43 results about "Organic complexation" patented technology

The invention discloses a method for simulating reaction migration of metal in a xanthate-loaded porous medium. On the basis of a coupling reaction mechanism of metal and an organic complexing agent (xanthogenate) in a porous medium, a multi-surface morphology complexing model (MSM) containing soil native components and xanthogenate is constructed and is combined with a reactive migration numerical model (a coupling water flow and solute migration equation); according to the method, through model calibration and experimental verification, the dynamic migration process of each metal component and the competitive retention distribution of the metal component on different solid-phase components can be accurately simulated and quantitatively analyzed under the complex condition that metal and xanthate coexist.

The invention relates to the technical field of p-fluorobenzaldehyde production, and particularly discloses a production process of high-purity p-fluorobenzaldehyde. The invention relates to a production process of high-purity p-fluorobenzaldehyde. The production process comprises the following steps: S1, carrying out a chlorination reaction by taking p-fluorotoluene and chlorine as raw materials to prepare a mixed chlorination solution of p-fluoromethyl benzyl monochloride, p-fluoromethyl benzyl dichloride and p-fluoromethyl benzyl trichloride; s2, adding an organic complexing agent, which is a water-soluble aprotic solvent, into the mixed chlorinated liquid prepared in the step S1, and then performing vacuum rectification to obtain distillate and residual liquid; rectifying by taking the residual liquid as a raw material to obtain kettle liquid and rectified liquid; and S3, carrying out hydrolysis reaction by taking the rectification liquid and water as raw materials, separating, and drying to obtain the product. The production process of the high-purity p-fluorobenzaldehyde has the advantages of high raw material conversion rate, high product purity and few three-waste products.

The invention discloses a method for preparing gamma aluminum oxide nanosheets based on precise regulation and control of complex precipitation, which comprises the following steps: introducing an organic complexing agent into a water phase system, constructing an organic-inorganic mixed solvent environment, and inducing an aluminum precursor to generate two-dimensional oriented growth under an alkaline condition to obtain a flaky boehmite precursor; then carrying out high-temperature calcination to prepare gamma aluminum oxide nanosheets; the preparation method is simple in process, mild in condition and easy for large-scale preparation, and the prepared gamma aluminum oxide nanosheet can still keep stable sheet-shaped morphology and gamma phase structure after being re-sintered for five times at 1000 DEG C, has a hierarchical pore structure and a specific surface area of more than 40 m < 2 > / g, and shows excellent high-temperature structural stability; the material can be widely applied to the fields of high-temperature catalyst carriers, adsorption separation materials, advanced ceramics and the like, and has a good application prospect.

The application relates to the field of agricultural planting cultivation technology and discloses a high-temperature-resistant and stress-resistant millet cultivation regulation method, which comprises the following steps: adding deionized water, boric acid and 1,2-propylene glycol into a reaction kettle, adding potassium hydroxide aqueous solution dropwise after heating and constant temperature to adjust pH value and react; cooling water is introduced to cool, calcium lignosulfonate is added to form a fluid system through high-shear dispersion; gamma-aminobutyric acid is added and stirred to obtain a high-temperature-resistant and stress-resistant foliar spraying composition product; the relative water content of soil is maintained before millet seeding to the jointing stage, and the composition product is diluted and uniformly sprayed on the millet leaves before continuous high temperature and low humidity drought weather predicted by the weather forecast. The boric acid is converted into an organic complex state, the water solubility and leaf absorption rate of the effective component are improved, the stomata are adjusted through gamma-aminobutyric acid, the calcium lignosulfonate is used to form a film on the leaves, and the damages caused by high temperature and drought to the plants are synergistically relieved.

