533 results about "Fluorosilicic acid" patented technology

Compositions useful for the selective removal of silicon nitride materials relative to poly-silicon, silicon oxide materials and/or silicide materials from a microelectronic device having same thereon. The removal compositions include fluorosilicic acid, silicic acid, and at least one organic solvent. Typical process temperatures are less than about 100° C. and typical selectivity for nitride versus oxide etch is about 200:1 to about 2000:1. Under typical process conditions, nickel-based silicides as well as titanium and tantalum nitrides are largely unaffected, and polysilicon etch rates are less than about 1 Å min⁻¹.

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 invention discloses a new method for preparing silicon dioxide by utilizing rice hull ash, comprising the following steps: neutralizing and dissolving the soluble impurities in the rice hull ash by utilizing a sulfuric acid solution; adding an ammonium fluoride solution in proportion; heating and dissolving to generate ammonium fluosilicate and discharge ammonia; modulating the concentration of the ammonia water to be 10-30wt% by the ammonia generated in the water recovering reaction; placing into a seal stillpot; regulating the temperature to be 50-90 DEG C; adding the ammonium fluosilicate solution into the ammonia water in proportion; separating out the sedimentation; ageing for 0.5-3h; filtering and performing solid-liquid separation; returning the filter liquor to a silicon dissolving procedure for recycling after the filter liquor concentration is adjusted; and washing and drying the filter cakes to obtain the silicon dioxide. The method of the invention takes the regenerated resource rice hull ash as a silicon source, and adopts constant-voltage low-temperature liquid phase dissolving silicon; and the reactant ammonium fluoride and the by-product ammonia can be recycled, which not only saves the energy consumption and lowers the cost, but also has no other by-product generation and no greenhouse gas emission, thus belonging to a low-carbon green new process.

The invention discloses a producing method of calcium fluoride with white carbon black. The producing method comprises the steps of allowing fluorosilicic acid (a wet-process phosphoric acid by-product) and ammonia to react continuously in a tubular reactor, ageing and filtering generated slurry to obtain an ammonium fluoride filtrate and a white carbon black filter cake, and washing and drying the white carbon black filter cake to obtain the white carbon black. Produced ammonium fluoride is good in quality and high in purity; the white carbon black is high in content, small in particle size, large in specific surface area and excellent in reinforcement performance, can be used for completely substituting the existing industrial water glass precipitation-process white carbon black; the ammonium fluoride filtrate and calcium hydroxide react to form a crude product of calcium fluoride and ammonia water; the crude product of calcium fluoride is washed and dried to form calcium fluoride; and the ammonia water is distilled into ammonia to serve as a raw material for ammoniation of fluorosilicic acid.

The invention discloses a surface treating agent of recycled aggregate. The surface treating agent is mainly prepared by the following raw materials by weight: 0.5-1.5% of polyvinyl alcohol, 4-10% of sodium silicate, 0.5-3% of urea, 0.2-1% of sodium fluosilicate and 88-93.8% of water. The surface treating agent has the advantages of being capable of improving surface state of the recycled aggregate and remarkably reducing water absorption rate of the recycled aggregate by utilizing the polyvinyl alcohol, sodium silicate and sodium fluosilicate which are good in film formation performance, utilizing sodium silicate and sodium fluosilicate solution to fill holes and micro cracks of the recycled aggregate and obviously improving strength of the recycled aggregate accordingly. In addition, when the recycled aggregate is processed and used for preparing concrete, the film-shaped sodium silicate and sodium fluosilicate on the surface of the recycled aggregate and cement are hydrated to be subjected to calcium hydroxide reaction to produce calcium silicate and calcium fluosilicate which are capable of remarkably improving strength of a concrete transition area and improving bounding performance between the aggregate and cement stone.

A process for preparing potassium fluoride and white carbon black simultaneously includes such steps as reaction between fluorosilicic acid (or potassium fluorsilicate) and potassium hydroxide to obtain the slurry of white carbon black and potassium fluoride solution, filtering, washing to obtain white carbon black paste and potassium fluoride solution, and respectively preparing white carbon black and potassium fluride from them.

A method for the production of inorganic aluminum substances and amorphous silica from aluminum oxide containing ores, comprising: (a) leaching of said ores with fluorosilicic acid to obtain aluminum fluosilicate solution; (b) filtering said leached solution from insoluble materials; and (c) washing said insoluble materials.

