862 results about "Fluoride calcium" patented technology

The present invention belongs to the technical field of glass preparation, and specifically relates to an ultra-white glass and a preparation method thereof. The ultra-white glass of the present invention is composed of the following raw materials by weight: 110 parts of quartz sand, 18-20 parts of sodium carbonate, 14-16 parts of colemanite, 4.5-5.5 parts of magnesia, 2.6-2.8 parts of calcined alumina, 1.1-1.3 parts of potassium oxide, 0.8-1.0 parts of zinc oxide, 1.5-1.7 parts of phosphorus pentoxide, 0.15-0.20 parts of strontium chloride, 0.3-0.34 parts of calcium fluoride, 0.25-0.27 parts of barium nitrate, and 0.16-0.18 parts of zirconium oxide. The ultra-white glass of the present invention has a synergistic effect between the raw materials to ensure that the prepared ultra-white glass has excellent whiteness and visible light transmittance.

The invention relates to a modified chrome corundum ramming material and a preparation and construction process thereof, and belongs to the technical field of chrome corundum ramming materials. The ramming material comprises a material A, a material B and a material C, wherein the material A comprises chrome corundum aggregate, titanium dioxide coated aluminum oxide microspheres, calcium sulfide dehydrate and silicon carbide porous microspheres; the material B comprises chromium oxide-zirconium oxide composite nano powder, sodium thiosulfate pentahydrate, tricalcium phosphate and hexagonal boron nitride flaky crystals; and the material C comprises an aluminum dihydrogen phosphate-magnesium hydroxide compound, a calcium fluoride-aluminum oxide co-melt and a silane coupling agent. The preparation process comprises the steps of pretreatment of all the components, preparation of composite powder and layered preparation. The construction process comprises the steps of pretreatment, wet-process mixing, layered ramming, negative-pressure permeation, medium-temperature reaction, spraying curing, integral firing and the like. Generation of hexavalent chromium can be effectively inhibited, the thermal shock resistance, the mechanical strength and the heat-conducting property of the material are remarkably improved, and the material has the advantages of being good in environment friendliness, long in service life, excellent in construction performance and the like.

The utility model belongs to the field of chemical raw material recovery, and discloses a continuous resourceful treatment system for photovoltaic fluorine-containing wastewater. The system comprises a first-stage fluorine removal unit, a second-stage fluorine removal unit and a silicon removal unit. According to the utility model, the fluorine element is subjected to resource recovery in the form of high-purity calcium fluoride with the purity of more than 95%, meanwhile, the consumption of a fresh sodium hydroxide solution is avoided, the purpose of treating waste with waste is realized, and the residual fluorine quantity in the effluent of the system is reduced to be less than 5mg / L.

The invention discloses a composite clarifying agent for alkali-free glass and a manufacturing method of an alkali-free glass substrate, and relates to the technical field of glass manufacturing, the composite clarifying agent for alkali-free glass comprises the following components by mass: 12-30% of ammonium chloride, 48-73% of sulfate, and 11-25% of calcium fluoride; the preparation method comprises the following steps: adding a composite clarifying agent accounting for 0.2-1.2% of the total weight of the glass raw material into the glass raw material, uniformly mixing to form a batch, and carrying out melting, molding, spraying, annealing, cutting, alkali cleaning and other processes on the batch to finally prepare the glass substrate. The prepared composite clarifying agent does not contain toxic substances such as arsenic oxide and antimony oxide, the glass substrate produced by using the clarifying agent not only has an excellent clarifying effect, but also can recycle SO2 and NH3 gas generated in the melting process, can effectively solve the quality problems such as micro-flaws on the surface of the glass substrate in the production process, and has a good application prospect. And the production cost can be reduced and the product quality can be improved.

