87results about "Fluosilicic acid" patented technology

A phosphor composition includes a red phosphor material having a red decay rate and a green phosphor material having a green decay rate. The red phosphor material includes a Mn4+ doped phosphor of Formula I and a Eu3+ doped uranium phosphor, and a difference between the red decay rate and the green decay rate is no more than 7 ms, AxMFy:Mn4+ (I), wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the MFy ion; and y is 5, 6 or 7. A device is also provided.

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 metal ion doped lithium hexafluorosilicate and a preparation method thereof, a negative plate and a preparation method thereof, and a lithium ion battery, the chemical formula of the metal ion doped lithium hexafluorosilicate is Li (2-x) AxSiF6, A is a first main group metal and does not comprise Li, x is 0.5-1.5, x is 0.5-1.5, and x is 0.5-1.5. And the negative plate comprises a current collector, an active material layer attached to the surface of the current collector, and an SEI film prepared from the Li2-xAxSiF6. The Li < 2-x > AxSiF6 has a relatively large interlayer spacing and a rich pore structure, an SEI film is pre-formed on the surface of the negative electrode plate by adopting the Li < 2-x > AxSiF6, and the desolvation capability of Li < + > can be better improved by the rich pore structure and the relatively large interlayer spacing in the circulation process; according to the present invention, the transmission of Li < + > is accelerated, and the inorganic matter-rich SEI film is generated between the SEI film and the active material layer after the uniform deposition of the lithium is induced, such that the generation of the lithium dendrites is further inhibited, the cycle stability and the service life of the lithium ion battery are improved, and the stability and the capacity of the negative electrode plate during the rapid charging are significantly improved.

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 a method for preparing fluosilicate from acidic fluorine-containing wastewater, and belongs to the technical field of wastewater treatment. The method comprises the following steps: carrying out conversion reaction on the acidic fluorine-containing wastewater and a silicon source to obtain conversion reaction clear liquid; adjusting the concentration of the conversion reaction clear liquid by adopting a synthetic reaction clear liquid to obtain a mixed adjusting liquid; carrying out a synthetic reaction on the mixed adjusting solution and a potassium-sodium precipitant solution, and after the synthetic reaction is completed, carrying out solid-liquid separation to obtain a synthetic reaction clear solution and fluosilicate; part of the synthetic reaction clear liquid is used for concentration adjustment, part of the synthetic reaction clear liquid is used for potassium-sodium precipitant solution preparation, and the rest of the synthetic reaction clear liquid enters a subsequent treatment process. According to the method, the acidic fluorine-containing wastewater is used as a raw material, full resource recycling of fluorine elements in the fluorine-containing wastewater is achieved, the synthesis cost of fluosilicate is reduced, and a fluosilicate product which is large in particle size, uniform in particle size, low in water content, high in purity and qualified in quality can be obtained.

The invention relates to the technical field of fluorine-containing waste acid treatment, and in particular to a method for comprehensively utilizing fluorine-containing waste acid to recover hydrofluoric acid, which is used to solve the problem that a large amount of fluorine resources are converted into sludge without economic utilization value in the existing fluorine-containing waste acid treatment method, which not only causes waste of fluorine resources, but also has the risk of secondary pollution. The method is to strip the fluorine-containing waste acid with ultrafine bubbles, and subject a part of the stripped gas to low-temperature water spray treatment to obtain aqueous hydrofluoric acid, and subject the other part of the stripped gas to temperature control to remove water vapor, and then subject it to chemical dehydration and condensation to obtain industrial anhydrous hydrogen fluoride, and subject residual liquid remaining after the ultrafine bubbles are stripped to reaction treatment, and acid solution and fluorosilicate are recovered. Through the reuse of the fluorine-containing waste acid, not only the resource utilization rate is improved, but also the impact on the environment is reduced. In addition, the process flow of the invention is simple and easy to implement, and is suitable for large-scale industrial production.

