251 results about "Fluorosilicic acid" patented technology

The invention discloses an integrated reaction process for preparing potassium fluoborate through efficient conversion of fluosilicic acid, and relates to the technical field of inorganic fluorine chemical industry, and the potassium fluoborate is prepared through the technologies of complexing metal impurities through EDTA disodium, catalyzing condensation reaction through Fe-TiO2, carrying out K2CO3 / nano gamma-Al2O3 composite desilicication, deeply removing sodium through ion exchange and carrying out mother liquor closed-loop circulation. The problems of serious sodium pollution, low reaction efficiency and resource waste in the traditional process are solved. The composite desiliconization agent improves the desiliconization rate to 96%, the reaction time is shortened by 40% through nanometer catalysis, the mother liquor recycling rate is 80%, and the silicon slag is converted into high-added-value nanometer white carbon black. The product purity is greater than or equal to 99.5%, the sodium residue is less than or equal to 0.003%, and the method is suitable for industrial production of electronic-grade potassium fluoborate.

The invention belongs to the technical field of preparation of fluorescent powder, and particularly relates to double-shell narrow-band red-light fluorescent powder as well as a preparation method and application thereof. The narrow-band red-light fluorescent powder is Mn < 4 + >-doped potassium fluosilicate fluorescent powder, and the narrow-band red-light fluorescent powder is coated with a potassium fluosilicate inner shell layer and a cystine outer shell layer. The preparation method comprises the following steps: mixing a cysteine solution with the narrow-band red-light fluorescent powder, stirring, centrifuging, and drying the precipitate obtained by centrifuging to obtain the double-shell narrow-band red-light fluorescent powder. The surface of the prepared fluorescent powder is provided with the Mn < 4 + >-free potassium fluosilicate inner shell layer and the outer hydrophobic cystine layer, the surface of the core narrow-band red-light fluorescent powder is covered with the double-shell structure, the water resistance and the light-emitting characteristic of the narrow-band red-light fluorescent powder can be remarkably improved, and the wide application prospect is achieved.

The invention relates to the technical field of industrial solid waste resource utilization, and particularly discloses a fluorine-containing silicon slag recycling process which comprises five steps of fluorine-containing silicon slag raw material pretreatment, acid leaching fluorine extraction, ammonium fluosilicate preparation, nanometer silica gel purification and wastewater recycling. Fluorine in the fluorine-containing silicon slag is converted into ammonium fluosilicate solid to be recycled, fluorine in the fluorine-containing silicon slag is converted into sodium silicate to be manufactured into nano silica gel to be recycled, only feeding reaction is needed in the whole process, then filtering is conducted, the technological process is simple, and the treatment efficiency of the fluorine-containing silicon slag is improved. 0.3 ton of ammonium fluosilicate (the market price is 8000 yuan / ton) and 0.2 ton of nano silica gel (the market price is 15000 yuan / ton) can be produced from each ton of fluorine-containing silicon slag, and huge economic value can be brought to factories.

The invention relates to a phosphorite wet processing method, and belongs to the technical field of chemical engineering. The phosphorite wet processing method comprises the following steps: A, phosphorite acid leaching: carrying out acidolysis leaching on a phosphorite raw material, and carrying out solid-liquid separation to obtain wet-process phosphoric acid; b, removing metal ions from wet-process phosphoric acid; and C, wet-process phosphoric acid defluorination: extracting fluosilicic acid in wet-process phosphoric acid at 10-70 DEG C by adopting a wet-process phosphoric acid defluorination extraction agent, and carrying out phase splitting to obtain defluorinated purified phosphoric acid and an organic phase loaded with fluosilicate. According to the invention, high-value utilization of low-grade phosphorite resources is realized. According to the method, impurities can be fully removed, the loss rate of phosphoric acid is low, the purity of the finally obtained phosphate product reaches 97% or above, the product quality is high, and the requirements of different fields for high-quality phosphate can be met. The method is simple in process, low in energy consumption and low in cost.