The invention relates to the technical field of welding, in particular to a lead-free solder composition and a preparation method thereof. The composition comprises brazing filler metal and a brazing flux, wherein the brazing filler metal comprises 55 to 65 parts of copper, 30 to 40 parts of zinc, 0.5 to 1 part of silver, 0.1 to 1 part of tin, 0.1 to 0.5 part of nickel, 0.02 to 0.15 part of lanthanum, 0.03 to 0.15 part of cerium and 0.05 to 0.2 part of indium; the brazing flux comprises 18-22 parts of borax, 13-17 parts of boric acid, 25-32 parts of a potassium fluoride and potassium fluoborate compound, 3-5 parts of calcium fluoride, 12-16 parts of aluminum oxide and 8-11 parts of magnesium oxide. The lead-free solder composition does not contain toxic lead elements, pollution to the environment and the ecological system is little, the wettability, corrosion resistance, strength, stability and the like of the lead-free solder composition are improved, and the welding quality is comprehensively improved. According to the preparation method, uniform distribution and accurate control of the brazing filler metal and the brazing flux are guaranteed, stability and consistency of product quality are guaranteed, and the preparation method is easy and convenient to operate and suitable for mass production.

The invention relates to a glass bead, in particular to a high-refractive-index large-particle-size glass bead for road marking and a spheroidizing forming preparation method of the high-refractive-index large-particle-size glass bead. The material comprises the following components in parts by weight: 30 to 40 parts of titanium dioxide, 30 to 40 parts of silicon dioxide, 10 to 15 parts of barium nitrate, 10 to 15 parts of zirconium nitrate, 5 to 7 parts of zinc oxide, 3 to 5 parts of boric acid, 3 to 5 parts of calcium fluoride, 5 to 110 parts of Nb2O5 and 5 to 15 parts of a La2O3-ZrO2 compound. According to the invention, calcination is carried out at 900 DEG C for 12 hours, which is helpful for improving the thermal stability and mechanical strength of the glass beads, so that the glass beads can be used for a long time in a severe outdoor environment and are not easy to damage. And at the high temperature of 1300 DEG C and the spraying speed of 75 m / s, through precise intersection of the two nozzles in the combustion chamber, precise control over the melting and forming process of the glass beads is ensured, and therefore the high-quality high-refractive-index glass beads are obtained. The Nb2O5 and La2O3-ZrO2 compound is added, so that the refractive index of the glass beads is improved, and a relatively high yield is maintained.

The invention relates to a method for recovering lithium and fluorine from electrolytic aluminum solid waste, which comprises the following steps: firstly mixing the electrolytic aluminum solid waste and an iron-containing acid solution for complexing leaching to obtain a lithium-containing leachate; mixing the lithium-containing leaching solution with a calcium-containing additive for precipitation reaction to obtain a fluorine-removed lithium-containing leaching solution and calcium fluoride; then the fluorine-removed lithium-containing leaching solution is subjected to pH adjustment through alkali liquor, and an iron-removed and aluminum-removed lithium-containing leaching solution is obtained; finally, adsorbing and separating the lithium-containing leaching solution with iron and aluminum removed to obtain a lithium-rich solution; according to the method, lithium and fluorine resources in the electrolytic aluminum solid waste are efficiently recycled, the leaching rate of Li < + > is preferably as high as 87.2% or above, the loss rate of lithium is preferably as low as 1.00% or below, the recovery rate of the fluorine element is preferably as high as 85.9% or above, generation of a large amount of HF gas is avoided, and the method is environmentally friendly and low in recovery cost.

The invention discloses a rapid tubular induced crystallization reaction process and device for fluorine-containing wastewater, the device comprises a tubular reactor, a crystal sedimentation tank and crystal dehydration equipment, the fluorine-containing wastewater is pumped from a water inlet at one end of the tubular reactor, calcium liquid is pumped from dosing ports at intervals on the tubular reactor along the flowing direction of the wastewater at a set flow rate, and the calcium liquid is pumped from the dosing ports at intervals along the flowing direction of the wastewater; the fluorine-containing wastewater reacts with a calcium agent in the tubular reactor to generate calcium fluoride crystals with the particle size range of 10-80 microns, a mixture is discharged into a crystal sedimentation tank through a water outlet in the other end of the tubular reactor, clear water is discharged from a water outlet in the upper portion of the crystal sedimentation tank, and crystal slurry sinking to the bottom of the crystal sedimentation tank is pumped into a cyclone separator through a crystal discharging pump; large-particle crystals discharged from an outlet in the lower end of the cyclone separator are collected by a crystal collection pool and are regularly discharged into crystal dehydration equipment for dehydration, small-particle crystals discharged from an outlet in the upper end of the cyclone separator flow back to the water inlet end of the tubular reactor, the reactor is small in size and low in investment, and the stability of the calcium fluoride crystal product quality is guaranteed.

