781 results about "Sodium sulfites" patented technology

The invention relates to a sodium hydrosulfite production risk assessment method and system based on multi-source data fusion. The system comprises a production process data acquisition module, a key variable linkage analysis module, a real-time risk detection module, a dynamic risk trigger analysis module and a comprehensive risk score calculation module. The method not only improves the risk assessment precision in the sodium hydrosulfite production process, but also realizes effective risk early warning and control through real-time and dynamic monitoring and regulation means. Meanwhile, the method fully combines the particularity of the sodium hydrosulfite production process, has significant value in safety guarantee, production efficiency improvement and management optimization, and establishes a new risk assessment normal form with scientificity and practicability for the chemical industry.

The invention discloses a high-temperature-resistant lignite resin and a preparation method thereof, and belongs to the field of drilling fluids, and the preparation method comprises the following steps: obtaining and preparing an extracting solution containing humic acid from lignite; adding hydrochloric acid into the extracting solution, separating, filtering and precipitating, dissolving the precipitating in a sodium hydroxide solution to obtain a humic acid solution, adding formaldehyde and sodium pyrosulfite into the humic acid solution, preheating to 80 DEG C, adding the extracting solution, heating to 110-130 DEG C, continuously stirring, reacting for 1-3 hours, and cooling to 60 DEG C or below to obtain a reaction product; transferring a reaction product to a neutralizing tank, dropwise adding a NaOH solution, adjusting the pH value to 10-11, and controlling the temperature below 55 DEG C; the mass ratio of the dry basis mass of sulfonated humic acid to ECH is 1: (0.05-0.15), the temperature is kept at 45-55 DEG C, the stirring speed is 400-600 rpm, and the reaction is performed for 2-4 hours; meanwhile, a NaOH solution is continuously added, and the pH is kept at 10-11. Adjusting the pH value of the reaction liquid to 7-8 by using dilute HCl, and terminating the reaction; and obtaining a resin product.

The invention discloses a modification method of humic acid and modified humic acid, and relates to the technical field of humic acid modification. The modification method comprises the following steps: activating mineral source humic acid to obtain activated humic acid; adding activated humic acid, a grafting agent and a propenyl monomer into the cross-linking system, stirring, standing, and then heating for reaction; after the reaction is finished, adjusting the pH value to be alkaline, keeping heating and stirring, and then drying to obtain modified humic acid; wherein the grafting agent comprises the following raw materials: sodium sulfite and pyruvic acid. More hydrophilic groups are introduced into the grafted and modified humic acid, water molecules can be adsorbed to form hydrogen bonds, meanwhile, the hydrophilic groups can be adsorbed to the surfaces of soil particles, the solubility of the humic acid molecules is improved, and the water retention capacity of the humic acid molecules in soil is improved; therefore, the application range and adaptability of the humic acid water-soluble fertilizer are also increased in actual agricultural application.

The invention provides a preparation method of 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride, which comprises the following steps: salifying 4-fluoro-3, 5-dimethylaniline serving as a substrate with concentrated hydrochloric acid, reacting with sodium nitrite to prepare a diazo solution, reducing the diazo solution into corresponding phenylhydrazine by using alkaline sodium sulfite as a reducing agent system, and reacting the 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride with the diazo solution to prepare the 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride. And acidizing the 2, 5-dimethyl phenylhydrazine to obtain corresponding phenylhydrazine hydrochloride. According to the preparation method, sodium sulfite which is low in cost and easy to obtain is used as a reducing agent, the defects that metal residues are high, the environment is prone to being polluted and the raw material cost is high due to the fact that a metal reducing agent is adopted when phenylhydrazine hydrochloride is prepared in the prior art are overcome, the reaction is completed in a water phase, no organic solvent is adopted, and the concept of green chemistry is met; and the problems of complicated post-treatment and easy pollution caused by the adoption of an organic solvent can be effectively avoided.