This invention discloses a nitrogen-sulfur co-doped multi-chamber carbon-supported copper nanocluster composite material and its preparation method. By integrating polyether F127, 2,6-diaminopyridine, sodium dodecylbenzenesulfonate, fulvic acid, and copper acetate (II), a semi-open and surface-fully embedded copper cluster multi-chamber carbon was successfully constructed. The surface of this multi-chamber carbon is rich in -NH2 and -SO3. ‑ With abundant active groups, it not only boasts a large specific surface area and ample adsorption sites, but also exhibits excellent anti-interference and wide pH adaptability. As an environmentally friendly material, it can simultaneously and efficiently adsorb and remove Cu²⁺ from electroplating wastewater. + Ni² + Pb² + Cd² + It contains heavy metals and organic complexing agents such as ethylenediaminetetraacetic acid (EDTA) and hydroxyethylidene diphosphonic acid (HEDDI). After electroplating wastewater treatment, it achieves convenient solid-liquid separation and recovery through centrifugation and filtration. After acid washing and alcohol washing regeneration, it exhibits excellent cycle stability. With its superior purification efficiency and recycling advantages, it has shown promising development potential in the field of electroplating wastewater treatment.

The invention discloses an etching solution for displaying the three-dimensional shape of a nickel-based metal material and a display method, and relates to the technical field of etching solutions, the key points of the technical scheme are that the etching solution for displaying the three-dimensional shape of the nickel-based metal material is formed by compounding an alcohol solvent, inorganic strong acid and an organic complexing agent; wherein the organic complexing agent accounts for 1%-3% of the total weight of the etching liquid. The special etching solution formula designed by the invention has a good dissolution rate on a nickel-based superalloy matrix, has excellent protectiveness on various types of carbides by virtue of the synergistic effect of the organic complexing agent (tartaric acid), and is suitable for wide nickel-based superalloy systems.

The invention provides a metal-nitrogen-carbon material and a preparation method thereof, and relates to the technical field of functional composite material preparation. The preparation method comprises the following steps: providing a metal source, a nitrogen source, a carbon carrier and a polytetrafluoroethylene emulsion, dissolving the metal source and the nitrogen source in an alcohol solvent to obtain a metal-organic complex solution, adding the carbon carrier and the polytetrafluoroethylene emulsion into the metal-organic complex solution, and carrying out ball milling to obtain homogeneous composite slurry, the preparation method comprises the following steps: preparing a homogeneous-phase composite slurry, sequentially drying and grinding the homogeneous-phase composite slurry to obtain carbon-based composite precursor powder, and finally performing microwave pyrolysis on the carbon-based composite precursor powder under a vacuum condition at the temperature of 300-350 DEG C, the power of 500-700 W and the duration of 40-60 minutes to obtain the metal-nitrogen-carbon material. According to the method, the metal-nitrogen-carbon material can be prepared only through one-time medium-temperature microwave pyrolysis, and compared with the prior art, the technological process is greatly shortened, energy consumption is remarkably reduced, the single-batch yield is high, and the method is suitable for continuous large-scale production.

A multi-barrier coupled treatment process for organic complexed heavy metals in wastewater from battery cathode material production is disclosed, relating to the field of wastewater treatment. The method involves: 1. Adjusting the pH of the wastewater to 3.0-4.5; 2. Adding iron salt and peracetic acid to an oxidation reaction tank; 3. Achieving primary removal of heavy metals through neutralization and precipitation after oxidation; 4. Adjusting the pH of the wastewater back to 6.0-6.5; 5. Passing the wastewater sequentially through a primary adsorption unit and a secondary adsorption unit. This invention utilizes the low bond energy characteristics of PAA and the synergistic oxidation advantages of multiple free radicals to solve the bottleneck problems of incomplete complex breaking, large sludge production, and narrow pH application range in traditional methods. After treatment by this invention, the total nickel concentration in the effluent is less than 0.05 mg / L, and the total cobalt concentration is less than 0.02 mg / L, consistently exceeding the limits of the "Emission Standard of Pollutants for Battery Industry" (GB 30484-2013), demonstrating broad industrial application prospects.

