88 results about "Metaphosphoric acid" patented technology

The invention relates to the technical field of fireproof plates, and discloses a flame-retardant fireproof plate material and a preparation method thereof. Modified benzoxazine, an aromatic bromine modified phosphate flame retardant, polyvinyl chloride, lignocellulose and calcium carbonate are mixed, stirred, pressed, maintained and cut, and the flame-retardant fireproof plate material is obtained. Nitrogen and oxygen six-membered heterocycles in benzoxazine form a stable compound at a high temperature to prevent flame propagation; the silicon element promotes carbonization of combustion products to form a carbonaceous layer, and a cross-linked network formed by silicon-oxygen bonds improves the mechanical property of the fireproof plate material; a net-shaped structure formed by boron-oxygen bonds has high flame retardance; hydrogen fluoride generated by the fluorine element can interrupt the combustion chain reaction; aromatic bromine generates hydrogen bromide to cover the combustion surface, so that a flame-retardant effect is achieved; a carbonization layer is formed on the surface of the fireproof plate material through polymetaphosphoric acid generated by phosphate, so that a flame-retardant effect is achieved; the aromatic bromine modified phosphate flame retardant plays a plasticizing role in polyvinyl chloride, and the mechanical property of the polyvinyl chloride is improved.

The invention belongs to the technical field of preparation processes of barium metaphosphate, and particularly relates to a preparation method of monodisperse micron-sized barium metaphosphate. The preparation method comprises the following steps: mixing purified barium carbonate slurry and phosphoric acid according to a certain molar ratio, reacting to obtain barium dihydrogen phosphate slurry, adding ethanol and a particle size regulating agent, uniformly mixing, and carrying out spray drying to obtain a crude product; the particle size regulating agent comprises ammonium citrate, polyalcohol and barium metaphosphate; and calcining the crude product to obtain the product monodisperse micron-sized barium metaphosphate. According to the preparation method, a small amount of particle size regulating agent and a certain amount of ethanol are added, a crude product with uniform particle size distribution is prepared under a spray drying process condition, and then calcination is performed to obtain the micron-sized barium metaphosphate with uniform particle size distribution.

The invention provides a long-circulation high-rate negative electrode material as well as a preparation method and application thereof, and belongs to the technical field of negative electrode materials. Silicon powder, tin powder and graphene are compounded and subjected to carbon coating, a three-dimensional conductive network is constructed, volume expansion is relieved, and conductivity, cycling stability and rate capability are improved; tungsten oxide serves as an interface stabilizer to form a protective layer, side reaction is inhibited, interface impedance is reduced, and a conductive network is enhanced; metaphosphoric acid is decomposed to generate an inorganic phosphate protective film, and nitrogen-doped carbon generated by urea decomposition is combined, so that the interface stability and conductivity are remarkably improved, and the cycle life is remarkably prolonged; lithium carbide reacts with vinylidene fluoride to generate a lithium fluorocarbon additive, and lithium ions are released in stages to reduce the first lithium loss and stabilize an interface; a vanadium-based metal-organic framework prepared from ammonium metavanadate and terephthalic acid is combined with pre-embedded lithium and graphitized carbon coating, so that a lithium ion transmission path is optimized, and the performance of the lithium ion battery is improved. The synergistic modification measures improve the long cycle stability and high rate performance of the negative electrode material.

The invention discloses a low dynamic fatigue type polyurethane elastomer, and relates to the technical field of organic polymer compounds, the low dynamic fatigue type polyurethane elastomer comprises 50-70 parts of polytetramethylene ether glycol, 75-100 parts of 1, 6-hexamethylene diisocyanate, 5-10 parts of a chain extender, 3-8 parts of a dispersant, 1-5 parts of a lubricant, 4-10 parts of a plasticizer, and 6-12 parts of a flame retardant filler. According to the low-dynamic-fatigue type polyurethane elastomer, due to the addition of the flame-retardant filler, during combustion, melamine is decomposed to generate non-combustible gases such as ammonia gas, the gases can dilute the concentration of oxygen and combustible gas in a combustion area and reduce the intensity of a combustion reaction, and meanwhile, phosphorus elements can form substances such as phosphoric acid and metaphosphoric acid at high temperature, so that the flame-retardant property of the polyurethane elastomer is improved. According to the present invention, the polyurethane elastomer and the flame retardant can capture free radicals in the gas phase and interrupt the chain reaction of combustion so as to inhibit the flame propagation, and can promote the char formation during the combustion process to form a compact carbon layer covering the surface of the polyurethane elastomer so as to provide good thermal insulation and oxygen insulation effects;