The invention discloses a far-infrared high-transmittance composite material, a preparation method thereof and an optical device, and the far-infrared high-transmittance composite material comprises the following components in parts by weight: 70-99 parts of a polymer matrix; 1-30 parts of an anti-reflection auxiliary agent; the polymer matrix is a sulfur-containing polymer prepared by polymerization reaction of a polymeric monomer and sulfur, and the proportion of carbon-carbon unsaturated bonds is less than 3%; the polymeric monomer is selected from at least one of a vinyl monomer, a propenyl monomer, an acrylic acid monomer, a methacrylic acid monomer, an epoxide monomer, a thiopropyl ring monomer, an alkynyl monomer, a butadiene monomer, an isoprene monomer and a norbornene monomer; the anti-reflection auxiliary agent comprises at least one of nano zinc sulfide, nano zinc selenide, nano calcium fluoride, nano magnesium fluoride and nano magnesium oxide. The composite material and the optical device thereof have high far infrared transmittance and good mechanical properties and processability, and can meet the requirements of various far infrared optical fields.

The invention discloses a photovoltaic wastewater lime-process crystallization treatment process and a treatment system used by the same, which are characterized in that acid fluoride wastewater and alkali washing wastewater generated in a photovoltaic sheet production process are respectively collected by an acid fluoride wastewater collecting pool and an alkali washing wastewater collecting pool; the acid fluoride wastewater and a lime agent are subjected to a crystallization reaction in a crystallization fluidized bed to obtain calcium fluoride crystals, effluent of the crystallization fluidized bed and alkali washing wastewater are mixed in a secondary defluorination unit, and calcium chloride is added for a defluorination reaction after the pH value is adjusted; the effluent of the second-stage fluorine removal unit reacts with a fluorine removal agent or polyaluminum chloride in the third-stage fluorine removal unit to remove fluorine again, polyacrylamide is added into the third-stage fluorine removal unit to perform a flocculation reaction, and finally, the fluorine ion concentration in the effluent of the third-stage fluorine removal unit meets the discharge requirement. The agent input cost and the sludge treatment cost are reduced, the secondary pollution of chloride ions is avoided, and the effluent is ensured to stably reach the standard.

The invention relates to the technical field of environmental science and engineering, and discloses a method for removing and recycling fluorine ions by promoting calcium fluoride precipitation through sulfate doping, and the method comprises the following steps: S1, preparing sodium fluoride solutions of sulfate with different concentrations, and analyzing the influence of different sulfate concentrations on calcium fluoride precipitation; s2, respectively adding calcium chloride solutions into the prepared sodium fluoride solutions of the sulfates with different concentrations; s3, the two solutions are subjected to a reaction within a set time, filtering is conducted after the reaction is conducted for a period of time, and the fluorine ion removal reaction is completed. By changing the concentration of sulfate in the sodium fluoride solution, the effect of the sulfate in calcium fluoride precipitation and the influence of the sulfate on the fluorine ion removal efficiency are researched; the positive effect and the action mechanism of the low-concentration sulfate in the calcium fluoride precipitation process are defined, and the problems that the influence of the sulfate in the high-fluoride wastewater on calcium fluoride precipitation is ignored, the calcium fluoride purity is low and the recovery difficulty is large are finally solved.

