190 results about "Sulfite salt" patented technology

The invention relates to the technical field of water treatment agents, and particularly discloses an anti-corrosion deoxidizing composite agent for geothermal well recharge water and a preparation method of the anti-corrosion deoxidizing composite agent. The invention relates to an anti-corrosion and deoxidizing composite agent for geothermal well recharge water. The anti-corrosion and deoxidizing composite agent comprises the following raw materials: 30-40 parts of double modified sodium sulfite, 10-20 parts of a corrosion inhibitor, 8-15 parts of a scale inhibitor, 5-10 parts of amino trimethylene phosphonic acid, 5-10 parts of etidronic acid, 3-8 parts of polyethylene glycol monomethyl ether acrylate and 40-50 parts of deionized water. The dual-modified sodium sulfite is obtained by sequentially modifying sodium sulfite with a silane coupling agent and acrylic acid. The corrosion-resistant and oxygen-removing composite agent has the advantage of being high in oxygen-removing efficiency stability, the corrosion-resistant and scale-inhibiting functions are synchronously and synergistically improved on the basis that the oxygen-removing efficiency stability is guaranteed, and the complex working condition requirements of geothermal well recharge are completely met.

The application provides a method for synthesizing an eplerenone intermediate N-1 by one-pot method, and belongs to the technical field of organic synthesis. The method is characterized in that: the eplerenone intermediate N-4 is dissolved in dichloromethane, a potassium carbonate aqueous solution and dibromohydantoin are added to perform an opening ring reaction; after the reaction is completed, hydrochloric acid is directly added to perform a rearrangement reaction; then water is separated and methanol is added in the organic layer to perform an ozonation reaction; then sodium sulfite is added to perform a reduction reaction; then hydrochloric acid is added to perform a methyl esterification reaction, so as to obtain the eplerenone intermediate N-1 crude product, and finally the eplerenone intermediate N-1 fine product is obtained through refining. The method realizes the one-pot synthesis of the eplerenone intermediate N-1 from the eplerenone intermediate N-4 through the continuous reactions of opening ring, rearrangement, ozonation, reduction and methyl esterification, and can avoid column chromatography purification, so that the method becomes a green chemical process route with greatly reduced organic solvent consumption and wastewater.

The invention relates to the technical field of industrial wastewater treatment, in particular to a treatment method for treating high-sulfonic-group wastewater by advanced oxidation, which comprises the following steps: regulating the pH value of the wastewater to 3.0-4.0, then carrying out photo-Fenton oxidation, controlling the molar ratio of H2O2 to Fe < 2 + > to be 300: 1-400: 1, regulating the pH value of the effluent to 5.0-6.0, adding sodium sulfite to quench residual H2O2 and flocculate and precipitate iron mud, and finally, carrying out secondary oxidation on the wastewater to obtain the high-sulfonic-group wastewater. Performing anaerobic-aerobic biochemical treatment on the supernate, adding sodium carbonate and sodium hydroxide into biochemical effluent to soften and descale, concentrating in a mechanical vapor recompression evaporator, washing and recrystallizing crystallized mother liquor, and adsorbing and purifying the crystallized mother liquor with activated carbon to obtain an industrial salt product. The problem of MVR evaporation scaling is effectively solved by accurately controlling the neutralization pH and combining the softening step, finally, wastewater standard treatment and salt high-quality recovery are achieved, the COD removal rate can reach 95% or above, and excellent environmental and economic benefits are achieved.

This invention discloses an acetic acid-modified inorganic composite gel material and its preparation method, belonging to the field of organic material synthesis technology. The acetic acid-modified inorganic composite gel material comprises the following materials in parts by weight: 0.2-0.4 parts of acetic acid-Co3O4, 1.5-2.5 parts of acrylamide, 1-1.5 parts of glycerol, 0.05-0.1 parts of N-N-dimethylformamide, 0.25-0.5 parts of ammonium persulfate, 0.1-0.15 parts of sulfonated-Bi2O3, 0.6-0.9 parts of ethylenediamine, and 0.2-0.4 parts of PVP; the acetic acid-Co3O4 comprises materials in the following mass ratio: acetic acid:cobalt nitrate:thiourea:ammonium fluoride:sodium bicarbonate = 3-7:1.5-2.5:0.8-1.2:0.5-1:6; the sulfonated-Bi2O3 comprises materials in the following mass ratio: Bi2O3:sodium sulfite:H2O2:ammonium bicarbonate = 3-5:0.2-0.6:1-1.5:1. This material achieves efficient and stable catalysis for nitrogen reduction under mild conditions through structural defect regulation, interfacial functional group modification, heterojunction electronic regulation, and synergistic enhancement with organic gel.