The invention relates to the technical field of batteries, in particular to a battery monomer, a preparation method of a secondary battery, an electrolyte and an electric device. Each single battery comprises a positive pole piece, a negative pole piece and an electrolyte, at least partial structures of the positive pole piece and the negative pole piece are located in the electrolyte, the electrolyte comprises a metal ion complexing agent, and the metal ion complexing agent comprises an organic complexing agent and / or an inorganic complexing agent; the organic complexing agent comprises at least one of phenanthroline, a crown ether compound, oxalic acid, citric acid, tartaric acid, ethylenediamine tetraacetic acid and deferoxamine; and / or the inorganic complexing agent comprises at least one of sodium oxalate, sodium citrate, sodium tartrate and sodium ethylene diamine tetracetate. The metal ion complexing agent in the electrolyte can be combined with impurity metal ions in the electrolyte to form a stable complex, so that the risk that the impurity metal ions are separated out into dendritic metal foreign matters at an anode to pierce a diaphragm to cause self-discharge of the battery is reduced.

The present invention relates to an anti-microbial composition and preparation process and use thereof. The anti-microbial composition comprises at least one silver compound, at least one organic complexing agent and one or more bases, wherein the organic complexing agent has the structure of Formula (I), wherein R1 is independently hydrogen, a linear or branched C1-C5 alkyl, or an amino group optionally substituted with a C1-C5 alkyl, R2 is independently a linear C1-C5 alkylene, optionally substituted with a C1-C5 alkyl, and R3 is independently hydrogen, a linear or branched C1-C5 alkyl, or a linear or branched C2-C5 alkyl substituted with a carboxyl group. When formulated into an aqueous composition, the composition has good physical stability and even good color stability, particularly against heat and / or light, and pleasant aesthetics for consumers, and it is non-toxic and cost-effective, and particularly can be used in home care compositions, personal care compositions and industrial cleaning compositions.

This invention relates to a monodisperse spherical micro / nano silica, its preparation method, and its applications. First, an aqueous sodium silicate solution is added to a crown ether aqueous solution, followed by the dropwise addition of sulfuric acid solution and stirring to initiate the reaction. Then, an organic extractant is added to extract the aqueous and organic phases. The aqueous phase is then mixed with an aqueous sulfuric acid solution and an alcohol solvent, respectively, to obtain two different solutions. These two solutions are then mixed and stirred, followed by centrifugation, washing, and drying to obtain the target product. The organic phase is subjected to vacuum distillation, water dissolution, and adsorption with an ion exchange resin to obtain a regenerated crown ether aqueous solution, which is then recycled. This invention adjusts the ionic strength of the reaction system by adding an organic complexing agent, precisely controlling the particle size of SiO2 particles to 20-1300 nm. This results in particles with uniform size, high sphericity, and good dispersibility. The entire preparation process has advantages such as simple technology, low cost, high yield, and ease of large-scale industrial production, showing promising application prospects in aerospace, biomedicine, and electronic packaging fields.

A method for producing organic microelement complexes based on humic acid salts is characterized in that an aqueous solution of lignosulfonate is mixed with dry or aqueous solutions of copper, zinc, manganese, iron, cobalt, ammonium molybdate sulfates, boric acid or potassium metaborate to achieve a total mass concentration of microelement ions in the range of 0.5-4.0% of the absolutely dry matter. An alkaline agent is added. The resulting working solution undergoes intensive mixing with cavitation treatment. The solution is loaded into a reactor, sealed, pressurized to 22 bar, and heated to 150°C. The synthesis of microelement complexes based on humic acid salts occurs for 120-150 minutes at a pressure of 22-23 bar, temperature of +170-180°C with an air flow rate of 60-80 1 / h passing through the reactor. The synthesis process is stopped when the pH drops below 8.5 by turning off the heating and air supply. The finished product is unloaded after natural cooling below 70°C. The invention enhances the stability of organic complexes based on humic acids with high concentrations of retained biogenic microelements.