The invention relates to a quartz crucible coating and a preparation method thereof.The coating is of a double-layer composite structure and comprises a substrate layer and a functional layer, the substrate layer is composed of 40-65 vol% of polycrystalline silicon powder (the particle size D50 ranges from 1 micrometer to 5 micrometers) and 35-60 vol% of nanometer silica sol, and the functional layer covers the surface of the substrate layer and is composed of 50-70 vol% of polycrystalline silicon powder, 20-35 vol% of nanometer silica sol and 5-15 vol% of calcium fluoride powder (the particle size D90 is smaller than 0.5 micrometer). The preparation method comprises the following steps: preparing a substrate layer slurry and a functional layer slurry, sequentially coating the inner wall of a crucible with the slurry, drying, and sintering in an inert atmosphere according to a three-step temperature control program to finally form a coating with the thickness of 180-300 microns and the porosity of 8-15 vol%; the coating structure can avoid pollution of silicon nitride or silicon carbide particles, has excellent demolding performance, thermal stability and adhesive force, further improves the service life of a crucible and the purity of a silicon ingot, and meets the requirements of an advanced semiconductor process for cleanliness and reliability.

The invention discloses a comprehensive utilization method of high-salinity wastewater produced by hydrometallurgical treatment of bastnaesite, which comprises the following steps: A, mixing alkaline wastewater and acidic wastewater, neutralizing and clarifying to obtain calcium fluoride and sodium chloride wastewater; b, mixing the sodium chloride wastewater with the precipitation wastewater, adding lime water in an aeration manner to adjust the pH value, hydrolyzing heavy metal ions in the wastewater, and performing solid-liquid separation to obtain filter residues and filtrate which is sodium chloride high-salinity wastewater; and C, adding oxalic acid into the sodium chloride high-salinity wastewater, stirring, standing, carrying out solid-liquid separation, pressurizing, concentrating, recovering hydrochloric acid, and crystallizing to obtain a crystal substance, namely a sodium chloride product. According to the method, fluorine in the wastewater is removed firstly, then the wastewater is recovered into wastewater containing sodium chloride, oxalate is dissolved into the high-salinity wastewater to separate out sodium oxalate and recover hydrochloric acid, so that the content of sodium chloride in the system is greatly reduced, and the recovery efficiency of sodium ions in the wastewater is improved.

The invention relates to the field of nylon materials, provides a high-performance, scratch-resistant, wear-resistant and corrosion-resistant nylon material replacing steel with plastic, and solves the problem that an existing nylon material is insufficient in scratch resistance, wear resistance and corrosion resistance. The material is prepared from a surface modified calcium fluoride and aluminum oxide whisker filler, polytetrafluoroethylene coated boron nitride particles, nylon matrix resin, a compatilizer, an antioxidant and a lubricant. The dispersibility and the interface compatibility of the key components are improved by adopting a special preparation process, so that the mechanical property, the wear resistance and the chemical stability of the composite material are remarkably enhanced. The material is suitable for metal replacement application in the fields of automobiles, machinery and the like, realizes excellent scratch resistance and wear resistance, solves the problem of poor corrosion resistance of nylon materials, and has wide application value.

The invention provides a method for decomposing and mineralizing fluorine-containing organic matter wastewater, which is applied to the technical field of treatment of fluorine-containing organic matter wastewater generated in a perfluoroether elastomer emulsion flocculation process, and comprises the following steps: S1, carrying out adsorption and desorption treatment on the fluorine-containing organic matter wastewater to obtain a concentrated solution of the fluorine-containing organic matter wastewater; s2, hydrogen peroxide and ferrous ions are added into a container containing the concentrated solution to obtain a mixed solution, the pH of the mixed solution is adjusted to be 2-4, the concentration mass ratio of the hydrogen peroxide to organic matter contained in the fluorine-containing organic matter wastewater is 1: 1-2, the molar ratio of the hydrogen peroxide to the ferrous ions is 1-6: 1, micro-nano bubbles are introduced into the mixed solution, and ultrasonic treatment is conducted; s3, calcium hydroxide is added into the treated mixed solution, calcium fluoride precipitates are obtained through centrifugal treatment, and the fluorine-containing organic matter in the wastewater can be degraded and mineralized.