The invention discloses an aggregation-induced emission material with high fluorescence quantum yield and large Stokes shift as well as a preparation method and application of the aggregation-induced emission material, and belongs to the technical field of preparation of aggregation-induced emission materials. Comprising the following steps: carrying out Suzuki-Miyaura coupling reaction on organic boric acid and bromosalicylaldehyde to obtain an intermediate; and adding the intermediate, sodium pyrosulfite and aminothiophenol into an organic solvent, and then carrying out high-temperature reaction to prepare the aggregation-induced emission material. The aggregation-induced emission material is synthesized by a two-step method, so that the aggregation-induced emission material can be rapidly synthesized on a large scale, and the prepared aggregation-induced emission material also has the advantages of high fluorescence efficiency, large Stokes shift, good stability and the like.

The invention discloses a yellow reduction dyeing agent, a dyeing solution and a preparation method and application thereof, and relates to the technical field of dyeing and finishing. According to the yellow reduction dyeing agent provided by the invention, the 5-hydroxy-3-aminopyridine-2, 6-(1H, 3H)-diketone is adopted as a reduction dye, and the sodium sulfite is independently used as a reducing agent for reduction dyeing, so that the obtained dye leuco body is proper in dyeing capacity, and a dyed fabric can show excellent light brittle damage resistance. The fabric dyed by the dyeing agent has similar breaking strength before and after dyeing and even is slightly improved after dyeing and illumination, meanwhile, the color depth K / S of the fabric dyed by the dyeing agent reaches 3.2 or above, the dry and wet rubbing color fastness can reach level 4 or above, and the color fastness to illumination reaches level 6 or above.

The invention belongs to the field of high polymer materials, and particularly discloses a novel method for synthesizing a high-viscosity salt-tolerant sodium polyacrylate thickener and preparation of a three-in-one thickener, and the novel method comprises the following steps: weighing a certain amount of acrylic acid without a polymerization inhibitor, adding a certain amount of pure water, neutralizing with a NaOH solution with a certain concentration, slowly dropwise adding into the NaOH solution, and reacting at the temperature of 50-60 DEG C for 2-3 hours to obtain the high-viscosity salt-tolerant sodium polyacrylate thickener. The preparation method comprises the following steps: adding sodium acrylate into a sodium acrylate solution, keeping the temperature to be less than 40 DEG C, preparing a sodium acrylate neutralization solution with the neutralization degree of 80% and the solid content of 20-45%, and polymerizing under ultraviolet irradiation by using sodium sulfite (Na2SO3) and utilizing a UV photocuring technology, thereby obtaining the high-viscosity salt-tolerant sodium polyacrylate thickener. On the basis, the three-in-one thickening agent with high viscosity, salt resistance and moisturizing functions is further prepared, and wider application of the sodium polyacrylate thickening agent is developed.

The invention relates to the technical field of preparation of an electrolyte for a vanadium redox flow battery, in particular to a reduction method of an alkaline vanadium-containing solution during short-process preparation of a vanadium electrolyte. The reduction method comprises the following steps: (1) adding a reducing agent sodium sulfite into an alkaline vanadium-containing solution and dissolving; and (2) acid is added into the solution obtained after dissolving in the step (1), the pH is adjusted, a reduction reaction is conducted, and vanadium is reduced to be tetravalent. The method provided by the invention effectively solves the problem of vanadium loss caused by precipitation generated in the sequential operation process of acidification and reduction of the alkaline vanadium-containing solution in the prior art, and meanwhile, the method provided by the invention is easy for engineering implementation.