The application discloses a preparation method of a pesticide lignosulfonate sodium dispersant composition and belongs to the technical field of dispersants. The method comprises the following steps: S1, taking papermaking black liquor as raw material, performing standing precipitation, flocculation precipitation, membrane concentration and acid precipitation treatment to obtain purified lignin; S2, adding the purified lignin into water, adjusting the pH of the system to 10-11, then adding hydrogen peroxide to perform pre-oxidation, then adding formaldehyde and sodium sulfite to perform sulfomethylation reaction, and adding formaldehyde to perform polycondensation reaction; cooling and discharging, and performing spray drying to obtain lignosulfonate sodium; and S3, adding the lignosulfonate sodium and 1-ethyl-3-methyl imidazolium L-lactate into water and stirring and uniformly mixing, adding stevioside to perform ultrasonic treatment, forming a homogeneous system, and performing spray drying to obtain the pesticide lignosulfonate sodium dispersant composition. The lignosulfonate sodium dispersant composition can effectively improve the pesticide dispersion stability and pesticide biological activity, and meets the pesticide use requirement.

The application discloses a feed oil and meat and bone meal co-production preparation process for improving protein retention rate, and relates to the field of animal feed.The preparation process comprises the following steps: S1, after crushing livestock and poultry slaughter by-products, water, lactic acid and sodium sulfite are added, and stirring treatment is conducted to obtain pretreated materials; S2, composite strain seed liquid is inoculated into the pretreated materials, and fermentation is conducted; S3, the fermented materials are heated, enzyme inactivation and sterilization treatment are conducted, and three-phase centrifugal separation is conducted to obtain upper oil, middle layer fermentation protein liquid and lower layer very fine bone residue; S4, the upper oil is subjected to water washing and vacuum dewatering to obtain feed oil; and the middle layer fermentation protein liquid and the lower layer very fine bone residue are combined and then subjected to low-temperature vacuum drying to obtain meat and bone meal.The process can effectively improve protein digestibility and protein retention rate, does not need high-temperature and high-pressure treatment, effectively retains heat-sensitive amino acids, and the product is rich in small-molecule peptides and soluble calcium and has excellent quality.

The invention relates to a synthesis method of sulfopropionic anhydride. The synthesis method comprises the following steps: (1) mixing 3-bromopropionic acid and sodium sulfite in water, and carrying out sulfonation reaction to obtain a mixture; (2) mixing the mixture with an acidifying agent, and carrying out acidification reaction to obtain 3-sulfonyl propionic acid; and (3) mixing the 3-sulfonyl propionic acid with a dehydrating agent and an organic solvent, and carrying out a dehydration reaction to obtain the sulfopropionic anhydride. According to the invention, compounds such as 3-bromopropionic acid and sodium sulfite are used as reaction raw materials to prepare sulfopropionic anhydride. The method has the advantages of cheap and easily available raw materials, simple operation and high yield, and is suitable for large-scale production.

The application relates to an ultrasonic treatment method of high-impurity copper anode slime. The ultrasonic treatment method is realized through hierarchical ultrasonic strengthening and synergistic leaching. In the first-stage leaching, hydrogen peroxide-oxygen-rich air composite oxidants are combined with ultrasonic cavitation effects to realize efficient oxidation leaching of arsenic, antimony and bismuth; in the second-stage leaching, sulfuric acid-sodium sulfite mixed leaching agents are used to remove harmful impurities such as arsenic, antimony and bismuth under ultrasonic strengthening, and to efficiently enrich valuable metals such as gold, silver, selenium and tellurium, so that the treatment period is shortened, energy consumption and reagent consumption are reduced, resource comprehensive utilization is improved, and the method is suitable for efficient separation and resource recovery of high-impurity copper anode slime containing refractory impurities such as arsenic, antimony and bismuth and valuable metals such as gold, silver, selenium and tellurium.