The invention discloses a method for measuring the concentration of various dissolved phosphorus forms in industrial sewage. The method comprises the following steps: S1, preparing a plurality of mixed solutions with different concentrations and containing various phosphorus forms in a dissolved state, and respectively carrying out ion chromatographic analysis on the mixed solution with each concentration; establishing a standard curve of each phosphorus form according to the concentration of each phosphorus form and the chromatographic peak of each phosphorus form in the ion chromatogram corresponding to the concentration; the multiple phosphorus forms comprise orthophosphate radicals, pyrophosphate radicals, trimetaphosphate radicals and tripolyphosphate radicals; s2, adjusting the pH value of a to-be-detected industrial sewage sample to be neutral, enabling the to-be-detected industrial sewage sample to sequentially pass through the column 1, the column 2 and the column 3, and then performing ion chromatographic analysis on the water sample passing through the columns to obtain an ion chromatogram of the water sample; and obtaining the concentration of each phosphorus form in the water sample according to the ion chromatogram of the water sample and the standard curve of each phosphorus form. The purpose of automatically analyzing the concentrations of various phosphates in the industrial sewage is achieved, operation is easy, and accuracy is high.

The present invention provides a preparation method for high-content 2-trifluoromethyl-4-heptafluoroisopropyl aniline. In the presence of dithionous acid, a solvent, and a catalyst, 2-trifluoromethyl aniline and 2-bromoheptafluoropropane undergo a reaction and post-treatment to obtain high-content 2-trifluoromethyl-4-heptafluoroisopropyl aniline, wherein the catalyst is selected from phosphoric acid, pyrophosphoric acid, hypophosphorous acid, metaphosphoric acid, phosphorous acid, pyrophosphorous acid, hydrobromic acid, hydrogen bromide gas, hydrogen chloride gas or sodium bisulfite. The preparation method of the present invention is simple to operate, has mild chemical reaction conditions, achieves a primary reaction conversion content of 96% or above under good reaction conditions, has few post-treatment steps, requires no rectification, achieves a final product content of 98% or above, achieves a total reaction yield of 93% or above, is easy for industrial production, and has good prospects for application.

The invention discloses a method and system for preparing nano barium sulfate uniform particles based on ultrasonic assistance, and the method comprises the steps: conveying a sodium sulfate solution and a barium chloride solution into a reaction container in an isopyknic manner, adjusting the position and parameters of an ultrasonic transducer, and adjusting the power and frequency according to a preset curve; slowly transferring the slurry obtained by the reaction into a post-treatment container, adding a sodium hexametaphosphate solution, and carrying out dispersion treatment in an ultrasonic cleaning device; and subpackaging the product into a sealed container subjected to cleaning treatment in a continuous flowing manner, controlling the filling amount, and sealing for constant-temperature storage. According to the scheme of the invention, nano barium sulfate particles with small particle size and uniform distribution can be generated.

The application discloses a kind of high flame-retardant tpe materials and preparation method thereof, by polytetrahydrofuran, modified monomer and 4,4'-dicyclohexyl methane diisocyanate are reacted, chain extension is used with 1,4-butanediol, finally join flame-retardant additive, form branched structure, and the molecular structure of the pte material is branched structure, and molecular chain segment contains organic silicon composite organic phosphorus structure, when heat decomposition, can generate phosphoric acid, poly-metaphosphoric acid and other acidic substances, these acidic substances will catalyze pte molecule to occur dehydration reaction, accelerate its crosslinking, organic silicon chain segment will produce inorganic silicate or silicon-carbon, and then form a dense carbon layer on the surface of material, can heat insulation and oxygen isolation, prevent combustible gas to escape outward and oxygen diffusion inward, and slow down the further thermal decomposition of internal material, prevent carbon layer from being burnt through or collapse under high temperature, improve the durability of barrier, so that pte material has good flame-retardant effect.