The present application discloses a method for wet-process phosphoric acid to recover fluorine, which includes: an acidolysis step: reacting fluorapatite ore powder containing 26%-28% water with concentrated sulfuric acid, maintaining the reaction temperature above 135°C to generate a fluorine-containing gas and a defluorinated slurry containing anhydrous calcium sulfate, wherein the mass fraction of P2O5 in the defluorinated slurry containing calcium sulfate is greater than or equal to 55%, and the fluorine content is 200 ppm to 2000 ppm; an absorption step: absorbing the fluorine-containing gas with an absorption liquid to obtain a fluorine-containing solution, wherein the fluorine in the fluorine-containing solution accounts for more than 95 wt% of the fluorine in the fluorapatite ore powder; a crystal form reconstruction step: performing crystal form reconstruction on the defluorinated slurry containing anhydrous calcium sulfate and filtering to obtain a hemihydrate calcium sulfate filter cake and a filtrate containing phosphoric acid.

The invention belongs to the technical field of wastewater treatment and recycling, and particularly relates to a tantalum-niobium acid wastewater recycling treatment method. The invention provides a tantalum-niobium acid wastewater resourceful treatment method which comprises the following steps: mixing tantalum-niobium acid wastewater and a potassium salt aqueous solution for crystallization reaction, and carrying out solid-liquid separation to obtain a potassium fluosilicate crystal product and a potassium fluosilicate mother solution; and washing the potassium fluosilicate crystallization product with water to obtain potassium fluosilicate. According to the method provided by the invention, firstly, the tantalum-niobium acid wastewater is treated with the potassium salt aqueous solution, the fluorine resource in the tantalum-niobium acid wastewater is recovered in the form of potassium fluosilicate, and more than 80% of the fluorine resource in the tantalum-niobium acid wastewater can be effectively recovered.

The present invention relates to the technical field of sodium fluorosilicate preparation, and specifically to a method and device for preparing sodium fluorosilicate from fluorosilicic acid produced as a byproduct of wet-process phosphoric acid, the method comprising the following steps: adjusting the fluorosilicic acid solution after centrifugation so that the fluorosilicic acid mass concentration is 15-25%; mixing the fluorosilicic acid solution with a sodium sulfate solution for primary reaction crystallization, the molar ratio of fluorosilicic acid to sodium sulfate being 1:0.95-1.15; placing a polytetrafluoroethylene membrane loaded with sodium sulfate particles, and continuing secondary reaction crystallization, wherein the polytetrafluoroethylene membrane loaded with sodium sulfate particles is prepared by an impregnation method, and the addition amount of sodium sulfate particles is: the molar ratio of fluorosilicic acid to sodium sulfate is 1:0.15-0.5; taking out the polytetrafluoroethylene membrane for recycling and reuse, and centrifugation to obtain filtrate and sodium fluorosilicate. The scheme adopts a polytetrafluoroethylene membrane as a carrier to allow solid sodium sulfate to directly participate in the reaction, which not only reduces the amount of wastewater discharged, but also avoids the phenomenon of easy crystallization, and improves the product purity and the utilization rate of fluorosilicic acid and sodium sulfate.

The invention relates to a method for preparing high-purity fluosilicate by taking industrial fluorine-containing sludge as a raw material. Comprising the following steps: slurrying calcium fluoride sludge, acidifying with inorganic acid, adding an adsorbent, and filtering; adding soluble salt into the filtrate to carry out crystallization reaction and adjusting the pH value; and cooling, filtering, washing and drying to obtain a target product. Solid waste resource utilization is achieved, the product purity is larger than or equal to 98%, and energy consumption is reduced by 60% or above compared with a traditional process.

The present invention discloses a method for ultra-stable mineralization of beryllium in "artificial fragrant flower stone". The amounts of Ca 2+ , Li + , SiO3 2‑ and F ‑ in the beryllium-containing wastewater or beryllium-containing solid waste slurry are adjusted to an appropriate range for mineralization reaction, so that the free beryllium cations and anions are mineralized into a stable fragrant flower stone [Ca3Li2(BeSiO4)3F2] form, realizing the long-term stabilization of the toxic beryllium element, eliminating the beryllium pollution risk of beryllium-containing wastewater and solid waste, and being particularly suitable for the harmless treatment of beryllium-containing waste generated in the processes of mining, ore dressing, smelting and material processing of beryllium-containing ores such as beryllium ore, lithium ore and fluorite ore. It can make the beryllium content in the wastewater and the beryllium leaching toxicity in the solid waste lower than the national standard, and has the advantages of low cost, no toxicity, simple construction process, high stabilization efficiency, good long-term stability and no secondary pollution.

