325 results about "Sodium persulfate" patented technology

The invention relates to the field of environmental remediation, and discloses a remediation method for high-concentration organic pollutants in soil, which comprises the following steps: firstly, injecting a nano zero-valent iron (nZVI) suspension into the contaminated soil for chemical reduction treatment, then adding sodium persulfate for oxidation treatment, and then adding a nano zero-valent iron (nZVI) suspension into the contaminated soil; the complex organic pollutants are converted into biodegradable intermediate products; then, two-stage microbial communities are introduced in sequence, the first-stage microbial community is used for degrading alcohol and ketone intermediate products, the second-stage microbial community is used for degrading organic acid intermediate products, and thorough mineralization of pollutants is achieved. According to the method, the pollutant degradation rate and the final removal effect can be remarkably improved, and the method is suitable for treatment scenes of various high-concentration organic pollutants and has high adaptability and economic benefits.

The invention discloses a method for recovering lithium phosphate from lithium iron phosphate black powder. The method comprises the following steps: mixing black powder recovered from waste lithium iron phosphate batteries with sodium persulfate, and calcining; adding water into the obtained calcined product, dissolving, filtering to obtain water extract A and leaching residues, washing the leaching residues with water, and calcining at high temperature to obtain battery-grade iron phosphate; adding a sodium hydroxide solution into the water extract A, and reacting to obtain a water extract B; adding a trisodium phosphate solution into the water immersion liquid B, fully reacting, performing suction filtration to obtain lithium phosphate and filtrate, and cleaning and drying the lithium phosphate to obtain battery-grade lithium phosphate; and freezing and denitrifying the filtrate to obtain a denitrified solution, and adding the denitrified solution into the sodium hydroxide solution for recycling. The method does not generate wastes, recycles the filtrate in the whole process, theoretically realizes zero loss of the lithium element, prevents the iron element from entering the solution, simplifies the preparation steps of the lithium phosphate, and has the advantages of cost reduction and environmental protection.

A low-carbon near zero emission process of industrial waste water, comprising: S1: entering industrial waste water into a pre-oxidation system to improve biodegradability of organics; S2: after treatment in the pre-oxidation unit, entering the waste water into an anaerobic biological treatment system, sodium chloride and sulfate is deeply removed and carbon sources in the waste water can be used to remove the sulfate and nitrate; S3: entering water output from the anaerobic biological treatment system into a membrane concentration system and membrane concentrated solution enters a nano-filtration salt fractionation system for salt fractionation; and S4: refluxing nano-filtration concentrate solution generated by the nano-filtration salt fractionation system to the anaerobic biologic treatment system for biological desulfurization, or synthesizing the nano-filtration concentrate solution to be sodium persulfate by electro chemical methods, and refluxing proportionately to a waste water pre-oxidation system for use in-situ.

According to the environment-friendly scale and corrosion inhibitor for the green treatment of the circulating cooling water of the thermal power plant, the polyepoxysuccinate copolymer is synthesized, itaconic acid, sodium p-styrenesulfonate and sodium epoxysuccinate synthesized by maleic anhydride are adopted as monomers, sodium persulfate is adopted as an initiator, and a terpolymer IA / PESA / SSS is synthesized in a free combination manner; according to the optimal synthesis scheme, the molar ratio of IA to PESA is 4: 1, the molar ratio of PESA to SSS is 1: 4, the use amount of the initiator accounts for 2% of the mass of the monomer, the polymerization temperature is 95 DEG C, and the reaction time is 4 h. A dynamic simulation experiment shows that the copolymer is excellent in scale inhibition performance, and meanwhile, the synthesis evaluation is successful. According to the invention, the concentration ratio of the circulating cooling water is improved, so that the utilization ratio is improved, and the purpose of saving water is achieved; meanwhile, generation of scale substances is reduced, and high heat exchange efficiency is maintained; the corrosion condition of the system is relieved and prevented, safe operation of the system is kept, and safe and stable operation of the system is kept.