A multi-component mortar system contains a curable aqueous-phase aluminous cement component A and an initiator component B in aqueous-phase for initiating the curing process. Component A further contains at least one plasticizer, water, and at least one blocking agent selected from phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acids. Component B contains an initiator, at least one retarder, at least one mineral filler, and water. A multi-component system is useful, which is ready-for-use, for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone as well as its use for chemical fastening of anchoring means.

The invention provides a selective desulfurizer and a method for removing acid gas in gas. The selective desulfurizer comprises the following components in percentage by mass: 30-40% of organic amine A, 10-20% of organic amine B, 5-10% of an additive and 30-55% of water, the organic amine A comprises first organic amine and second organic amine, the first organic amine is methyldiethanolamine, and the second organic amine is monoethanolamine and / or diethanolamine; the mass ratio of the first organic amine to the second organic amine is (1-5): 1; the organic amine B comprises one or a combination of more than two of secondary amine 1, secondary amine 2 and secondary amine 3; the additive comprises one or a combination of more than two of phosphorous acid, hypophosphorous acid, metaphosphoric acid and pyrophosphoric acid. According to the technical scheme, carbonyl sulfide in the raw material natural gas can be selectively removed, carbon dioxide meeting the national standard is reserved, the defects of an existing process are overcome, and an efficient and green novel method is provided for natural gas purification.

This invention relates to the field of polymer materials technology, specifically disclosing a flame-retardant thermoplastic elastomer compound and its preparation method. The flame-retardant thermoplastic elastomer compound comprises 50-80 parts SEBS, 10-30 parts PP, 5-15 parts compatibilizer, 10-30 parts composite flame retardant, 3-10 parts plasticizer, 0.2-1 parts antioxidant, and 0.1-0.5 parts lubricant. The composite flame retardant is prepared by reacting and mixing an intumescent flame retardant, barium metaphosphate, boron nitride, triallyl isocyanurate, and SEBS. The flame-retardant thermoplastic elastomer compound of this application possesses good flame retardancy, mechanical properties, and water resistance stability.

At least one alkali and / or earth alkaline metal salt in an inorganic mortar system can be used for a chemical fastening of anchoring means in mineral substrates. The inorganic mortar system has a curable aluminous cement component A and an initiator component B for initiating the curing process. Component A further has at least one blocking agent selected from the group of phosphoric acid, metaphosphoric acid, phosphorous acid, boric acid, and phosphonic acids, and component B has an activator. The at least one alkali and / or earth alkaline metal salt in an inorganic mortar can accelerate curing of the cements as well as increase load values. A method for a chemical fastening of anchoring means, preferably of metal elements, in mineral substrates such as structures made of brickwork, concrete, pervious concrete or natural stone can also be performed.

The present application relates to the technical field of lithium ion battery recycling, in particular to a method for stripping lithium ion battery pole piece and application thereof. The method for stripping lithium ion battery pole piece comprises: immersing the pole piece into a mixed solution containing a stripping agent and a stripping aid for reaction, and obtaining the separated active material layer and the current collector layer after a period of time; the stripping agent comprises a carboxylic acid containing at least two carboxyl groups; the stripping aid comprises at least one of sodium fluoride, potassium fluoride, ammonium fluoride, phosphoric acid, sodium phosphate, monosodium phosphate, sodium metaphosphate, potassium phosphate, monopotassium phosphate, potassium metaphosphate, ammonium phosphate, disodium ethylenediaminetetraacetate, tetrasodium ethylenediaminetetraacetate, inositol hexaphosphate and its salt, inositol pentaphosphate and its salt, inositol tetraphosphate and its salt, and inositol triphosphate and its salt. The method can realize the separation of the active material and the current collector, the hydrogen production amount is small during the whole stripping process, the current collector obtained after stripping is intact, the separation time is short, and the separation efficiency is high.