The invention discloses a wear-resistant floor concrete and a preparation method thereof, which is composed of 250-300 kg / m 3 , lithium slag powder 50~100kg / m 3 , magnesium fluorosilicate 1~3kg / m 3 , aluminum dihydrogen phosphate 0.5~2kg / m 3 , hydroxyapatite 0.5~5kg / m 3 , nano calcium sulfate 0.5~1kg / m 3 , crushed stone 1200~1400kg / m 3 , machine-made sand 700~900kg / m 3 , water reducing agent 5~10kg / m 3 , water 140~170kg / m 3 On the one hand, by improving the particle shape of machine-made sand, the matching effect between aggregates is fully utilized to form a dense skeleton structure; on the other hand, by introducing lithium slag powder, magnesium fluorosilicate, aluminum dihydrogen phosphate, hydroxyapatite, and nano-calcium sulfate, the density, wear resistance and crack resistance of concrete are improved, and the shrinkage can be effectively reduced. The resulting product has good workability, strong water retention capacity, strong surface wear resistance, and strong crack resistance.

The utility model relates to the technical field of chemical production equipment, and particularly discloses a chlorine-containing hydrogen fluoride separation system which comprises a condensing tower and an absorption separation tower which are sequentially connected, an absorption separation device comprises a tower body, a distribution disc and a filler section are sequentially arranged in the tower body from top to bottom, and a liquid inlet and a gas outlet are formed in the upper end of the tower body; a liquid outlet and an air inlet are formed in the lower end of the tower body, the air inlet and the liquid inlet are both formed in the radial direction of the tower body, and the liquid outlet and the air outlet are both formed in the axial direction of the tower body; dilute sulfuric acid is introduced into the liquid inlet. The utility model aims to solve the problem that the absorption and separation effect of chloride ions in fluosilicic acid of a separation system is not ideal in an existing production system for preparing hydrofluoric acid by a fluosilicic acid method.

The present invention relates to a method for decomposing and utilizing phosphate-potassium ore, belonging to the technical field of phosphate-potassium ore treatment. The technical problem solved by the present invention is to provide a method for decomposing and utilizing phosphate-potassium ore. The method comprises the following steps: mixing nitric acid and phosphate-potassium ore, and carrying out an acidolysis reaction; after the reaction is completed, performing solid-liquid separation to obtain a phosphorus-containing filtrate and potassium-containing acid-insoluble substances; wherein, the leaching rate of potassium in the phosphate-potassium ore is ≤3%, and the leaching rate of phosphorus is ≥96%. The present invention for the first time uses nitric acid to treat phosphate-potassium ore, controls the reaction conditions of the acidolysis process to reduce the leaching rate of K element, realizes the separation of phosphorus and potassium elements, avoids the problem that potassium fluorosilicate precipitates and clogs the filter cloth during vacuum filtration and cooling, perfectly avoids the disadvantages of the traditional wet-process phosphoric acid for treating phosphate-potassium ore, and has rich products.

The invention relates to a rapid filtering device and method for potassium fluoborate production, aiming at the characteristics of slurry containing KBF4 crystal (D50 = 20-50 [mu] m), colloidal metaboric acid (HBO2) and potassium fluosilicate (K2SiF6) impurities prepared by a hydrofluoric acid-boric acid method, the device adopts a sliding block type filter frame and inflatable elastic filter cloth structure, and is matched with a rotary scraper and a hydraulic turning plate mechanism; the method comprises the following steps: controlling the temperature of reaction slurry with the solid content of 15-30wt% to 38-58 DEG C, pumping the reaction slurry into a device, breaking KBF4-K2SiF6 heterogeneous aggregates through 5-22rpm rotary stirring, triggering 0.48-0.82 MPa inflatable extrusion to peel boric acid colloid when the filtering pressure difference reaches 0.3-0.6 MPa, driving a scraper to radially feed 5-18mm crushed pressed cakes after a gas source is closed, further separating crystals and wrapping mother liquor through secondary extrusion (0.42-0.68 MPa), and finally obtaining the high-purity KBF4-K2SiF6 / KBF4-K2SiF6 / KBF4-K2SiF6 / KBF4-K2SiF6 / KBF4-K2SiF6 composite material. And finally, a filter cake with the water content of 15-25wt% is discharged by a hydraulic overturning guide plate (the inclination angle of 25-40 degrees). Compared with a traditional process, the method has the advantages that the B2O3 residual quantity is reduced to be less than or equal to 0.15 wt% (reduced by more than 50%), the filtering efficiency is improved by 2.1-3.2 times, and the method is suitable for a ten-thousand-ton potassium fluoborate production line.