This invention discloses an apparatus and process for removing sulfur dioxide from flue gas using siderite slurry, relating to the field of environmental protection technology. The apparatus comprises six major components: desulfurization, slurry circulation, slurry replenishment, oxidation, defoaming emission, and spent slurry treatment. The components are interconnected by pipelines. The process includes siderite pretreatment slurry preparation, slurry replenishment, flue gas desulfurization, sulfite oxidation, flue gas defoaming emission, and spent slurry treatment. Siderite is crushed and ground into a slurry with a specific particle size and solids content, which is then contacted countercurrently with sulfur-containing flue gas. Utilizing ferric carbonate, magnesium carbonate, and calcium carbonate in the slurry as desulfurizing agents, combined with the oxidation effect of air and ferric ions, sulfur dioxide is converted into ferric sulfate and calcium sulfate, achieving desulfurization. This invention has high desulfurization efficiency, with the sulfur dioxide content in the purified flue gas below 50 mg / Nm³. 3 It makes full use of low-grade siderite resources, and the desulfurization by-products can be utilized as resources. The process is simple and has no secondary pollution, resulting in significant economic and environmental benefits.

The invention relates to the technical field of vanadium batteries, and provides a vanadium battery electrolyte and a preparation method thereof.The preparation method comprises the steps that vanadium pentoxide, concentrated sulfuric acid and water are mixed and then heated, then acid ester is added, then boiling, cooling and filtering are conducted in sequence, and the vanadium battery electrolyte is obtained; the mass ratio of vanadium pentoxide to concentrated sulfuric acid is 1: (1.3-1.5); the mass ratio of the vanadium pentoxide to the acid ester is 1: (1.1-1.3); the acid ester comprises the following components in percentage by mass: 50-51% of oxalic acid, 4-5% of sodium sulfite and 45-46% of ethyl acetate. Compared with the traditional vanadium battery electrolyte, the use amount of the concentrated sulfuric acid and oxalic acid is greatly reduced, the obtained electrolyte is weakly acidic, the corrosivity and danger are greatly reduced, and the electrolyte is not easy to separate out and not easy to block a film in the charging and discharging process. In conclusion, compared with the traditional electrolyte, the vanadium battery electrolyte provided by the invention is safer, more environment-friendly and more efficient.

The present application relates to the field of natural gas decarburization, and discloses a decarburization solvent, a decarburization method and system of carbon-containing natural gas, the decarburization solvent comprising a main agent, an activator and an auxiliary agent; wherein the main agent is N-methyldiethanolamine, the activator comprises a primary amine and a secondary amine, and the auxiliary agent is selected from at least one of potassium sorbate, sodium sorbate and sodium sulfite.The decarburization solvent and the decarburization method provided by the present application can not only make the absorption and regeneration equipment flexible to follow the change of the CO2 content of the raw gas in the natural gas development process and expand, but also avoid the corrosion and foaming of the tower equipment in the conventional process; meanwhile, the absorption and regeneration performance of the decarburization solution can be improved under the condition of meeting the purification index, and the regeneration heat consumption and the power consumption for pressurization of the amine liquid circulation can be greatly reduced.

The invention belongs to the technical field of hydrochloric acid recovery, and discloses a benzene chlorination process byproduct hydrochloric acid impurity removal refining system and method.The method comprises the steps that sodium sulfite is added into hydrochloric acid to remove free chlorine, organic matter in hydrochloric acid is adsorbed through polystyrene-based macroporous resin, iron ions are adsorbed through amino-containing ion exchange resin, and the hydrochloric acid is recycled; hydrochloric acid is fed into a desorption tower for heating desorption, obtained pure hydrogen chloride gas is fed into an absorption tower for secondary absorption, and absorbed water is ultrapure water. According to the method, a combined process of resin adsorption and hydrogen chloride desorption and reabsorption is adopted, volatile impurities are firstly removed, then non-volatile inorganic impurities are deeply adsorbed, the labor division is clear, the efficiency is high, the final product is clear and transparent, the quality is stable, the economic benefit is remarkable, low-value and difficult-to-treat waste acid is converted into high-value commodity hydrochloric acid, waste is turned into wealth, and the method is suitable for industrial production. And remarkable economic benefits are created, and the environmental protection pressure is reduced.