The present invention pertains to a use of sodium polyphosphate, preferably selected from the group consisting of sodium tripolyphosphate (STPP, Na5P3O10), sodium hexametaphosphate (SHMP, Na6P6O18), sodium trimetaphosphate (STMP, Na3P3O9), sodium metaphosphate (SMP, NaPO3) and mixtures thereof, in an inorganic mortar system for a chemical fastening of anchors and post-installed reinforcing bars in mineral substrates, comprising a curable aluminous cement component A and an initiator component B for initiating the curing process. Component A comprises a calcium aluminate cement, at least one blocking agent selected from the group consisting of boric acid, phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids and water, and component B comprises an activator and water. Moreover, the present invention pertains to a use of sodium polyphosphate, preferably selected from the group consisting of sodium tripolyphosphate (STPP, Na5P3O10), sodium hexametaphosphate (SHMP, Na6P6O18), sodium trimetaphosphate (STMP, Na3P3O9), sodium metaphosphate (SMP, NaPO3) and mixtures thereof, in an inorganic mortar to accelerate calcium aluminate cement hydration as well as to a method for a chemical fastening of anchors and post-installed reinforcing bars, preferably of metal anchors and post-installed reinforcing bars, in mineral substrates, such as structures made of brickwork, concrete, pervious concrete or natural stone.

The invention relates to the technical field of high polymer materials, and discloses a modified L-arginine material containing lipoic acid and a preparation method thereof.The modified L-arginine material containing lipoic acid is obtained by adding lipoic acid and modified L-arginine into a stirrer, stirring and blending, stirring, vacuum drying and compression molding. Lipoic acid in the modified L-arginine material containing the lipoic acid has a good antibacterial effect, and growth of staphylococcus aureus is inhibited. Phosphorus in the modified L-arginine can generate polyphosphoric acid and metaphosphoric acid which are high in dehydration property during combustion, and the polyphosphoric acid and the metaphosphoric acid are not prone to volatilization and can form a compact protective layer on the surface of the coating, so that the flame-retardant effect is achieved; guanidyl in the L-arginine and phosphorus form a P-N flame-retardant system, so that a relatively good flame-retardant effect is achieved; benzoxazine in the modified L-arginine can form a heat-resistant phenolic resin structure at a high temperature, so that the modified L-arginine has a relatively good flame-retardant effect.

The invention relates to a part made from synthetic graphite, preferably isostatic synthetic graphite, impregnated with aluminium metaphosphate Al(PO3)3, and characterised in that the aluminium metaphosphate content is at least 1% by weight for the cubic form and does not exceed 0.4% by weight, and preferably does not exceed 0.3% by weight, for monoclinic forms. Such a part has good resistance to oxidation and can be used under hydrothermal conditions.

The invention belongs to the field of fruit quality analysis, and particularly relates to a high performance liquid chromatography method for simultaneously determining organic acid and vitamin C in kiwi fruit, which comprises the following steps: grinding kiwi fruit into powder in liquid nitrogen, extracting with metaphosphoric acid solution, centrifuging, and collecting supernate to obtain test solution; a high performance liquid chromatograph is utilized, and under the chromatographic conditions that a C18 column is selected as a chromatographic column, the column temperature is 25-35 DEG C, the sample injection volume is 10 microliters, a 0.01 mol / L monopotassium phosphate buffer solution is used as a mobile phase for isocratic elution, and the organic acid and the vitamin C in a test solution are detected under the conditions that the flow speed is 0.5-0.8 mL / min and the wavelengths are 210 nm and 245 nm. The detection method provided by the invention can realize qualitative and quantitative analysis of flavor and nutritional ingredients of kiwi fruits, and has good specificity, accuracy, durability and stability and high detection sensitivity.