The invention discloses a method for modifying a nano-cluster Y molecular sieve, which comprises the following steps of: (a) controlling the sodium oxide content of the nano-cluster Y molecular sieve to be 2.0-4.5% through ion exchange treatment; (b) adopting an ammonium fluosilicate solution to carry out shallow dealumination and silicon supplementation on the nano-cluster Y molecular sieve obtained in the step (a), wherein the shallow dealumination and silicon supplementation means that the silica-alumina ratio of the nano-cluster Y molecular sieve after dealumination and silicon supplementation is controlled to be increased by 50-200% compared with that of the nano-cluster Y molecular sieve before treatment, and preferably, the silica-alumina ratio of the nano-cluster Y molecular sieve after dealumination and silicon supplementation is increased by 80-150%; (c) carrying out hydrothermal dealumination treatment on the material obtained in the step (b); and (d) carrying out acid treatment on the material subjected to hydro-thermal treatment to obtain the modified nano-cluster Y molecular sieve. Compared with a nano-cluster Y molecular sieve before treatment, the modified Y molecular sieve prepared by adopting the modification method not only keeps the nano-cluster shape, but also greatly improves the mesoporous content and the hydrothermal stability.

The invention belongs to the field of inorganic chemical industry, and particularly relates to a method and a system for efficiently utilizing a phosphate fertilizer byproduct, the method comprises the following steps: carrying out acidolysis on fluosilicic acid with the concentration of more than or equal to 45% wt and concentrated sulfuric acid to generate a mixed solution of silicon tetrafluoride gas and fluorosulfonic acid; the mass ratio of the fluosilicic acid to the concentrated sulfuric acid is controlled to be 1: (4-15); pyrolyzing the obtained fluorosulfonic acid to generate dilute sulphuric acid, hydrogen fluoride and water vapor, forming 98% concentrated sulphuric acid from part of dilute sulphuric acid and fuming sulphuric acid, drying hydrogen fluoride to obtain crude hydrogen fluoride gas, and condensing and rectifying to obtain anhydrous hydrogen fluoride; the rest dilute sulphuric acid is partially compounded and then returned for acidolysis, and the rest dilute sulphuric acid is used for producing white carbon black and flows back to a wet-process phosphoric acid system; and circularly absorbing the obtained silicon tetrafluoride gas by using secondary concentrated fluosilicic acid to obtain fluosilicic acid with the mass concentration of more than or equal to 45%, recycling the fluosilicic acid for acidolysis reaction, and modifying the concentrated by-product silicon dioxide to obtain the high-activity white carbon black. The problems of energy consumption and cost are solved, and efficient circulation and poly-generation of fluorine and silicon resources are achieved in the whole process.

The invention discloses an environment-friendly early-strength alkali-free accelerator as well as a preparation method and application thereof, and belongs to the technical field of concrete admixtures. When the environment-friendly early-strength alkali-free accelerator is prepared, aluminum sulfate is not directly adopted to participate in the reaction, the accelerator is obtained by reacting concentrated sulfuric acid and fluosilicic acid with an aluminum oxide component in the industrial byproduct aluminum mud, and the solubility of aluminum ions is further improved by utilizing the principle that concentrated sulfuric acid releases a large amount of heat when encountering water and the principle that acid-base reaction releases heat; the resource utilization of the industrial byproduct aluminum mud is realized. According to the invention, the industrial by-product fluorosilicon slag is subjected to mechanical activation and chemical excitation and the synergistic effect of the grinding aid, so that the reaction activity of the fluorosilicon slag is greatly improved, the fluorosilicon slag is used for preparing the accelerator, the effects of accelerating and early strength are exerted, waste is turned into wealth, and the raw material cost of the accelerator is saved.

The invention belongs to the technical field of chemical production, and particularly discloses a preparation method of high-purity silicon dioxide, which comprises the following steps: S1, grinding: crushing and grinding minerals or waste residues containing silicon dioxide or silicate; s2, leaching: mixing with a leaching agent according to a ratio, carrying out a leaching reaction, and carrying out solid-liquid separation to obtain a fluorine ion complex solution containing fluosilicic acid; s3, extraction: separating fluosilicic acid from fluorine ion complex impurities by adopting an extraction method to obtain a high-purity fluosilicic acid or fluosilicate solution; s4, pH adjustment: carrying out a double decomposition reaction by adjusting the pH, and carrying out solid-liquid separation to obtain a silicic acid solid and soluble fluoride; and S5, obtaining high-purity silicon dioxide. The preparation method of the high-purity silicon dioxide is suitable for most silicon-containing raw materials, the content of impurities in the silicon slag is effectively reduced, and the purity of the prepared high-purity silicon dioxide can reach 99.99%.

