244results about "Fluorine/hydrogen-fluoride" patented technology

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.

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.

A method comprising: providing a halogen stream; providing an alkane stream; providing a decoking agent; and reacting at least a portion of the halogen stream with at least a portion of the alkane stream in the presence of a halogenation catalyst and the decoking agent to form a halogenated stream.

A disclosed preparation method for anhydrous hydrogen fluoride comprises the following steps: respectively adding a mixed sulfuric acid ( concentrated sulfuric acid and oleum) and fluorspar powder according to a certain material pouring ratio into a pre-reactor for a pre-reaction; sending to a converter reactor, reacting under the heating condition to obtain a large amount of crude hydrogen fluoride gas; and processing by a washing tower, a condenser, a rectifying tower and a degassing tower, so as to prepare pure hydrogen fluoride gas. An incompletely reacted material in the converter reactor is processed through recycle, and a gas uncollected after the crude hydrogen fluoride gas generated in the reaction is refined is secondarily utilizable through two-time circulation absorption, so that the yield of the preparation method is substantially improved.

A method comprising: providing an alkyl halide stream; contacting at least some of the alkyl halides with a coupling catalyst to form a product stream comprising higher hydrocarbons and hydrogen halide; contacting the product stream with a solid reactant to remove at least a portion of the hydrogen halide from the product stream; and reacting the solid reactant with a source of oxygen to generate a corresponding halogen.

The invention provides a method for comprehensively recovering tungsten and fluorine from minerals, namely a mixed acid of phosphoric acid and sulfuric acid is adopted for decomposing complex calcium-containing minerals containing fluorite, scheelite, apatite, and calcite, wherein the fluorite is decomposed to fluorine hydride or silicon tetrafluoride to escape, and absorption treatment is performed for preparing hydrofluoric acid or a fluoride salt; and the scheelite is transformed to phosphotungstic acid to enter into a solution, and filtrate after filtration is supplemented into the consumed sulfuric acid and the phosphoric acid after extraction of the tungsten and returned to the new-round mineral leaching. The method disclosed by the invention has the advantages of comprehensively recovering the fluorine and the tungsten from the minerals, reducing the requirements on the fluorite or the tungsten ore raw material, reducing the pressure on a mineral dressing link, improving the comprehensive recovery rate and simultaneously ensuring the decomposition rate of the fluorite and the scheelite, wherein the decomposition rate of the fluorite is above 98%, and WO3 contained in decomposition slag is reduced to below 0.5%; furthermore, a leaching agent can be recycled, so that leaching cost and wastewater emission are greatly reduced; and the method also has the advantages of simple leaching equipment, convenience in operation and easiness in realization of industrialization.

The method of comprehensively utilizing phosphate fertilizer by-product includes utilizing ammonium fluoride solution of 3-14% concentration to absorb side product fluorine containing tail gas ammonium fluorosilicate solution; adding iron scrap or iron salt to fluorosilicic acid as one other by-product to eliminate phosphorus; adding liquid ammonia, ammonia water or ammonium bicarbonate; filtering, washing, and eliminating silica precipitate; returning ammonium fluoride solution to phosphate fertilizer absorbing system, concentration and drying to obtain ammonium hydrogen fluoride; reacting solid ammonium hydrogen fluoride and sulfuric acid at high temperature to obtain HF gas, absorbing HF gas to obtain hydrofluoric acid, purification and condensation to obtain anhydrous HF; and mixing the mixture of ammonium sulfate and ammonium bisulfate with ammonium bicarbonate or ammonia in a mixer, curing and crushing to ammonium sulfate fertilizer.

The present invention pertains to ternary azeotrope and azeotrope-like composition including 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), HF, and either 1,1,2,3-tetrachloropropene (TCP) or 1,1,1,2,2-pentafluoropropane (HFC-245cb). The present invention also relates to binary azeotropes of 2,3,3,3-tetrachloropropene and HF. Such azeotropic and azeotrope-like compositions are useful as intermediates in the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf).

The invention discloses an anhydrous hydrogen fluoride production method which comprises the following steps: conveying fluorite powder and sulfuric acid to a pre-reactor, fully mixing the fluorite powder and the sulfuric acid and enabling the fluorite powder and sulfuric acid to react to generate coarse hydrogen fluoride gas; removing impurities from the coarse hydrogen fluoride gas through a pre-purifying tower and a washing tower, cooling the coarse hydrogen fluoride gas, and conveying the coarse hydrogen fluoride gas to a rectifying tower for refining; enabling the anhydrous hydrofluoric acid to get out of the rectifying tower with the help of the pressure of the tower, and leading the anhydrous hydrofluoric acid to an anhydrous hydrofluoric acid finished product storage tank through a finished product cooler. According to the invention, the hydrogen fluoride discharged from the gas can be recycled, the conversion rate of the product is increased, the cost is lowered, and useful by-products such as gypsum and fluosilicic acid are produced.

