42 results about "Lead acetate" patented technology

The invention relates to the technical field of gas detection, in particular to response type aerogel and application thereof. The response type aerogel is prepared according to the following steps: mixing and dissolving a metal organic framework material and lead acetate to obtain an adsorption and response integrated probe; mixing silk fibroin, polyethylene glycol diacrylate and the adsorption-response integrated probe, and performing light curing reaction under the action of a photo-crosslinking agent to obtain the adsorption-response integrated probe. Wherein a double-grid aerogel substrate generated by reaction of silk fibroin and polyethylene glycol diacrylate can adsorb water molecules in environments with different humidity to wet the substrate, and a saturated microscopic water environment is provided for colorimetric reaction on the surface of a pore wall, so that interference of environmental humidity on response is effectively relieved. The quantitative method established by using the response type aerogel can be used for high-sensitivity quantitative detection of hydrogen sulfide in livestock and poultry farms.

The application belongs to the technical field of ion batteries, and particularly relates to a lead-carbon composite material and a preparation method and application thereof. The preparation method comprises the following steps: grinding and tabletting a lead source and a carbon source, and roasting the tabletted tablet to obtain the lead-carbon composite material; the lead source comprises at least one of lead citrate, lead acetate, lead chloride and lead oxalate; and the carbon source comprises at least one of polyvinylpyrrolidone, carboxymethyl cellulose, glucose and sucrose. The lead-carbon composite material has a three-dimensional porous structure formed by metal lead particles embedded in a carbon skeleton, and the carbon skeleton can effectively alleviate the volume expansion generated in the alloying process of metal lead and metal sodium in the charging and discharging process, so as to improve the conductivity and electrochemical performance of the material.

The invention discloses a method for recycling lead from waste lead-acid storage battery lead plaster through electrolysis, and belongs to the technical field of solid waste treatment and recycling. The method for recycling lead through electrolysis of the waste lead-acid storage battery lead plaster comprises the following steps that the waste lead-acid storage battery lead plaster, an additional lead source containing metal lead and an acetate solution are mixed and leached, a lead acetate leaching solution is obtained, then the lead acetate leaching solution serves as an electrolyte for electrolysis, and a metal lead product is obtained. According to the method, the lead-containing electrolyte can be obtained through one-step leaching, and the electrolyte is neutral, so that the corrosion of strong acid and strong alkali is avoided. According to the technical method provided by the invention, the metal lead with high purity and low impurity content can be obtained. In the electrolysis step, the electrolysis energy consumption is not higher than 600 kwh / t lead, the current efficiency is higher than 97%, and the lead recovery rate reaches 99% or above.

The invention relates to a synthesis method of a perovskite microcrystalline material, and belongs to the field of perovskite materials. The invention provides a synthesis method of a perovskite microcrystalline material, which comprises the following steps: mixing alkali metal iodide salt, lead acetate trihydrate and formamidine acetate, and reacting under preset conditions to obtain the formamidine lead iodide perovskite microcrystalline material. According to the method, an acid-free system is adopted for synthesizing the formamidine lead iodide perovskite microcrystal material for the first time, hydroiodic acid which is indispensable and extremely high in danger coefficient in a traditional aqueous phase method is completely abandoned, alkali metal iodide salt is creatively adopted as a green iodine source, high-quality formamidine lead iodide perovskite microcrystals are successfully synthesized, the material performance is guaranteed, and meanwhile the yield of the formamidine lead iodide perovskite microcrystals is increased. The safety of the synthesis process is greatly improved; in addition, the solid salt with stable properties is adopted, so that the sensitivity of the whole synthesis process to air and humidity is reduced, and better repeatability and stability are achieved.

The invention discloses a molybdenum alloy total molybdenum content detection method based on a lead molybdate gravimetric method. The method comprises the following steps: dissolving a ferromolybdenum alloy sample through a nitric acid-potassium chlorate saturated solution and the like, carrying out lead molybdate precipitation through ammonia water, an acetic acid-ammonium acetate buffer solution, lead acetate and the like, carrying out high-temperature gradient sintering on filter residues through a mixed solvent of anhydrous sodium carbonate and zinc oxide, and determining residual molybdenum through a potassium thiocyanate spectrophotometric method after dissolving. And performing correction calculation. According to the method, a gravimetric method and a spectrophotometric method are combined for use, the filter residues are corrected, the precipitation process technology is optimized, the problems that a traditional method is tedious in operation and large in residual molybdenum error of the filter residues are solved, and high-precision, high-efficiency and low-cost molybdenum content detection is achieved.