The invention discloses a preparation method of a high-flame-retardant graphene polystyrene board, modified polystyrene is added into a mold, heat preservation is carried out for 30-60 s under the conditions that the steam temperature is 110-130 DEG C and the pressure is 0.3-0.5 MPa, the high-flame-retardant graphene polystyrene board is prepared, when the polystyrene board is burnt, a phosphorus compound in modified filler is decomposed to generate a phosphoric acid liquid film, a polystyrene board matrix is protected, and the high-flame-retardant graphene polystyrene board is prepared. The phosphoric acid is further dehydrated to generate metaphosphoric acid, the metaphosphoric acid is polymerized to generate polymetaphosphoric acid, the substances can form stable cross-linked solid substances and form a carbonization layer, internal silicon and boron elements can promote the carbonization layer to form a ceramic silicon carbon layer, and nitrogen elements can generate a large amount of gas, so that the ceramic silicon carbon layer expands; the expanded ceramic silicon-carbon layer has better heat insulation and oxygen insulation effects, and a lamellar structure continuous with graphene can effectively prevent oxygen from entering the material, so that combustion is prevented, and the flame-retardant effect is achieved.

The present invention provides a liquid enzyme preparation of an enzyme having excellent activity stability. Stability of enzymatic activity is improved by accommodating a liquid enzyme preparation that includes an enzyme into a container the internal space of which has been replaced by an inert gas, or by adding, to a liquid enzyme preparation containing a protein deamidase, an additive selected from the group consisting of sugar alcohols, glycerin, ethanol, sulfites, lecithins, citrates, polyphosphates, tartrates, phytic acid, metaphosphoric acid, sodium chloride, tocotrienols, methionine, pectins, beet pigment, capsicum pigment, rosemary extract, tocopherols, tea extract, and butylated hydroxyanisole.

In order to solve the technical problem that an industrial preparation method of scandium metaphosphate is lacked in China at present, the invention provides a preparation method of optical-grade scandium metaphosphate, and the optical-grade scandium metaphosphate with the purity reaching 99.9% or above can be produced. The method comprises the following steps: dissolving scandium chloride hexahydrate by using a hydrochloric acid solution to obtain a scandium chloride solution, filtering and recrystallizing to obtain scandium chloride hexahydrate crystals, and reacting the scandium chloride hexahydrate crystals with an ammonium carbonate solution to obtain high-purity scandium carbonate; then, the diluted food-grade phosphoric acid and the high-purity scandium carbonate are subjected to a heat preservation stirring reaction, scandium dihydrogen phosphate crystals are obtained, the scandium dihydrogen phosphate crystals are subjected to low-temperature drying foaming treatment and high-temperature treatment, and scandium metaphosphate is obtained. According to the method, the optical-grade scandium metaphosphate with the purity reaching 99.9% or above can be industrially produced, and the use requirement of optical glass firing is met.

The invention relates to the technical field of flame retardance, and discloses a flame-retardant liquid and a preparation method thereof.The flame-retardant liquid is obtained by adding zinc borate, a silicon-containing flame retardant and water into a reactor and stirring. The silicon element, the sulfur element, the phosphorus element and the zinc phytate in the silicon-containing flame retardant all have good flame retardant effects. When the silicon element is heated, a vitreous substance can be generated on the surface of the material, and substance transportation and energy transfer are isolated. Phosphorus can generate polyphosphoric acid and metaphosphoric acid which are high in dehydration property during combustion, and the polyphosphoric acid and the metaphosphoric acid are not prone to volatilization and can form a compact protective layer on the surface of the coating, so that the flame-retardant effect is achieved. The sulfur element contained in the polymer can promote the formation of a carbon layer on the surface of the polymer at a high temperature, and the carbon layer can be used as a heat and oxygen barrier layer, so that the combustion speed is reduced, and the flame-retardant effect is achieved. Zinc phytate also has good flame retardance, and meanwhile, an imidazole group in the zinc phytate has a good antibacterial effect.

The application provides a preparation method of high-content 2-trifluoromethyl-4-heptafluoroisopropylaniline, in which 2-trifluoromethyl aniline and 2-bromine heptafluoropropane are reacted in the presence of hydrosulfite, a solvent and a catalyst to obtain high-content 2-trifluoromethyl-4-heptafluoroisopropylaniline through reaction and post-treatment; the catalyst is selected from phosphoric acid, pyrophosphoric acid, hypophosphorous acid, metaphosphoric acid, phosphorous acid, pyrophosphorous acid, hydrobromic acid, hydrogen bromide gas, hydrogen chloride gas or sodium bisulfite. The preparation method is simple in operation and mild in chemical reaction conditions; under the preferred reaction conditions, the conversion content reaches more than 96% in one reaction, the post-treatment steps are few, rectification is not needed, the content of the final product is more than 98%, the total reaction yield is more than 93%, the industrial production is easy, and the method has a high application prospect.

