190 results about "Fluoride salt" patented technology

The invention discloses a fluoride salt-free nitrate-free cast iron enamel semitransparent glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, sodium carbonate, potassium carbonate, calcium carbonate, potassium feldspar, zinc oxide, lithium carbonate, zirconium silicate, titanium dioxide, aluminum oxide, trisodium phosphate, antimony oxide, magnesium carbonate and barium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and low-temperature firing adaptability, and is suitable for cast iron matrixes, the firing temperature is 740-760 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride-salt-free and nitrate-free medium-temperature semitransparent glaze for steel plate enamel as well as a preparation method and application of the medium-temperature semitransparent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, potassium feldspar, anhydrous borax, sodium carbonate, titanium dioxide, monopotassium phosphate and zinc oxide according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 800-840 DEG C and the firing time of 20-30 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride-salt-free and nitrate-free high-temperature acid-resistant translucent glaze for steel plate enamel as well as a preparation method and application of the translucent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, titanium dioxide, trisodium phosphate, potassium carbonate, lithium carbonate, aluminum oxide, zinc oxide and sodium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 840-880 DEG C and the firing time of 820-830 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride salt-free and nitrate-free low-temperature matte glaze for steel plate enamel as well as a preparation method and application of the low-temperature matte glaze, and belongs to the technical field of enamel. The matte glaze is prepared from quartz, borax pentahydrate, sodium carbonate, titanium dioxide, magnesium oxide, monopotassium phosphate, calcium carbonate, zinc oxide, magnesium carbonate, lithium carbonate, aluminum oxide and zirconium silicate according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The matte glaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are eliminated from the source, the fluorine content of the product is not detected through detection, and the limit value requirements of European Union REACH regulations are met. Zinc oxide and ZnO / TiO2 are added, so that the liquid phase viscosity is reduced, ion diffusion is accelerated, and the opacity (opacification performance) and gloss of the porcelain glaze are enhanced.

The invention discloses a method for regulating and controlling the size of a cobalt-free single crystal lithium-rich manganese-based positive electrode material, which comprises the following steps of: firstly, preparing a cobalt-free lithium-rich positive electrode material precursor from manganese salt and nickel salt by adopting a solid phase method or a coprecipitation method, then uniformly mixing the cobalt-free lithium-rich positive electrode material precursor, a lithium source and mixed salt of chloride salt and fluoride salt, and then preparing the cobalt-free single crystal lithium-rich manganese-based positive electrode material. The preparation method comprises the following steps: carrying out primary calcination at the temperature of 280-550 DEG C, then carrying out secondary calcination at the temperature of 600-800 DEG C, further heating, and then carrying out tertiary calcination at the temperature of 900-1100 DEG C, so as to obtain the cobalt-free single crystal lithium-rich manganese-based positive electrode material after the calcination is finished. The method provided by the invention realizes regulation and control of the size of the cobalt-free single crystal lithium-rich manganese-based positive electrode material; therefore, the cobalt-free single crystal lithium-rich manganese-based positive electrode material with high specific capacity and cycle performance is obtained.

The invention relates to a method and a device for preparing an organic alkali salt of bis (fluorosulfonyl) imide. Ammonia gas, sulfuryl fluoride and liquid organic alkali are adopted as reaction raw materials, and under the condition that no solvent is added or a small amount of solvent is added, the raw materials react through pressurization to generate the organic alkali salt of the bis (fluorosulfonyl) imide. As no solvent is used or only a small amount of solvent is used in the reaction, the chroma of the obtained product is relatively low, and subsequent preparation of lithium bis (fluorosulfonyl) imide as a precursor is facilitated. The invention provides a simple and effective method for reducing the chromaticity of the imidodisulfuryl fluoride salt.

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 utility model relates to an automatic feeding device for small-surface fluoride salt of an electrolytic tank, which belongs to the technical field of electrolysis and comprises a steel pipe body, a feeding cylinder is arranged at the top of the steel pipe body, an air inlet cylinder is arranged on one side of the steel pipe body, a discharging cylinder is arranged on the other side of the steel pipe body, and a filter cylinder is arranged in the steel pipe body. The problems that traditional equipment adopts a hopper for feeding, the feeding period is long, feeding wastes time and labor, and a feeding opening is prone to being damaged due to overweight of the hopper are solved.

The present invention provides a fluorine-containing accelerator and a preparation method thereof, relating to the technical field of accelerator preparation. The fluorine-containing accelerator comprises the following weight percentages: liquid sodium aluminate: 8-15%; aluminum sulfate: 40-50%; fluoride salt: 6-9%; alcoholamine: 4-8%; and water: 25-32%; the sum of these components being 100%. The fluorine-containing accelerator does not produce particle precipitation during preparation, making the preparation process easy to operate.