The invention discloses a perovskite nanocrystal with low lead loss and high fluorescence quantum efficiency and a preparation method thereof, which can effectively reduce environmental pollution caused by discharge of lead element, and the preparation method comprises the following steps: placing A2CO3 or A (CH3COOH), lead acetate and metal salt in a container, adding organic acid and a non-coordination solvent to construct a reaction environment, after high temperature dissolution, injecting a halogen reaction source, and after the reaction is completed, adding an organic acid and a non-coordination solvent to prepare a perovskite nanocrystal with low lead loss and high fluorescence quantum efficiency. Performing reaction to synthesize coarse nanocrystals, performing surface reconstruction by using a quaternary ammonium salt solution to promote separation and purification, and cleaning to obtain a clear and transparent quantum dot solution; on the basis of an original ternary synthesis method, nucleation growth of the nanocrystals is achieved by introducing non-toxic metal elements, efficient conversion from lead element feeding to a product is promoted, and therefore the strong emission characteristic and stability of the nanocrystals are guaranteed while lead source emission and environmental pollution in the synthesis process are reduced.

The invention discloses a preparation method and application of a high-stability hydrogen sulfide detection card, and the preparation method at least comprises the following steps: step I, dispersing dithizone in ethanol to obtain a dithizone solution; iI, dissolving lead acetate in water to obtain a lead acetate solution; iII, under the alkaline condition, mixing the dithizone solution obtained in the step I with the lead acetate solution obtained in the step II to obtain a dithizone-Pb complex; step IV, mixing the methanol solution containing tetrabutyl ammonium hydroxide, N, N-dimethylformamide, water and ethanol, and carrying out water bath reaction to obtain an alkaline silica gel solid carrier; v, dispersing the dithizone-Pb complex obtained in the step III into the alkaline silica gel solid carrier obtained in the step IV to obtain a dithizone-Pb complex solid carrier; and step VI, dispensing the dithizone-Pb complex solid carrier obtained in the step V on a thin film to obtain the hydrogen sulfide detection card. The detection card can be used for quantitative detection of hydrogen sulfide and drug sensitivity analysis of bacteria.

The invention belongs to the field of electronic functional materials and devices, and particularly relates to a lead scandium tantalate thin film with high energy storage performance and high electrocaloric performance and a preparation method of the lead scandium tantalate thin film. The lead scandium tantalate thin film is composed of a substrate, a ferroelectric thin film layer and a top electrode, and the chemical formula of the thin film is PbSc0. 5Ta0. 5O3 (PST). The preparation method is a sol-gel method, scandium nitrate, lead acetate and ethyoxyl tantalum are used as precursor raw materials, ethylene glycol monomethyl ether is used as a solvent, concentrated nitric acid is used for regulating the pH value, ethanolamine is used as a stabilizer, and the PST film is obtained after aging, glue homogenizing, drying, pyrolysis and layer-by-layer annealing. Compared with other preparation methods, the preparation process has the advantages of being simple, low in cost, high in production efficiency and the like. The energy storage density of the lead scandium tantalate thin film can reach 40.4 J / cm < 3 > in a medium electric field, and the energy storage efficiency exceeds 71.8%. The adiabatic temperature change of the lead scandium tantalate thin film in a low electric field can reach 4.75 K, and the lead scandium tantalate thin film has high temperature stability. The high energy storage characteristic of the lead scandium tantalate thin film can provide low-loss capacitance for a pulse power amplifier, a base station energy storage unit and the like, the high electrocaloric effect can provide a solid-state refrigeration solution for the heat management field of electronic devices such as chips and the like, and in addition, a new generation of multifunctional integrated devices are expected to be developed by utilizing the synergistic effect of energy storage and heat management of the lead scandium tantalate thin film.