The process of producing calciumfluoride with fluorosilicic acid and calcium oxide as material includes the following steps: 1. reacting fluorosilicic acid solution and calcium oxide for 10-60 min, filtering to obtain solid calcium fluorosilicate; 2. decomposing calcium fluorosilicate at 200-600 deg.c for 1-5 hr to produce solid calcium fluoride product and silicon tetrafluoride gas; and 3. absorbing silicon tetrafluoride gas with water and hydrolyzing, filtering to obtain fluorosilicic acid solution to be returned to the step 1 and solid silica, and washing and drying silica to obtain carbon white. The process utilizes fluorosilicic acid as one side product of phosphate fertilizer production as one main material, and has low cost and environment friendship.

The invention provides a phosphorus-free graphene-oxide-containing metal surface pretreatment solution and an application method thereof. The phosphorus-free graphene-oxide-containing metal surface pretreatment solution comprises the following components in percentage by weight: 1-2% of fluosilicic acid, 0.2-1% of sodium molybdate, 1-2% of sodium nitrate, 0.6-1.2% of metal surface oxidizer, 1-2% of disodium edetate, 0.8-1.5% of tartaric acid, 0.1-0.3% of graphene oxide and the balance of water, totaling 100%. The product has the advantages of stable and excellent properties and wide application range. The added graphene oxide can effectively enhance the paint film adhesion of the conversion coating.

The invention relates to a method for preparing a babbitt alloy from residue containing silver of copper anode slime. The method comprises the following steps:1, adding sodium carbonate, powdered carbon and borax according to the mass of the residue containing silver, and uniformly mixing; 2, melting to obtain a crude alloy containing lead; 3, preparing an electrolyte from fluosilicic acid, lead fluorosilicate, stannous oxide and potassium antimonyl tartrate, and adding with gelatin and ethyl naphthol; 4, treating the crude alloy as an anode and a stainless steel plate as a cathode, and taking the cathode plate (the stainless steel plate) and peeling cathode products each 12h; and 5, adding lead, antimony and copper or tin, antimony and copper to the cathode products, and melting to obtain the lead-based or tin-based babbitt alloy. The method which has the advantages of short flow, low cost, and strong practicality and allows the lead-based or tin-based babbitt alloy to be prepared from the residue containing silver of the copper anode slime is especially suitable for anode slime processing in electrolyzing electronic wastes with regenerated copper, and has the characteristics of simple and feasible operation, and high recovery rate of valuable metals.

The invention relates to a comprehensive utilization method of industrial waste residues and particularly relates to a comprehensive utilization method of manganese slag. The method comprises the following steps: reaction, namely crushing the manganese slag, mixing the crushed manganese slag with a fluosilicic acid aqueous solution to react, and carrying out solid-liquid separation after reaction to obtain solid A and liquid A; decomposition, namely adding the solid A to a decomposing agent to undergo a decomposition reaction, adding a dissolving agent after the decomposition is finished, uniformly mixing and carrying out solid-liquid separation to obtain solid B and liquid B; absorption, namely enabling generated fluorine-containing gas to pass through an absorption tower to realize multistage circular absorption to obtain solid C and liquid C, and drying the solid C to obtain white carbon black; and neutralization, namely adding a neutralizing agent to the liquid B to obtain solid D and liquid D, carrying out high-temperature crystallization on the liquid D to obtain manganese sulfate and sulfate, and drying the solid D to obtain lightweight aluminium hydroxide. According to the comprehensive utilization method disclosed by the invention, useful elements in the manganese slag can be effectively extracted to produce basic chemical materials; in addition, the process is simple and no three-waste emission is caused; the effect of comprehensive utilization of manganese slag at high efficiency and low energy can be practically achieved.

The present invention relates to process of producing aluminum fluoride with fluorosilicic acid and aluminum hydroxide as material. The process includes the following steps: 1. reacting fluorosilicic acid solution and sodium sulfate for 10-60 min, filtering to obtain solid sodium fluorosilicate and waste sulfuric acid solution to be treated and drained; 2. decomposing aluminum fluorosilicate at 300-800 deg.c for 1-5 hr to produce solid sodium fluoride and silicon tetrafluoride gas; 3. absorbing silicon tetrafluoride gas with water and hydrolyzing, filtering to obtain fluorosilicic acid solution to be returned to the step 1 and solid silica, and washing and drying silica to obtain carbon white; 4. reacting solid sodium fluoride and sulfuric acid, condensing, rectifying to obtain anhydrous hydrofluoric acid and solid sodium sulfate returned to the step 1; and 5. reacting anhydrous hydrofluoric acid and aluminum hydroxide to produce aluminum fluoride product. The process is environment friendly.

