obtain a second hydrocarbon-based liquid fraction (230).

Abstract: Disclosed is a purification method for removing a metal component from a fluorine compound gas containing hydrogen fluoride and a metal component. This method includes a removing step for removing the hydrogen fluoride and the metal component therefrom by bringing the fluorine compound gas into contact with a solid metal fluoride to adsorb the hydrogen fluoride and the metal component on the metal fluoride. It is preferable for the fluorine compound gas to contain at least one kind selected from the group consisting of CIF, CIF3, IF5, IF7, BrF3, BrF5, NF3, WF6, SiF4, CF4, SF6 and BF3. It is also preferable for the metal fluoride to be an alkali metal fluoride or an alkali earth metal fluoride. Surprisingly, the presence of hydrogen fluoride in a fluorine compound gas makes it possible to remove a metal component therefrom as an impurity as a result of adsorption thereof by a metal fluoride.

Abstract: A method for obtaining or recovering acids, in particular nitric acid and hydrofluoric acid, from solutions and/or metal salts of these acids containing solutions, comprising the steps of: a) spray-drying the solutions at temperatures below the decomposition temperature of the acids, the requisite energy for which is introduced via a gaseous heat-transfer medium, in order to obtain dry metal salts and gaseous acids; b) absorbing the gaseous acids formed in step a); c) separating out the dry metal salts formed in step a); optionally d) roasting the dry metal salts obtained in step a) at temperatures in the range from 400 to 900° C., in order to obtain metal oxides and gaseous acids; and e) absorbing the gaseous acids formed in step d).

Abstract: A process for regenerating a used acidic catalyst which has been deactivated by conjunct polymers by removing the conjunct polymers so as to increase the activity of the catalyst is disclosed. Methods for removing the conjunct polymers include addition of a basic reagent and alkylation. The methods are applicable to all acidic catalysts and are described with reference to certain ionic liquid catalysts.

Abstract: Methods for producing highly pure solutions containing hydrogen fluoride, one or more salts thereof or a mixture of two or more thereof, by adding hydrogen fluoride to at least one anhydrous solvent, wherein the hydrogen fluoride is added to the anhydrous solvent or solvents in the form of a gas or as a liquified gas or as a mixture of gas and liquefied gas. High purity hydrogen fluoride and ammonium fluoride solutions produced by the inventive method are also disclosed.

Abstract: The present technology provides compositions that are intimate mixtures of hydrogen fluoride and a polyacrylate-polyacrylamide cross-linked copolymer, as well as methods and preparing and using such compositions. The compositions are less hazardous and, therefore, more conveniently stored, transported, and handled in comparison to pure hydrogen fluoride. Further, the hydrogen fluoride may be readily recovered from the compositions of the invention for use.

Abstract: To provide a novel method for purifying hydrogen fluoride, capable of efficiently reducing the content of arsenic in hydrogen fluoride. The step (a) of bringing a crude hydrogen fluoride containing arsenic trifluoride into contact with an oxidizing agent of a metal fluoride in a liquid state is carried out, for example, in a reactor (11) to obtain a reaction mixture wherein arsenic pentafluoride is formed by oxidizing arsenic trifluoride with the oxidizing agent of the metal fluoride through a liquid-liquid reaction; and the step (b) of separating purified hydrogen fluoride from the reaction mixture is carried out, for example, by a separator (13), the thus obtained purified hydrogen fluoride having a lower content of arsenic than that of the crude hydrogen fluoride.

Abstract: The present invention provides compositions that are intimate mixtures of hydrogen fluoride and a polyacrylate-polyacrylamide cross-linked copolymer. The compositions of the invention are less hazardous and, therefore, more conveniently stored, transported, and handled in comparison to pure hydrogen fluoride. Further, the hydrogen fluoride may be readily recovered from the compositions of the invention for use.

Abstract: The present invention relates to the conversion of waste and low-value materials into useful products in reliable purities in a cost-effective and energy-efficient manner. More specifially, the invention provides processes that can handle mixed streams of various feedstocks, e.g. shredder residue, offal, animal manures, municipal sewage sludge, tires, and plastics, that otherwise have little commercial value, to useful products including gas, oil, specialty chemicals, and carbon solids. The process subjects the feedstock to heat and pressure, separates out various components, then further applies heat and pressure to one or more of those components, according to processes based on thermal or catalytic cracking. The invention further comprises an apparatus for performing a multi-stage process of converting waste materials into useful materials, and at least one oil product that arises from the process. Useful products can also be obtained or derived from materials diverted at different points of the process.