The invention discloses a treatment process of photovoltaic cell production wastewater, and relates to the technical field of industrial wastewater treatment. Comprising the following steps: treating dilute acid and dilute alkali through a reclaimed water recovery membrane system to obtain first produced water and reclaimed water concentrated water; treating the concentrated acid wastewater and the reclaimed concentrated water through a fluorine-calcium crystallization system to obtain defluorinated concentrated water and calcium fluoride crystals; treating the RO concentrated water and the defluorinated concentrated water by a hardness removal recycling system to obtain hardness-removed concentrated water and second produced water; treating the concentrated alkali wastewater through an alkali recovery membrane system to obtain purified alkali and alkali-removed concentrated water; hardness-removed concentrated water and alkali-removed concentrated water are treated by a comprehensive physicochemical system, and then are sequentially treated by a high-power concentration membrane system and a zero-discharge crystallization system to obtain solid wastes. The photovoltaic cell production wastewater treatment process provided by the invention achieves an economical and feasible zero-emission solution.

The invention discloses a process and a treatment system for preparing white carbon black by utilizing photovoltaic cell wastewater, which are characterized in that concentrated alkali wastewater in a concentrated alkali regulating tank and part of concentrated acid wastewater in a concentrated acid regulating tank are mixed in a primary mixing tank, and then a primary gelation reaction is carried out through a primary gelation reactor; the method comprises the following steps: preparing concentrated acid wastewater from concentrated acid wastewater, dehydrating the concentrated acid wastewater by a primary dehydration device to obtain coarse gel particles, dissolving the coarse gel particles in an alkali dissolution tank by liquid alkali, mixing the coarse gel particles with the rest concentrated acid wastewater in a secondary mixing tank, feeding the mixture into a secondary gelation reactor for secondary gelation reaction, and supporting the fine gel particles by a secondary dehydration device to obtain fine gel particles. According to the method disclosed by the invention, the yield of silicon-containing sludge in subsequent fluorine removal is reduced, the purity of calcium fluoride sludge is favorably improved, silicon resources in the concentrated alkali wastewater are recycled, and resourceful treatment of the concentrated alkali wastewater is realized.

The invention provides a method and system for recovering phosphate radicals, fluorine ions and sulfate radicals from phosphogypsum washing water step by step, and belongs to the technical field of industrial wastewater resourceful treatment. The method comprises the following steps: (1) adjusting the pH value of the wastewater to 3.0 + / -0.5, adding ferric sulfate according to the molar ratio of Fe to PO4 < 3-> of (1.0-1.5): 1, and selectively precipitating phosphate radicals to generate iron phosphate with the purity of more than or equal to 97%; (2) adjusting the pH value of the first filtrate to 4.7 + / -0.5, adding calcium fluoride seed crystals with the particle size of 50-200mm and CaCl2 (the molar ratio of Ca to F <-> is 0.5: 1-0.6: 1), and carrying out induced crystallization to recover calcium fluoride with the purity of more than or equal to 96%; and (3) adding Ca (OH) 2 (Ca: SO4 < 2-> molar ratio of 1.0: 1-1.2: 1) into the second filtrate, and directionally precipitating sulfate radicals to generate calcium sulfate dihydrate with the purity of more than or equal to 98%. According to the method, the pH and the precipitation sequence are controlled step by step, so that the problem of polyanion competition is solved, the recovery rates of phosphate radical, fluorine ion and sulfate radical respectively reach 98.8%, 96.3% and 97.5%, the content of PO4 < 3-> in purified water is less than or equal to 10 mg.L <-1 >, the content of F <-1 > is less than or equal to 5 mg.L <-1 >, and the content of SO4 < 2-> in purified water is less than or equal to 100 mg.L <-1 >, and the purified water can be directly recycled.