The present invention discloses a stain-resistant, long-lasting anti-slip agent and a preparation method thereof. The anti-slip agent comprises, by weight, 10-15 parts of an organic acid, 5-10 parts of a fluoride salt, 0.5-2 parts of a surfactant, 0.5-1 parts of zirconium phosphate, 5-10 parts of a silane coupling agent, 0.2-0.5 parts of a defoaming agent, and 30-60 parts of water. The surfactant is a mixture of sodium dodecylbenzenesulfonate and dodecylethoxysulfobetaine in a mass ratio of 1:2-3. The formula of the present invention is gentle and can form uniform micro-nanoscale pores on the surface of floor tiles without compromising the glossiness of the tiles. Zirconium phosphate, as a filling material, can be distributed in the micro-nanoscale pores formed by the floor tiles where the anti-slip agent is applied, forming new friction points to increase friction. At the same time, zirconium phosphate and dodecylethoxysulfobetaine can also impart certain antibacterial properties to the floor tiles, enhancing their stain resistance.

The invention provides a sodium vanadium fluorophosphate positive electrode material and a preparation method and application thereof, and belongs to the technical field of sodium ion battery positive electrode materials. The preparation method comprises the following steps: mixing sodium salt, a vanadium source, a phosphorus source, villiaumite and a carbon source in water, obtaining xerogel by adopting a sol-gel method, calcining to obtain a carbon-coated sodium vanadium fluorophosphate positive electrode material, dispersing the carbon-coated sodium vanadium fluorophosphate positive electrode material in water to form a suspension, adding polyvinyl alcohol and manganese salt, uniformly stirring, heating to evaporate a solvent, and annealing in inert gas to obtain the carbon-coated sodium vanadium fluorophosphate positive electrode material. The carbon and manganese dioxide synergistically co-coated sodium vanadium fluorophosphate positive electrode material is obtained. A sol-gel method and a suspension coating technology are combined to construct the carbon and manganese dioxide dual-coated NVPF composite material, so that the problems of slow sodium ion diffusion kinetics, low electronic conductivity, interface side reaction and the like when the NVPF is used as a sodium ion battery positive electrode material are solved.

The invention belongs to the field of industrial environment-friendly processes, and provides a process for preparing a powdery anhydrous accelerator by synergistic resource treatment of organic waste sulfuric acid and aluminum ash, which comprises the following steps: extracting aluminum ash, denitrifying and desalting, adjusting the acidity of waste sulfuric acid, calcining and reacting at high temperature, treating calcined waste gas and preparing the anhydrous accelerator. In a high-temperature state, sulfuric acid and metal oxides in the aluminum ash generate composite sulfate, and if the waste sulfuric acid contains organic matters, the organic matters are firstly combusted and removed; fluorine in the aluminum ash exists in the form of fluoride salt; adding magnesium sulfate, sodium fluosilicate and the like into the clinker, and uniformly mixing in a mixer to obtain the powdery anhydrous accelerator. The method is reasonable in design, capable of achieving co-processing, resource utilization and energy recovery, environmentally friendly, stable in process, diversified in product and suitable for large-scale popularization.

Aiming at the problems that the high-temperature stability of an existing nickel-zinc battery is reduced and the cycle life of the battery is shortened due to hydrogen evolution reaction or zinc corrosion, the invention provides the electrolyte for the nickel-zinc battery and the nickel-zinc battery thereof. The electrolyte for the nickel-zinc battery comprises a first additive and a second additive, the first additive comprises borate, and the second additive comprises one or two of villiaumite and chlorine salt. According to the electrolyte for the nickel-zinc battery provided by the invention, the first additive can form a barrier structure on a zinc negative electrode interface, and the first additive and the second additive are synergistic, so that the stability of the zinc negative electrode interface can be enhanced, a stable interface film is formed on the negative electrode interface, and side reactions such as hydrogen evolution reaction or zinc corrosion are inhibited; therefore, the cycle life of the battery is prolonged, and the high-temperature performance and the safety performance of the battery are improved.

