Abstract: A method of processing waste chlorosilanes which comprises: obtaining a source of waste chlorosilanes; combining the waste chlorosilanes with a solution of ammonium hydroxide to form a reaction product of ammonium chloride and a siloxane gel; and separating the ammonium chloride from the siloxane gel.

Abstract: According to one embodiment, a method for removing carbon dioxide in an exhaust gas utilizing seawater includes: blowing ammonia into seawater to produce ammonia-saturated seawater; contacting an exhaust gas under a state of non-heat with the ammonia-saturated seawater so that carbon dioxide in the exhaust gas is absorbed in the ammonia-saturated seawater; and splaying a solution containing sodium hydrogen carbonate and ammonium chloride which are produced through absorption of the carbon dioxide by the ammonia-saturated seawater utilizing pressure of the exhaust gas while cooling the solution utilizing heat of evaporation of a solvent of the solution so as to settle out and recover the sodium hydrogen carbonate and the ammonium chloride.

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 invention relates to a process for the treatment and purification of dangerous wastes containing ammonium salts, particularly ammonium chloride, derived from pharmaceutical and chemical technologies. The process includes the following steps: removing the organic solvent content of the waste mixture, containing an aqueous and non-aqueous phase, by phase separation based on the difference in the special weight and/or by azeotrop distillation, and heating the obtained aqueous solution at its boiling point or at a temperature belonging to the maximal saturation boiling point of the ammonium salt until the non-solvent type organic substances precipitate in the form of a well separable polymerisate phase, whereafter this phase is separated from the aqueous solution of the ammonium salt and the ammonium salt, preferably the ammonium chloride is purified by a method known per se.

Abstract: Methods and systems for a zero discharge waste water treatment system are provided. The system includes a filtration train including filter media having successively smaller diameter filtration elements, a reverse osmosis apparatus including a pump and a membrane coupled in flow communication with said filtration train, a vapor compressor coupled in flow communication with said reverse osmosis apparatus, and a spray dryer coupled in flow communication with said vapor compressor, said spray dryer configured to separate moisture in a brine solution from particulate suspended in the brine solution.

Abstract: Silazanes and/or polysilazanes are prepared by ammonolysis reaction in liquid anhydrous ammonia by introducing at least one halosilane into the ammonia. In addition to the silazane and/or polysilazane, an ammonolysis by-product also results. A substantially more efficient process is disclosed for treating the by-product through the addition of a liquid, namely water, or a solution comprising a strong base, or an aqueous acid solution. The process may be employed for more efficient, economical recovery of ammonia from such waste stream solutions of ammonia halide, or acids thereof for use as recycle in the further production of silazanes and polysilazanes, and/or for producing a less hazardous, more readily disposable salt residue thereof.

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: 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 invention relates to desalination of Sea water and of brakish water, and removal of harmful CO2 gas in exhaust from combustion apparatuses. The exhaust, rich in carbon dioxide (CO2) is diverted to a process chamber, where Sea water, after being mixed with Ammonia, as a catalyst to weaken the salt molecules, is pumped into the chamber and dispersed at many points near the top, as a fine spray, exposing the salt to the CO2 gas there. The internal bond of the salt molecules (NaCl) are weaker by the Ammonia in the water attaching and pulling on their Cl atom. The CO2 in the chamber is attaching and pulling on the Na atom of the salt molecules and are further reduces the bond, breaking them apart. Two heavy solids are formed, they settle in a clarifier below and are removed. Desalinated Sea water, in large quantities per ton of salt, over flows from the clarifier, for use in communities and for agriculture.