Described herein are methods and systems for increasing the injectivity of wells used to inject water or water containing various chemicals such as water-soluble polymers for the purpose of increasing the recovery of hydrocarbons such as crude oil from a hydrocarbon-bearing formation. Injectivity often decreases because of adverse reactions or plugging at or near the wellbore. The treatment procedure involves injecting reducing agents (e.g., sulfite or metabisulfite salts) dissolved in water or water containing other chemicals such as polymers.

To provide a functional composition reduced in sulfur dioxide in a composition containing mannose and / or mannooligosaccharide.SOLUTION: The sulfur dioxide concentration in the functional composition can be reduced by decomposing devil's tongue powder derived from devil's tongue as a raw material and then heat-treating the resultant composition containing mannose and / or mannooligosaccharide at ≥ 105 °C. The functional composition with reduced sulfur dioxide (sulfurous acid) can be distributed as food and drink without legal problems.SELECTED DRAWING: None

The application provides a method for preparing bismuth trioxide-cuprous oxide nanocomposite based on a synergistic reaction, which comprises the following steps: dispersing sodium bismuthate, sodium sulfite and cuprous chloride in deionized water to obtain a solid-liquid mixture; and placing the solid-liquid mixture under a hydrothermal condition, so as to in-situ prepare the Bi2O3-Cu2O nanocomposite through the synergistic effect of the redox reaction between sodium bismuthate and sodium sulfite in the system and the anion exchange reaction between cuprous chloride and hydroxyl ions generated in-situ. The application is based on the synergistic effect of the redox reaction and the anion exchange reaction under the same hydrothermal condition, and high-purity Bi2O3-Cu2O nanocomposite can be prepared in-situ in one step without adding an alkali source and a template agent. The prepared composite can effectively form a p-n heterojunction, significantly inhibit the recombination of photo-generated carriers, improve the photocatalytic activity and redox capacity of the material, and the preparation process is simple, green and economical, and easy for industrialized production.

The application discloses a water coal slurry additive prepared by using industrial by-products, which comprises the following raw material components in parts by weight: amino benzene sulfonic acid 10-20 parts, meta-amino phenol 10-20 parts, sulfite 5-15 parts, a basic adjusting agent in an appropriate amount and water 50-70 parts. The water coal slurry additive is prepared by directly using industrial by-products, realizes resource recycling, and has high slurry concentration, low viscosity, good fluidity and stability.

The utility model discloses an intrinsically safe oven device for sulfite production, which comprises an oven body, a mixing pipe fixedly connected to the side surface of the oven body, a sulfur spraying pipe fixedly connected to the side surface of the mixing pipe, a gas conveying pipe fixedly connected to the side surface of the mixing pipe, and a spiral plate fixedly connected to the side inner wall of the mixing pipe. A fan is fixedly connected to the upper surface of the furnace body, a filter box is fixedly connected to the output end of the fan, a heating tank is fixedly connected to the filter box through a pipeline, an air inlet is fixedly connected to the side surface of the heating tank, and an exhaust pipe is fixedly connected to the end, away from the heating tank, of the air inlet; the inner wall of the heating tank is fixedly connected with a heating pipe, and the side surface of the heating tank is fixedly connected with a gas-guide pipe. By means of the components, liquid sulfur and combustion-supporting gas are fully mixed through the gas conveying pipe and the spiral plate, the utilization rate of raw materials is increased, smoke generated by combustion is used for conducting waste heat treatment on the combustion-supporting gas, energy is effectively utilized, and the combustion effect is improved.