The present application relates to a kind of high hardness polyurethane and its preparation method and application.The phosphorus-containing polyol structural formula is as follows: the phosphorus-containing polyol is prepared by ester exchange reaction using phosphorus-containing diol and dialkyl carbonate.High hardness flame-retardant thermoplastic polyurethane elastomer is prepared from the phosphorus-containing polyol.The phosphorus-containing polyol can decompose phosphoric acid, metaphosphoric acid and other substances during heating, promote the dehydration and carbonization of polyurethane, and form a dense carbon layer that is not easy to burn, thereby achieving excellent flame-retardant effect.

The invention discloses a metaphosphoric acid rapid cooling device and a use method thereof. The metaphosphoric acid rapid cooling device comprises a cylindrical barrel; the barrel cover covers the top of the cylindrical barrel body; the feeding hole is formed in the center of the cylinder cover; the chassis is hermetically and rotatably connected with the bottom of the cylindrical barrel; the telescopic rod comprises a sleeve and a piston rod, and the sleeve is fixedly connected with the center of the chassis; the large bottom of the conical drainage piece is fixedly connected with the tail end of the piston rod, and the conical head part of the cylindrical drainage piece corresponds to the feeding hole; the annular cavity is distributed around the inner wall of the cylindrical barrel and surrounds the telescopic rod and the conical drainage piece, a first gap is reserved between the edge of the conical drainage piece and the inner wall of the annular cavity, and a second gap is reserved between the bottom of the annular cavity and the base plate; and the cooling medium is filled in the annular cavity. The metaphosphoric acid cooling device has the beneficial effects that metaphosphoric acid is cooled for multiple times, and the cooling rate is increased.

To provide a calcium carbonate filler for biodegradable resin that can enhance the efficiency of biodegradability of the biodegradable resin used in combination, a biodegradable resin composition using the same, and a resin molded article. 【Solution means】 The calcium carbonate filler for biodegradable resin of the present invention is a surface treatment agent containing a polyphosphoric acid-based surface treatment agent component, the polyphosphoric acid surface treatment agent component contains at least one polyphosphoric acid, and the converted amount of metaphosphoric acid (P2O5) contained in the polyphosphoric acid is 75% by mass or more and less than 100% by mass based on the mass of the polyphosphoric acid. It is surface-treated with a surface treatment agent and contains surface-treated calcium carbonate particles that satisfy the following formula: 0.8 ≦ A ≦ 3.0 (μm), 13,000 ≦ B ≦ 30,000 (cm 2 / g), C ≦ 100 (ppm), 4.0 ≦ D ≦ 8.5, 800 ≦ E ≦ 5000 (ppm), 0.1 ≦ Tw ≦ 0.8 (mass%). Here, A is the average particle diameter of 50% of the surface-treated calcium carbonate particles, B is the specific surface area by the air permeability method, C is the residue on a 45 μm sieve of the JIS standard sieve, D is the pH when made into a 10% by mass aqueous suspension, E is the content of phosphorus element measured by an inductively coupled plasma optical emission spectrometer, and Tw is the thermal weight loss at 200 to 500 °C measured by a differential thermal balance device.

A multi-component mortar system contains a curable aqueous-phase aluminous cement component A and an initiator component B in aqueous-phase for initiating the curing process. Component A further contains at least one plasticizer, water, and at least one blocking agent selected from phosphoric acid, metaphosphoric acid, phosphorous acid, and phosphonic acids. Component B contains an initiator, at least one retarder, at least one mineral filler, and water. A multi-component system is useful, which is ready-for-use, for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone as well as its use for chemical fastening of anchoring means.