Abstract: The invention provides a method for reducing atmospheric pollution caused by a pollutant selected from the group consisting of CO.sub.2, SO.sub.2 and a mixture thereof, the pollutant being contained in industrial gases being emitted to the atmosphere, through the conversion of CO.sub.2 to calcium carbonate and the conversion of SO.sub.2 to calcium sulfite using conventionally available calcium salt-containing reactant; said method comprising reacting the pollutant-containing gas, prior to the venting thereof to the atmosphere, with an alkali base and an aqueous liquor, whereby the pollutant reacts with the base and transfers to the liquor, and the resulting gas vented to the atmosphere has a reduced pollutant content; and reacting the pollutant-loaded liquor with a calcium salt-containing reactant to form calcium carbonate and calcium sulfite respectively, with the co-formation of a commercially utilizable salt containing an anion from the calcium salt reactant and a cation from the alkali base.

Abstract: The present invention provides a basic method for producing high purity silica and ammonium fluoride from silicon tetrafluoride-containing gas, particularly the gas generated by acidulation. The basic method comprises recovering silicon tetrafluoride-containing gas from the acidulation of a fluorine-containing phosphorus source, separating liquid entrainment from the gas, converting the gas recovered to an ammonium fluosilicate solution, and ammoniating said ammonium fluosilicate solution to produce high purity silica and ammonium fluoride.

Abstract: A process for producing a high-purity silica, which comprises the steps of reacting a crude silica with ammonium fluoride, acid ammonium fluoride or a mixture thereof in an aqueous medium to produce ammonium silicofluoride, separating the ammonium silicofluoride from an unreacted silica and impurities by the means of a solid/liquid separation, and reacting the thus-obtained ammonium silicofluoride with ammonia in an aqueous medium. This process is a low cost process, and enables to control properties of silica.

Abstract: A method of converting sodium bromide brine to ammonium bromide brine and optionally to calcium bromide is disclosed. The method involves introducing ammonia and carbon dioxide into the reactant brine, removing a resulting bicarbonate precipitate, driving off any excess ammonium carbonate, and optionally contacting with lime.

Abstract: A process for producing a high-purity silica, which comprises the steps of reacting a crude silica with ammonium fluoride, acid ammonium fluoride or a mixture thereof in an aqueous medium to produce ammonium silicofluoride, separating the ammonium silicofluoride from an unreacted silica and impurities by the means of a solid/liquid separation, and reacting the thus-obtained ammonium silicofluoride with ammonia in an aqueous medium. This process is a low cost process, and enables to control properties of silica.

Abstract: A method for producing high purity silica and ammonium fluoride from silicon tetrafluoride-containing gas wherein silicon tetrafluoride-containing gas from the acidulation of phosphorus-containing rock is recovered and the liquid entrainment is separated from the gas. The recovered gas is converted to an ammonium fluosilicate solution and is ammoniated to produce high purity silica and ammonium fluoride. The recovered gas can be converted to an ammonium fluosilicate solution either by absorbing the gas directly in a solution of ammonium fluoride or by first absorbing the gas in water to produce fluosilicic acid and then reacting the fluosilicic acid with ammonia or ammonium fluoride.

Abstract: A particulate mixture of Fe.sub.2 O.sub.3 and RE.sub.2 O.sub.3, where RE is a rare earth element, is reacted with an excess of HF acid to form an insoluble fluoride compound (salt) comprising REF.sub.3 and FeF.sub.3 present in solid solution in the REF.sub.3 crystal lattice. The REF.sub.3 /FeF.sub.3 compound is dried to render it usable as a reactant in the thermite reduction process as well as other processes which require an REF.sub.3 /FeF.sub.3 mixture. The dried REF.sub.3 /FeF.sub.3 compound comprises about 5 weight % to about 40 weight % of FeF.sub.3 and the balance REF.sub.3 to this end.

Abstract: A method of producing a high purity silica powder which can be fused to form transparent, bubble-free particles. An ammonium fluosilicate solution is purified preliminarily by removing colloidal-sized silica onto which impurities in the solution have been adsorbed. The high purity powder is produced by ammoniation of an unsaturated aqueous solution of ammonium fluosilicate. Silica powder produced is filtered, washed, and dried before fusion. Additional pre-fusion treatments such as washing, hydrothermal leaching, calcination, and a combination thereof, may be utilized to ensure that the concentration of volatile material is low.