The invention relates to a preparation method of a sodium gold sulfite solution. The preparation method comprises the following steps: S1, preparing chloroauric acid; s2, slowly dropwise adding the prepared chloroauric acid into a sodium sulfite solution, when the solution becomes light yellow, temporarily stopping dropwise adding the chloroauric acid, adjusting the pH value, and after the solution becomes colorless and transparent, continuously dropwise adding the chloroauric acid until the chloroauric acid is completely dropwise added to obtain a crude sodium gold sulfite solution; s3, ethanol is added into the crude sodium gold sulfite solution, a crystal product is precipitated through an anti-solvent, after solid-liquid separation, the crystal product is washed multiple times with ethanol, and a sodium gold sulfite crystal is obtained; and S4, dissolving the obtained sodium gold sulfite crystals in a sodium sulfite solution to prepare a sodium gold sulfite solution, thereby obtaining the sodium gold sulfite solution.

The present invention provides a preparation method of high-viscosity hydroxypropyl methylcellulose. A preparation method of high-viscosity hydroxypropyl methylcellulose comprises the following steps: grinding and alkalizing refined cotton cellulose; adding methyl chloride and propylene oxide for etherification reaction; successively adding a crosslinking agent and an aqueous fulvic acid solution for reaction; adding potassium naphthylacetate, sodium sulfite and sodium molybdate and then drying. In the present invention, during the etherification reaction of alkalized cellulose, a crosslinking agent prepared by mixing sodium tetraborate and sodium tripolyphosphate is added for crosslinking reaction, which can reduce the content of water-soluble groups of the prepared hydroxypropyl methylcellulose, achieving the effect of increasing the viscosity of hydroxypropyl methylcellulose. Coating the crop surface with the high-viscosity hydroxypropyl methylcellulose not only has a better surface glazing effect, but also can increase its sugar content.

The invention provides high-performance silver powder suitable for TOPCon battery fine grid silver paste, a preparation method of the high-performance silver powder and the silver paste, and belongs to the technical field of photovoltaic materials. The preparation method comprises the steps that a silver salt solution and a composite reducing agent are mixed, a first-stage hydrothermal reaction is carried out at the first temperature, a second-stage hydrothermal reaction is carried out at the second temperature, and silver powder is obtained after centrifugation, washing and drying; wherein the composite reducing agent is selected from a mixture of two of potassium tartrate, sodium sulfite and ferrous sulfate. According to the method, gradual growth and crystallinity improvement of silver crystal nucleuses are achieved through two-stage heating, particle aggregation or uneven morphology caused by rapid reduction is avoided, in addition, the adopted composite reducing agent combination is remarkably superior to a single reducing agent (such as ascorbic acid), and the morphology and particle size distribution of the silver powder can be more accurately regulated and controlled.

The invention belongs to the technical field of biological medicine, and particularly relates to sterile cefepime hydrochloride and a direct preparation method thereof. The method comprises the following steps: firstly, carrying out condensation reaction on a 7-MPCA solution and an AE active ester solution through a solid base catalyst column at the same time; then, carrying out extraction phase separation, two times of pH regulation crystallization, activated carbon decoloration and sodium sulfite reduction on the condensation liquid to obtain a cefepime hydrochloride liquid to be crystallized; and then taking a part of the cefepime hydrochloride to-be-crystallized liquid to prepare a seed crystal mixed liquid, and adding the rest of the cefepime hydrochloride to-be-crystallized liquid and the crystallization solvent into the seed crystal mixed liquid at a specific speed to obtain the sterile cefepime hydrochloride. According to the method disclosed by the invention, the continuous production of the sterile cefepime hydrochloride is realized, the preparation period of the sterile cefepime hydrochloride is greatly shortened, side reactions and product degradation are reduced, the quality and yield of the obtained cefepime hydrochloride product are relatively high and stable, and industrial production is facilitated.

A pharmaceutical composition comprising sitagliptin or a pharmaceutically acceptable salt thereof, wherein the composition comprises less than 5 ppm of 7-Nitroso-3-(trifluoromethyl)- 5,6,7,8-tetrahydr

The invention relates to the technical field of industrial wastewater pollution treatment, in particular to a graded recovery method for copper and arsenic in wastewater. According to the method, the copper ions and the trivalent arsenic ions in the wastewater are respectively recovered by adopting sodium hydrosulfite under the condition of different pH values, so that the elementary substance copper and the elementary substance arsenic are obtained. According to the method, efficient graded recovery of copper and arsenic can be realized without introducing excessive substances; the treated wastewater can also reach the discharge standard, so that the effective treatment of the wastewater is realized; the method is simple to operate, high in efficiency, low in cost and wide in applicability.