Provided are: a gold plating method for achieving soft gold plating; a composition for gold plating; and a plating solution. The gold plating method is performed using a plating solution comprising: a gold sulfite salt; and at least one among thiosulfate ions and trithionic acid ions.

The invention discloses an organic inhibitor for galena and application of the organic inhibitor. The inhibitor is 3-mercapto-1 sodium propane sulfonate (MPS). Aiming at the characteristics of close copper and lead symbiosis, high iron and zinc content and fine disseminated particle size of raw ore, the method adopts the technological process of'copper and lead partial bulk flotation tailing discarding-bulk concentrate regrinding-copper and lead separation flotation ', and comprises the following steps: firstly, in a bulk flotation section, utilizing a zinc sulfate and sodium sulfite combined reagent to efficiently inhibit sphalerite and pyrite under a weakly alkaline condition; a large number of gangue and zinc-sulfur minerals are thrown away in advance; the method comprises the following steps of: carrying out superfine regrinding dissociation on obtained bulk concentrate, then carrying out separation operation, and in a copper-lead separation section, replacing traditional dichromate with 3-mercapto-1 sodium propane sulfonate (MPS), carrying out a closed-loop process of one-roughing, three-refining and three-sweeping, and supplementing an inhibitor in fine selection operation, so that efficient inhibition of galena and preferable flotation of chalcopyrite are realized. The technological process is rigorous in design, the reagent system is green and environmentally friendly, and the resource recovery rate of the low-grade complex ore is remarkably increased.

The invention relates to the technical field of medical analysis, in particular to a method for detecting the content of an antioxidant in bromfenac sodium eye drops through liquid chromatography, and particularly relates to a method for detecting the content of the antioxidant anhydrous sodium sulfite of the bromfenac sodium eye drops through high performance liquid chromatography. Wherein the mobile phase A is a methanol-buffer salt solution; a mobile phase B is methanol; eluting by using a gradient mobile phase, wherein the volume ratio of the mobile phase is 100%; preparing a reference solution and a test solution by taking the mobile phase A as a diluent, then respectively injecting the reference solution and the test solution into a liquid chromatograph, and recording chromatograms; calculating the content of anhydrous sodium sulfite by adopting an external standard method; the method comprises the following specific steps: (1) preparation of a reference substance solution: taking an anhydrous sodium sulfite reference substance, and adding a diluent for dissolving to obtain the reference substance solution; and (2) preparation of a test solution: taking the bromfenac sodium eye drops, and adding a diluent to dilute the bromfenac sodium eye drops to obtain the bromfenac sodium eye drops. The method disclosed by the invention is strong in specificity, high in stability, high in precision and high in accuracy, and has practical significance on quality control of the bromfenac sodium eye drops.

The invention belongs to the technical field of sludge treatment, and provides a method for strengthening anaerobic fermentation of sludge by activated sodium pyrosulfite, which comprises the following steps: pretreating sludge to obtain a sludge system; adding ferric salt and sodium pyrosulfite into the sludge system to obtain an activation system; and performing anaerobic fermentation on the active system to finish the treatment. By constructing a Fe < 3 + > / sodium pyrosulfite free radical system, the dissolution of organic matters in the sludge is improved, so that the generation of short-chain fatty acid (SCFAs) in the anaerobic fermentation process is promoted. Sodium pyrosulfite is dissolved in water to form sulfite species, under the action of ferric ions, the sulfite species can generate various active free radicals through electron transfer, and the free radicals have high oxidation capacity and can destroy sludge floc structures and extracellular polymeric substances, so that cell lysis is promoted, intracellular organic substances are released, and the sludge can be degraded. The concentration of a substrate available for anaerobic fermentation is improved, and the yield of short-chain acid is substantially improved.

This invention relates to the field of waste sludge treatment technology, specifically to an in-situ resource utilization method for a microbial-algae system and its application. The in-situ resource utilization method for the microbial-algae system includes: placing waste sludge, microalgae, and sodium sulfite in an anaerobic fermentation reactor, then adjusting the pH of the mixture and fermenting under anaerobic conditions; wherein the microalgae include at least one of the phyla of green algae, cyanobacteria, and diatoms; and no anaerobic sludge is added to the anaerobic fermentation reactor. This method can effectively utilize the microbial-algae system to increase the yield of volatile fatty acids during anaerobic fermentation in situ, and can also reduce the yield of waste sludge in situ, thereby lowering the subsequent disposal costs of sludge and microalgae in the secondary sedimentation tank.