Abstract: A method for producing high purity silica and ammonium fluoride from silicon tetrafluoride-containing gas wherein silicon tetrafluoride-containing gas from the acidulation of phosphorus-containing rock is recovered and the liquid entrainment is separated from the gas. The recovered gas is converted to an ammonium fluosilicate solution and is ammoniated to produce high purity silica and ammonium fluoride. The recovered gas can be converted to an ammonium fluosilicate solution either by absorbing the gas directly in a solution of ammonium fluoride or by first absorbing the gas in water to produce fluosilicic acid and then reacting the fluosilicic acid with ammonia or ammonium fluoride.

Abstract: The process of the invention is carried out in gaseous phase by the action of ammonia on the aqueous solutions of iron salts in an appropriate reacting vessels.

Abstract: New processes and equipment are disclosed for producing elemental phosphorus and thermal phosphoric acid. Benefits are listed below.1. Phosphorus-containing solids are recycled to smelting furnaces thus eliminating hazardous waste generation.2. Phosphorus furnace feedstock is upgraded and this permits unbeneficiated phosphate ore to be smelted.3. Energy is conserved during manufacture of elemental phosphorus and phosphoric acid.4. Electric energy is produced by cogeneration.5. Fluorine in phosphate ore is recovered as ammonium fluoride.6. Phosphorus-containing liquids are used as feedstock for production of suspension fertilizers.Benefits are achieved by agglomerating phosphate ore with monocalcium phosphate binder by a method which upgrades the ore. Phosphorus-containing solids are fluidized and burned to form an impure phosphoric acid mixture which is reacted with small sized phosphate ore to form monocalcium phosphate binder.

Abstract: A process for producing high grade silica and fluorine-containing coproducts from fluosilicic acid is described. To produce silica, the fluosilicic acid is reacted with aqueous ammonia to produce a solid silica product and a solution of ammonium fluoride. The solid silica is washed under controlled conditions and further processed to produce a high grade product. The ammonium fluoride solution is concentrated and sold as a concentrated ammonium fluoride solution product or reacted with metal hydoxides or oxides to produce metal fluorides.

Abstract: A method of recovering HF from an aqueous solution containing NH.sub.4 F and HF is provided. The solution is contacted with a water-immiscible, amine-containing extractant which extracts HF in preference to NH.sub.4 F. The HF:NH.sub.4 F molar ratio of the solution, the amine, the concentration of the amine in the extractant and the contact temperature are selected so as to form an HF-loaded organic liquid phase having an HF:amine molar ratio of at least about 1.2. The extractant is preferably selected from amines, amine-HF complexes, quaternary amine fluorides and mixtures thereof with inert organic diluents. After equilibration, the HF-loaded amine is separated from the solution and HF is stripped therefrom in an amount sufficient to lower the HF:amine molar ratio by at least about 0.2.

Abstract: Silicon nitride powder is prepared in a gas-phase reaction by reacting silicon tetrachloride with ammonia at above 500.degree. C. in a fluidized bed of silicon nitride particles. An amorphous silicon nitride having a BET specific surface area of greater than 50 m.sup.2 /g is used at the beginning of the reaction. The resulting silicon nitride is then separated from the ammonium chloride simultaneously formed.

Abstract: Process for producing fluorides of Mo, W, Nb, Ta, V, Re, Ti, Zr, Hf, Co, Ni, Cr, Sb, Sn, Zn, Pb, Al and rare earth metals comprising heating fluorine-containing ammonium salts of corresponding metals in a stream of an inert or reducing gas to convert them into fluorides of the metals.