The invention discloses a method for treating heavy metal lead-organic complex wastewater. According to the method, wet carbon felt is used as a working electrode to carry out electrochemical reduction treatment on the heavy metal lead-organic complex wastewater. According to the method, the mass transfer efficiency of the carbon felt and the selectivity to the heavy metal lead can be effectively improved by adopting the wet carbon felt, so that when the wet carbon felt is used as a working electrode to carry out electrochemical reduction treatment on the heavy metal lead-organic complex wastewater, not only can the heavy metal lead in the wastewater be efficiently removed, but also high-quality elemental lead can be obtained; in addition, the method for treating the heavy metal lead-organic complex wastewater has the advantages of simple process, convenience in operation, low cost and the like, and is of great significance in efficiently treating the wastewater containing the heavy metal lead-organic complex and realizing high-value recovery of lead in the wastewater.

The present application belongs to the technical field of resource recycling, and discloses a method for resource utilization of pickling wastewater. First, the nitric acid and hydrofluoric acid pickling solution of titanium material is filtered to remove insoluble solids as raw water, and an organic complexing agent is added to complex fluoride ions. Then, CaO is added to the solution to adjust the pH, and after filtration, a filtrate and a titanium-rich precipitate are obtained. H2O2 / Fe is added to the filtrate to oxidize and break the complex, and then CaO is added to adjust the pH. After filtration, a filtrate and a fluorine-rich precipitate are obtained. A composite adsorbent is added to the filtrate for deep defluorination, and after filtration, the solution is concentrated by high-salt reverse osmosis to obtain a 15-18 wt.% calcium nitrate solution. Ammonium calcium nitrate is added to supplement nitric acid and ammonia water, and finally the solution is evaporated to obtain a solid ammonium calcium nitrate product. Concentrated liquid can also be obtained, which can be directly used for drip irrigation. The method can effectively utilize the titanium material pickling solution resources, and has great economic and environmental benefits.

The application discloses a gradient-loaded oil hydrogenation dearsenification catalyst and a preparation method thereof. The preparation method comprises the following steps: preparing stable dispersion impregnation component A-1 by mixing organic complexing agent I, hole expansion aid II, active component IV containing group ⅥB metal and deionized water; preparing stable dispersion impregnation component A-2 by mixing organic complexing agent I, hole expansion aid III and deionized water; dissolving component X1 containing group Ⅷ metal in the stable dispersion impregnation component A-1 to form stable complex impregnation liquid B-1; dissolving component X2 containing group Ⅷ metal in the stable dispersion impregnation component A-2 to form stable complex impregnation liquid B-2; impregnating porous carrier Z with the stable complex impregnation liquid B-1 to obtain catalyst C1; impregnating the catalyst C1 with the stable complex impregnation liquid B-2 to obtain catalyst C2; dissolving organic aid V and hole expansion aid VI in deionized water, and then impregnating the catalyst C2 to obtain the hydrogenation dearsenification catalyst C3. The preparation method can increase arsenic poisoning sites of the catalyst.

The utility model provides an ozonation separation treatment device for iron-containing organic complex wastewater, which relates to the field of wastewater ozonation equipment, and comprises a catalytic ozonation assembly, the catalytic ozonation assembly comprises an oxidation reaction tower and an ozone generator, the ozone generator is used for generating ozone, and the oxidation reaction tower is used for generating ozone. The oxidation reaction tower is used for providing catalytic reaction, a separation assembly is mounted on one side of the ozone catalytic oxidation assembly, and the separation assembly comprises a tank body, a conical hopper, a filter plate, a blow-off pipe, a blow-off valve, an overflow pipe and a liquid inlet pipe; under the joint cooperation of the ozone catalytic oxidation assembly, the separation assembly and the stirring assembly, not only can the ozone catalytic oxidation reaction be effectively carried out, but also particulate matters in the wastewater can be efficiently separated and discharged, so that the problem of residual particulate matters in the wastewater subjected to ozone catalytic oxidation treatment is effectively solved; the overall treatment efficiency is improved, and the normal operation of subsequent treatment equipment is protected.