According to the compound quaternary ammonium salt disinfectant for the sterile environment and the preparation method thereof, the benzalkonium chloride, the polyhexamethylene biguanide hydrochloride and the plant polysaccharide are compounded to form the positively charged plant polysaccharide compound disinfectant under the action of the sodium sulfite or the potassium sulfite by utilizing a compound synergistic principle, so that the compound quaternary ammonium salt disinfectant for the sterile environment is obtained. Positive charges are promoted to penetrate through cell walls of bacterial biofilms, so that an excellent bactericidal effect is achieved; the sodium hyaluronate, the enhancer and the glycerol are cooperatively used, so that sodium ions are combined with dehydrogenation groups in polysaccharide and hydroxyl groups, carboxyl groups and the like of other components to form a relatively stable internal net-shaped structure, and the situation that quaternary ammonium salt reacts with metal ions in the environment to reduce the disinfection effect is effectively avoided; meanwhile, the sodium hyaluronate and the glycerol are used for enhancing the compatibility of all the components, and the moisturizing effect of the components is fully utilized, so that the hand sanitizer is not only suitable for disinfection of object surfaces and space environments in a sterile environment, but also can be used for disinfection of hands of a human body.

The invention discloses modified humic acid as well as a preparation method and application thereof, and relates to the technical field of humic acid modification. The preparation method comprises the following steps: activating mineral source humic acid, and adding a manganese-based activator to obtain activated humic acid; adding activated humic acid, a grafting agent and a silane monomer into a cross-linking system, stirring, standing, and then heating for reaction; after the reaction is finished, adjusting the pH value to be alkaline, keeping heating and stirring, and then drying to obtain modified humic acid; wherein the grafting agent comprises the following raw materials: sodium sulfite and acetylacetone. The modified humic acid still has high water solubility in hard water, and flocculent precipitate formed by the humic acid and metal ions can be avoided.

The invention discloses an iron-based layered silicate material for efficiently removing variable-valence heavy metals and water treatment application of the iron-based layered silicate material, and belongs to the technical field of water treatment.The preparation method of iron-containing layered silicate minerals comprises the following steps that ferrous sulfate heptahydrate is dissolved in water, sodium dithionite and sodium orthosilicate are sequentially added, stirring is conducted, and a mixture is obtained; stirring, homogenizing and aging for two hours; the hydrothermal reaction kettle is used for reacting in a high-temperature and high-pressure environment; according to the iron-containing layered silicate mineral material, a unique layered structure similar to natural iron-containing layered silicate minerals and high adsorption performance are reserved, variable-valence heavy metal arsenic in a wastewater solution is synergistically and efficiently removed by means of the oxidation-reduction activity of the iron-containing layered silicate mineral material and induction of generation of Fenton-like reaction, and the iron-containing layered silicate mineral material is obtained. The method disclosed by the invention shows high treatment efficiency, environmental friendliness and remarkable economic benefits, and is expected to exert remarkable environmental benefits in the field of water treatment.