The invention belongs to the field of recycling treatment of waste lithium iron phosphate batteries, and particularly relates to a method for efficiently recycling waste lithium iron phosphate through oxygen-sodium persulfate leaching. According to the method, the lithium in the lithium iron phosphate waste battery is leached and extracted by adopting the environment-friendly reaction solution, and oxygen is additionally introduced in the extraction process, so that the leaching rate of the lithium is effectively improved, the leaching rate of iron is effectively reduced, and the overall leaching time is effectively shortened; therefore, the problem of secondary pollution to the environment when inorganic acid / alkali is recycled by an existing wet method is avoided, the process is low in cost and easy to implement, the extraction rate is high, and economic benefits of waste LFP battery recycling are considered from multiple aspects.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for improving the leaching rate and the carbon adsorption rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; a green oxygen activating agent and hydrogen peroxide are sequentially added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore, ore pulp activating liquid is formed, and the green oxygen activating agent is a mixture of calcium oxide, sodium persulfate and soluble bivalent iron salt; and adding a gold leaching agent into the ore pulp activation solution, adjusting the pH value of the ore pulp to 9-12, carrying out stirring gold leaching treatment, filtering to obtain a leaching solution, and then adding activated carbon to adsorb and extract gold. According to the method, a stronger oxidation environment is provided, meanwhile, the residual concentration of arsenate radicals in the solution is effectively reduced, the leaching rate of gold and the adsorption rate of activated carbon are greatly increased, excellent oxidation performance and environment friendliness are shown, and a more sustainable high-sulfur-arsenic gold ore pretreatment process is provided.

The invention relates to a high-salt scale inhibitor suitable for high-salt wastewater multi-evaporation working conditions and a use method, the scale inhibitor is composed of polyaspartic acid, polyepoxysuccinic acid, hydroxyethylidene diphosphonic acid, polymaleic anhydride, a composite quaternary ammonium salt, 2-phospho-1, 2, 4-tricarboxylic acid butane, a pH regulator, sodium persulfate, an antirust agent and a preservative, and has excellent scale inhibition performance. By using the scale inhibitor, the heat transfer efficiency of an evaporator can be remarkably improved, the service life of equipment can be prolonged, and the scale inhibitor is suitable for relieving aggregation and caking of salt on the wall surface of a quench tower under the condition of quench back-injection evaporation of high-salt wastewater; the evaporator is also suitable for relieving attached deposition of salt on the inner wall surface of the evaporator under the condition of multi-effect, double-effect and single-effect evaporation of high-salt wastewater; the scale inhibitor has excellent scale inhibition performance, can effectively prevent high-salinity wastewater from forming a scale layer under a multi-evaporation working condition, is simple and easy to understand in use method, is convenient to operate, and is suitable for a large-scale high-salinity wastewater treatment process.

The invention discloses a high-sulfate organic wastewater resourceful treatment method and system, and relates to the technical field of wastewater treatment. The method comprises the following steps: carrying out bipolar membrane separation treatment on the high-sulfate organic wastewater to obtain dilute alkali, dilute acid and dilute brine; carrying out evaporation and concentration treatment on the dilute alkali to obtain liquid alkali and condensed water; carrying out electrocatalytic oxidation treatment on the dilute brine to obtain electrocatalytic oxidation produced water; performing DTRO concentration on the electrocatalytic oxidation produced water to obtain DTRO produced water and DTRO concentrated water; the dilute acid and the DTRO concentrated water are subjected to photoelectrolysis treatment, and hydrogen and anolyte are obtained; performing crystallization separation on the anolyte to obtain mirabilite and sodium persulfate products; dTRO produced water is used for carrying out crystal dissolving treatment on mirabilite to obtain a saturated or near-saturated sodium sulfate solution, and the saturated or near-saturated sodium sulfate solution is returned to the photoelectrolysis step for circular treatment. According to the method, sulfate in the wastewater is converted into high-value sodium persulfate, the problem that a large amount of industrial by-product sodium sulfate is difficult to digest is avoided, meanwhile, liquid caustic soda, dilute acid, produced water, condensate water and hydrogen can be obtained and can be recycled, and resource utilization of the high-sulfate wastewater is achieved.