The present invention relates to the technical field of hydrogen fluoride preparation, and particularly to a method for separating a mixed solution containing hydrogen fluoride and sulfuric acid. The separation method includes: A) Concentrated fluorosilicic acid and concentrated sulfuric acid react in a reaction device to generate silicon tetrafluoride gas and a sulfuric acid solution containing hydrogen fluoride; B) The first part of the sulfuric acid solution containing hydrogen fluoride is subjected to two-stage separation to obtain hydrogen fluoride gas; the second part of the sulfuric acid solution containing hydrogen fluoride is heated and recycled to the reaction device. The present invention adopts two-stage separation; another path of the sulfuric acid solution containing hydrogen fluoride led out after the main reaction enters the reaction device again after being heated, with relatively low energy consumption. Therefore, the separation method provided by the present invention separates hydrogen fluoride from the sulfuric acid solution with relatively low energy consumption and can reduce fluorine loss.

The invention provides aerogel for sewage treatment and a preparation method thereof.The preparation method comprises the steps that a fluosilicate solution and a silicon source material are mixed, then a metal ion targeting polymer is added for a reaction, and fluosilicate modified silica sol is obtained; adding a titanium-based photocatalyst into the fluosilicate modified silica sol, and uniformly mixing to obtain a mixed solution; transferring the aerogel sol into a mold, keeping a constant temperature for gelatinization for 24 hours, putting into a freezing environment of-40 DEG C for freeze-drying, heating to 300 DEG C, and keeping the temperature for 3 hours to obtain the aerogel. Therefore, the adsorption capacity of the aerogel and the degradation effect on pollutants are improved.

The invention belongs to the technical field of cosmetics, and particularly discloses a freeze-dried powder base solution and a preparation method thereof. The freeze-dried powder base solution comprises a component A and a component B. The component A is prepared from magnesium potassium fluosilicate, a filling agent, lauroyl lysine, titanium dioxide, CI 77492, CI 77491, CI 77499 and the balance water, butanediol, xanthan gum, a thickening agent, trehalose, polysorbate-60, an emulsifying agent a, phenyl polytrimethylsiloxane, isononyl isononanoate and a preservative. The component B is prepared from the following components: the balance of water, butanediol, a preservative, magnesium sulfate, an emollient, disteardimonium hectorite, phenyl polytrimethylsiloxane, isododecane, trimethylsiloxy silicate ester, an emulsifier b and PEG-10 (Polyethylene Glycol) polydimethylsiloxane. Various raw materials are mixed, so that the obtained liquid foundation has relatively good dispersity, has smooth and refreshing skin feeling, and is prevented from being thick, sticky and greasy.

The present disclosure relates to a method or producing silicon tetrafluoride from fluorosilicic acid. In one implementation, a first stream comprising fluorosilicic acid and a second stream comprising sulfuric acid are reacted in a pressure regulator to produce an outgoing liquid stream comprising silicon tetrafluoride. The outgoing liquid is then fed into at least one separator which outputs at least one gas stream containing silicon tetrafluoride and at least one liquid stream. The at least one gas stream is fed into at least one additional separator which separates the at least one gas stream into at least one stream of purified silicon tetrafluoride gas. In some implementations, the at least one liquid stream is recycled back into the at least one separator.

The invention discloses a method for preparing anhydrous hydrogen fluoride, anhydrous hydrogen fluoride and application, and the method comprises the following steps: mixing first fluorine-containing sulfuric acid with water for reaction to obtain a reaction solution containing hydrogen fluoride; evaporating the reaction liquid containing hydrogen fluoride to obtain an evaporated liquid phase and an evaporated gas phase; washing the evaporated gas phase to obtain a washed gas phase; and condensing the washed gas phase to obtain anhydrous hydrogen fluoride. The method is low in cost and high in economic benefit, the yield of the by-product sulfuric acid is about 1.5 times lower than that of a fluosilicic acid method, the application channel of the by-product sulfuric acid is wider than that of the by-product sulfuric acid of the fluosilicic acid method, and the environmental protection pressure in the preparation process is low. Meanwhile, anhydrous hydrogen fluoride is prepared from the by-product fluorine-containing sulfuric acid, so that recycling of resources is realized.