The invention relates to the technical field of concrete crack repairing agents, in particular to a triggered precipitation type concrete crack repairing agent as well as a preparation method and application thereof. The repairing agent is prepared from the following raw materials: sulphoaluminate cement, nano anhydrite with a core-shell structure, fluorine-phosphorus composite seed crystal, magnesium oxide, metakaolin and a water reducing agent, wherein the core-shell structure nano anhydrite is prepared by coating mesoporous silica with nano anhydrite, and the fluorine-phosphorus composite seed crystal is prepared from calcium fluoride and monocalcium phosphate through a hydrothermal reaction. According to the trigger precipitation type concrete crack repairing agent prepared by the invention, sulfate ions are slowly released through the core-shell structure nano anhydrite, the crystal form of ettringite is regulated and controlled through the fluorine-phosphorus composite seed crystal, the problems that a traditional repairing agent shrinks and falls off in the later period, the high-temperature strength is suddenly reduced, and the binding power is insufficient are solved, and the trigger precipitation type concrete crack repairing agent is suitable for concrete structure crack repairing and high-temperature environment engineering.

The invention provides a calcium fluoride sludge purification method, calcium fluoride fine powder and application thereof, and belongs to the field of calcium fluoride sludge treatment.The calcium fluoride sludge purification method comprises the following steps that calcium fluoride sludge and water are mixed to form a first mixed solution, a phosphate conversion agent is added, heating and stirring are conducted, and then filtering is conducted to obtain a first solid mixture; adding an acid solution into the first solid mixture, heating, stirring and filtering to obtain a second solid mixture; and water, an inhibitor, a collecting agent and a foaming agent are sequentially added into the second solid mixture to form a third mixed solution, flotation is conducted, and calcium fluoride fine powder is obtained. Impurity elements can be removed through combination of phosphate conversion and a flotation method, and compared with a method for removing calcium phosphate and calcium sulfate through a chemical treatment method, the reagent dosage is greatly reduced, the temperature needed by conversion is low, the conversion time is short, and the cost is low.

The invention discloses a grading reaction crystallization recovery process and system for semiconductor fluorine-containing and phosphorus-containing waste liquid, the fluorine-containing and phosphorus-containing waste liquid and a lime solution react in a fluorine recovery crystallization reactor under the condition that the pH is 3-4 to form calcium fluoride crystals, and the calcium fluoride crystals are dehydrated to obtain calcium fluoride particle crystal products; the effluent of the fluorine recovery crystallization reactor, the calcium fluoride crystal dehydration filtrate, the lime solution and the calcium chloride solution react in a secondary reaction tank under the condition that the pH is 5-6, and calcium fluoride, fluorapatite, silicon dioxide and silicon-aluminum precipitates are removed through coagulation, flocculation and precipitation; effluent of the second-stage reaction tank, the lime solution and the calcium chloride solution react in the phosphorus recovery crystallization reactor under the condition that the pH is 7-8 to generate hydroxyapatite crystals, and the hydroxyapatite crystals are dehydrated to obtain hydroxyl calcium phosphate particle crystal products. Meanwhile, a high-purity calcium fluoride crystal product and a hydroxyl calcium phosphate crystal product are produced, and fluorine and phosphorus are recycled.

The invention relates to the technical field of metal material surface strengthening and modification, in particular to a preparation method and process of a titanium alloy laser cladding cobalt-based wear-resistant coating. The invention provides a titanium alloy surface laser cladding cobalt-based wear-resistant coating which takes titanium or a titanium alloy as a base material, comprises the following components in percentage by weight: 40-50% of cobalt (Co), 30-40% of tungsten carbide (WC), 10-15% of chromium (Cr), 1-5% of lanthanum hexaboride (LaB6), 2-5% of silicon (Si) and 0.5-3% of calcium fluoride (CaF2), and has the beneficial effects of improving wear resistance, high-temperature stability, corrosion resistance, high hardness, high bonding strength, difficulty in cracking and the like.