The invention discloses a method for improving the removal efficiency of COD (Chemical Oxygen Demand) and total oil in overflow water of a tailing pond of a copper mine, which comprises the following steps: S1, adjusting the pH (Potential of Hydrogen) of copper ore copper separation alkaline wastewater to 4.5 to 5.5 by adopting an acidic medicament; s2, the wastewater with the pH adjusted enters an iron-carbon micro-electrolysis reaction tank; s4, the wastewater subjected to advanced oxidation treatment enters a neutralization reaction tank, the pH of the wastewater is adjusted to 8-9 through an alkaline agent, the reaction is sufficient, and then a modified macromolecule anion flocculant solution is added. According to the technology, through the technical scheme of wastewater pH adjustment, iron-carbon micro-electrolysis oxidation, reduction reaction, advanced oxidation with sodium persulfate and flocculent precipitation, the concentration of pollutants such as COD and total oil in the copper ore copper separation alkaline wastewater can be remarkably reduced, and the problem that the removal efficiency of COD and total oil in existing copper ore copper separation wastewater is not high is solved; the risk that the wastewater affects the environment is effectively reduced, and a foundation is provided for effective utilization of the treated wastewater.

The invention discloses a PET electrical insulation adhesive tape and a preparation method thereof, the PET electrical insulation adhesive tape comprises a PET layer and a pressure-sensitive adhesive layer coated on the PET layer, the pressure-sensitive adhesive layer is formed by coating an acrylic acid pressure-sensitive adhesive, and the acrylic acid pressure-sensitive adhesive is prepared by the following steps: adding methyl methacrylate, acrylic acid, hydroxyethyl acrylate and a functional monomer into deionized water, and stirring to obtain a mixture; stirring at a constant speed, adding sodium persulfate and a surfactant, heating to 80-85 DEG C, continuously stirring and reacting for 2-4 hours to prepare an acrylic pressure-sensitive adhesive; according to the present invention, the excellent electrical insulation property of the PET material endows the substrate with the excellent insulation property, and in order to solve the problem of poor heat conduction and heat dissipation of the existing PET adhesive tape, the high thermal conductivity acrylic acid pressure-sensitive adhesive is prepared, such that the PET electrical insulation adhesive tape can rapidly dissipate heat.

The invention provides a method for extracting lithium carbonate from clay type lithium resources, and relates to the technical field of lithium extraction. The method comprises the following steps: carrying out first mixing on a clay type lithium resource and sodium sulfate, and roasting to obtain a roasted material; the roasted material is subjected to water leaching to obtain first ore pulp; the first ore pulp and sodium hydroxide are secondarily mixed to obtain second ore pulp; carrying out third mixing on the second ore pulp and calcium chloride, and carrying out solid-liquid separation to obtain tempered liquid; carrying out nanofiltration, first reverse osmosis and impurity removal on the conditioned solution to obtain an impurity-removed solution; and carrying out fourth mixing on the impurity-removed solution and the saturated sodium carbonate solution to obtain lithium carbonate. According to the method, sodium sulfate serves as an auxiliary agent to achieve selective efficient extraction of lithium in the clay type lithium ore, then lithium sulfate in second ore pulp is converted into lithium chloride through calcium chloride, and the obtained tempered liquid is suitable for a nanofiltration-reverse osmosis process.

The invention relates to the technical field of lithium adsorbents, in particular to a preparation and application method of a porous microsphere adsorbent for extracting lithium, and the preparation method comprises the following steps: preparing a water phase solution containing methacrylic acid, water and an emulsifier; the preparation method comprises the following steps: preparing an oil phase solution containing a fluorinated methacrylate monomer containing beta-diketone, cyclohexyl methacrylate, methoxyethyl methacrylate, N, N-bis (acryloyl) cystamine, ethylene glycol dimethacrylate, azodiisobutyronitrile and a solvent; dropwise adding the oil-phase solution into the water-phase solution for gradient emulsification, adding sodium persulfate to initiate polymerization, and performing centrifugal drying to obtain porous microspheres; and immersing the porous microspheres into a NaOH solution for hydrolysis activation, and drying to obtain the porous microsphere adsorbent for selective adsorption of lithium ions. Wherein the beta-diketone can enhance the targeted adsorption effect of the adsorbent on lithium ions and has relatively high selectivity and adsorption capacity, and the strong electron-withdrawing property of CF3 further polarizes carbonyl and enhances the coordination ability of the lithium ions.