Methods of forming a foldable apparatus can involve contacting an existing first major surface of a foldable substrate with an alkaline solution to remove an outer layer to form a new first major surface. In aspects, the alkaline solution comprises about 10 weight % or more of a hydroxide-containing base and / or a pH of about 14 or more. Methods of forming a foldable apparatus can comprise contacting a first major surface of a foldable substrate with a first alkaline detergent solution under sonication. Methods of forming a foldable apparatus can comprise contacting an existing first major surface of a foldable substrate with an acidic solution having a pH from about 3.3 to about 3.5 and a fluorine-containing compound. Methods of forming a foldable apparatus can comprise contacting an existing first major surface of a foldable substrate with a solution comprising fluorosilicic acid.

The invention belongs to the technical field of semiconductor materials, and particularly relates to a preparation method of high-purity silicon carbide powder. The preparation method comprises the following steps: reacting a mixture of fluosilicate and carbon powder at 1500-1600 DEG C in an inert atmosphere for 2-5 hours, cooling to 600-700 DEG C, preserving heat for 2-4 hours in an oxidizing atmosphere, cooling to room temperature, washing with water, and drying to obtain the high-purity silicon carbide powder. According to the method, the high-value silicon carbide is prepared from cheap fluosilicate as a raw material and carbon powder through a one-step reaction, and the method is low in cost, simple in process, free of corrosive byproducts and suitable for industrial application. Furthermore, the cheaper fluosilicic acid is taken as a raw material and is subjected to nano mixing with the carbon powder in a precipitation form, so that not only is new impurities prevented from being introduced by mechanical grinding, but also the two reaction raw materials are fully contacted and reacted, and the product yield reaches 98% or above. Furthermore, fluorine elements in the raw materials can be combined with impurities to form fluoride to be volatilized in a gas form, the impurities are removed while the product is prepared, and the impurity removal process is simplified.

The present invention belongs to the technical field of titanium metal processing waste acid treatment, and specifically relates to a method for regenerating titanium metal pickling waste liquid. The regeneration method comprises the following steps: adding a fluorosilicic acid solution to the titanium metal pickling waste liquid and mixing uniformly, then adding a potassium salt solution, stirring the reaction at room temperature, and centrifuging or filtering after the reaction is complete to separate the solid portion as a potassium fluorotitanate / potassium fluorosilicate complex; and the liquid portion as a regenerated titanium metal pickling liquid. The method of the present invention can significantly improve the titanium ion recovery rate without destroying the pickling liquid components. The titanium metal pickling waste liquid can be regenerated and reused, and has the advantages of good treatment effect and simple treatment process.

The application relates to a method and a preparation system for preparing hydrogen fluoride from fluosilicic acid, which comprises a reaction kettle, a hydrogen fluoride absorption tower, a condenser and a silicon tetrafluoride absorption tower which are sequentially communicated; a gas outlet of the reaction kettle is communicated with a gas inlet of the hydrogen fluoride absorption tower, and a gas outlet of the hydrogen fluoride absorption tower is communicated with a gas inlet of the condenser; the generated fluorosulfonic acid in the reaction kettle is introduced into a stripping tower, fluorosulfonic acid generated in a side reaction is re-generated into hydrogen fluoride, the generation of intermediate products is reduced, the process route of the application is free of waste residues and waste gas, and fluosilicic acid is effectively utilized.

The application provides a quartz sand acid washing waste liquid resource treatment method, and belongs to the field of industrial waste water treatment, and comprises the following steps: adding magnetic composite seeds to the quartz sand acid washing waste liquid, and performing magnetic separation after stirring treatment; adding soluble potassium salt to the treated waste liquid to recover potassium fluosilicate; treating the filtrate through diffusion dialysis to obtain recovered acid and dialysis residual liquid; the diffusion dialysis treatment adopts an asymmetric membrane, the asymmetric membrane has a physical gradient of one side being a dense structure and the other side being a loose structure, and the dense structure side is in contact with the waste liquid; and adding calcium oxide or calcium hydroxide to the dialysis residual liquid for deep treatment and calcium recovery. The application provides a quartz sand acid washing waste liquid resource treatment method which is low in treatment cost, high in resource recovery rate and friendly to the environment, and realizes the differentiated resource recovery of the quartz sand acid washing waste liquid.