Abstract: A process for regenerating a used acidic catalyst which has been deactivated by conjunct polymers by removing the conjunct polymers so as to increase the activity of the catalyst is disclosed. Methods for removing the conjunct polymers include hydrogenation, addition of a basic reagent and alkylation. The methods are applicable to all acidic catalysts and are described with reference to certain ionic liquid catalysts.

Abstract: The present invention provides compositions that are intimate mixtures of hydrogen fluoride and a polyacrylate-polyacrylamide cross-linked copolymer. The compositions of the invention are less hazardous and, therefore, more conveniently stored, transported, and handled in comparison to pure hydrogen fluoride. Further, the hydrogen fluoride may be readily recovered from the compositions of the invention for use.

Abstract: A method of treating a spent potliner after use in an aluminum smelting process, the method comprising crushing and classifying the spent potliner, placing the classified and crushed spent potliner in a furnace at a temperature greater than 450° C., heating the spent potliner to a temperature greater than 450° C., mixing the heated spent potliner with water to produce reaction gases and residue, burning the reaction gases, mixing the residue with water in a well ventilated area for a period of weeks to cure the residue. The method also embraces blending the cured residue with other chemicals and minerals to provide specific mineral products.

Abstract: Provided is a method for treating an aqueous feed stream containing an admixture of hexafluoroarsenic acid, or any salt thereof, and hydrogen fluoride, by contacting the feed stream with a counter-current stream of steam to remove substantially all of the hydrogen fluoride from the feed stream, and optionally to heat the feed stream. Further, provided is a method for continuously converting hexafluoroarsenic acid in an aqueous admixture, or any salt thereof, into arsenic acid by contacting the admixture with a counter-current stream of steam.

Abstract: A biocompatible tissue repair stimulating implant or “scaffold” device is used to repair tissue injuries, particularly injuries to ligaments, tendons, and nerves. Such implants are especially useful in methods that involve surgical procedures to repair injuries to ligament, tendon, and nerve tissue in the hand and foot. The repair procedures may be conducted with implants that contain a biological component that assists in healing or tissue repair.

Abstract: A process for treating acidic and metallic waste water, particularly the rinsing water and/or used acids from pickling plants. The process includes the step of adding an alkaline solution or gas to bind the free acids in the waste water, followed by separation of the waste water into a first partial stream with high metal content and a second partial stream with low metal content. To achieve a more economical embodiment, particularly in terms of favorable energy consumption, and also reduce the nitrate load as much as possible, the free acids are bonded by adding ammonia solution or gas, and the first partial stream with the high metal content is fed to a regeneration plant to undergo pyrohydrolytic treatment, preferably by spray roasting. The second stream can be recycled to a rinse station.

Abstract: The present invention relates to compositions, kits and processes for the brightening of metal surfaces by the application of the chemical compositions. These compositions act to release hydrofluoric acid as a brightening agent. The solutions are preferably mixed during application of the brightening composition to a metal surface by mixing the solutions immediately prior to or even during application of the solution. This can be readily accomplished by mixing two solutions, one having a fluoride source and the other having a strong acid to release hydrofluoric acid from the fluoride source, the mixing occurring immediately before spray application, during spraying, or immediately after spraying of the two solutions. Mixing may be done on-site, which means that mixing is performed at the site of use, usually on the same day of use or even within a few (less than 10) minutes of use.

Abstract: A process for separating and recovering hydrogen fluoride from a mixture with an organic compound especially a fluorine-containing compound by extraction with a solution of an alkali metal fluoride in hydrogen fluoride, phase separation and recovery. A process for producing a fluorine-containing organic compound by fluorinating a starting material with hydrogen fluoride and similarly recovering hydrogen fluoride from the product stream. The solution may be anhydrous or aqueous.

Abstract: A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.

Abstract: The present invention relates to compositions, kits and processes for the brightening of metal surfaces by the application of the chemical compositions. These compositions act to release hydrofluoric acid as a brightening agent. The solutions are preferably mixed during application of the brightening composition to a metal surface by mixing the solutions immediately prior to or even during application of the solution. This can be readily accomplished by mixing two solutions, one having a fluoride source and the other having a strong acid to release hydrofluoric acid from the fluoride source, the mixing occurring immediately before spray application, during spraying, or immediately after spraying of the two solutions. Mixing may be done on-site, which means that mixing is performed at the site of use, usually on the same day of use or even within a few (less than 10) minutes of use.