The invention provides a method for recovering high-purity lead carbonate from lead sulfate slag, which comprises the following steps: (1) mixing and slurrying lead sulfate slag, calcium salt, an activating agent and water, then adding the slurried material into a closed reaction kettle, introducing carbon dioxide gas, heating, stirring, and filtering after the reaction is finished to obtain filtrate and transformation slag; (2) mixing and slurrying the transformation slag and water, and adding the mixture into a centrifugal separator for beneficiation to obtain gravity concentrate and gravity tailings; (3) the gravity concentrate and an acetic acid solution are mixed and pulpified, then the pulpified material is added into a reaction kettle, heating and stirring are conducted, filtering is conducted after the reaction is finished, and lead acetate leaching liquid is obtained; and (4) adding the lead acetate leachate into a closed reaction kettle, introducing carbon dioxide gas, heating, stirring, and filtering after the reaction is finished to obtain high-purity lead carbonate and a regenerated acetic acid solution. Compared with the prior art, the method is low in cost, free of wastewater and good in environmental benefit.

The invention provides a preparation method of a graphite fluoride modified lead-copper composite catalyst. The preparation method comprises the following steps: preparing a graphite fluoride suspension; adding copper acetate and lead acetate in a formula ratio into the graphite fluoride suspension, performing ultrasonic dispersion, and performing constant-temperature water bath heating and stirring by using a heat collection type magnetic stirrer to obtain a copper acetate, lead acetate and graphite fluoride suspension; adding copper acetate, lead acetate and the graphite fluoride suspension into a reaction container, putting the reaction container into a heat collection type magnetic stirrer, heating and stirring in a constant-temperature water bath, dropwise adding a sodium hydroxide solution into the reaction container in the constant-temperature water bath heating and stirring process, filtering and collecting precipitates after the reaction is finished, and drying the precipitates to obtain the copper-lead-carbon composite material. A copper hydroxide, lead hydroxide and graphite fluoride compound is obtained; and calcining the copper hydroxide, lead hydroxide and graphite fluoride compound in a tubular furnace to obtain the composite material. The graphite fluoride modified lead-copper composite catalyst has good catalytic activity, the combustion performance of a solid propellant can be improved, and regulation and control of the combustion performance of the solid propellant are achieved.

The invention belongs to the field of preparation of perovskite materials, and relates to a preparation method for inducing phase change of perovskite crystals by an organic solvent. The invention provides a perovskite crystal phase change method which comprises the following steps: heating, mixing and stirring cesium carbonate, lead acetate trihydrate, hydrobromic acid and 1, 6-hexamethylenediamine, and cooling to obtain a two-dimensional (HDA) CsPb2Br7 perovskite crystal; (HDA) CsPb2Br7 is cleaned by using an organic cleaning agent, dried and dissolved in an organic solvent to obtain a precursor liquid 1, and reverse extraction is performed in the precursor liquid 1 by using an anti-solvent to obtain the three-dimensional CsPbBr3 perovskite crystal. Adding haloid acid into the precursor liquid 1 to obtain a precursor liquid 2, and adding an anti-solvent into the precursor liquid 2 for reverse extraction to obtain the 0-dimensional Cs4PbBr6 perovskite crystal. According to the perovskite crystal conversion method, the phase change of the perovskite crystal can be realized through simple dissolution and recrystallization, and a new technology is provided for forming a heterojunction structure in a perovskite thin film material by using a surface modification technology.

The application discloses a Pb (1‑x) Ln x (Zr 0.52 Ti 0.48 )O3-based piezoelectric thick film material and a preparation method thereof. The implementation scheme is as follows: lead oxide, zirconium dioxide, titanium dioxide and oxide of a lanthanide element are fired to form pre-fired powder; lead acetate trihydrate, tetrabutyl titanate, oxide of the lanthanide element and zirconium n-propyl alcohol or zirconium isopropyl alcohol are mixed into a precursor solution by a sol-gel method; the powder and the gel are mixed to form slurry, the slurry is spin-coated on a substrate, and after drying and pyrolysis treatment, annealing is performed in an air atmosphere or an ACB atmosphere compensation, so as to obtain Pb (1‑x) Ln x (Zr 0.52 Ti 0.48 )O3 piezoelectric thick film with a thickness greater than 10 microns. The application has the advantages of high crystallinity, good compactness, high breakdown field strength, high electrical comprehensive performance, simple process and good repeatability, and can be used in micro-electro-mechanical system (MEMS), micro-actuator, sensor and ultrasonic transducer.