The invention discloses a method for preparing white carbon black from silicon slag containing fluorine. The method comprises the steps of: adding silicon slag containing fluoride and measured alkaline solution according to the proportion into a reaction kettle provided with a stirrer and a heating device; heating the mixture to 40-80 DEG C under fully stirring condition for maintaining for 20-50 min, so that the fluosilicic acid in the silicon slag containing fluoride is reacted completely to prepare a mixed solution of silicon dioxide and fluoride salt; heating or cooling the prepared liquid-solid mixture of silicon dioxide and fluoride salt to 50 DEG C or less, then filtering or centrifuging the mixture for liquid-solid separation so as to prepare a wet cake of silica and a filtrate of fluoride salt; backwashing the prepared wet cake of silica for 4-6 times, merging the first washing solution with fluoride salt to prepare a fluoride salt solution for other uses, and putting the second to the sixth washing solution into the first to the fifth washing solution tank respectively for the next first to fifth washing; drying the wet filter cake of silica to obtain white carbon black products. The method has the advantages of simplicity in processing, less equipment, simplicity and convenience in operation, and low production cost, and is convenient to realize industrial production.

The method for producing ice spar and coproducing white carbon black includes the following steps: (1) adding ice mother and ammonia water in water to prepare dilute ammonia water, making fluorosilicic acid solution react with dilute ammonia water to obtain white carbon black crystal seed, controlling pH value of white carbon black in 6-8 and reaction temp. at 30-40 deg.C; (2). adding a certain quantity of white carbon black crystal seed into ammonolysis cell, in which the added quantity of crystal seed can be regulated according to the requirements, adding proper quantity of ice mother, in the presence of crystal seed making sodium fluorosilicate and ammonia water implement ammonolysis reaction at about 60 deg.C to obtain white carbon black slurry, filtering and washing to obtain white carbon black ointment, drying to obtain its finished product; (3). providing the steps for obtain ice spar product.

A process for electrolyzing the fluorosilicic acid sludge of bismuth ore concentrate to obtain high-purity (99.999%) bis muth includes such steps as preparing sludge, adding hydrochloric acid to regualte acidity, electrolyzing to educe out spongy bismuth from the cathode, pressure filter, smelting, and removing impurities by introducing chlorine gas and sodium hydroxide. Its advantages are low cost and energy consumption, and high quality of product.

The invention relates to a method for producing polishing powder used for a liquid crystal display device. The method comprises the following steps: at the room temperature, 30 to 40 percent of fluorosilicic acid is added into rare earth chloride solution with REO of between 80 and 100 gram/litre and CeO2/REO of more than or equal to 70 percent under the stirring; after five minutes, an additive A is added into the mixture, is heated to the temperature of between 70 and 80 DEG C, is kept at the temperature and is added with mixed precipitant solution till the reaction ends; the PH value of the mixture is 7; the mixture is stirred for 10 minutes, is kept stand for 3 to 5 hours and supernatant fluid of the mixture is removed through siphonage; under the stirring, cold water is added to nearly fill a groove fully; before the stirring is stopped, flocculant solution is added till appearing the flocculating effect; the mixture is kept stand, is deposited and the supernatant fluid of the mixture is removed through siphonage for three times; the mixture is washed, is heated up to 98 DEG C, is kept at the temperature for 10 minutes and is discharged to a stainless steel sieve with 120 meshes; the mixture is subjected to solid-liquid separation, vacuum extraction and filtering and dewatering by a centrifuge; a filter cake is transferred to a quartz material sagger; the charging thickness is less than or equal to 9 centimeters; the filter cake is transported to a muffle tunnel kiln at the temperature of 900 DEG C, is subjected to dehydration in a preheating section and decomposition and transformation at certain degree, is roasted for 3 to 4 hours at high temperature of 900 DEG C, is cooled to the temperature of less than 400 DEG C in a cooling section and comes out from the kiln; a roasted material is cooled to the room temperature and is subjected to stage treatment; and a quality part is the product.