780 results about "Sulfite salt" patented technology

The invention discloses a method for preparing battery-grade iron phosphate and lithium carbonate from a waste lithium iron phosphate battery, and belongs to the technical field of lithium batteries, the method comprises the following steps: slurrying a waste lithium iron phosphate positive electrode material, adding concentrated sulfuric acid for leaching, adding sodium sulfite, controlling reaction potential, and carrying out filter pressing after reaction to obtain a leachate; iron is added into the leachate to remove copper, and copper-removed liquid and copper slag are obtained after filter pressing; adding sodium dihydrogen phosphate into the copper-removed liquid to remove aluminum, and carrying out filter pressing to obtain aluminum slag and impurity-removed liquid; adjusting the pH value of the impurity-removed solution, adding hydrogen peroxide, reacting to obtain an iron phosphate dehydrate precipitate and an iron phosphate mother solution, and treating the iron phosphate dehydrate to obtain battery-grade anhydrous iron phosphate; adjusting the pH value of the iron phosphate mother liquor, carrying out filter pressing to obtain impurity-removed slag and a lithium sulfate solution, adding sodium carbonate into the lithium sulfate solution, carrying out heating reaction, filtering slurry to obtain a lithium carbonate wet material, and treating to obtain battery-grade lithium carbonate. According to the method, the problem of recycling the waste lithium iron phosphate battery material iron phosphate is solved, and comprehensive recycling of the iron phosphate and the lithium material is realized.

The invention discloses a method for degrading dioxin in fly ash and stabilizing heavy metals, which comprises the following steps: carrying out water washing treatment on the fly ash, and carrying out solid-liquid separation to obtain water washing slag; mixing the washed slag with water, adding zero-valent iron and sulfite, carrying out hydrothermal treatment, and carrying out solid-liquid separation to obtain hydrothermal slag and hydrothermal liquid; according to the method for degradation of dioxin in fly ash and stabilization of heavy metal in cooperation with degradation of dioxin in fly ash, under the combined action of zero-valent iron, chlorite and a hydrothermal environment, efficient degradation of dioxin in fly ash can be rapidly achieved under the lower reaction condition, stabilization of heavy metal in fly ash can be synchronously achieved, and the method is suitable for industrial production. The method has the advantages of being low in cost, mild in reaction condition, high in treatment efficiency, good in treatment effect, environmentally friendly and the like, can effectively solve the problems existing in the prior art, provides powerful support for harmless treatment and resource utilization of the waste incineration fly ash, and has wide engineering application prospects.

Methods, systems and devices for PFAS destruction including adding a sulfite salt to an aqueous solution containing PFAS and then irradiating the aqueous solution with light at 222 nm. The method may include adding a base to the aqueous solution in an amount sufficient to raise a pH of the aqueous solution including PFAS to about 10 or more. It may also include adding a halide salt such as a bromide salt or an iodine salt, and further adding a carbonate. Greater than 90%, or greater than 99%, of the PFAS in the solution may be destroyed by irradiating the aqueous solution in this way.

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 relates to the technical field of membrane separation, in particular to a high-flux high-salt rejection rate reverse osmosis membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: sequentially contacting a porous base membrane with a water phase solution and an oil phase solution to generate an interfacial polymerization reaction to form a primary reverse osmosis membrane, and sequentially contacting the primary reverse osmosis membrane with a nitrous acid or salt solution thereof and a hydrosulfite solution to obtain the reverse osmosis membrane with high flux and high salt rejection rate, the water-phase solution contains a water-phase cosolvent, and the oil-phase solution contains an oil-phase cosolvent. According to the preparation method, cosolvents are creatively added into a water-phase solution and an oil-phase solution in an interfacial polymerization reaction process to regulate and control the microstructure of a polyamide layer, and a diazo reaction promotes further crosslinking of residual aniline groups, so that in-situ densification regulation and control of a polyamide network structure are realized; the trade-off effect of the water flux and the salt rejection rate of the traditional reverse osmosis membrane is successfully broken through.