The invention discloses a chemical reduction gold working solution without additionally adding KCN. The working solution does not contain potassium cyanide (KCN); the gold-potassium alloy is prepared from the following components in percentage by mass or volume: gold potassium cyanide; pure water; the complexing agent comprises 8% of anhydrous sodium acetate, 6% of sodium ethylene diamine tetracetate, 3% of sodium sulfate, 2% of glycine, 0.08% of formaldehyde, 0.0002% of lead acetate trihydrate and 80.918% of water; the stabilizer comprises 2% of ethylene diamine tetraacetic acid tetrasodium salt, 1% of potassium ferrocyanide and 97% of water; the reducing agent comprises 5% of glycine, 4% of phosphoric acid, 0.8% of formaldehyde and 90.2% of water; and a pH adjusting agent. The invention further discloses a chemical gold plating method. The working solution provided by the invention does not contain potassium cyanide (KCN), so that a non-toxic chemical plating solution is realized; and meanwhile, the consistency and high stripping degree of a gold-plated layer after gold plating can be ensured.

The invention relates to a method for determining the content of trace cadmium in stainless steel, and belongs to the technical field of element detection. The method comprises the following steps: obtaining a stainless steel sample solution with a set pH value; adding a lead acetate solution into the stainless steel sample solution to generate a lead molybdate precipitate so as to obtain a first mixture containing the lead molybdate precipitate; fixing the volume of the first mixture to obtain a to-be-detected sample mixture; performing solid-liquid separation on the to-be-detected sample mixture to obtain a to-be-detected sample solution; preparing a series concentration solution of the cadmium element, and drawing a cadmium element standard curve according to the series concentration solution; and obtaining the cadmium content in the stainless steel sample according to the cadmium element standard curve. According to the method, the pH value in the stainless steel sample solution is adjusted to be a set value, conditions are provided for generating lead molybdate sediment, molybdenum is separated, signal interference or background interference generated in cadmium content determination is avoided, and the accuracy and reliability of a detection result are remarkably improved.

This invention belongs to the field of high-purity inorganic material preparation technology, and relates to a method for preparing ultra-high-purity lead fluoride from lead oxide based on supercritical complexation extraction. Using lead oxide as raw material, lead acetate is synthesized through acetylation, deep purification through SCC-CO2 supercritical complexation extraction, and fluorination precipitation to prepare 5N-grade ultra-high-purity lead fluoride. Lead acetate is a strongly polar ionic organic salt with high lattice energy, and it is almost insoluble and does not leak in the SCC-CO2 system. Cu, which is present as an associated component in the raw material... 2+ Fe 3+ Zn 2+ Cd 2+ Bi 3+ Impurity metal ions, under the action of a complexing agent, form weakly polar, fat-soluble metal complexes, which are then efficiently extracted by supercritical CO2 and continuously carried out of the system, achieving deep separation of lead acetate from impurities. The purified ultra-high purity lead acetate reacts with ultra-high purity hydrofluoric acid to directly produce 5N grade ultra-high purity lead fluoride with a purity ≥99.995%. This method is suitable for industrial production due to its simple process, environmental friendliness, high impurity removal depth, and stable preparation of ultra-high purity lead fluoride.

The present application relates to the technical field of gas detection, and particularly relates to a responsive aerogel and application thereof. The responsive aerogel is prepared according to the following steps: metal organic framework material is mixed and dissolved with lead acetate to obtain an adsorption and response integrated probe; silk fibroin, polyethylene glycol diacrylate and the adsorption and response integrated probe are mixed, and a light curing reaction is carried out under the action of a photo-crosslinking agent, and the responsive aerogel is obtained. The double-mesh aerogel base generated by the reaction of silk fibroin and polyethylene glycol diacrylate can adsorb water molecules in different humidity environments to cause the base to be wetted, and provide a saturated micro-water environment for the colorimetric reaction on the surface of the pore wall, thereby effectively reducing the interference of environmental humidity on the response. The quantitative method established by using the responsive aerogel can be used for high-sensitivity quantitative detection of hydrogen sulfide in livestock and poultry farms.