The invention discloses a method for deeply removing arsenic from a nickel sulfate solution, which comprises the following steps: adjusting the pH value by using nickel hydroxide to form colloid to preliminarily remove arsenic, oxidizing by using sodium sulfate, and adding polyferric sulfate to form ferric hydroxide colloid to deeply adsorb and remove arsenic, and is simple in process, convenient to implement in the production process, capable of greatly reducing the cost and reducing the environmental pollution, and suitable for industrial production. The method comprises the following steps: adjusting the pH value of a low-pH leaching solution / anolyte / crude nickel sulfate dissolving solution to 4.0 or more by using nickel hydroxide, carrying out filter pressing to remove slag, adding arsenic ions in a sodium persulfate oxidation solution, reacting for 30 minutes, adding polyferric sulfate, reacting for 30 minutes, and carrying out filter pressing to obtain a nickel sulfate solution which is almost free of arsenic, and the method is efficient, safe and environment-friendly.

The invention belongs to the field of coalification wastewater membrane concentrated solution treatment, and discloses a coalification wastewater membrane concentrated solution treatment agent and a preparation method thereof. The coalification wastewater membrane concentrated solution treating agent is prepared from the following raw materials in parts by weight: 20 to 40 parts of sodium persulfate, 1 to 5 parts of polyacrylamide, 30 to 50 parts of modified diatomite and 10 to 30 parts of modified starch. Wherein the modified diatomite is obtained by carrying out ring-opening reaction on silanized modified diatomite and beta-cyclodextrin, and the modified starch is obtained by carrying out oxidation ring-opening reaction on starch after being pretreated by Na2S. Through dual modification and synergistic effect of the modified diatomite and the modified starch, efficient removal of organic matters and heavy metal ions in coalification wastewater is realized. Wherein hydroxyl and siloxane groups on the surface of the modified diatomite and beta-cyclodextrin have an inclusion effect, so that multiple types of organic pollutants can be adsorbed at the same time, carboxyl on the surface of the modified starch is used for complexing heavy metal ions, and the treatment efficiency is improved.

The utility model relates to the technical field of soil remediation, and discloses a circulating chemical injection system for contaminated soil, which comprises a sodium persulfate dissolving and activating tank, a solution tank stirrer is arranged at the top of the sodium persulfate dissolving and activating tank, and a small-flow metering pump is arranged at the output end of the sodium persulfate dissolving and activating tank. One side of the small-flow metering pump is connected to the input end of a sodium persulfate solution storage tank through a chemical conveying pipe, a solution tank stirrer is arranged at the top of the sodium persulfate solution storage tank, and a large-flow metering pump is arranged at the output end of the sodium persulfate solution storage tank; the output end of the pressurization system is evenly connected with adjusting valves through chemical conveying pipes. According to the utility model, by introducing an innovative small-tooth-mouth steel sheet pile waterproof curtain technology, the environmental safety and efficiency of the repair work are remarkably improved, the small-tooth-mouth steel sheet piles are unique in design, so that the installation process is rapid and efficient, and the exchange between peripheral underground water and underground water in a repair area can be cut off to prevent secondary diffusion of pollution.