The invention discloses a method for removing thiocyanate radicals in cyanide-containing wastewater, and belongs to the technical field of metal refining. The method comprises the following steps: adding concentrated sulfuric acid to adjust the pH value of cyanogen-containing wastewater to 2-3, carrying out a stirring reaction, filtering, adding sodium hydrosulfite into a filtrate, simultaneously adding concentrated sulfuric acid to maintain the pH value to 3-5, carrying out a stirring reaction, firstly introducing a sodium sulfite acidic solution into overflowed H2S and HCN gas to absorb H2S gas, and then introducing a sodium hydroxide strong alkaline solution to absorb HCN gas. Aiming at cyanide-containing wastewater subjected to acidification treatment, firstly, a strong reducing agent sodium hydrosulfite is added to reduce SCN <-> into H2S and HCN with recycling value, then H2S is absorbed, elemental sulfur is recovered, finally HCN is absorbed, CN <-> is recovered, and the method is used for cyaniding gold extraction of a gold leaching system. The absorption and separation of H2S and HCN gas are realized, the recovery of elemental sulfur and CN <-> is further realized, and other ions are not introduced into a water supply system.

The present invention relates to the technical field of cosmetics, and in particular to a hair dye composition for preventing hair breakage, hypoallergenic and repairing, and a preparation method and application thereof. The composition is composed of agent A and agent B in a mass ratio of 1:0.8-1.5. The raw materials of agent A are hydrogen peroxide, glycerol, thickener, cetearyl alcohol polyether, sodium stannate, hydroxyethylidene diphosphoric acid and water. The raw materials of agent B are: p-phenylenediamine, sodium sulfite, triethanolamine, urea, Polygonum multiflorum extract, Acorus calamus extract, Nepeta tenuifolia extract, chelating agent, ascorbate, preservative, keratin, trehalose, 4-amino-2-hydroxytoluene, polyquaternium salt, squalane, arbutin, allantoin, bisabolol, emulsifier, polyglutamic acid, octadecyl alcohol, wheat germ oil and water. The hair dye of the present invention has a good hair dyeing effect, and has hypoallergenicity, and also has a good effect of preventing hair breakage and repairing hair quality.

The invention relates to the technical field of photocatalysis, and provides a preparation method of a copper-cuprous oxide-copper bismuthate ternary complex, which comprises the following steps: adding sodium bismuthate dihydrate, copper sulfate and sodium sulfite into a hydrothermal reaction kettle containing distilled water to obtain a solid-liquid mixture; and the solid-liquid mixture generates the copper-cuprous oxide-copper bismuthate ternary compound under a hydrothermal condition through a synergistic effect of a heterogeneous interface in-situ oxidation-reduction reaction of sodium bismuthate and a sodium sulfite solution and a homogeneous oxidation-reduction reaction of a copper sulfate solution and the sodium sulfite solution. The preparation method has the advantages that the elemental copper-cuprous oxide-copper bismuthate ternary compound is prepared by a one-pot method through cooperation of the out-phase interface in-situ oxidation-reduction reaction and the homogeneous oxidation-reduction reaction, and the preparation method is simple in preparation step, convenient to operate and easy to quantitatively control.

The invention discloses a method for producing a green packaging material by using field planting tobacco waste, which comprises the following steps: by taking tobacco stems as raw materials, extracting to obtain high-purity nicotine, extracting active chemical components to obtain tobacco stem residues, primarily treating the residual tobacco stems by an extruding and tearing machine to cut off and separate the tobacco stems into shreds, and drying the shreds to obtain the green packaging material. The cut tobacco stems enter a closed reaction bin, steam heating is adopted, ammonium sulfite or sodium sulfite and sodium hydroxide are added, EDTA and the ammonium sulfite or sodium sulfite and sodium hydroxide solution can dissolve fibrous adhesive lignin in the tobacco stems, and the tobacco stems can be used for producing green packaging materials after further mechanical treatment. Tobacco stem waste residues obtained after nicotine and pectic substance extraction are used as plant fiber paper pulp for producing the green packaging material, holocellulose in the tobacco stem residues is fully recycled and subjected to high-value resource utilization, the waste recycling value is increased, and the problem of waste environmental pollution is solved.