The application provides a copper-lead sulfide ore flotation separation inhibitor and a preparation method and application thereof, and belongs to the technical field of ore-dressing reagents. The main components of the inhibitor are maleic acid acrylic acid copolymer, trisodium nitrilotriacetate and sodium sulfite. In the preparation, the maleic acid acrylic acid copolymer, the trisodium nitrilotriacetate and the sodium sulfite are mixed at normal temperature, and then are added into a high-shear emulsifying machine to be emulsified and dispersed, so that a uniform viscous suspension inhibitor is obtained. In the application, after the raw ore is treated, preselected ore slurry is obtained; copper-lead mixed flotation is performed first to obtain copper-lead mixed concentrate and copper-lead tailings; active carbon and sodium sulfide are added into the copper-lead mixed concentrate first, and reagents are added to perform copper-lead separation flotation to obtain copper and lead concentrates. The inhibitor has the advantages of being cheap, easy to obtain and store and environment-friendly. The inhibition effect on galena is good, the copper-lead sulfide ore separation effect is good, and the ore-dressing indexes are effectively improved.

The application discloses a treatment method for efficiently removing selenium from waste acid, and specifically comprises the following steps: preheating waste acid to be treated for removing selenium, adding sulfuric acid to adjust the H + concentration of 4-6 mol / L, then adding a reducing agent sodium sulfite Na2SO3, and fully stirring and mixing; controlling the temperature to be 55-70 DEG C to perform a first-stage reaction, then adding a composite catalyst prepared by mixing sodium thiosulfate Na2S2O3 and iodine I2, stirring and mixing, continuing to perform a deep reaction, and performing solid-liquid separation after filtration when the reaction is completed. The application uses sodium sulfite reduction, iodine and sodium thiosulfate catalysis as a substitute for the traditional SO2 reduction mode, solves the problem that the traditional SO2 reduction method is limited by pH liquid, accelerates the reaction rate through iodine and sodium thiosulfate catalysis, simultaneously solves the problem that the traditional sulfite cannot reduce selenium-containing substances other than selenite, and improves the reduction effect of selenium.

This invention relates to the field of biomaterial synthesis technology, specifically disclosing a method for preparing a class of catechol derivatives and their applications, administration, and preparation apparatus. The methods include: preparing dopa or carbidopa derivatives using a sodium sulfite-boric acid-argon protective system in an organic-aqueous mixture; or using dopa as a raw material, performing a methyl esterification reaction with SOCl2 and anhydrous methanol, followed by an exchange reaction with methyl trifluoroacetate to achieve a one-pot synthesis of Tfa-DOPA-OMe; or preparing acetal-protected tanshinone derivatives based on dopa derivatives or tanshinone and its derivatives; or using acetal-protected tanshinone and its esters to prepare natural catechol compounds such as Shimobashiric acid C, and preparing non-natural catechol compounds through coupling reactions with organic acids, amino acids and their derivatives, oligopeptides and polypeptides, alcohols, or sugars. Highly selective deprotection conditions achieve the goal of completely and thoroughly removing the acetal protection of catechols without destroying the ester bonds within the molecular structure.

The invention discloses a method for treating multiple pollutants in ship waste gas washing waste liquid by adding exogenous C14-HSL. The method comprises the following steps: 1, placing aerobic sludge in a completely mixed anaerobic stirred reactor for domestication, and completing domestication of glycerine sulfite mixotrophic denitrification activated sludge in a manner of intermittent water feeding and continuous water feeding in sequence; and 2, adding C14-HSL into the completely mixed anaerobic stirred reactor in stages, and regulating to form a stable microbial community composition so as to promote synchronous degradation of multiple pollutants. The comprehensive treatment of the ship waste gas denitration wastewater and the ship organic wastewater has higher environmental and economic benefits.