Abstract: Processes for separating and recovering hydrogen fluoride from a gaseous mixture of an organic compound and hydrogen fluoride are disclosed. The processes include contacting the gaseous mixture with a solution of an alkali metal fluoride in hydrogen fluoride, separating a gas phase depleted in hydrogen fluoride and containing the organic compound from a liquid phase, and recovering hydrogen fluoride from the liquid phase.

Abstract: A process for separating and recovering hydrogen fluoride from a mixture with an organic compound especially a fluorine-containing compound by extraction with a solution of an alkali metal fluoride in hydrogen fluoride, phase separation and recovery. A process for producing a fluorine-containing organic compound by fluorinating a starting material with hydrogen fluoride and similarly recovering hydrogen fluoride from the product stream. The solution may be anhydrous or aqueous.

Abstract: Provided is a method for regulating the concentration of water in the acid feed stream in a process for the production of HF by the reaction with a fluorine containing material, the method comprising:

Abstract: The object of the present invention is to simplify the depleted UF6 processing plant and processing method and to prevent calcium fluoride to be a fine powder, wherein the processing plant comprises a first fluidized bed reactor for forming UO2F2 and hydrogen fluoride by allowing depleted UF6 to react with steam, a second fluidized bed reactor for forming U3Oa, hydrogen fluoride and oxygen by allowing UO2F2 to react with steam, a gas cooler for cooling hydrogen fluoride at 150 to 300° C., and a fluoride fixing reactor for forming calcium fluoride by allowing cooled hydrogen fluoride to contact calcium carbonate; and wherein the processing process comprises a dry vapor-phase reaction step for forcing UO2F2 and hydrogen fluoride by allowing depleted UF6 to react with steam at a temperature of 230 to 280° C.

Abstract: The invention relates to a process for utilizing waste salt mixtures from HALEX reactions, comprising at least one alkali metal chloride and at least one alkali metal fluoride or bifluoride, and optionally one or more organic compounds, which are depleted by extraction, by contacting the resulting waste salt mixture with concentrated sulfuric acid, removing the resulting hydrogen chloride for the most part by flushing with an inert gas, and reacting the salt-containing sulfuric acid with calcium fluoride to give hydrogen fluoride and alkali metal sulfate-containing calcium sulfate, which can be processed to give a building material binder.

Abstract: A method of treating a surface of a metal is provided. A source of fluoride ion is mixed with a source of acid to form hydrofluoric acid and, when applied to a metal surface to be treated, the hydrofluoric acid acts as a brightening agent.

Abstract: A process is disclosed for producing calcium fluoride. The process comprises (a) mixing phosphate rock with aqueous H2SiF6 at ambient temperature for at least one hour; (b) nucleating the calcium fluoride in the slurry prepared in step (a) by reacting the slurry at a temperature and for a time sufficient to initiate and sustain nucleation of calcium fluoride and SiO2 by-product; (c) aggregating the SiO2 by-product by heating the slurry produced in step (b) at a temperature of about 90° C. to about 105° C. for at least 0.5 hours; and (d) recovering a calcium fluoride-containing product of an average particle size of less than 1 micron.

Abstract: An organic solvent is separated from a waste stream comprising hydrofluoric acid, an organic solvent and etchant contaminants. The process comprises separating the hydrofluoric acid by subjecting the waste stream to at least one of the following processes: ion exchange; extraction of the hydrofluoric acid; electrophoresis; converting the hydrofluoric acid to an insoluble salt; to thereby obtain a first composition containing the hydrofluoric acid and a second stream containing the organic solvent and being substantially free of the hydrofluoric acid; and then distilling the second stream to recover the organic solvent free of the etching contaminants.

Abstract: The invention relates to a novel process for removing arsenic compounds using amino/ammonium-functionalized anion exchangers from the distillation bottoms obtained in the purification of hydrogen fluoride by distillation.