A method of forming a lubricant coating, a method of coating a bearing surface with a lubricant coating, and a vehicle including a bearing including a lubricant coating. A substrate, such as a bearing, including a surface and an electrode are immersed in an electrolyte bath. The electrolyte bath includes an aqueous electrolyte solution including sodium metabisulfite (Na2S2O5), sodium molybdate (Na2MoO4·2H2O), a pH modifier, an anionic surfactant, and water. A first pulsed direct current is applied through the aqueous electrolyte solution using a direct current power supply and a molybdenum disulfide (MoS2) layer is formed on the surface of the substrate.

The invention discloses a filtering aid method for improving the filtering efficiency of monazite superior soluble slag, which comprises the following steps: step 1, carrying out solid-liquid separation on mixed slurry after alkali cake superior soluble callback to obtain filter residue 1 and filtrate 1; step 2, adding water into the filter residue 1, mixing and stirring according to a liquid-solid ratio of (1-2.5): 1 to react for 0.5-4 hours, and carrying out solid-liquid separation on ore pulp after the reaction to obtain a filter residue 2 and a filtrate 2; 3, if the ore pulp filtering speed in the step 2 is lower than 20 L / (m < 2 > * h) or the water content of obtained filter residues 2 is larger than 60%, the step 2 is repeated for the filter residues 2, the composite reducing agent with the preset mass is added, and stirring reaction is conducted for 2 hours till the water content of the filter residues is smaller than or equal to 60% or the ore pulp filtering speed in the plate and frame filtering process is larger than or equal to 20 L / (m < 2 > * h); in the step 3, the mass ratio of the added composite reducing agent to the original dry slag is (5-50) kg: 1t, and the composite reducing agent comprises sodium sulfite and thiourea in the mass ratio of (1-2): 1. The invention aims at shortening and improving the slag filtering performance so as to shorten the filtering time.

The invention belongs to the technical field of synthetic ester, and particularly relates to a preparation method of fatty acid pentaerythritol ester base oil, which comprises the following steps: carrying out esterification reaction on pentaerythritol and fatty acid in the presence of a catalyst and a color retention agent, and carrying out post-treatment to obtain the fatty acid pentaerythritol ester base oil, the catalyst comprises at least one of stannous octoate, stannous oxalate, stannous oxide, tetrabutyl titanate, isopropyl titanate and sodium hydrogen sulfate; the color retention agent comprises at least one of sodium hypophosphite, hypophosphorous acid, activated carbon and sodium sulfite. The color retention agent sodium hypophosphite is matched with the specific catalyst such as stannous oxalate, so that the petroleum color number of the produced fatty acid pentaerythritol ester base oil is smaller, and meanwhile, the esterification reaction time is shorter.

The invention provides a method for treating discharge wastewater of a waste lithium battery, which comprises the following steps: S1, pulping a lithium cobalt oxide material by using discharge wastewater, and adding a first oxidant for reaction to obtain primary oxidized slurry; s2, mixing the primary oxidized slurry with high-grade matte nickel, and adding a second oxidizing agent for reaction to obtain secondary oxidized slurry; s3, the secondary oxidation slurry and an iron circulation activating agent are mixed for acid leaching, a liquid phase is taken after solid-liquid separation, and metal leaching liquid containing nickel and cobalt is obtained; wherein the first oxidizing agent comprises persulfate, the second oxidizing agent is selected from hydrogen peroxide, and the iron circulation activating agent is at least one of sodium hydrosulfite or sodium pyrosulfite. According to the method, short-range efficient selective recovery of valuable metals is realized through cooperation of lithium cobalt oxide and high nickel matte, the influence on the environment is greatly reduced, and the economic cost of the process is reduced.