The application discloses a preparation method of 1,3-propanedisulfonic acid, which uses sodium sulfite and 1,3-dichloropropane as starting materials, and synthesizes sodium propanedisulfonate through sulfonation, and then concentrates, acidifies, separates sodium chloride, secondarily concentrates, evaporates and dehydrates, so as to obtain 1,3-propanedisulfonic acid with a purity of greater than or equal to 95.0%. The method is stable in process, high in yield (greater than or equal to 60.0%), and suitable for industrial production, and the raw materials are easy to obtain, so that the problems of low yield and low purity in the prior art are solved.

The invention belongs to the technical field of beneficiation, and particularly discloses a beneficiation method of low-grade refractory lead-zinc oxide ore, which comprises the following steps: crushing and screening raw lead-zinc oxide ore to obtain a material with the particle size of 10-40mm, and carrying out photoelectric separation and waste rock removal to obtain an ore raw material with improved grade; the ore raw materials are finely crushed and then subjected to screening and photoelectric separation, fine ore materials with the particle size being-10 mm are screened, and coarse-grain materials are separated through a cyclone; an overflow object is screened to remove waste rocks, settled sand is screened to obtain a material meeting the particle size requirement, the material is subjected to chemical adding bulk flotation and chemical removal treatment, and bulk concentrate obtained after chemical removal is obtained; and sodium sulfite and zinc sulfate are added for lead-zinc separation treatment, and lead concentrate and zinc concentrate are obtained correspondingly. By means of the two-stage waste pre-throwing and oxygen-sulfur mixed flotation system, the agent consumption is remarkably reduced, slime interference is relieved, the lead-zinc recovery rate is increased, and the method is suitable for efficient comprehensive utilization of the low-grade lead-zinc oxide ore.

The invention provides a synthesis method of L-3-aminoisobutyric acid. The synthesis method comprises the following steps: enabling a dichloromethane solution of cyanoacetic acid to react with oxalyl chloride; a reaction product, (S)-4-benzyl-2-oxazolidinone dissolved in dichloromethane and triethylamine are respectively fed into a continuous flow reactor to be mixed and react with the (S)-4-benzyl-2-oxazolidinone dissolved in dichloromethane; collecting reaction liquid, extracting, concentrating and recrystallizing to obtain a compound 2; dissolving the compound 2 in tetrahydrofuran, and adding iodomethane; respectively feeding the mixed solution and a tetrahydrofuran solution of lithium diisopropylamide into a continuous flow reactor for mixing reaction; collecting reaction liquid, quenching and purifying to obtain a compound 3; dissolving the compound 3 in a mixed solvent of an organic solvent and water, adding lithium hydroxide and hydrogen peroxide, and reacting; adding a sodium sulfite aqueous solution for quenching reaction, extracting, concentrating and purifying to obtain a compound 4; dissolving a compound 4 in ethanol, and carrying out a continuous flow hydrogenation reaction with hydrogen through a continuous flow hydrogenation reactor; and collecting a reaction product, concentrating, cooling and crystallizing to obtain the L-3-aminoisobutyric acid.

The invention discloses a method for comprehensively enriching and recovering cadmium and thallium from complex arsenic sulfide slag, belongs to the technical field of harmless treatment of dangerous waste residues and resource recovery of rare and noble metals, and aims to solve the problems that the existing process is difficult to realize fractional separation of fluorine, chlorine, arsenic, cadmium and thallium in the arsenic sulfide slag, and the thallium is low in recovery rate and insufficient in purity. According to the method, fluorine and chlorine and thallium arsenic-cadmium lead are separated through graded alkaline leaching; the cadmium-containing lead slag is subjected to zinc electrodeposition waste liquid acid leaching and sodium sulfite and citric acid purification, and cadmium-containing coarse filtrate is obtained; adjusting the pH value of the thallium-containing arsenic liquid step by step, and adding sodium hydrosulfide for precipitation to obtain high-purity thallium slag; according to the method, no toxic gas is generated, the emission of wastewater is reduced by 80%, conventional equipment is used, industrialization is easy, and unification of harmlessness of hazardous waste and efficient recycling of resources is achieved.