The invention discloses a method for improving phosphorite reaction activity and fluorine resource recovery rate. The method mainly aims at medium-low-grade collophanite after flotation, and comprises the following steps: firstly, pretreating phosphorite by using fluosilicic acid to prepare high-concentration phosphorite slurry; carrying out premixing reaction on the phosphoric ore pulp and phosphoric acid, and then carrying out crystallization reaction with sulfuric acid with a certain concentration; a flash cooling and flue gas washing system is arranged in each reaction area, so that escape and recovery of fluorine are enhanced; and after the reaction is finished, filtering and washing to obtain phosphoric acid and phosphogypsum. The phosphorite is pretreated by using low-concentration fluosilicic acid recovered in a phosphoric acid concentration section, the phosphorite pre-decomposition pH is adjusted by using fluosilicic acid, carbonate, silicate and quartz impurities in the phosphorite are preferentially dissolved, and micro-channels are formed on the surfaces of phosphorite particles, so that the subsequent use amounts of phosphoric acid and sulfuric acid are reduced, and the content of aluminum phosphate ions in the product is reduced; the phosphorite acidolysis efficiency is improved. Meanwhile, introduction of fluosilicate accelerates escape of fluorine in phosphorite, and the fluorine yield of the system is increased.

The invention discloses a wet-process phosphoric acid defluorination residue recycling coupling device and a production method, the coupling device is arranged in a wet-process phosphoric acid production system, and the coupling device comprises a spiral mixing reactor (1), a mixing reactor (2) and a fluorine-containing gas washing and recycling device (3) which are sequentially arranged and connected; the production method comprises the following steps: adding concentrated sulfuric acid with the temperature of 80-90 DEG C into the wet-process phosphoric acid defluorination residues and silica fume in a spiral mixing reactor according to the mass ratio of 100: (5-10), reacting for 40-60 minutes, controlling the reaction temperature to be 90-100 DEG C, returning slurry B to a wet-process phosphoric acid production pre-extraction system, and separating and purifying the slurry B to obtain the wet-process phosphoric acid defluorination residues. Fluorine-containing gases SiF and HF generated by the mixing reaction are sent to a fluorine-containing gas washing and recycling device through a waste gas main pipe to be washed to obtain a 8-15% fluosilicic acid solution. The coupling device is coupled with an existing wet-process phosphoric acid production system, a large number of newly-added equipment and procedures are reduced, the whole process is free of three-waste emission, the method is simple in process, the fluorine recovery rate is larger than or equal to 83%, meanwhile, phosphorus is efficiently recovered, and pollution of fluorine resources to the environment is reduced.

The invention belongs to the technical field of chemical product preparation, and particularly relates to a method for efficiently separating and purifying aluminum fluoride silicon slag and preparing white carbon black. Dropwise adding the ammonium fluoride solution into the aluminum fluoride silicon slag solution, then heating and stirring, then adding melamine and formaldehyde as dispersing agents, filtering after the reaction is finished, and filtering by adopting a carbon fiber membrane to obtain a filter cake which is high-purity aluminum fluoride and a filtrate which is an ammonium fluosilicate solution for later use; then slowly dripping the ammonium fluosilicate solution into the ammonia water solution, and maintaining the pH value of the reaction solution at 9.3-9.4; and after the reaction is finished, carrying out solid-liquid separation and drying to obtain the white carbon black. When the white carbon black is prepared, ammonia water is selected as a base solution, the white carbon black is ensured to be separated out under an alkaline condition, the purity of the prepared white carbon black is 99% or above, the specific surface area is larger than 300 m / g, the oil absorption value exceeds 250 mL / 100 g, and the fluorine ion concentration is lower than 50 ppm. The silicon slag used in the invention is derived from solid waste of aluminum fluoride prepared from fluosilicic acid, the cost is low, and the whole process is environment-friendly and is suitable for industrial-scale production and application.