Abstract: A process for selectively stripping and separating iron ions from an organic solvent (A) which comprises bringing the organic solvent (A) containing iron and zinc ions, and containing one or more compounds selected from the group consisting of alkyl phosphoric acid, alkyl-aryl phosphoric acid, alkyl thio phosphoric acid and alkyl-aryl thio phosphoric acid together with a petroleum hydrocarbon as a diluent, into contact with an aqueous solution containing NH.sub.4.sup.+ and F.sup.- ions so as to selectively strip the iron ions into the aqueous solution despite the coexistence of zinc ions.

Abstract: A process for treating a hydrogen sulfide-containing hydrogenated Claus process tail gas to convert the hydrogen sulfide to elemental sulfur in which said gas is contacted with an aqueous alkaline solution containing a water-soluble metal vanadate, a water-soluble anthraquinone disulfonate, and a water-soluble, inorganic fluoride, borate, or phosphate complexing agent to yield an effluent gas to reduced sulfur content. The solution is thereafter regenerated by contact with an oxygen-containing gas, elemental sulfur is recovered from the solution, and the regenerated solution is recycled to the gas-contacting step. The complexing agent contained in the solution reduces the chemical consumption of the anthraquinone disulfonate.

Abstract: Particulate matter collected by an environmental air quality control device may be in part toxic in nature and thus not readily disposable. By separating the toxic portion of the particulate matter from a nontoxic portion, disposal of nontoxic portion may be more easily accomplished. This separation may be readily effected where the toxic portion is soluble and the nontoxic portion is insoluble, thus allowing the toxic soluble portion to be formed into a solution with a dissolving liquid. The nontoxic insoluble portion then may be filtered from the toxic solution, rinsed, dried and disposed of accordingly.

Abstract: In the purification of an ammonium fluoride solution containing silicic acid by adding iron (III) ions and precipitating the iron (III) ions at a pH above 8.5 and a concentration of free ammonia in the solution of more than about 1% by weight, the silicic acid being carried with the iron (III) ion precipitate, the improvement which comprises adding the iron (III) ions to the ammonium fluoride solution at a temperature below about 30.degree. C. and, before removal of the precipitate, to the solution a salt of at least one of the alkali metals, alkaline earth metals, zinc, aluminum and lead in such quantity that the solution becomes saturated with such salt.

Abstract: Silicon nitride bodies are improved by being impregnated with a silicon halide which is then converted to silicon imide in the pores of the body, which, in turn, is converted into silicon nitride.

Abstract: A process for treating a hydrogen sulfide-containing hydrogenated Claus process tail gas to convert the hydrogen sulfide to elemental sulfur in which said gas is contacted with an aqueous alkaline solution containing a water-soluble metal vanadate, a water-soluble anthraquinone disulfonate, and a water-soluble, inorganic fluoride, borate, or phosphate complexing agent to yield an effluent gas of reduced sulfur content. The solution is thereafter regenerated by contact with an oxygen-containing gas, elemental sulfur is recovered from the solution, and the regenerated solution is recycled to the gas-contacting step. The complexing agent contained in the solution reduces the chemical consumption of the anthraquinone disulfonate.

Abstract: Newly precipitated MnO(OH).sub.2 is either added to an NH.sub.4 F solution that has been made slightly basic or this compound is formed in the NH.sub.4 F solution by adding an Mn (II) and an Mn (VII) salt solution. MnO(OH).sub.2 absorbs As and noble metal ions. The purity obtained is 10.sup..sup.-8 per cent by weight (starting from .ltoreq.10.sup..sup.-5 per cent by weight) of NH.sub.4 F solution.

Abstract: A process is described whereby aluminum chlorohydroxide having a controlled chlorine content is prepared by subjecting a mineral containing aluminum oxide or hydroxide (e.g. bayerite, gibbsite, diaspore, boehmite or alumina bayer) is subjected to a preliminary etching with hydrochloric acid at a temperature in the range from 110.degree. to 150.degree. C, the solution so obtained is neutralized with ammonia and the desired aluminum chlorohydroxide (e.g. Al.sub.2 (OH).sub.5 Cl) is crystallized out.