The invention discloses a method for upgrading and regenerating a specifically repaired waste lithium iron phosphate battery. The method comprises the following steps: (1) dissolving waste lithium iron phosphate powder in water to prepare a solution A; (2) dissolving a lithium source and a multifunctional targeting complexing agent in water to prepare a solution B, wherein the multifunctional targeting complexing agent is selected from one or more of an organic complexing agent or organic phosphonic acid; (3) gradually dropwise adding the solution B into the solution A, then adding a buffer carbon source, and heating until the solvent is evaporated to dryness to obtain a regenerated precursor; and (4) calcining the regenerated precursor to obtain the regenerated lithium iron phosphate material. According to the method, targeted adsorption of Li < + > to a lithium-poor phase can be accurately controlled, the regeneration steps are greatly shortened, the energy consumption in the regeneration process is reduced, and the electrochemical performance of a lithium iron phosphate product is improved.

This invention belongs to the field of soil conditioner technology, and relates to an organic-inorganic coupled conditioner for improving soda saline-alkali land and its preparation method. The inorganic particles are composed of a mixture of activated polyaluminum ferric sulfate, activated zeolite powder, transcrystalline gypsum, trace elements, and reinforcing agents. The organic slurry is homogenized from activated humic acid extract, modified lignin sulfonate, functional biochar complex, and polyglutamic acid concentrate, and then subjected to spray granulation and high-temperature, high-humidity aging to achieve chemical cross-linking at the organic-inorganic interface, forming a stable three-dimensional network structure. The resulting conditioner integrates chemical exchange, physical adsorption, organic complexation, and biostimulation, and can rapidly reduce soil pH and alkalinity, improve soil aggregate structure, enhance nutrient retention capacity, and has a long-lasting effect and is environmentally friendly, making it suitable for the comprehensive management of soda saline-alkali land.

Disclosed is an organic-inorganic composite thermal insulation medium, which is a nanoparticle having a structure of (Mx-Rn)WOy, where M represents a doped metal element, R represents an organic complex group, 0.3≤x≤0.7, 2<y<4, n represents a polymerization degree of the organic complex group, and n≥10; M is selected from the group consisting of an alkali metal, an alkaline earth metal, a transition metal, and a rare earth metal; and R is selected from the group consisting of pyrrole and a derivative thereof, aniline and a derivative thereof, and thiophene and a derivative thereof. In addition, also disclosed is a method for preparing the thermal insulation medium.

This invention discloses a graded purification method for wet-process phosphoric acid, relating to the field of phosphoric acid chemical industry. The method includes the following steps: S100, adding an inorganic precipitant to wet-process phosphoric acid to carry out a main precipitation reaction; S200, adding active seed crystals to the material obtained in step S100 to carry out a seed-induced interface activation reaction; S300, adding an organic complexing agent to the material obtained in step S200 to carry out a complexation reaction; S400, adding a flocculant to the material obtained in step S300, and obtaining purified phosphoric acid through solid-liquid separation; wherein the inorganic precipitant is a diatomaceous earth-based composite precipitant modified with phytic acid and ionic liquid; and the organic complexing agent is a mixture of dithiophosphate compounds and hydroxyquinoline compounds. This invention achieves a removal rate of over 85% for major impurities such as iron, aluminum, and magnesium, and a removal rate of over 95% for trace heavy metals such as arsenic, cadmium, and lead, with a phosphorus yield of over 96.5%, by constructing a four-stage synergistic system of main precipitation-seed activation-deep complexation-flocculation enhancement.

The invention belongs to the technical field of preparation of rare earth nano materials, and particularly discloses a preparation system and method of nano cerium oxide and high-dispersity nano cerium oxide. The preparation system comprises an organic complexing agent and a surface modifier; the organic complexing agent is at least one of polyaspartic acid and derivatives thereof, polyglutamic acid, ethylenediamine disuccinic acid, iminodiacetic acid and sodium alginate; the surface modifier is a silane coupling agent. The preparation method comprises the following steps: preparing a cerium source precursor solution; adding an organic complexing agent and a surface modifier; regulating and controlling the pH value; and washing, aging, drying, grinding and calcining. The nano cerium oxide is prepared by the method. According to the invention, the organic complexing agent is combined with in-situ surface modification, and the complexing mechanism and the preparation process are optimized, so that high dispersity, uniform particle size distribution and controllable synthesis of the nano cerium oxide particles are realized, meanwhile, the harm of the process to the environment is reduced, and the operation process is simplified so as to adapt to industrial production requirements.