Abstract: In a method of regenerating a spent pickling solution composed of nitric acid and hydrofluoric acid and containing metal fluorides and metal nitrates, the pickling solution is heated in a reactor to about 300-1,000° C., the metal fluorides and the metal nitrates are pyrohydrolized, and the metal oxides formed as a result are removed as a granulate, and the gas produced in the fluodized bed reactor is dedusted, cooled and fed to an acid recovery unit. The spent pickling solution is initially separated in a separating process into a partial flow with free acid and into a partial flow enriched with metal salts, and the partial flow enriched with free acid is fed to the acid recovery unit and the partial flow enriched with metal salts is fed to the fluidized bed reactor.

Abstract: Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration The method comprises bubbling purified ammonia vapor into ultra-pure hydrofluoric acid. The inventive method and system can be used as an on-site subsystem in a semiconductor device fabrication facility for supplying the buffered-hydrofluoric acid and ammonium fluoride to points of use in the semiconductor device fabrication facility.

Abstract: The novel process for preparing pure hydrofluoric acid or pure hydrogen fluoride is characterized in that, after pretreatment by distillatioil/oxidation, a two-stage scrub is carried out using 65-90% strength by weight hydrofluoric acid and 90-100% strength by weight hydrofluoric acid and water is fed into the first or second scrubbing circuit and a corresponding amount of hydrofluoric acid is bled off to remove impurities.

Abstract: Provided is a novel method and system for preparing ultra-high-purity buffered-hydrofluoric acid or ammonium fluoride controlled concentration. The method comprises bubbling purified ammonia vapor into ultra-pure hydrofluoric acid. The inventive method and system can be used as an on-site subsystem in a semiconductor device fabrication facility for supplying the buffered-hydrofluoric acid and ammonium fluoride to points of use in the semiconductor device fabrication facility.

Abstract: A process for purifying anhydrous HF by contacting anhydrous HF containing phosphate impurities with an effective amount of activated carbon so that the phosphate impurities are adsorbed on the activated carbon, and anhydrous hydrogen fluoride having a reduced phosphate impurity content is obtained.

Abstract: A process for separating and recovering hydrogen fluoride from a mixture with an organic compound especially a fluorine-containing compound by extraction with a solution of an alkali metal fluoride in hydrogen fluoride, phase separation and recovery. A process for producing a fluorine-containing organic compound by fluorinating a starting material with hydrogen fluoride and similarly recovering hydrogen fluoride from the product stream. The solution may be anhydrous or aqueous.

Abstract: A process is disclosed for producing calcium fluoride comprising: (a) mixing aqueous H3PO4 with aqueous H2SiF6 to form a mixture such that the concentration of H3PO4 is at least about 3 moles/liter, (b) adding phosphate rock to the mixture at a rate such that the pH of the mixture is maintained at less than about 1.0 and at a temperature sufficient to form a second mixture containing calcium fluoride, and (c) separating calcium fluoride from the second mixture.

Abstract: Spent potliner from aluminum reduction cells is treated, for example, with sulfuric acid to recover carbon, silica and alumina or to recover a vitrified product of silca and alumina.

Abstract: A method for producing fumed silica and a fluorine-containing product from a source of silica in solid form and a solid material containing fluorine, the solid material selected from the group consisting of sodium aluminum tetrafluoride, cryolite, aluminum fluosilicate ammonium bifluoride, sodium aluminum silicofluoride, and sodium fluosilicate. The method comprises the steps of digesting the silica in solid form and the solid material selected from the group consisting of sodium aluminum tetrafluoride, cryolite, aluminum fluosilicate, ammonium bifluoride, sodium aluminum silicofluoride, and sodium flurosilicate in a sulfuric acid digester. The digestion step produces a first gas component comprised of silicon tetrafluoride, hydrogen fluoride and water vapor. The first gas component is removed from the digester.

Abstract: Flux residues from aluminium soldering fluxes composed of alkali metal metallates, especially fluoroaluminates of the alkali metals, in particular potassium and cesium, can be recycled by adding them to the reaction mixture used for the production of hydrogen fluoride from fluorspar and sulfuric acid or oleum. In this way the fluorine content of the flux residues becomes reusable, and the anhydrite which is produced can advantageously be used for conventional purposes.

Abstract: Spent potliner from an aluminum reduction cell is subject to an acid digest and the digest may be adjusted to produce a first gas component comprised of at least one material selected from the group consisting of silicon tetrafluoride, hydrogen fluoride, hydrogen cyanide gas and water vapor, and a slurry component comprised of at least one material selected from the group consisting of carbon, silica, alumina, and sodium, iron, calcium and magnesium compounds. The first gas component is removed from the digester and heated to a temperature sufficiently high to convert said silicon tetrafluoride to fumed silica and hydrogen fluoride. Thereafter, the fumed silica is separated from the hydrogen fluoride to recover fumed silica from spent potliner material.