This invention relates to the field of health food testing technology, and particularly to a method and system for rapid determination of ascorbic acid enantiomer content in health foods using ultra-high performance phase chromatography (UHPLC). After extraction with metaphosphoric acid solution via ultrasonication in the dark, centrifugation, and filtration, the sample is separated using a Waters Acquity BEH column. Gradient elution is performed using supercritical carbon dioxide and 0.1% phosphoric acid methanol solution as the mobile phase, under conditions of 13.8 MPa system back pressure, 31 °C column temperature, and 245 nm detection wavelength. The contents of D(−)-ascorbic acid and L(+)-ascorbic acid are determined using the external standard method. This invention can achieve effective separation of the two ascorbic acid enantiomers in a short time, and has advantages such as fast analysis speed, good separation effect, high accuracy, good repeatability, and low organic solvent consumption. It is suitable for quality control and regulatory detection of ascorbic acid enantiomers in various health foods such as tablets, capsules, and liquids.

The invention relates to an optical cable belting material with high flame retardance and high resistivity, and belongs to the technical field of flame-retardant materials. The preparation method of the optical cable belting material comprises the step of coating the calcium carbonate powder and the intumescent flame retardant on a base material through vinyl acetate-ethylene copolymer emulsion and water to obtain the optical cable belting material. When the optical cable belting material is combusted, the calcium carbonate powder and the intumescent flame retardant are subjected to chemical reaction in flame combustion to form a calcium metaphosphate / carbonaceous composite flame-retardant coating, and the flame-retardant coating is constructed by embedding lamellar calcium metaphosphate continuous networks in a carbon layer. The calcium metaphosphate continuous network can control the combustion process of the composite coating, and the peak heat release rate and the smoke generation rate are remarkably reduced; and the expansion degree and the structural uniformity of the carbon residues are effectively improved, and a conductive path of a carbon layer is destroyed, so that the surface resistivity of the flame-retardant coating is improved. The preparation process is simple, the coating performance is excellent, and the coating is suitable for high-flame-retardant and high-resistivity optical cable belting materials.

The application relates to the technical field of heat-sensitive materials, and discloses a film-coated heat-sensitive material and a preparation method thereof. The application is characterized by the following steps: preparing a base material, cutting the base material into a required shape and size, coating a heat-sensitive dye, uniformly spraying the heat-sensitive dye on the base material, drying the base material coated with the heat-sensitive dye, preparing a finished product, cutting the dried base material into a required final product shape and size, and obtaining the film-coated heat-sensitive material. The modified polyurethane and boron element in the phosphorus-containing flame retardant have good flame-retardant effects. In the combustion process, the phosphorus element in the phosphorus-containing flame retardant decomposes into a non-flammable liquid film of phosphoric acid, further generates metaphosphoric acid and poly-metaphosphoric acid, these substances form a protective layer on the material surface, isolate oxygen and high temperature, and have the flame-retardant effect. The quaternary ammonium salt in the quaternary ammonium chain extender has good antibacterial effect.

The invention discloses a beneficiation method for recovering tungsten from polymetallic tungsten ore tailings, which is characterized by comprising the following steps: carrying out strong magnetic separation to obtain strong magnetic concentrate and strong magnetic tailings; concentrating the strong magnetic concentrate until the concentration is 30% of ore pulp, adding sodium carbonate until the pH value of the ore pulp is 7.0-9.0, then adding sodium hexametaphosphate, OS, salinized water glass, lead nitrate and a tungsten catching agent, mixing, and feeding into a flotation machine to obtain wolframite concentrate and wolframite tailings; the strong magnetic tailings are blended into ore pulp with the concentration being 30%, oxalic acid, water glass and a catching agent LLR are added, the mixture enters a flotation machine after being mixed, and scheelite-fluorite concentrate and co-flotation tailings are obtained; and the scheelite-fluorite concentrate is concentrated until the concentration is 30%, and then one-roughing and three-refining centrifugal reselection is carried out, so that scheelite concentrate and fluorite concentrate are obtained. Under the acidic condition, the flotation effect of fluorite is enhanced, interference on scheelite flotation is reduced as much as possible, and the recovery rate and grade of wolframite concentrate and scheelite concentrate are both improved.