A process for preparing high-purity anhydrous hydrogen fluoride from the fluorosilicic acid as industrial by-product and concentrated sulfuric acid features that the fluorosilicid acid is deposited out in salt mode and the traditional fluorespar approach is then used. The generated sulfate as by-product can be used as precipitant of fluorosilicic acid system.

The invention provides a method for preparing silicon tetrafluoride and anhydrous hydrogen fluoride from sodium fluosilicate acidified by sulfuric acid, which relates to the technical field of fluorine chemical industry, in particular to a method for preparing silicon tetrafluoride gas and anhydrous hydrogen fluoride gas by reaction of sodium fluosilicate and sulfuric acid. The method of the invention comprises the following steps: (a) stirring sodium fluosilicate and excessive sulfuric acid at the temperature lower than 150 DEG C for reacting to obtain silicon tetrafluoride gas, wherein hydrogen fluoride remains in solid residues; (b) dedusting, cooling, drying, refining and compressing the silicon tetrafluoride gas generated in the step (a) to obtain high-purity silicon tetrafluoride gas; (c) continuously heating to 200 DEG C to enable the hydrogen fluoride gas to escape; and (d) dedusting, cooling, drying, refining and compressing the hydrogen fluoride gas escaping in the step (c) to obtain the anhydrous hydrogen fluoride (AHF) gas. The invention enables the specific fluorine and silicon resources of phosphate fertilizer enterprises to be fully and efficiently utilized.

The invention discloses a method for treating fluorine-containing wastewater and recycling fluorine-containing sludge produced by treatment of fluorine-containing wastewater. The method comprises the steps of reacting the fluorine-containing wastewater with calcium chloride under the acidic condition formed by adding a waste acid matter, performing crystallization sedimentation to remove most fluorine ions from the wastewater to form high-purity fluorine-containing sludge, removing dissolved calcium fluoride and other impurities from supernate through alkali sedimentation to form a small amount of fluorine-containing sludge with relatively low purity, then neutralizing the supernate, and discharging effluent, wherein the concentration of fluorine ions of the effluent is lower than 10 mg/L and accords with national discharge standards; drying the high-purity fluorine-containing sludge, then adding the dried sludge and excessive sulfuric acid into a reactor with a stirring device, reacting at 150-300 DEG C to prepare hydrogen fluoride, and condensing and rectifying the obtained crude hydrogen fluoride gas to obtain an anhydrous hydrogen fluoride product.

Durable antireflective multispectral infrared coatings comprising at least one layer of a metal oxyfluoride are provided.

The invention provides a method for preparing electronic grade ultrahigh purity hydrofluoric acid. The method comprises the following technical steps: (1) pretreating industrial anhydrous hydrogen fluoride; (2) treating in a reboiler; (3) distilling; (4) cooling; (5) absorbing; (6) performing ion exchange adsorption; and (7) filtering. The invention has the following beneficial effects: hydrogen peroxide is used to oxidize As<3+>, thus the problem that As<3+> is difficult to remove can be completely solved; chelating agent and a weak-base anion-exchange resin system are adopted to deeply remove a small amount of metal ions and impurities; through secondary filtration, all the indexes of hydrofluoric acid can meet the requirements of the electronic grade ultrahigh purity agent; and the method of the invention can be used for large-scale production, and the technology is stable, is easy to control and is suitable for popularization.

A two-step method is adopted to carry out low temperature gas phase hydrolysis and fluoride-silicon separation operations of silicon tetrafluoride. In a first step, a silicon tetrafluoride gas is hydrolyzed into a fluosilicic acid gas and silicon dioxide particles at a low temperature; in a second step, a hydrogen fluoride gas is dissolved by a washing operation of high concentrated sulfuric acid so as to promote complete decomposition of the fluosilicic acid into the hydrogen fluoride gas and a silicon tetrafluoride gas; decomposed and separated hydrogen fluoride gas is completely dissolved in high concentrated sulfuric acid; decomposed and separated silicon tetrafluoride can be continuously carried out hydrolysis and fluoride-silicon separation operations; and finally complete separation of the fluoride and silicon elements are realized. The method has the beneficial effects that a gas raw material containing relatively low silicon tetrafluoride content can be used; a method for purifying the raw material is simple; total conversion rate of silicon tetrafluoride introduced into a production apparatus system can reach over 98%; and hydrolysis temperature is relatively low, so that the method can realize industrial production relatively easily. The method is suitable for recovery and utilization of fluoride- and silicon-containing materials from industries such as phosphorus chemical industry, fluorine chemical industry, electron industry, glass processing industry and aluminium alloy processing industry.