The invention discloses a tantalum-niobium production ore raffinate comprehensive treatment method, which comprises: 1, carrying out a heating reaction on an ore raffinate and a preset amount of silica fume to obtain a fluosilicic acid-containing solution; 2, sequentially adding citric acid and oxalic acid particles into the fluosilicic acid-containing solution to remove heavy metal impurities, and then filtering to obtain fluosilicic acid-containing clear liquid and filter residues 1, and 3, reacting the fluosilicic acid-containing clear liquid with a potassium salt solution, controlling the temperature at 45-55 DEG C, and filtering to obtain potassium fluosilicate crystals and crystallization mother liquor; step 4, adding the crystallization mother liquor into lime milk for neutralization and precipitation treatment, controlling the pH value of precipitation reaction to be 8-9, and filtering to obtain filtrate and filter residues 2; 5, the filtrate is subjected to adsorption treatment, and adsorption tail liquid capable of being discharged is obtained. The invention aims to improve the comprehensive treatment efficiency of the tantalum-niobium production ore raffinate.

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.

The present invention relates to the field of water treatment, and discloses a method for resource recycling and reuse of fluorine-containing waste acid and recovery equipment. The equipment includes a fluorine-containing waste acid regulating water tank, a mixing reactor, a fully automatic drum microfilter, an inorganic membrane separation device and a control module. The fluorine-containing waste acid is first pre-treated in the regulating water tank, and then sequentially processed through the mixing reactor reaction, the fully automatic drum microfilter solid-liquid separation, and the inorganic membrane separation device for deep treatment to achieve waste acid resource recycling; the method steps cover the waste acid pretreatment, reaction treatment, solid-liquid separation, and membrane separation treatment links, and are precisely controlled using a sequential control algorithm and a PID control algorithm. The dosage of the reagent and the pressure adjustment are calculated according to specific formulas, respectively, and the influence of historical data is fully considered, so that the treatment process can be controlled more accurately; the invention can efficiently remove fluorosilicic acid impurities, effectively solve the problem of fluorine-containing waste acid treatment, and provide strong support for related enterprises to reduce costs and achieve green production.

The invention relates to the field of water treatment, and discloses a fluorine-containing waste acid resource recycling method and recycling equipment, and the equipment comprises a fluorine-containing waste acid adjusting water tank, a mixing reactor, a full-automatic roller microfilter, inorganic membrane separation equipment and a control module. The waste acid is subjected to reaction in a mixing reactor, solid-liquid separation by a full-automatic roller microfilter and advanced treatment by inorganic membrane separation equipment in sequence, so that the waste acid is recycled; the method comprises the steps of waste acid pretreatment, reaction treatment, solid-liquid separation and membrane separation treatment, and accurate regulation and control are carried out by utilizing a sequence control algorithm and a PID control algorithm. The chemical dosage and the pressure regulation are respectively calculated according to a specific formula, and the influence of historical data is fully considered, so that the treatment process can be more accurately controlled; according to the method, fluosilicic acid impurities can be efficiently removed, the problem of fluorine-containing waste acid treatment is effectively solved, and powerful support is provided for related enterprises to reduce cost and realize green production.

The invention belongs to the field of waste liquid recycling, and discloses a method for preparing potassium fluosilicate by using mixed waste acid, which comprises the following steps: S1, silica fume acidification pretreatment: soaking silica fume in an acid solution for acidification, carrying out precipitation separation on the silica fume, drying, and grinding to obtain acidified silica fume; s2, mixing the raw materials: uniformly mixing the acidified silica fume and the silicon dioxide powder; s3, preparation of fluosilicic acid: adding a mixture of acidified silica fume and silicon dioxide powder into the mixed waste acid, and uniformly stirring by a mechanical stirrer; and S4, preparation of potassium fluosilicate: adding a potassium chloride saturated solution into the fluosilicic acid solution to generate potassium fluosilicate precipitate. The method has the advantages and effects of being high in fluorine ion utilization efficiency, low in production cost and high in finished product purity.