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 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 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 relates to an indole hair dye based on air oxidation. The hair dye provided by the invention is characterized in that a chemical strong oxidant is not added, and oxygen in air can be catalyzed by using an air oxidation catalyst and a metal ion catalyst to naturally finish the oxidative polymerization process of indole substances (natural bionic melanin precursor substances). The used reducing agent is a combination of cysteine and a derivative thereof and sodium sulfite and a derivative thereof, the oxidative polymerization speed of indole substances can be controlled, and finally generated melanin macromolecules are embedded in hair cortex, so that white hair is obviously blackened. The natural oxidation process does not need hydrogen peroxide, destructive strong base or organic base, so that the use of harmful chemical reagents is reduced, the formula is simplified, the hair dyeing process is milder, potential hazards to hair and scalp are reduced, and the natural oxidation hair dye is safe, environmentally friendly and sustainable.

The invention belongs to the technical field of chemical medicine preparations, and particularly relates to a promethazine hydrochloride injection and a preparation method, the promethazine hydrochloride injection comprises the following components by weight concentration: 20-30 mg / mL of promethazine hydrochloride, 0.4-0.6 mg / mL of anhydrous sodium sulfite, 0.6-0.8 mg / mL of sodium pyrosulfite and 0.03-0.07 mg / mL of thioglycerol; the stability of the injection can be improved.

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.

The present invention provides a ship exhaust gas desulfurization device and a desulfurization method, which include a sulfur-containing ship exhaust gas pretreatment system, a seawater pretreatment system, a membrane contactor, and a seawater post-treatment system; the outlet end of the sulfur-containing ship exhaust gas pretreatment system is connected to the shell-side inlet end of the membrane contactor for sending the dust- and oil-removed exhaust gas into the shell side of the membrane contactor; the outlet end of the seawater pretreatment system is connected to the tube-side inlet end of the membrane contactor for sending the pretreated seawater into the tube side of the membrane contactor; the membrane contactor is a membrane contactor filled with polytetrafluoroethylene hollow fiber hydrophobic microporous membranes; the inlet end of the seawater post-treatment system is connected to the tube-side outlet end of the membrane contactor for post-treating the seawater after absorbing sulfur dioxide and oxidizing sulfite into sulfate. The ship exhaust gas desulfurization device described in the present invention has a high integration degree, a compact volume, and a high desulfurization efficiency, can achieve efficient desulfurization of ship exhaust gas, and has good application prospects.

A sodium ion battery electrolyte, a sodium ion battery and an electrical device. The sodium ion battery electrolyte comprises a sodium salt and a sulfonate compound, and the sulfonate compound comprises one or more of compounds represented by formula (I), formula (II) and formula (III), wherein R1, R5, R6, R9 and R10 are each selected from C1-C3 alkylene groups, and R2, R3, R4, R7, R8 and R11 are each selected from C1-C3 alkyl groups or C1-C3 fluoroalkyl groups. The sulfonate compound contains both a sulfonate group and a carbonate group in the molecules, and thus can be used as a film-forming additive to promote generation of a uniform and stable SEI film rich in sulfates and sulfites on the surface of an electrode, thereby improving the cycle performance and the rate capability of the sodium ion battery.

The embodiment of the present invention discloses a sodium ion battery electrolyte, a sodium ion battery and an electrical device, wherein the sodium ion battery electrolyte comprises a sodium salt and a sulfonate compound, wherein the sulfonate compound comprises one or more compounds represented by formula (I), formula (II) and formula (III), wherein R1, R5, R6, R9 and R 10 independently selected from C1-C3 alkylene, R2, R3, R4, R7, R8 and R 11 Independently selected from C1-C3 alkyl or C1-C3 fluoroalkyl. The sulfonate compound contains both sulfonate and carbonate groups in its molecule, acting as a film-forming additive to promote the formation of a uniform and stable SEI film rich in sulfate and sulfite on the electrode surface, thereby improving the cycle performance and rate performance of sodium-ion batteries.