The invention discloses a method for absorbing fluorine. Phosphoric acid gas enters into a fluorine washing vacuum tube A(2) with a fluorine washing nozzle A(1) for the first time parallel current and washing in a pipeline, and then enters into a first level separator (3) for gas-liquid separation; the separated liquid phase part enters into a first level scrubber liquid seal trough (4) for circulation cleaning; the separated phosphoric acid gas enters into a fluorine washing vacuum tube B(6) with a fluorine washing nozzle B(5) for the second time washing; the washed gas enters into a secondary level separator (7) for gas-liquid separation; the separated liquid phase enters into a secondary level scrubber liquid seal trough (8) for circulation cleaning; the separated gas phase enters into a fluorine separator (9) for gas-liquid separation; the separated liquid phase part passes through the secondary level scrubber liquid seal trough (8) by a lower liquid pipe; the separated gas enters into a circulating water system. The method has high recovery rate, can effectively lighten corrosion maintenance on devices, thus being convenient for cleaning; in addition, the method has low cost.

The invention discloses a method for preparing fumed silica and anhydrous hydrofluoric acid by utilizing phosphatic fertilizer by-product fluosilicate as raw material. The method comprises the steps as follows: performing pyrolysis on the phosphatic fertilizer by-product fluosilicate at the temperature of 200-400 DEG C to obtain silicon tetrafluoride, utilizing a filter to remove dust containing in the silicon tetrafluoride, washing the silicon tetrafluoride by 93-98 percent of concentrated sulfuric acid to remove the moisture and impurities, mixing the silicon tetrafluoride, air with hydrogen in a hydrolysis reactor via the volume ratio of 1:2:(0.05-0.3) and performing high-temperature hydrolysis reaction, and then performing aggregation, separation, dust removal, condensation and distillation to obtain the fumed silica and the anhydrous hydrofluoric acid respectively. The method has the advantages that the technical process is simple, the raw material is easy to get, the utilization rate of the raw material is high, energy conservation and environmental protection are realized, the corrosion to the equipment is less, the production cost is reduced, and the produced white carbon black is high in purity.

The invention discloses a method for preparing silicon tetrafluoride and anhydrous hydrogen fluoride by taking sodium fluorosilicate as a raw material. The method is characterized by comprising the following steps of: (1) drying sodium fluorosilicate for removing water; (2) adding the dried sodium fluorosilicate and sulfuric acid into a rotary kiln reactor in the molar ratio of 1:1, and reacting at the temperature of 160-220 DEG C for 30-180 minutes to generate a sodium sulfate solid and a mixed gas of silicon tetrafluoride and hydrogen fluoride; (3) dedusting, pressurizing and precooling to between 20 DEG C below zero and 30 DEG C below zero; (4) feeding the precooled mixed gas into a rectifying tower for separating, controlling the pressure of the rectifying tower at 0.6-0.75 MPaG and the temperature of tower top condenser between 70 DEG C below zero and 80 DEG C below zero, and discharging anhydrous hydrogen fluoride from the tower bottom; and (5) discharging silicon tetrafluoride from the tower top in the form of a liquid phase, decompressing, gasifying, dedusting and feeding into a silicon tetrafluoride washing tower to obtain silicon tetrafluoride gas. The method has the advantages that: corrosion to equipment can be reduced greatly, the obtained silicon tetrafluoride and hydrogen fluoride products have high purity, and the production process has low energy consumption and is environmentally-friendly.

The invention provides a method for comprehensively recovering fluorine and tungsten from tungsten-containing fluorite mineral. In the method, the tungsten-containing fluorite mineral is roasted by use of sulfuric acid and phosphoric acid (or phosphorite), and the HF gas generated by decomposing the fluorite by sulfuric acid is used for preparing hydrofluoric acid; and meanwhile, the tungsten-containing mineral reacts with the sulfuric acid and phosphoric acid to obtain soluble heteropoly acid which is left in fluorgypsum and can be recovered by a water leaching or acid leaching method. Through the invention, the tungsten in mineral can be efficiently recovered while preparing the hydrofluoric acid; the decomposition rate of fluorite is over 95%, the recovery rate of tungsten exceeds 90%, and the content of WO3 in the fluorgypsum is reduced to below 0.1%; a leaching reagent can be recycled, thus the cost and the waste water discharge are greatly reduced; and the equipment is simple, the operation is convenient, and the industrialization is easy to realize.