Abstract: A method of recovering AlF3 from spent potliner using an acid digest to form gaseous HF which is converted to hydrofluoric acid and reacted with alumina trihydrate to form AlF3.

Abstract: A process for producing a high-purity liquid chemical is provided. A chemical gas is successively purified over first and second purification columns by passing, countercurrently, a scrubbing solution of initially deionized high-purity water through the first and second purification columns, or by passing, countercurrently, a first scrubbing solution of initially deionized high-purity water through the first column and a second scrubbing solution of initially deionized water through the second column. Each of the scrubbing solutions gradually becomes a spent scrubbing solution loaded with impurity. A high-purity chemical gas leaves the second purification column with a low content of metallic elements. The high-purity chemical gas is subsequently dissolved in a liquid in a dissolution column including a top and a bottom. The liquid at the bottom of the dissolution column is collected and continuously recirculated, and is enriched with purified chemical gas, thereby forming a high-purity liquid chemical.

Abstract: The present invention provides compositions that are intimate mixtures of hydrogen fluoride and a polymer. The compositions of the invention are less hazardous and, therefore, more conveniently stored, transported, and handled in comparison to pure hydrogen fluoride. Further, the hydrogen fluoride may be readily recovered from the compositions of the invention for use.

Abstract: A process of treating spent potliner material from aluminum reduction cells and recovering useful products. In the process of the present invention, spent potliner material is introduced into an acid digester containing, for example, sulfuric acid. As a result of this step, a gas component is produced which includes hydrogen fluoride, silicon tetrafluoride and hydrogen cyanide. Also, a slurry component is produced which includes carbon, a refractory material including silica, alumina, sodium compounds such as sodium sulfate, aluminum compounds such as aluminum sulfate, iron compounds such as iron sulfate, magnesium and calcium compounds such as magnesium and calcium sulfate. The slurry component remains in the digester after the gas component is removed. The gas component is recovered and heated an effective amount to convert or decompose the silicon tetrafluoride to fumed silica, hydrogen cyanide to a remaining gas component including CO.sub.2, H.sub.2 O, and nitrogen oxides, as well as HF gas.

Abstract: Highly purified ammonia for use in processes for the production of high-precision electronic components is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.

Abstract: Process for extraction or recovery of acids, in particular hydrofluoric acid, hydrochloric acid and nitric acid, from solutions of these acids containing metal, by pyrohydrolytic treatment and subsequent absorption and/or condensation of the acid gases thus formed in an aqueous absorption solution, in which process the solids produced are removed. In order to guarantee economical acid recovery in existing plants without requiring large-scale adaptation, the waste pickling liquor is subjected to pre-concentration first of all before pyrohydrolysis, using the heat contained in the exhaust gas from the pyrohydrolysis.

Abstract: A process for treating spent potliner material from aluminum reduction cells and recovering useful products. In the process, spent potliner material is introduced into an acid digester containing, for example, sulfuric acid. A gas component is produced which includes hydrogen fluoride and hydrogen cyanide. A slurry component is produced which includes carbon, silica, alumina, sodium compounds such as sodium sulfate, aluminum compounds such as aluminum sulfate, iron compounds such as iron sulfate, magnesium and calcium compounds such as magnesium and calcium sulfate. The slurry component remains in the digester after the gas component is removed. The gas component is recovered and heated an effective amount to convert or decompose the hydrogen cyanide to a remaining gas component including CO.sub.2, H.sub.2 O, and nitrogen oxides, as well as HF gas. The remaining gas component is directed through a water scrubber in which the HF gas is converted to liquid hydrofluoric acid.

Abstract: The invention provides a process for separating fluorinated organic compounds from mixtures of the such compounds and hydrogen fluoride. More particularly, the invention provides a method for separating a fluorinated organic compound from a mixture containing at least one fluorinated organic compound and hydrogen fluoride by adding an inorganic salt to the mixture.

Abstract: Highly purified HCl for use in semiconductor manufacturing is prepared on-site by drawing HCl vapor from a liquid HCl reservoir, and scrubbing the filtered vapor in a low-pH aqueous scrubber.