Cement-based retarding mortar test mold and preparation method thereof, relate to the technical field of retarding mortar test mold, and particularly relate to a cement-based retarding mortar test mold and a preparation method thereof.The cement-based retarding mortar test mold comprises a test mold main body, the test mold main body is a cement-based test mold, the compressive strength value is 155-170 MPa, and a test groove is arranged in the test mold main body; the inner surface of the test groove is sprayed with a composite aqueous solution of sodium silicate, magnesium fluorosilicate and potassium fluorosilicate for surface treatment, and the spraying ratio is that the mass ratio of sodium silicate, magnesium fluorosilicate, potassium fluorosilicate and deionized water is (2.9-3.1) :(1.9-2.1) :(0.9-1.1) :(3.9-4.1). The cement-based retarding mortar test mold has the positive effect that the test data in a laboratory can be matched with the field construction data, and production enterprises can adjust the mixing ratio in time according to the field construction to improve the engineering quality.

The present invention discloses a method for preparing perfluorooctyl bromide by catalytic bromination of perfluorooctyl iodide. First, fluorosilicic acid reacts with aluminum hydroxide, and after filtering to remove silicon dioxide, a mixed solution of fluoroaluminate and fluorosilicic acid is obtained. Then, a soluble metal salt additive and graphite powder are added thereto. After coprecipitation, granulation, and sintering, metal oxide-doped aluminum-based catalyst particles are obtained, which are loaded into a fixed-bed reactor. After fluorination with an N2 / HF mixed gas, perfluorooctyl iodide and bromine are vaporized and mixed and then enter the fixed-bed reactor, and perfluorooctyl bromide is prepared by reaction. In the present invention, the reaction raw materials are easily available; the reaction conditions are mild, and materials and equipment matching the process can be found in the existing equipment and material system to support the long-term stable operation of production; through the efficient catalysis of the catalyst and the continuous progress of the reaction gas phase, the reaction efficiency is improved and the consumption of bromine is reduced, so that the whole process has good atom economy and has good application prospects.

The invention discloses a separation system for preparing hydrogen fluoride from fluosilicic acid, and relates to the technical field of separation equipment, the separation system comprises a box body and a conveying pipe, liquid is pumped into the box body through the conveying pipe, an inclined plate formed by splicing rectangular plates is arranged in the box body, a stop block protruding out of the upper surface of the rectangular plate is arranged to stop the liquid from forming a swirling vortex, and solid-liquid separation is conducted through centrifugal force. Different from an existing common solid-liquid separation device which is provided with a compact net structure, the solid-liquid separation device has the advantages that liquid is intercepted to form a swirling vortex, solid impurities in the liquid are thrown to the outermost side and are precipitated along the inclined surface of the baffle plate, the baffle plate is periodically driven by the periodic driving part to carry, and precipitated solids are flushed out by using the liquid to realize separation; a net-shaped structure without direct separation in the equipment is not easy to corrode by acid liquor, the separation effect can be regulated and controlled by controlling the flow rate of liquid and the extension height of the baffle, the filter screen does not need to be frequently overhauled and replaced, and the use is more convenient.

The present disclosure relates to a system for the production of silicon tetrafluoride. In one implementation, a reactor is configured to at least convert fluorosilicic acid (FSA) into silicon tetrafluoride at a reaction zone. A separator receives the products of the reactor and is configured to separate the products into at least a gaseous stream and a liquid stream. At least one additional reactor is configured receive the at least a liquid stream of the reactor and configured to yield a refined product at a reaction zone. At least one additional separator is configured to separate the refined product into at least a gaseous stream and a liquid stream at a separating zone. Finally, a washer is configured to receive and wash the gaseous stream of the product and the gaseous stream of the refined product at a washing zone, wherein the washer yields a purified silicon tetrafluoride product.

The present disclosure relates to a method for concentrating fluorosilicic acid from a first liquid stream comprising fluorosilicic acid. In one implementation, the solution comprising fluorosilicic acid and a gaseous stream comprising silicon tetrafluoride is introduced into a first reactor. The first reactor reacts to form the products and separates the products into at least one intermediate gas stream and at least one intermediate liquid stream. The at least one intermediate liquid stream is then introduced into at least one additional reactor. At least one product of the reactor is then separated using the at least one additional reactor. The at least one additional reactor separates the at least one product into at least a final liquid stream comprising fluorosilicic acid. The fluorosilicic acid mass percentage in the at least one final liquid stream is greater than the fluorosilicic acid mass percentage in the at least one first liquid stream.