The present invention discloses a method and system for extracting and recovering heavy metals in sludge, and belongs to the technical field of electroplating sludge treatment. The present invention utilizes biological leaching to dissolve a variety of heavy metals into the leaching solution, first recovers iron by precipitation, and then recovers copper, zinc, lead, and cadmium by combining porous zeolite and multi-stage stripping, which can greatly reduce the influence of various impurities in the leaching solution. Specifically, firstly, copper, zinc, lead, and cadmium are adsorbed by porous zeolite, and then copper, zinc, and cadmium are dissolved from the porous zeolite into the organic phase. At this time, the organic phase is rich in copper, zinc, and cadmium, and the porous zeolite is rich in lead. Then, the cadmium, zinc, and copper in the organic phase are recovered separately by multi-stage stripping, and the porous zeolite is washed with ammonium acetate, and further solid-liquid separation is performed to obtain a lead acetate solution, thereby completing the separation and recovery of iron, copper, zinc, lead, and cadmium heavy metal elements in heavy metal sludge.

The invention discloses a pleuromutilin derivative capable of inhibiting biosynthesis of bacterial hydrogen sulfide as well as a preparation method and application of the pleuromutilin derivative, and belongs to the field of medicinal chemistry. The derivative is introduced into an indole structure through structural modification, so that the biosynthesis of hydrogen sulfide in bacteria is effectively inhibited, and the sensitivity of bacteria to antibiotics is enhanced. Experiments of a trace double dilution method and a lead acetate test strip colorimetric method show that the derivative shows good antibacterial activity and safety on pathogenic microorganisms, especially drug-resistant bacteria and mycoplasmas, and compared with drugs on the market, the derivative has the advantages of stronger inhibition ability on the drug-resistant bacteria, better inhibition effect on hydrogen sulfide, lower toxicity, better solubility and better application prospect. The derivative and the stereoisomer, salt and other forms of the derivative are easy in preparation raw material obtaining, safe in operation, mild in reaction condition, high in yield and suitable for large-scale production, can be widely used for preventing and treating infectious diseases caused by gram-positive bacteria and gram-negative bacteria, drug-resistant bacteria or mycoplasma, and have remarkable medical development value and application prospect.

The invention discloses a thallium removal method for a zinc hydrometallurgy system, which comprises the following steps: 1) in a neutral leaching supernatant purification process, adding potassium permanganate and ferrous sulfate in a first purification stage of a liquid purification process, and reacting for 1-2 hours; 2) adding zinc powder into the solution, adding activated carbon, and reacting for 1-2 hours; 3) adding lead acetate, and reacting for 1-2 hours; and 4) carrying out solid-liquid separation through a plate filter press, and removing purified residues. A combined thallium removal mode is adopted, so that the thallium content of the purified solution is low, the requirement of electrolytic zinc can be met, and electrolytic'plate burning 'caused by thallium is avoided; according to the thallium removal method for the zinc hydrometallurgy system, additional reaction time does not need to be increased, the thallium removal method can be synchronously carried out with the original neutral leaching supernatant liquid purification process, the production period is not prolonged, additional equipment investment is not increased, the cost is low, and the effect is good.

The invention discloses a method for extracting lead from waste lead plaster by taking sulfide minerals as a reducing agent, and belongs to the field of hydrometallurgy. The method comprises the following steps: mixing, heating and stirring the waste lead plaster, sulfide minerals, ferric salt and a sulfuric acid solution, reducing and converting a lead-containing phase in the waste lead plaster into insoluble lead sulfate to obtain reducing slag, generating ferrous ions from the sulfide minerals under the action of a ferric salt catalyst, and reducing and converting lead dioxide in the waste lead plaster into lead sulfate; the reducing slag and an acetate solution are mixed, heated and stirred, lead sulfate is desulfurized and leached into soluble lead acetate, and a lead-containing leaching solution is obtained. Aiming at the waste lead plaster in the waste lead-acid storage battery, the low-cost sulfide mineral is used as a reducing agent, so that the process cost is reduced. By means of the two-step process of reduction conversion and desulfurization leaching, the additional impurity separation procedure is avoided, the extraction efficiency of lead in the waste lead plaster is 99% or above, the pure lead-containing leaching solution is obtained, and a new thought is provided for efficient recycling of the waste lead plaster.