This invention belongs to the field of fly ash treatment technology, specifically disclosing a method for separating potassium and sodium from fly ash, including the following steps: adjusting the acid concentration in the fly ash washing solution to 40-65% and the temperature to 40-65℃, adding a sodium precipitating agent and maintaining the reaction temperature, and filtering to obtain sodium salt and potassium-containing waste liquid. This invention utilizes precipitation to recover sodium ions from fly ash washing solution. After filtration, sodium salt precipitate and potassium-containing waste liquid are obtained. During this process, the reaction is controlled under acidic conditions to prevent potassium ion precipitation. At 40-60℃, the sodium precipitating agent reacts with sodium ions to obtain sodium salt precipitate with large crystals, which allows for more convenient and thorough filtration, resulting in better separation of potassium and sodium ions in the fly ash washing solution. The sodium salt precipitate is further washed with a displacement agent to replace the potassium ions attached to the surface of the sodium salt precipitate with sodium, improving the purity of the sodium salt product. Finally, multiple water washings are performed to reduce the acidity of the sodium salt precipitate, resulting in a sodium salt product with stable quality.

The invention belongs to the technical field of wet-process phosphoric acid production, and particularly relates to a method and system for preparing fluosilicic acid from wet-process phosphoric acid extraction tail gas. After the concentration of the tail washing fluosilicic acid is adjusted to 5-8%, the tail washing fluosilicic acid is transferred to a concentrated fluorine recovery system to serve as primary fluorine replenishing water for secondary concentration production, the timing and the replenishing amount of water replenishing and tail washing fluosilicic acid replenishing in a cycle period are controlled through a DCS control system, circulating concentration is conducted on the fluosilicic acid, and the concentration of the tail washing fluosilicic acid is improved. The fluosilicic acid product with the mass concentration larger than or equal to 16% can be prepared, the current production situation of fluorine loss of a tail washing system is fundamentally solved, and the fluorine yield is obviously increased.

The invention relates to the field of photovoltaic production, in particular to a photovoltaic wastewater treatment method which comprises the following steps: mixing fluorine-containing wastewater with waste acid to obtain fluorine ion wastewater; adding waste silicon dioxide powder into the fluorine ion wastewater to obtain fluosilicic acid wastewater; adding an alkaline sodium source into the fluosilicic acid wastewater to obtain sodium fluosilicate wastewater; and carrying out separation treatment on the sodium fluosilicate wastewater, and extracting bottom-layer jelly to obtain sodium fluosilicate and photovoltaic treatment water. According to the method, waste acid and waste silicon dioxide powder generated in the photovoltaic production process are both utilized, the fluorine content in the wastewater is greatly reduced while no extra chlorine-containing fluorine removal agent is added, fluorine is extracted as a by-product with high purity, photovoltaic wastewater pollution is reduced, the environmental friendliness is improved, and meanwhile, the energy consumption is reduced. The wastewater treatment cost is further reduced, and potential profits are created.

Provided are a liquid dispersion of fluoride particles, which has low viscosity and excellent dispersibility, and is suitable for producing an optical film such as an antireflection film; a method for producing the same; and an optical film using the same. The liquid dispersion of fluoride particles according to the present invention is that in which particles of a fluoride represented by the chemical formula AxCFy (wherein A represents sodium or potassium, C represents silicon or boron, x is 1 or 2, and y is 4 or 6) are dispersed in an aprotic organic solvent having a relative permittivity of 5 to 40, and the optical film according to the present invention is produced by using the liquid dispersion of fluoride particles.

The invention discloses a method for preparing sodium fluosilicate by using copper smelting arsenic-removed waste acid and an aging container, and the method comprises the following steps: S1, filtering the arsenic-removed fluorine-containing waste acid, and then placing the arsenic-removed fluorine-containing waste acid in a reaction tank I to remove solid particles and impurities in the waste acid; s2, adding silicon dioxide, heating, stirring and reacting for 0.5-1 hour, converting fluoride in the waste acid to produce fluosilicic acid, and filtering a reaction product; s3, conveying the generated fluosilicic acid into a reaction tank II, adding a proper amount of sodium sulfate saturated liquid, and preparing sodium fluosilicate; s4, carrying out aging treatment; and S5, washing and drying the generated sodium fluosilicate precipitate to obtain a final product. According to the method, high-purity sodium fluosilicate is prepared from the fluorine-containing waste acid in copper smelting, and fluorine in the waste acid is efficiently removed and recycled, so that pollution to the environment is reduced, and the resource utilization rate is increased.