The invention discloses a method for preparing battery-grade lithium phosphate and iron phosphate by recycling waste lithium iron phosphate batteries, and belongs to the technical field of lithium ion battery recycling. The method comprises the following steps: mixing and calcining black powder recovered from the waste lithium iron phosphate battery and sodium persulfate; adding water for dissolving, filtering to obtain a water leaching solution A and leaching residues, washing the leaching residues with water, and calcining at high temperature to obtain battery-grade iron phosphate; adding a sodium hydroxide solution into the water extract A, and reacting to obtain a water extract B; adding a trisodium phosphate solution into the water immersion liquid B, performing suction filtration after reaction to obtain lithium phosphate and filtrate, and cleaning and drying the lithium phosphate to obtain battery-grade lithium phosphate; and freezing and denitrifying the filtrate to obtain a denitrified solution, and adding the denitrified solution into the sodium hydroxide solution for recycling. The filtrate is recycled in the whole production process, zero loss of the lithium element is theoretically realized, the iron element is prevented from entering the solution, the preparation steps of the lithium phosphate are simplified, and the method has the advantages of economy and environmental protection.

The invention relates to the technical field of textile chemicals, in particular to an electrolyte-resistant printing thickening agent for improving the coloring effect and a preparation method thereof.The electrolyte-resistant printing thickening agent is prepared from, by weight, 10-20 parts of methacrylic acid, 15-30 parts of triethanolamine, 0.1-0.5 part of N, N '-methylene bisacrylamide, 4-8 parts of functional monomers and 2-5 parts of organic modified nano bentonite. 3-6 parts of an emulsifier, 0.1-0.6 part of sodium hydrogen sulfite, 0.1-0.6 part of sodium persulfate, 8-15 parts of an oil-phase solvent, 2-5 parts of a reverse-phase emulsifier and 30-50 parts of water; the functional monomer is prepared from p-styrene propanesulfonic acid, 2-acrylamide-2-methyl propanesulfonic acid and triphenylethyl phenol polyoxyethylene ether methacrylate according to the weight ratio of (3 to 5) to (1 to 2) to 1. According to the electrolyte-resistant printing thickening agent capable of improving the coloring effect, through matching and combination of the raw materials, the electrolyte resistance of the thickening agent can be improved, and the coloring effect in textile printing is improved.

The invention relates to the technical field of soil detection, and particularly discloses a rapid detection method for residual sodium persulfate in soil, which comprises the following steps: S1, measuring the moisture content of soil; s2, calculating the mass of a soil dry basis according to the water content, adding deionized water into the soil to be detected, uniformly stirring, adding a flocculating agent, and filtering to obtain a soil leachate; s3, taking the soil leachate in the S2, and adding dilute sulfuric acid; s4, adding potassium iodide into the solution in S3, uniformly stirring, and carrying out dark treatment; s5, titrating the solution in S4 with a sodium thiosulfate standard solution, adding a starch indicator when the solution becomes light yellow, ending titration when the solution becomes colorless, and measuring the volume of the consumed sodium thiosulfate standard solution; and S6, calculating the content of sodium persulfate in the to-be-detected soil dry basis. The rapid detection method for residual sodium persulfate in soil provided by the invention can effectively remove humus colloid in the soil leachate, and improves the accuracy and reliability of the detection result.

The invention relates to the technical field of agriculture, in particular to a soil conditioner for degrading soil fertilizer and pesticide residues and a preparation method thereof, and aims to solve the problems that although an existing soil conditioner can reduce the fertilizer and pesticide residues to a certain extent, secondary pollution is often caused, the cost is high, and the effect of degrading the soil fertilizer and pesticide residues is limited. According to the soil conditioner, humic acid, plant ash, corn straw, kieselguhr, polyglutamic acid and potassium fulvic acid are reasonably compounded, the physical and chemical properties of soil can be improved, the fertility of the soil can be improved, and after the complex microbial inoculants, the loaded pore-increasing charcoal and the coated sodium persulfate are added into the soil conditioner, under the synergistic effect of the three, the soil conditioner can improve the soil fertility. The efficient and long-acting degradation of fertilizer and pesticide residues in the soil is realized, the soil quality, the soil structure and the fertility can be improved, the healthy growth of crops can be promoted, the yield and the quality of the crops can be improved, the sustainable development of agriculture is guaranteed, and finally the comprehensive improvement of the soil is realized.