The application relates to application of a filter electrode to reduction recovery of complex copper in wastewater, and relates to the technical field of water treatment. The application relates to application of the filter electrode to recovery of metal copper in wastewater containing organic complex copper, the filter electrode takes carbon felt as a substrate, and an active layer containing polybenzimidazole is wrapped on the surface of the substrate; the active layer further comprises a binder and a conductive agent; when the filter electrode filters feed liquid containing complex copper, an electric reduction reaction is carried out, copper is deposited on the surface of the electrode in the form of metal single substance, and recovery of copper resources in wastewater containing organic complex copper is realized. The filter electrode has the advantages of low energy consumption, high stability and the like, can directly capture copper ions in wastewater without breaking the complex, and realizes efficient electric reduction of organic complex copper.

The application relates to the technical field of concrete admixtures, and particularly discloses a waterproof dense type accelerating agent as well as a preparation method and application thereof, which comprises the following components in parts by weight: 5-10 parts of a suspending agent, 50-250 parts of modified silica sol, 100-250 parts of an organic complex waterproof agent, 400-600 parts of an accelerating agent and water; wherein the modified silica sol is obtained by modifying acidic silica sol by a modifier, and the modifier is a silane coupling agent; and wherein the organic complex waterproof agent is an aluminum complex of a higher fatty acid. The waterproof dense type accelerating agent of the application can not cause a large amount of air entrainment of concrete after being mixed into the concrete, can fill microcracks of the sprayed concrete, and can improve the compactness of the concrete; meanwhile, the waterproof effect is formed on the inside and the surface of the sprayed concrete; and the addition of the organic complex waterproof agent can promote the coagulation of the concrete, and the accelerating agent can realize the rapid coagulation of the concrete.

The invention relates to an organic selenium fertilizer and a preparation method and application thereof, and belongs to the technical field of organic fertilizers. The preparation method comprises the following steps: firstly, preparing selenium-containing inorganic salt sodium selenite / sodium selenate into a solution, and then carrying out chelation reaction on the solution and specific organic complexing agents such as humic acid, amino acid and alginic acid to generate a stable selenium-organic matter complexing solution; and then uniformly spraying the solution onto an adsorption carrier in a rolling state in a spraying manner, and finally drying to obtain the solid organic selenium fertilizer. According to the invention, through organic complexing and carrier adsorption processes, uniform fixation of the selenium element at the carrier particle level is realized, and agglomeration and segregation are fundamentally prevented. The prepared organic selenium fertilizer is high in mixing uniformity and good in stability, selenium in an organic complex state is more easily absorbed and converted by plants, meanwhile, the complexing agent and the carrier have the synergistic interaction effect of promoting plant growth and improving soil, the complexing agent and the carrier can be used independently or mixed with basic fertilizer for use, and the selenium content and quality of agricultural products are effectively improved.

The invention discloses a yield-increasing foliar calcium fertilizer and a preparation method thereof, and belongs to the technical field of agriculture, and the calcium fertilizer is prepared from an organic complexing calcium source, a small molecule organic acid compound, alginic acid oligosaccharide, a phosphatidylserine analogue, boric acid, a surfactant and water according to a specific ratio. The preparation method comprises the steps of sequential dissolution, complex reaction, low-temperature active ingredient addition and the like. The preparation method comprises the following steps: dissolving the boric acid and the small molecular organic acid in hot water, adding the organic complexing calcium source, adjusting the pH value, carrying out a complexing reaction, cooling, adding the alginate oligosaccharide and the phosphatidylserine analogue, finally adding the surfactant, and uniformly stirring. Through the synergistic effect of all the components, leaf surface absorption and phloem transportation of calcium are effectively promoted, the calcium content of crops is remarkably increased, the occurrence rate of physiological diseases is reduced, and the yield and the fruit quality are improved.