The invention relates to the technical field of rare earth mineral wet-process smelting, in particular to a method for preparing mixed acid of hydrofluoric acid and fluosilicic acid through desulfurization and concentration of rare earth mineral sulfuric acid slurrying decomposition tail gas. The method comprises the following steps: enabling tail gas generated by a rare earth mineral sulfuric acid slurrying decomposition reaction to sequentially pass through a carbon fiber demister, a condenser and an alkali spray tower to obtain mixed acid of hydrofluoric acid and fluosilicic acid; and the condensing temperature of the condenser is less than or equal to 10 DEG C. Sulfuric acid mist and water mist in the tail gas generated in the rare earth mineral sulfuric acid slurrying decomposition reaction are separated preferentially and flow back to a reaction system, purification of the mixed acid of hydrofluoric acid and fluosilicic acid can be achieved, the content of sulfuric acid in the mixed acid is reduced, the concentration of the mixed acid of hydrofluoric acid and fluosilicic acid is increased to be larger than or equal to 20%, and the fluorine recovery rate is larger than or equal to 95%; reflux of sulfuric acid mist and water mist can also reduce sulfuric acid consumption of the reaction. The acid mist and water mist trapping efficiency of the carbon fiber demister can be larger than or equal to 99% by limiting the diameter of the carbon fibers to be smaller than or equal to 1 micrometer.

A phosphor composition includes a red phosphor material having a red decay rate and a green phosphor material having a green decay rate. The red phosphor material includes a Mn4+ doped phosphor of Formula I and a Eu3+ doped uranium phosphor,and a difference between the red decay rate and the green decay rate is no more than 7 ms, AxMFy:Mn4+ (I), wherein A is Li, Na, K, Rb, Cs, or a combination thereof; M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is an absolute value of a charge of the MFy ion; and y is 5, 6 or 7. A device is also provided.

The invention discloses a method for synergistically preparing and purifying sodium fluosilicate by using fluorine-containing waste acid and fly ash. The method comprises the following steps: crushing household garbage incineration fly ash, pulping, pickling, and carrying out solid-liquid separation to obtain crude calcium water; sequentially carrying out heavy metal removal, denitrification, oxidation and neutralization treatment on the crude calcium water, and carrying out solid-liquid separation to obtain refined calcium water; carrying out primary calcium removal treatment on the obtained refined calcium water, and carrying out solid-liquid separation to obtain crude brine; carrying out deep calcium removal treatment on the crude brine to obtain refined brine mainly containing sodium chloride; pretreating the fluorine-containing waste acid to obtain a fluosilicic acid solution; mixing and reacting the fluosilicic acid solution with refined salt water, controlling the pH value of a reaction system to be less than 2, and performing solid-liquid separation to obtain crude sodium fluosilicate; and carrying out multistage countercurrent oxidation washing on the crude sodium fluosilicate, and drying to obtain a sodium fluosilicate product. And resource comprehensive utilization of the fluorine-containing waste acid and the fly ash is realized.

The invention relates to the technical field of chemical raw material production, and particularly discloses a potassium fluosilicate synthesis device and a synthesis method thereof. The device comprises a box body, a feeding mechanism, a mixing mechanism, a multi-stage detection mechanism and an adjusting mechanism. The feeding mechanism realizes accurate proportioning and conveying of fluosilicic acid solution and sylvite solution (such as potassium chloride and potassium sulfate solution) through a plurality of independent conveying pumps. The mixing mechanism adopts a multi-stage disc type reaction tube, a bending part and an inner diameter expansion design, so that fluosilicate (SiF) and potassium ions (K) fully react to generate potassium fluosilicate (K2SiF6) precipitate, and an electric heating tube synchronously regulates and controls the reaction temperature (40-80 DEG C). And the multi-stage detection mechanism performs three-stage pH real-time detection on the slurry through the three detection boxes connected in series and the rotary mixing shaft, so that the detection precision is improved. And dynamically adjusting the pH value to a target range (5.5-6.5) through an acid adding pipe (such as injection of hydrochloric acid) or an alkali adding pipe (such as injection of a sodium hydroxide solution) according to a detection result.