The invention discloses a preparation process of a cefpodoxime mother nucleus 7-AMCA, and relates to the technical field of 7-AMCA. According to the technical scheme, the method comprises the following steps: adding dimethyl carbonate and a boron trifluoride-dimethyl carbonate complex into a reaction bottle A, and dropwise adding an alkylation reagent; adding D-7ACA, and reacting at room temperature; adding purified water, sodium pyrosulfite and edetate disodium into the reaction bottle B; transferring the feed liquid in the reaction bottle B into a reaction bottle A, adding an organic solvent into the mixed liquid at room temperature, and extracting and separating the liquid to obtain a water phase; dropwise adding an alkaline solution into the water phase, adjusting the pH value to 2.8-3, and cooling to grow crystals; dropwise adding an alkaline solution, adjusting the pH value to 4.5-5.2, and cooling to grow crystals; and filtering out mother liquor, washing to be colorless, leaching by using an organic solvent, pumping, and drying in vacuum to obtain the cefpodoxime mother nucleus 7-AMCA. According to the invention, D-7ACA is taken as a starting raw material, the process flow is improved, the preparation process of 7-AMCA is optimized, and the purposes of improving the product quality and increasing the yield are achieved.

The invention discloses a composition for improving the stability of 4-butylresorcinol, application of the composition and an external skin preparation, and belongs to the technical field of cosmetics. The composition is prepared from the following components in parts by weight: 0.01 to 5 parts of 4-butyl resorcinol, 0.005 to 0.195 part of sodium pyrosulfite, 0.005 to 0.195 part of sodium hydrogen sulfite, 0.005 to 3 parts of ergothioneine and 0.003 to 0.2 part of troxerutin. The composition can maintain the 4-butylresorcinol not to change color for a long time, and especially can maintain the original color under the conditions of ultraviolet irradiation and light irradiation for 3 months. The composition is used for preparing the external skin preparation, so that the external skin preparation also has better color stability, and the product quality of the external skin preparation is improved.

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 invention relates to preparation of a cefazolin compound, in particular to a preparation method of a cefazolin acid three-position intermediate TDA. The preparation method comprises the following steps: carrying out condensation reaction on 7-ACA and MMTD serving as raw materials, dimethyl carbonate serving as a solvent and a boron trifluoride dimethyl carbonate complex and glacial acetic acid serving as catalysts to obtain condensation reaction liquid; adding EDTA (Ethylene Diamine Tetraacetic Acid) and sodium pyrosulfite into water, carrying out stirring reaction, transferring the condensation reaction liquid into water, and continuously carrying out heat-preservation stirring, so as to obtain a hydrolysis reaction liquid; and adding a sodium carbonate solution into the hydrolysis reaction solution while stirring, adjusting the pH value, growing crystals, and then performing suction filtration, washing and drying to obtain a finished product. A boron trifluoride dimethyl carbonate complex-glacial acetic acid catalysis method is adopted, the product quality and yield are guaranteed in industrial production, meanwhile, the reagent usage amount and the waste liquid generation amount are reduced, the production cost and the environment pressure are reduced, normal reaction is maintained at normal pressure, and the reaction is prevented from being too severe.

The utility model discloses an ethylene oxide absorption dealdehyding system in the field of dealdehyding, which comprises an ethylene oxide absorption tower, and the bottom of the ethylene oxide absorption tower is connected with a desalting delivery pump, a 20% sodium hydroxide solution metering pump and a dealdehyding buffer tank through pipelines. The dealdehyding buffer tank is further connected with a sodium hydrogen sulfite solution metering pump and a quenching stripping tower through pipelines, the top of the dealdehyding buffer tank is provided with a first EO re-absorption tower connecting pipe, the desalting delivery pump is connected with a cooler through a pipeline, the cooler is connected with an ethylene oxide absorption tower through a pipeline, and the ethylene oxide absorption tower is connected with a second EO re-absorption tower through a pipeline. And desalted water equipment is mounted on a pipeline between the cooler and the ethylene oxide absorption tower through a three-way valve. The dealdehyding resin is adopted for dealdehyding of the lean absorption water part, sodium sulfite is added to the quenching section of the EO absorption tower for dealdehyding, and then flash evaporation is performed, so that the content of aldehyde in the lean absorption water can be effectively reduced, and the content of aldehyde in an EO absorption system can be effectively reduced.