The invention belongs to the technical field of gas sensing materials and safety monitoring, and discloses a gas leakage detection color-changing flexible film based on lead acetate dual-mode response and a preparation method and application thereof, and the method comprises the following steps: coating a molecular sieve layer: mixing ZSM-5 zeolite powder with polyvinyl alcohol, and blade-coating a PET substrate; catalytic layer loading: ball-milling and mixing lead acetate, Pd nanoparticles and mesoporous SiO2, and coating the molecular sieve layer with the mixture to obtain a Pd-lead acetate catalytic layer; performing reaction layer and packaging: performing pure lead acetate slurry coating to obtain a reaction layer, and performing vapor deposition on a PI layer to obtain a packaging layer; gum treatment: spraying high-temperature-resistant silica gel, and curing to form a self-adhesive layer; the mass ratio of the molecular sieve layer to the Pd-lead acetate catalyst layer to the reaction layer to the encapsulation layer is (20-30): (50-60): (10-15): (5-10). The product provided by the invention has relatively good flexible adaptability and environmental robustness; and quick response and low-cost mass production can be realized.

The application belongs to the field of chemical industry and environmental protection, and particularly relates to a functionalized ionic liquid capable of absorbing VOC, and simultaneously relates to a preparation method of the ionic liquid. The raw materials used in the ionic liquid are butyl-methyl imidazolium p-toluene sulfonic acid, 1-butyl-3-methyl imidazole tetrafluoroborate, lead acetate and potassium permanganate. The functionalized ionic liquid prepared in the application serves as a solvent, an absorbent and a reaction reagent in the system, so that VOC is physically dissolved and absorbed and chemically captured in the gas-liquid exchange of the functionalized ionic liquid, thereby achieving efficient treatment of VOC.

The invention discloses a high-stability thio polar metal halide perovskite crystal and a preparation method and application thereof, and belongs to the technical field of artificial crystal materials in the field of functional crystal materials. The chemical formula of the crystal is (4-SP) 4Pb3Br10. 2H2O, the crystal belongs to an orthorhombic system, the space group is Aea2, the cell parameters are as follows: alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, Z = 4, and the density is 2.842 g / cm < 3 >. The preparation method comprises the following steps: mixing 4-aminothiophenol and lead acetate trihydrate, adding an HBr aqueous solution, heating and stirring to obtain a colorless clear solution, and performing post-treatment to obtain the crystal. The crystal has application potential in an X-ray detector.

The invention discloses a chemical plating solution, which comprises the following components by mass concentration: 15g / L-34g / L of nickel sulfate; 16 g / L to 28 g / L of sodium hypophosphite; propionic acid: 16 g / L to 28 mL / L; boric acid: 15 g / L-25 g / L; 0 g / L to 8 g / L of citric acid; 0.35 g / L-5mL / L of lactic acid; the concentration of the surfactant is 0.01 g / L-0. 08 g / L; a stabilizing agent: 0.0001 g / L to 0.001 g / L; the content of lead acetate is 0.0003 g / L to 0.001 g / L; the surfactant is one or more of lauryl sodium sulfate, sodium dodecyl benzene sulfonate and n-octyl sodium sulfate, and the stabilizer is thiourea and / or potassium iodate. The chemical plating solution formula is improved, the pretreatment process is simplified, the chemical plating solution can be repeatedly used, and the plating quality can be improved.

The invention discloses a method for intensifying dissolution of arsenic lead ore solid solution through an electric field and application. The method comprises the following steps: preparing a mixed solution from a sodium arsenate solution and a sodium chloride solution in proportion, and preparing an arsenite solid solution by taking a lead acetate solution as a basic solution; different electrolytes are selected at the temperature of 25 DEG C according to the dissolving-out speed and concentration requirements of arsenic ions and lead ions, an arsenite solid solution is subjected to electric field strengthening rapid dissolution, and the technology provides technical support for electrokinetic remediation of soil polluted by arsenic and lead and resource utilization of tailings containing arsenic and lead.

The invention relates to the technical field of chemical component analysis, in particular to a method for measuring fluorine in cryolite, and aims to solve the problems that when the fluorine content in the cryolite is measured by adopting a traditional distillation-thorium nitrate titration method or lead fluoride chloride precipitation-mercuric nitrate volumetric method and the like at present, the operation is time-consuming and labor-consuming, the reagent is relatively high in harmfulness and the detection precision is relatively low. The method comprises the following steps: decomposing a cryolite sample by using a sodium carbonate-sodium silicate mixed solvent to enable fluorine to become water-soluble fluoride, generating a lead fluorochloride precipitate by using hydrochloric acid and lead acetate as precipitants, filtering out the precipitate, dissolving the precipitate in nitric acid, precipitating chloride ions by using a silver nitrate standard solution, and measuring the concentration of the excessive silver nitrate by using ferric sulfate as an indicator. Compared with traditional fluorine content determination, the method has the advantages that the detection difficulty is reduced, the use of highly toxic reagents is effectively avoided, the test safety risk is greatly reduced, and the method is widely applicable to determination of fluorine in cryolite for factory inspection.