The invention belongs to the technical field of industrial wastewater treatment and resource recovery, and particularly relates to an enhanced treatment method for recovering fluorine resources in semiconductor processing fluorine-containing wastewater. And step-by-step efficient recovery of sodium fluosilicate and calcium fluoride is realized through cooperation of precipitant compounding and pH regulation. The method comprises the following steps: firstly, adding a NaCl-NaHCO3 composite precipitator and sodium fluosilicate seed crystals to induce crystallization and recover hexagonal prism-shaped sodium fluosilicate single crystals; and after filtering, adding a CaCl2-Ca (OH) 2 composite precipitator and calcium fluoride seed crystals into the filtrate to generate large-particle calcium fluoride. And the impurity content in the recovered product respectively reaches the industrial sodium fluosilicate superior product standard and the metallurgical grade calcium fluoride secondary product standard. And the treated wastewater is neutral or weakly alkaline, so that the subsequent mixed treatment with other wastewater is facilitated.

A method for preparing monodisperse nanoscale calcium fluoride, comprising the following steps: (S1) dispersing calcium long-chain alkylbenzenesulfonate and an acrylate copolymer in a mixed solution of water, n-hexane, and an alcohol to form a stable emulsion A, wherein monomers of the acrylate copolymer comprise (meth)acrylic acid, a polyether macromonomer, and a C1-4 alkyl (meth)acrylate; (S2) dissolving a fluoride salt in water, adding polyvinyl alcohol, and uniformly mixing these materials to obtain a solution B; and (S3) slowly dropwise adding the solution B to the emulsion A under stirring and ultrasonic conditions, and carrying out standing for aging, centrifugal separation, washing, and drying to obtain monodisperse nanoscale calcium fluoride. By using the calcium long-chain alkylbenzenesulfonate with surface activity as a calcium source in combination with homemade acrylate as a dispersing agent, an emulsion is formed in a specific combined solvent, and by dropwise adding a fluorine salt aqueous solution to the emulsion under an ultrasonic condition, nanoscale calcium fluoride with a uniform and controllable particle size can be prepared under the action of a microemulsion.

The invention relates to a large-size glass product with a natural ice crystal imitating effect and an industrial casting method of the large-size glass product. The product is a lead-free glass casting with the weight larger than or equal to 100 kg, dendritic crystal-shaped or snowflake-shaped devitrified phases which are formed by growing calcium fluoride as crystal nucleuses and are distributed randomly are arranged in the product, and the three-dimensional aesthetic effect imitating natural ice crystals is achieved. The method comprises the following steps: mixing lead-free glass particles with a calcium fluoride nucleating agent with a specific particle size, and filling a mixture into a special mold with a three-layer composite structure and a temperature monitoring function; and executing a four-stage programmed thermal regulation including melting homogenization, nucleation cooling, isothermal crystallization and super-slow multi-step annealing, wherein the melting and heat preservation time and the maximum thickness of the product meet the quantitative relation of t = k.H. Through systematic collaboration of materials, molds and processes, the technical problems that crystallization in large-size glass is not uniform and cracking is easily caused by thermal stress are solved, high yield and stable mass production of products of 500 kg or above are achieved, and the method is suitable for the fields of high-end buildings, art devices and decoration.

The invention discloses a resourceful treatment method and a resourceful treatment system for removing silicon and fluorine from wastewater in the photovoltaic industry, which are characterized in that alkaline water in photovoltaic wastewater and other photovoltaic wastewater are respectively collected through an alkaline water collecting tank and a fluorine-containing wastewater regulating tank, and the alkaline water reacts with lime milk in a dosing tank to form calcium silicate sludge; the calcium silicate sludge enters a calcium silicate pickling tank and is subjected to pickling by a hydrochloric acid solution to generate a calcium chloride solution, and the calcium silicate sludge with the purity meeting the resource recycling requirement is obtained; clear water obtained after reaction in the chemical adding pool and other photovoltaic wastewater are mixed and enter the two-stage fluorine removal system together for fluorine removal treatment, fluorine ions and calcium ions are combined to form calcium fluoride sludge, the fluorine concentration of effluent of the two-stage fluorine removal system is lower than 8 ppm, and the effluent reaches the standard and is discharged. Meanwhile, resource recycling of calcium fluoride and calcium silicate sludge is realized.