The present invention discloses a method for producing potassium fluorosilicate. The process for generating potassium fluorosilicate in the present invention includes the following steps: 1) Refine fluosilicic acid and place it in a fluosilicic acid storage tank for standby; 2) Dissolve and remove impurities from potassium chloride to obtain a potassium chloride solution; 3) React the refined fluosilicic acid and the potassium chloride solution in a synthesis tank to obtain a potassium fluorosilicate crystal slurry, and then centrifuge and wash it with a centrifuge to obtain potassium fluorosilicate. The production method of potassium fluorosilicate in the present invention is simple, and can reasonably utilize the filtrate and filter residue generated during the production process, reducing the production cost.

In one aspect, there is provided a method for preparing a Mn4 + doped phosphor of Formula I: Ax [MFy]: Mn4 + (I). The method comprises combining a first aqueous solution comprising a source of Mn with a second solution comprising H2MF6 to form a third solution, and combining the third solution with a fourth solution comprising a source of A to form the Mn4 + doped phosphor, where A is Li, Na, K, Rb, Cs, or a combination thereof; m is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Y, La, Nb, Ta, Bi, Gd, or a combination thereof; x is the absolute value of the charge of the [MFy] ion; and y is 5, 6 or 7. Methods, phosphors, and devices are also provided.

This invention discloses a method for separating fluorosilicic acid and hydrofluoric acid using an anion exchange membrane, comprising the following steps: adding a flocculant to a fluorosilicic acid-hydrofluoric acid mixture, aging it, then adding a desulfurizing agent to carry out a desulfurization reaction to obtain a mixed solution, adding the mixed solution to the feed side of an anion exchange membrane for membrane separation, and obtaining a hydrofluoric acid solution with a mass concentration of 2-30% on the clear water side after separation. This invention uses a flocculant to rapidly settle solids such as sodium fluorosilicate and potassium fluorosilicate in the fluorosilicic acid-hydrofluoric acid mixture, uses a desulfurizing agent to remove sulfuric acid, and then uses an anion exchange membrane to effectively separate fluorosilicic acid and hydrofluoric acid in the fluorosilicic acid-hydrofluoric acid mixed solution. The hydrofluoric acid separated by membrane separation has high purity and high output value, increases the utilization rate of by-product hydrofluoric acid, and reduces costs.

The invention relates to the technical field of calcium superphosphate preparation and fluorine resource recycling, in particular to a method for preparing calcium superphosphate and co-producing fluosilicic acid by using wet-process phosphoric acid sludge acid filter residues, which comprises the following steps: carrying out filter pressing on wet-process phosphoric acid sludge acid to prepare clear liquid and acid sludge, and returning the clear liquid to a clear acid tank; acidifying the acid sludge with sulfuric acid and repulping to obtain a mixture A; filtering and washing the mixture A to obtain filter residues B and filtrate C; the filter residue B is subjected to acidolysis again with concentrated sulfuric acid under the conditions of high temperature and negative pressure, gas generated by acidolysis is washed and absorbed to prepare fluosilicic acid D, a solid-liquid mixture E left after acidolysis and the filtrate C are mixed and react with the pretreated phosphate tailings in proportion to obtain a transition product G, and after a curing reaction is conducted at the temperature of 50-60 DEG C, a single superphosphate product H is obtained; a feasible way is provided for comprehensive utilization of the wet-process phosphoric acid sludge and the phosphate tailings, the channel of the superphosphate raw material is widened, and the recycling efficiency of fluorine resources is improved.

The invention discloses a method for preparing fluosilicic acid from yellow phosphorus slag, which comprises the following steps: drying the yellow phosphorus slag, pretreating, and carrying out acidolysis reaction on the pretreated yellow phosphorus slag; solid residues in reactants obtained after the reaction are removed, and filtrate containing fluosilicic acid is obtained; adding sodium sulfide into the obtained filtrate to purify and remove impurities, removing heavy metal ions, adjusting the pH value of the filtrate, and filtering again to obtain purified filtrate; and concentrating the purified filtrate under reduced pressure to separate out fluosilicic acid crystals or directly obtain a fluosilicic acid solution. According to the method disclosed by the invention, resource utilization of the yellow phosphorus slag is realized, accumulation of wastes is reduced, and pollution to the environment is reduced; by optimizing process conditions, the recovery rate of fluorine resources is increased, and the production cost is reduced; in addition, the method is simple in process and suitable for large-scale industrial production, has both technical feasibility and industrial application prospects, and provides important technical support for green transformation of the phosphorus chemical industry.