The invention relates to a negative electrode slurry and a preparation method thereof, a negative plate and a lithium ion battery, the negative electrode slurry mainly comprises a negative electrode active material, a binder composition, a conductive agent and a negative electrode additive, the mass ratio of the binder composition to the negative electrode additive is 2.0-2.4: 1.0-2.0, the binder composition comprises a component A, a component B and a component C, the component A is a fluorine-containing polymer, the component C is a fluorine-containing polymer, and the component B is a fluorine-containing polymer. The component B comprises a carboxylic acid compound, the component C is carboxymethyl cellulose salt, the negative electrode additive is alkali metal fluoride salt and / or alkaline earth metal fluoride salt, the pH value of the negative electrode slurry is 6.5-7.5, and the viscosity of the negative electrode slurry is 1000-4000 mpas. The negative electrode slurry disclosed by the invention has good dispersity and stability, and the prepared negative electrode plate can effectively relieve volume expansion of silicon, so that the rate capability, the cycling stability, the coulombic efficiency and the battery safety of the lithium ion battery can be effectively improved, and the consistency of the lithium ion battery is improved.

The invention relates to the technical field of graphite purification, and discloses a method for high-temperature purification of natural graphite by using light metal halide salt, which comprises the following steps: mixing a natural graphite raw material with composite light metal halide salt according to a mass ratio of 1: 0.1-0.3, the composite light metal halide salt comprising a mixture of chloride salt and fluoride salt; the method comprises the following steps: in a first stage, heating to 800-1000 DEG C under the protection of inert gas, and keeping the temperature for 1-2 hours; in the second stage, the atmosphere is switched into a reducing gas atmosphere, the temperature is increased to 1200-1400 DEG C, and heat preservation is conducted for 3-5 h; in the third stage, the temperature is raised to 1800-2000 DEG C by utilizing halogen gas generated by halogen salt pyrolysis, and heat preservation is carried out for 0.5-1 h; and performing acid pickling, water washing and vacuum drying on the pyrolysis product to obtain graphite. Compared with a traditional high-temperature purification method, the highest pyrolysis temperature is reduced by 500-800 DEG C, the energy consumption is reduced by 40-60%, the production cost is greatly reduced, and the economical efficiency and sustainability of the process are improved.

The invention discloses a preparation method of sulfuryl fluoride and the sulfuryl fluoride. The preparation method comprises the following steps: mixing fluoride salt powder and an anti-sticking agent to obtain a mixture; introducing sulfuryl chloride gas into the mixture for reaction to prepare sulfuryl fluoride; wherein the anti-sticking agent is used for preventing the fluoride salt powder from being stuck. According to the technical scheme, the production cost is reduced, the product purity is improved, and the method is suitable for industrial production.

A low-alkali accelerator and a preparation method therefor are provided. The preparation method comprises: S1, preparing a sodium metaaluminate solution; S2, adding water to the sodium metaaluminate solution, stirring same until uniform, then adding aluminum sulfate thereto, and reacting same at 50-80° C. for 0.5-1 h under stirring conditions; S3, within 10-30 min after complete reaction of the aluminum sulfate, adding, in a dropwise manner, a regulator to regulate the pH value to a neutral state; S4, mixing a strong-alkali weak-acid salt and a silicon dioxide gel until uniform, then adding same to a fluoride salt, and mixing same until uniform, to obtain a modified fluoride salt; and adding the modified fluoride salt to a neutral solution obtained in S3, and reacting same for 1-1.5 h, with the temperature maintained at 50-80° C.; and S5, adding an organic alcohol amine thereto, and stirring same for 0.5-1 h, to obtain the low-alkali accelerator.

The application discloses a preparation method of an aluminum shielding tape surface conductive self-repairing coating. First, a clean aluminum shielding tape surface is obtained through an in-situ reduction / etching pretreatment method based on an aluminum salt / fluoride salt compound solution; second, a conductive / self-repairing dual-effect enhancer is prepared and introduced into a conductive / self-repairing coating synthesized by polyether amine, diisocyanate, a multiple active amine compound, p-xylene glycol and aniline; finally, the solid content of the coating is adjusted and sprayed on the clean aluminum shielding tape surface to obtain the conductive self-repairing coating. The application converts the Al2O3 film on the aluminum surface into a new substance Al, simultaneously constructs a regular porous structure, increases the bonding strength of the film layer, improves the adaptability and self-repairing efficiency of the coating in cable manufacturing and subsequent operation through the construction of a coating with multiple dynamic hydrogen bonds and imine bond synergistic effect, and realizes good conductive enhancement effect and rapid thermal self-repairing purpose of the coating by using isocyanate modified carbon nanotubes as the enhancer.