The invention belongs to the technical field of uranium mining, and particularly relates to a sodium persulfate acid oxidation green in-situ leaching uranium mining method. The method comprises the following steps: (1) exploring and pretreating an ore bed; (2) arranging an injection well and an extraction well; (3) preparing an acidic leaching solution; (4) injecting a leaching solution; (5) in-situ leaching circulation and monitoring; and (6) post-harvest treatment. The novel green acid in-situ leaching uranium mining method is developed, the oxidation rate of tetravalent uranium can be greatly increased, the uranium leaching rate is increased, and compared with an existing acid leaching method, the uranium leaching rate is remarkably increased, and environmental protection is achieved.

The invention provides a sodium-rich ferric sodium pyrophosphate positive electrode precursor and a preparation method and application thereof.The preparation method comprises the following steps that a ferrite solution, a phosphoric acid source solution, a pyrophosphoric acid source solution, an alkaline solution and a sodium persulfate solution are injected into a base solution in a parallel flow mode for a co-precipitation reaction, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is obtained; wherein the base solution is pure water. The method disclosed by the invention is simple to operate, the sodium-rich ferric sodium pyrophosphate positive electrode precursor with high sodium content, uniform element distribution and uniform phase can be prepared, the sodium-rich ferric sodium pyrophosphate positive electrode precursor is low in gas production rate in the subsequent sintering process, and the sodium-rich ferric sodium pyrophosphate positive electrode material with high compaction density can be prepared.

The invention belongs to the technical field of wastewater treatment, and particularly relates to a zero-discharge treatment system and method for polycrystalline silicon wastewater. Comprising a pretreatment system, a membrane treatment system and an evaporative crystallization system which are sequentially connected along a water flow direction, the pretreatment system comprises a sodium sulfate softening and precipitating unit, a dual-alkali softening and precipitating unit, an enhanced hardness and silicon removal unit, a ceramic membrane filtering unit, a decarburization unit and an ion exchange unit; the membrane treatment system comprises a COD (Chemical Oxygen Demand) purification membrane unit and a two-stage nanofiltration unit; the evaporative crystallization system comprises an evaporation unit, a circulating evaporative crystallization unit, a separation unit and a mother liquor drying unit. According to the method, high-value industrial byproduct gypsum is generated through sodium sulfate softening precipitation in the pretreatment stage, meanwhile, the cost of a softening agent is reduced, sodium sulfate generated by a membrane treatment system is recycled, the investment cost of an evaporative crystallization system is reduced, and resource utilization of wastewater treatment byproducts and sustainable development of the environment are achieved.

The invention relates to the technical field of acrylic emulsion, in particular to high-stability salt-spray-resistant water-based acrylic emulsion and a preparation method thereof. The preparation method comprises the following steps: adding amino-terminated polyamidoamine into dichloromethane, uniformly stirring, dropwise adding acryloyl chloride, carrying out rotary evaporation, adding into water, adding butyl acrylate, styrene, 3-mercaptopropionic acid, acrylic acid and an emulsifier, and stirring to obtain a prefabricated material a; adding sodium carbonate into water, stirring, adding the prefabricated material a and sodium persulfate, and stirring to obtain a prefabricated material b; adding carbon nanotubes into an ethanol aqueous solution for ultrasonic dispersion, adjusting the pH value of the system, adding tetrabutyl titanate for ultrasonic treatment, adding triethylamine and a silane coupling agent for ultrasonic treatment, and performing vacuum drying to obtain a prefabricated material c; adding the prefabricated material a into the prefabricated material b, stirring, adding ammonium persulfate, stirring, filtering, adding the prefabricated material c, a dispersing agent, an anti-rust pigment and water, uniformly mixing, grinding and filtering. The emulsion can be dispersed to form a stable emulsion, the film forming compactness is excellent, the water resistance and the salt fog resistance are improved, and the heat-resistant stability is greatly enhanced.