This invention relates to the field of microbial technology, providing a *Lactobacillus crispatus* YYS-J3 with acrylamide degradation and lead adsorption functions, and its applications. The preservation number of *Lactobacillus crispatus* YYS-J3 is CGMCC No. 28184. This *Lactobacillus crispatus* YYS-J3 can degrade or adsorb acrylamide, adsorb lead acetate, has good SOD enzyme production capacity, exhibits good aggregation properties, and has broad adaptability to carbon sources. This bacterium can provide a new probiotic source for the development of functional products such as acrylamide or heavy metal detoxification products and SOD enzyme products, and has significant application value.

The invention provides a CsPbBr3 perovskite quantum dot material and a preparation method thereof, and relates to the technical field of perovskite nanocrystal preparation. The method comprises the following steps: (1) mixing cesium carbonate, lead acetate, octadecene and dodecylbenzene sulfonic acid, and heating under the protection of inert gas to obtain a precursor solution of a cesium source and a lead source; (2) mixing oleylamine and hydrogen bromide under the protection of inert gas to obtain an oleylamine bromide precursor solution; (3) heating the precursor solution in the step (1), injecting the precursor solution in the step (2), mixing, and cooling to obtain a quantum dot colloid coarse solution; and (4) carrying out centrifugal separation on the solution obtained in the step (3), adding a detergent into the supernatant, carrying out secondary centrifugation, collecting the precipitate, and drying to obtain the CsPbBr3 perovskite quantum dot material. The surface ligand of the prepared cesium-lead-bromine quantum dot has strong binding force with the quantum dot and is not easy to fall off, so that the cesium-lead-bromine quantum dot shows higher colloid structure stability.

The invention discloses a method for preparing high-purity lead sulfate by recovering lead from lead slag, and relates to the technical field of non-ferrous metal rare earth metallurgy recovery. The method specifically comprises the following steps: adding acetic acid into the lead slag, adding titanium dioxide as an oxidation catalyst, stirring, heating, dropwise adding hydrogen peroxide, reacting, filtering to obtain a mixed solution of lead acetate and lanthanum acetate, adding a sulfuric acid solution, heating, evaporating, recovering the acetic acid solution, returning to the previous step for recycling, evaporating, cooling, filtering, and drying to obtain the lanthanum acetate. And washing the obtained precipitate and drying to obtain the high-purity lead sulfate. Through the synergistic effect of acetic acid, hydrogen peroxide and titanium dioxide, the purity of the product lead sulfate is improved, meanwhile, the lead recovery rate is increased, the purity of the obtained lead sulfate product is larger than 98.5%, the lead recovery rate can reach 97% or above, and the problems that an existing lead recovery method is high in energy consumption, serious in environment pollution and low in recovery rate are effectively solved.

This invention discloses a method for removing impurities from a palladium extraction pre-liquid, relating to the field of precious metal hydrometallurgy. The method includes: Step 1, Oxidation Pretreatment: The palladium extraction pre-liquid is heated and concentrated, then water is added, followed by the addition of a mixed acid oxidant, chlorine gas is passed through, and the liquid is boiled to remove the chlorine, then filtered to obtain pretreated solution 1; Step 2, Purification and Impurity Removal 1: Basic lead acetate solution is mixed with pretreated solution 1, and after solid-liquid separation, a purified palladium extraction pre-liquid 2 is obtained; Step 3, Purification and Impurity Removal 2: Thiourea reagent, ammonium oxalate reagent, and liquid alkali are added to palladium extraction pre-liquid 2, mixed, filtered, and the filtrate is used as purified palladium extraction pre-liquid 3; Step 4, High-Efficiency Extraction: Diisopentyl sulfide is washed with a washing solution, and the washed diisopentyl sulfide is used to extract palladium solution 3 to obtain a palladium solution. This method removes selenium and base metal impurities from the palladium extraction pre-liquid, achieving purification and impurity removal, ensuring the extraction efficiency of the solvent extraction process, and reducing reagent consumption and precious metal dispersion loss.