The utility model relates to the technical field of electrolytic bath blanking and filtering, and particularly discloses an electrolytic bath fluoride salt blanking port filtering device which comprises a feeding port, support legs are fixedly installed on the outer surface of the feeding port, the support legs are designed in a stacking mode and located on the inner side of the feeding port, an installation frame is inserted into the feeding port in a sliding mode, and the installation frame is connected with the feeding port in a sliding mode. And a filter screen is placed on the outer surface of the mounting frame in a clamped mode, the filter screen and the mounting frame are obliquely designed, and the mounting frame and the feeding opening are concentrically designed. According to the filter device for the fluoride salt feed opening of the electrolytic cell, fluoride salt added into the feed opening through a crown block can be filtered through the filter screen, and the filter screen can also filter impurities falling into the feed opening daily when the feed opening is not sealed; impurities in fluoride salt and impurities accidentally falling into the feeding port in daily use cannot enter the material box, and the impurities cannot enter the inside of the electrolytic bath to affect operation.

The present invention provides a post-treatment method for improving the purity of K / NaMgF3 particles, particularly relating to the field of chemistry. The method comprises the following specific steps: (1) placing K / NaMgF3 particles in an aqueous solution and stirring and dissolving them thoroughly; (2) adding a fluoride salt and a buffer to the solution treated in step (1) and stirring thoroughly; (3) adding a magnesium salt and a chloride salt to the solution treated in step (2) and stirring thoroughly; and (4) pouring out the residual solution treated in step (3) and drying the residual solid in step (4). The K / NaMgF3 of the present invention remains unchanged and does not introduce new impurities. The method can remove MgF2 impurities while neither destroying the structure of K / NaMgF3 nor introducing new impurities. The steps are closely related, and no intermediate rinsing or treatment is required. The process is simple, and while ensuring efficient impurity removal, energy conservation and environmental protection are also taken into account. The method is applicable to various K / NaMgF3 preparation methods, does not use toxic and hazardous substances, and has low waste liquid treatment costs.

To provide a new method for producing a fluorinated organic compound in which removal or separation of an auxiliary is easy and which is advantageous in production cost.SOLUTION: A compound represented by the following formula (1): wherein R1, R2 and n are as defined in the description. The method comprises reacting the compound represented by the formula (1) with (A) at least one fluorine source selected from hydrogen fluoride, a hydrogen fluoride salt and a fluoride salt, (B) at least one iodine source selected from iodine and ammonium iodide, and (C) a compound having at least one fluorinated quaternary nitrogen atom in the molecule. A step of difluorinating the compound represented by the formula (1), wherein the amount of the iodine source (B) used is less than 1.0 mol per 1 mol of the compound represented by the formula (1).SELECTED DRAWING: None

The present application relates to waste residue recycling, and provides a system for extracting valuable lithium elements from aluminum electrolysis solid waste water treatment residue, which comprises a ball milling system, a slurry preparation system, an alkali leaching system, an acid leaching system, a fluoride salt directional conversion system, a impurity removal system and a post-treatment system connected in sequence; the alkali leaching system is connected with the fluoride salt directional conversion system. The system for extracting valuable lithium elements from aluminum electrolysis solid waste water treatment residue can efficiently extract valuable lithium elements in the water treatment residue, and significantly improves the economic benefits of harmless disposal and comprehensive utilization of aluminum electrolysis overhaul residue and carbon residue.

To provide an electrolyte for a fluoride ion battery that is highly safe and has a wide potential window.SOLUTION: The present invention provides a solution containing two or more alkali metal fluoride salts dissolved in water.SELECTED DRAWING: Figure 1

The present invention relates to a method for jointly extracting niobium and iron from Bayan Obo rare earth tailings, belonging to the technical field of mineral recovery metallurgy, and solving at least one of the problems of low recovery efficiency, environmental pollution by hydrofluoric acid, and low extraction efficiency of niobium in the prior art. The method includes: pickling the Bayan Obo rare earth tailings, filtering to obtain pickling solution and filter residue; drying the filter residue, mixing it with ammonium sulfate and concentrated sulfuric acid, roasting, and leaching niobium for the first time; mixing the mixture after the first leaching with fluoride salt and water, leaching niobium for the second time, separating solid and liquid, extracting niobium from the obtained filtrate to obtain raffinate and an extraction solution containing niobium ions; mixing the pickling solution and the raffinate, adjusting the pH to 3 - 4.5, then adding hydrogen peroxide solution, and carrying out a precipitation reaction to form Fe(OH)3 precipitate. This method can realize the joint extraction of niobium and iron from Bayan Obo rare earth tailings, avoid the use of hydrofluoric acid, and has a relatively high leaching rate of niobium.