The utility model discloses a pesticide wastewater advanced treatment device which comprises a first-stage oxidation tower, a second-stage main reaction tower and a third-stage delay reaction tower which are sequentially arranged, a water outlet of the first-stage oxidation tower is communicated with a water inlet of the second-stage main reaction tower, and a water outlet of the second-stage main reaction tower is communicated with a water inlet of the third-stage delay reaction tower; the primary oxidation tower comprises a first tower body, a water inlet pipe, a first hydrogen peroxide adding pipe and an ozone jet device, the water inlet pipe is communicated with the first tower body, the first hydrogen peroxide adding pipe is communicated with the water inlet pipe, and the ozone jet device is mounted on the first tower body to introduce ozone into the first tower body; the secondary main reaction tower comprises a second tower body, a sodium persulfate dosing pipe and an ozone aeration disc; the sodium persulfate dosing pipe is communicated with a water inlet of the second tower body; the ozone aeration disc is arranged at the bottom in the second tower body; the third-stage delay reaction tower comprises a third tower body and a second hydrogen peroxide adding pipe, and the second hydrogen peroxide adding pipe is communicated with a water inlet of the third tower body.

Embodiments herein relate to recycling of used lithium battery materials. In some aspects, a method may include suspending a lithium source in a solvent containing an oxidizing agent to extract lithium, forming an extracted lithium solution, separating the extracted lithium solution from residual solids of the lithium source, purifying the extracted lithium solution by precipitating and filtering impurities, and precipitating lithium in the purified lithium solution to produce lithium carbonate (Li2CO3). In some embodiments, the method may also include pre-treating the lithium source to improve the kinetics of the lithium extraction. In some embodiments, the pretreatment may include a cutting or comminution step to reduce the size of the lithium source. In some embodiments, the lithium source may include lithium ion battery waste. In some embodiments, the oxidizing agent may include sodium persulfate (Na2S2O8), potassium persulfate ((NH4) 2S2O8), ammonium persulfate (NH4) 2S2O8, hydrogen peroxide (H2O2), ozone (O3), and / or nitrous oxide (N2O).

The invention relates to the technical field of switch valves, in particular to a switch valve for sodium persulfate production, which comprises a gas source, a valve body assembly and a sealing assembly, the valve body assembly comprises a valve body, the valve body comprises a hollow cylinder and a connecting rod, and the connecting rod is vertically connected to the outer wall of the hollow cylinder; a transmission channel and an airflow channel are arranged in the connecting rod and penetrate through the outer wall of the hollow cylinder; the sealing assembly comprises a second air source valve and a sealing ring, and the sealing ring is made of an elastic material; a plurality of cavities are formed in the sealing ring and are communicated with the airflow channel; the second air source valve is communicated with the air source, the outside and the airflow channel; by additionally arranging the additional airflow channel, intermittent inflation and deflation can be carried out by utilizing an air source when medium flow is generated in a discharging state, and sodium persulfate crystallized on the surface of the sealing ring is repeatedly extruded and stretched by combining with an elastic material, so that the sodium persulfate is crystallized and broken and then is taken away by a medium flow; and an emergency leaking stoppage effect can also be achieved.

The invention provides an organic solderability preservative and a preparation method for forming a protective film on the surface of copper, the organic solderability preservative comprises the following components in parts by weight: 3.0-4.5 parts of 2-(3, 4-dichlorobenzyl) benzimidazole, 52.5 parts of acetic acid, 0.75 part of n-heptanoic acid, 0.25-0.5 part of zinc acetate, 0.25-0.5 part of copper sulfate, 0.2 part of citric acid modified nano cerium oxide, and the balance of deionized water and a pH regulator; the preparation method for forming the protective film on the copper surface comprises the following steps: oil removal treatment: treating a circuit board in a sodium hydroxide solution; pickling treatment: treating in a sulfuric acid solution; micro-etching treatment: treating in a solution of sodium persulfate and sulfuric acid; pickling treatment: treating in a sulfuric acid solution; film forming treatment: dipping in an organic solderability preservative at 45 DEG C;