The present invention relates to improved phosphopeptide stabilised amorphous calcium phosphate and / or amorphous calcium fluoride phosphate complexes and compositions containing those complexes. Methods of making the complexes of the invention and of treatment dental hypersensitivity are also provided. In one embodiment, the invention provides a stannous-associated phosphopeptide (PP) stabilized amorphous calcium phosphate (ACP) or amorphous calcium fluoride phosphate (ACFP) complex having a stannous ion content of equal to, or greater than, 1 mole of stannous per mole of PP but less than 4 moles of stannous per mole of PP.

The invention provides a zinc-copper-nickel-copper smelting deslagging agent and a preparation method and a use method thereof. The zinc-copper-nickel-copper smelting deslagging agent comprises the following raw materials in percentage by mass: 5-15% of calcium fluoride, 20-30% of sodium carbonate, 5-15% of sodium fluoride, 10-20% of sodium hexafluoroaluminate and the balance of borax. Compared with the prior art, the zinc-copper-nickel-copper slag remover prepared by mixing the raw materials can effectively reduce impurities to be less than 0.14% of Fe, less than 0.005% of Pb and less than 0.003% of Si in the smelting process, the impurity components are obviously reduced, the number of times of component adjustment and unqualified sampling is reduced, impurities mixed in a casting blank are reduced, and finally the metal purity and the casting quality are improved. Meanwhile, loss of zinc and nickel is reduced to the maximum extent; and adverse effects on the zinc-copper-nickel alloy are avoided.

The application discloses a device for reducing fluorine-containing gas pollutant emission in electroslag remelting and a use method, which comprises a flue gas recovery cover (1), a flue gas discharge pipeline (7) and a purification tank (10). The flue gas recovery cover (1) is respectively provided with a remelted slag discharging hole (2), a self-consuming mother electrode (6) passing hole and a flue gas discharge pipeline (7) mounting hole. The flue gas discharge pipeline (7) is arranged through the flue gas discharge pipeline (7) mounting hole, one end of the flue gas discharge pipeline (7) is located in a closed space formed by the flue gas recovery cover (1) and a crystallizer (5), and the other end is inserted into the purification tank (10). A fan (8) is arranged on the flue gas discharge pipeline (7). Through the device, the fluorine-containing flue gas is recovered, and the fluorine-containing flue gas is converted into calcium fluoride by using an alkali solution. The device can realize the cyclic and repeated use of part of the calcium fluoride, greatly reduces the concentration of fluorine-containing harmful gas in the air environment of an electroslag remelting operation site, and makes the concentration of the fluorine-containing harmful gas reduce from the original 5.6 mg / m 3 to 0.02 mg / m 3 .

The invention provides a preparation method of a surface layer shell for precise casting production of a thick-wall titanium alloy. The preparation method comprises the following steps: S1, preparing a surface layer binder, wherein the surface layer binder comprises modified silica sol, a stabilizer, a reinforcing agent, a wetting agent and an acid-base regulator; the modified silica sol is diluted sodium-stabilized alkaline colloidal silicon dioxide; s2, preparing surface layer refractory powder, wherein the surface layer refractory powder comprises yttrium oxide powder, zirconium oxide powder and calcium fluoride powder; s3, preparing a surface layer coating; adding the surface layer refractory powder in the step S2 into the surface material binder in the step S1; s4, preparation of a surface layer shell, specifically, a module for preparing the surface layer shell enters the surface layer coating in the S3 to be subjected to slurry hanging, sand spraying and drying, and the step is repeated 1-2 times; and S5, the surface layer shell in the step S4 is subjected to firing forming, and the surface layer shell for precise casting production of the thick-wall titanium alloy is obtained. The surface layer shell obtained through the preparation method can be used for producing titanium alloy castings with the wall thickness ranging from 25 mm to 50 mm.