The present invention relates to a nickel-based alloy characterized in that it comprises, by mass percentage: - 15 to 25% molybdenum; - 0.4 to 5% aluminium; - 0 to 2% titanium; - < 3% chromium; - < 3% iron; - < 3% tungsten; - < 0.1% impurities (Im1), the impurities (Im1) being cobalt, zirconium, niobium, tantalum, hafnium, silicon, yttrium, lanthanum, cerium, manganese, magnesium, copper, palladium, platinum, vanadium and carbon; - < 0.01% impurities (Im2), the impurities (Im2) being sulfur, phosphorus and boron; nickel representing the balance to reach 100%. An alloy according to the invention can be used as a structural material or as a coating for parts subjected to corrosion by molten salts, particularly at high temperatures, i.e., between 400 and 800°C, such as fluoride salts and, more particularly, chloride salts. Figure for the abstract: None

A method of removing one or more impurities from an iron-containing feedstock includes grinding the iron-containing feedstock in the presence of a grinding aid to form a pretreated iron-containing feedstock, the grinding aid including an alkali metal chloride, a fluoride salt, or a combination thereof; contacting the pretreated iron-containing feedstock with a flux comprising a metal borate; fusing the pretreated iron-containing feedstock and the flux to form a fused mixture; treating the fused mixture with a leaching solution to form a purified iron-containing feedstock and a used leaching solution; and solid-liquid separating the purified iron-containing feedstock from the used leaching solution, wherein an amount of aluminum, silicon, or a combination thereof is less in the purified iron-containing feedstock than in the iron-containing feedstock. Methods of removing one or more impurities from an iron-containing feedstock also include leaching the pretreated iron-containing feedstock with acid or base without fusion.

The invention discloses fluoride-salt-free and nitrate-free medium-temperature acid-resistant translucent glaze for steel plate enamel as well as a preparation method and application of the translucent glaze, and belongs to the technical field of enamel. The semitransparent glaze is prepared from quartz, anhydrous borax, titanium dioxide, trisodium phosphate, potassium carbonate, lithium carbonate, aluminum oxide, zinc oxide and sodium carbonate according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The semitransparent glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the product has good porcelain surface, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 800-840 DEG C and the firing time of 20-30 minutes, and is suitable for a steel plate. The method can be used for producing green and environment-friendly enamel products.

The invention discloses fluoride-salt-free nitrate-free medium-temperature matte glaze for cast iron enamel as well as a preparation method and application of the fluoride-salt-free nitrate-free medium-temperature matte glaze, and belongs to the technical field of enamel. The matte glaze is prepared from quartz, borax pentahydrate, titanium dioxide, sodium carbonate, magnesium carbonate, calcium carbonate, barium carbonate, aluminum oxide, sodium tripolyphosphate and lithium carbonate according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The matte glaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are eliminated from the source, the fluorine content of the product is not detected through detection, and the limit value requirements of European Union REACH regulations are met. And meanwhile, the ceramic has a good ceramic surface and excellent sintering performance and matte performance, is suitable for a cast iron matrix, has the sintering temperature of 760-780 DEG C, and can be used for producing green and environment-friendly enamel products.

The invention discloses a fluoride-salt-free and nitrate-free stainless steel enamel low-temperature cobalt-nickel ground coat as well as a preparation method and application thereof, and belongs to the technical field of enamel. The ground coat is prepared from quartz, anhydrous borax, titanium dioxide, magnesium carbonate, monopotassium phosphate, sodium carbonate, potassium carbonate, potassium feldspar, calcium carbonate, barium carbonate, ferric oxide and a recycled ternary battery positive electrode material according to a specific mass ratio. The preparation method comprises the steps of raw material mixing, high-temperature melting under a pure oxygen condition, wiredrawing detection, quenching and the like. The ground glaze is completely free of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are avoided from the source, the fluorine content of the product is not detected through detection, the product meets the requirements of European Union REACH regulations, meanwhile, the ground glaze has good porcelain surface, luster and firing adaptability and is suitable for stainless steel substrates, the firing temperature is 760-800 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

The utility model discloses a fluoride salt feeding device for an aluminum electrolysis cell, which belongs to the technical field of aluminum electrolysis production and comprises a hollow feed box, a feed port and a discharge port are respectively arranged at the top and the bottom of the feed box, and a connecting rod penetrating through the feed port and the discharge port is arranged in the feed box. A plug with the outer diameter larger than that of the discharging port is arranged at the bottom end of the connecting rod, a hanging ring is arranged at the top end of the connecting rod, and a plurality of steel wire ropes connected with the hanging ring are arranged at the top of the material box. Compared with the prior art, the feeding device has the advantages that the connecting rod is matched with the plug and the hanging ring which are arranged at the two ends of the connecting rod respectively, so that feeding operation of the fluoride salt material box is rapidly and efficiently completed, the safety coefficient during operation is improved, and meanwhile the labor intensity of workers is reduced.