The invention relates to the technical field of degradable materials, in particular to a degradable material based on medium-chain and long-chain polyhydroxyalkanoate and a preparation method thereof.The degradable material comprises a lignocellulose / PHA film and biodegradable CPP films cast on the upper surface and the lower surface of the lignocellulose / PHA film; the lignocellulose / PHA film is prepared from the following components: bamboo-based lignocellulose, PHAMCL, polyvinyl alcohol resin, sodium polyacrylate, toluyl peroxide, sodium persulfate, ethylene glycol, ethanol and deionized water. According to the invention, the bamboo-based lignocellulose is compounded with medium-chain and long-chain polyhydroxyalkanoate, and the adhesion between fibers is enhanced by activating residual lignin and increasing the levels of phenolic hydroxyl groups and carboxyl groups in biomass, so that the barrier ability to water vapor and oxygen is improved; the flexible packaging bag is suitable for packaging bags, bottles, pipes, cans, boxes and other flexible packaging pieces in the industries of food, pharmacy, medical instruments, daily chemicals, stationery and the like.

The invention discloses a two-stage oxidation cobalt precipitation method which comprises the following steps: pre-treating purification residues before oxidation cobalt precipitation, leaching the purification residues by using a sulfuric acid diluent or a waste electrolyte to obtain a high-cadmium, high-cobalt and high-manganese precipitation pre-solution, then replacing and removing cadmium by using zinc powder, and adding the zinc powder into the leaching solution to replace and remove cadmium; first-stage oxidation: adding potassium permanganate into the cobalt precipitation pre-solution; second-stage oxidation: adding sodium persulfate into the high-cobalt pre-solution, and carrying out secondary oxidation; the slag with high manganese dioxide content obtained by carrying out first-stage oxidation precipitation through the method can be returned to zinc calcine to be leached to replace manganese powder to be reused, so that resource recycling of manganese metal is achieved, the grade of cobalt slag produced through second-stage oxidation is enriched by more than 30 times compared with that of purified slag, and the problems that the consumption of potassium permanganate precipitated through an oxidation method is too large; and primary oxidation cobalt deposition is not suitable for a high-manganese-content solution, and the grade of the produced cobalt slag is low.

A process for the production of iron phosphate, comprising the following steps: (1) Mixing an iron phosphide waste, an acidic liquid, an oxidizing agent and an adsorbent with stirring, heating to leaching and subjecting the resulting mixture to solid-liquid separation to obtain a first filtrate and a first filter residue; (2) Adding an alkaline liquid to the first filtrate to adjust the pH of the first filtrate, maintaining a temperature of the resulting mixture, and subjecting the resulting mixture to solid-liquid separation to obtain a second filter residue and a second filtrate; and subjecting the second filter residue to heat treatment to obtain iron oxide; (3) Subjecting the iron oxide to high-energy ball milling and adding a surfactant for activation to obtain a slurry; (4) Adding an extraction agent and an acidic liquid to the second filtrate obtained in step (2), carrying out an extraction and separation on a resulting mixture and subjecting a resulting organic phase to back-extraction to obtain phosphoric acid; and (5) Mixing the slurry obtained in step (3) with the phosphoric acid, heating to enable a reaction, subjecting the resulting mixture to solid-liquid separation to obtain a solid, and washing and sintering the solid to obtain the iron phosphate; where in step (1) the iron phosphide waste comprises a mixture of FeP and Fe2P; in step (1) the acidic liquid contains at least two from the following group: nitric acid, sulfuric acid and hydrochloric acid; In step (1) the oxidizing agent is at least one selected from the group consisting of hydrogen peroxide, oxygen, nitric acid and sodium persulfate; wherein in step (2) the alkaline liquid is at least one selected from the group consisting of a NaOH solution, a KOH solution, ammonia water, a urea solution, NH4Cl, NH4HCO3, Na2CO3 and NaHCO3; In step (2) the pH of the first filtrate is adjusted to 2.5 to 5; and In step (5) the molar ratio of Fe in the slurry to P in the phosphoric acid is 1:1–2; heating to enable a reaction is carried out at a temperature of 50 °C to 80 °C for 20 to 60 min; and the iron phosphate has a D 50 from 2 µm to 6 µm, a tapped density of 0.80 g / cm³ 3 up to 1.30 g / cm³ 3 , and a specific surface area of ​​4 m² 2 / g up to 8 m 2 / g indicates.