The invention belongs to the technical field of soil remediation, and particularly relates to a composite conditioning module for heavy metal pollution remediation of acid soil and a time sequence precise remediation method for heavy metal pollution of acid soil. On the basis of the composite conditioning module, time sequence precise remediation is conducted on acid soil heavy metal pollution, specifically, the first module composition is applied to conduct physicochemical passivation, heavy metal is preliminarily stabilized, and the pH value is adjusted; after 7-10 days, a second module composition is applied for organic complexing and structural improvement, and further passivation and improvement of the physical structure of the soil are achieved; inoculating a microbial agent after 3-5 days, and rapidly colonizing and propagating by utilizing a good environment strain created in the previous step; and finally, planting hyperaccumulators for extraction and removal. According to the repairing method, through precise sequential control, the antagonism problem in multi-component repairing is solved, and synergistic interaction is achieved.

The invention belongs to the technical field of comprehensive utilization of resources and preparation of inorganic materials, and particularly relates to a method for producing calcium carbonate from yellow phosphorus waste secondary carbonized solid calcium. According to the method, by-products phosphorus slag and yellow phosphorus tail gas in the yellow phosphorus production process are used as main raw materials, and efficient extraction of calcium and green preparation of nanoscale calcium carbonate are achieved through the process steps of organic complexing agent activation, impurity coprecipitation control, wet-process calcium extraction, carbonization reaction, surfactant regulation and control and the like. The method comprises the following steps: firstly, mixing and activating phosphorus slag and an organic complexing agent, then leaching with an ammonium salt solution under the action of an impurity coprecipitation control agent, and reacting filtrate with CO2 in tail gas to precipitate calcium carbonate. The whole-flow process is low in energy consumption, high in raw material utilization rate, small in particle size and high in purity of the obtained calcium carbonate, environment-friendly in process, excellent in product quality and suitable for high-end fields of plastics, rubber, printing ink and the like.

This invention provides a method for preparing nitrogen-modified lead-carbon composite materials from waste lead paste and its application. The method includes the following steps: reducing waste lead paste to obtain reduced lead paste; reacting the reduced lead paste in a desulfurizing agent to obtain desulfurized lead paste; reacting the desulfurized lead paste in a nitrogen-containing organic leaching agent solution to obtain a lead-containing organic complex solution; and then evaporating, crystallizing, and pyrolyzing to obtain the nitrogen-modified lead-carbon composite material. This invention achieves efficient lead leaching and simultaneous nitrogen introduction through a nitrogen-containing organic leaching agent, followed by evaporation, crystallization, and controlled pyrolysis to construct a lead-carbon-nitrogen composite structure in situ. The resulting nitrogen-modified lead-carbon composite material possesses high conductivity and excellent hydrogen evolution inhibition capability, making it suitable for high-performance lead-carbon battery anodes. It effectively solves the problems of lengthy processes, large reagent inputs, and hydrogen evolution in lead-carbon batteries associated with existing technologies.

The invention discloses a method and a system for directionally removing non-volatile acid radicals and recovering urea in high-concentration urea wastewater, and belongs to the technical field of wastewater treatment and resource recovery. The method comprises the following steps: firstly, introducing wastewater into a pretreatment unit, adding a synergistic treatment agent compounded by alkali metal salt, an organic complexing agent and nano catalytic particles, and directionally precipitating non-volatile acid radicals to form a compact precipitate; intensified solid-liquid separation is completed through an ultrasonic-assisted horizontal spiral discharging sedimentation centrifuge, residual acid radicals in supernate are deeply adsorbed through graphene quantum dot-temperature responsive magnetic nanoparticle composite modified anion exchange resin, and the acid radicals are almost completely removed; then, urea is concentrated by adopting a low-temperature evaporation-waste heat recovery coupling process, and high-purity urea crystals are separated out through segmented temperature-pressure gradient crystallization; the resin saturated by adsorption is separated and recovered through a magnetic field, and is recycled after temperature regulation and mild regeneration; the method is suitable for resourceful treatment of industrial high-concentration urea wastewater.