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 relates to a method for purifying rhodium from a complex-component rhodium leaching solution, and belongs to the technical field of precious metal refining and purification. The method comprises the following steps: adding a reducing agent into rhodium leaching liquid for reduction to obtain RhCl3 primary purification liquid and insoluble slag; simultaneously adding sulfite and ammonium salt into the RhCl3 primary purification liquid to precipitate rhodium in the form of (NH4) 3Rh (SO3) 3; hydrochloric acid is added into the (NH4) 3Rh (SO3) 3 precipitation residues, heating and boiling are conducted, the (NH4) 3Rh (SO3) 3 precipitation residues are dissolved in the form of RhCl3 and enter a solution, SO3 < 2-> in the solution is removed in the form of SO2, and a secondary purification solution of RhCl3 is obtained; adding a strong oxidant into the secondary purified solution of RhCl3, and carrying out oxidation reaction to obtain RhCl4; adding alkali into the RhCl4 solution to adjust the pH value, and boiling to obtain RhO2. 2H2O precipitation slag; and the RhO2. 2H2O precipitation slag is sequentially subjected to pure water slurrying, hydrazine hydrate reduction, calcination and hydrogen reduction to obtain the high-purity metal rhodium. According to the method disclosed by the invention, the high-purity metal rhodium of which the purity is greater than 99.95% can be prepared, and the direct recovery rate of rhodium is greater than 97%.

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 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.

The invention discloses a red mud acid leaching waste residue modified curing agent and a preparation method thereof, and belongs to the field of environmental protection engineering. The bauxite acid leaching waste residue modified curing agent is prepared from the following raw materials in parts by mass: 30 to 40 parts of magnesium sulfite, 30 to 35 parts of fly ash, 25 to 30 parts of alkaline residue, 1 to 5 parts of sodium sulfite, 1 to 5 parts of white carbon black and 0.5 part of polyaluminum ferric sulfate. Industrial solid waste and bauxite acid leaching waste residues are effectively utilized, and the curing agent has the advantages of being low in cost, simple in preparation method and high in resource utilization rate and is suitable for further application and popularization. According to the method, the pollution of the bauxite acid leaching waste residues can be effectively reduced, the long-term water stability of the bauxite acid leaching waste residue roadbed is improved, the requirement that the bauxite acid leaching waste residues are applied to road construction on a large scale is met, waste is turned into wealth, and non-renewable land resources are saved.

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.

Methods, systems and devices for PFAS destruction including adding a sulfite salt to an aqueous solution containing PFAS and then irradiating the aqueous solution with light at 222 nm. The method may include adding a base to the aqueous solution in an amount sufficient to raise a pH of the aqueous solution including PFAS to about 10 or more. It may also include adding a halide salt such as a bromide salt or an iodine salt, and further adding a carbonate. Greater than 90%, or greater than 99%, of the PFAS in the solution may be destroyed by irradiating the aqueous solution in this way.

The present invention relates to a method for removing organic pollutants in water by activating sulfite with Fe-N-C, belonging to the technical fields of new catalyst materials and environmental purification technologies. An iron salt and a carbon-nitrogen precursor are added to an organic solvent, and the iron salt and the carbon-nitrogen precursor form a complex. Then, the organic solvent is removed to obtain a dry powder. The dry powder is calcined under a protective atmosphere, and after carbonization, an Fe-N-C catalyst is obtained. The present invention solves the bottleneck problem of low efficiency in traditional heterogeneous sulfite activation technology due to few reactive sites and slow oxygen mass transfer by constructing carbon-based metal active sites with oxygen-rich properties. This catalytic oxidation method has high treatment efficiency and simple operation, has a wide pH application range, strong anti-ion interference ability, and high reusability, and has broad application prospects in the field of actual industrial wastewater treatment.

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.

Provided is a method for producing a water-absorbing resin composition, the method imparting high gel stability, suppressing an increase in the amount of water-absorbing resin particles that are dissolved by a sulfite-based compound, and suppressing yellowing that could occur under a high temperature and high humidity. This method for producing a water-absorbing resin composition comprises a step for spraying an aqueous solution of a sulfite-based compound on surface-crosslinked water-absorbing resin particles, and a step for spraying an aqueous solution of an organic antioxidant on the surface-crosslinked water-absorbing resin particles.

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.