321 results about "Acid dissolution" patented technology

The invention discloses a cross-linking agent for rubber and a preparation method thereof. The preparation method comprises the following steps: S11, dissolving 2, 4-dichlorobenzoic acid in tert-butyl alcohol, and dropwise adding concentrated sulfuric acid to obtain a mixed solution; s12, slowly dropwise adding a hydrogen peroxide solution into the mixed solution, and oxidizing to obtain a primary oxidized solution; s13, carrying out secondary oxidation on the primary oxidation solution obtained in the step S12 to obtain a secondary oxidation solution; and S14, purifying the secondary oxidation liquid obtained in the step S13 to obtain the cross-linking agent for rubber. The application of the cross-linking agent for the rubber in the rubber comprises the following steps: S21, banburying raw materials and the cross-linking agent for the rubber to prepare a rubber material; and S22, feeding the rubber material in the step S21 into a vulcanizing machine, and vulcanizing to obtain the rubber. The prepared cross-linking agent for the rubber is good in performance, the preparation method is simple, emission of three wastes is small, the atom utilization rate is high, and after the cross-linking agent is applied to the rubber, the prepared rubber is good in tensile strength, elongation at break and wear resistance index.

The invention discloses a method for preparing high-purity iron phosphate through low-cost aluminum removal of ferrophosphorus slag obtained after lithium extraction of waste lithium iron phosphate batteries. The method comprises the following steps that S1, the ferrophosphorus slag is subjected to size mixing, a complexing agent and a leaching agent are added, and leaching liquid 1 and leaching slag 1 are obtained after filtering and washing; s2, mixing the leachate 1 with a pH regulator 1, and filtering to obtain molten aluminum and purified ferrophosphorus slag; s3, the purified ferrophosphorus slag is subjected to acid pickling, filtering and washing, and then acid-pickled ferrophosphorus slag is obtained; s4, the leaching residues 1 are subjected to size mixing and stirring washing, and stirring washing residues are obtained; s5, slurry mixing is conducted on the stirring and washing residues, acid is added for dissolution, and leachate 2 and graphite residues are obtained after solid-liquid separation; s5, mixing the acid pickling ferrophosphorus slag with the leachate 2, and filtering to obtain regenerated ferrophosphorus liquid; and S6, a pH regulator 2 is added into the regenerated ferrophosphorus liquid, a regenerated iron phosphate product is obtained through synthesis, conversion and roasting, and efficient removal of aluminum impurities in the leachate is achieved under the conditions of short process and less acid through the processes of adding a complexing agent for acid leaching, precipitating, dissolving and the like.

The invention relates to the technical field of hydrometallurgy production, and particularly discloses a method for synergistically extracting gallium and scandium by coupling titanium white waste acid with vanadium extraction converter sludge, which comprises the following steps: mixing titanium white waste acid and vanadium extraction converter sludge in proportion, stirring and leaching to obtain a leaching solution; adding an extraction agent and a diluent into the leaching solution for extraction, and washing to obtain a gallium and scandium loaded organic phase; a first stripping agent is added into the loaded organic phase of gallium and scandium for stripping treatment, and a gallium stripping solution and a loaded organic phase of scandium are obtained; sequentially carrying out alkali precipitation, alkali dissolution and electrolytic treatment on the gallium reverse extraction solution to obtain crude gallium; a second stripping agent is added into the scandium-loaded organic phase for stripping treatment, and a scandium precipitation solution and an organic phase solution are obtained; and the scandium precipitation solution is filtered, washed and subjected to acid dissolution, and a scandium-containing solution is obtained. According to the method, the titanium white waste acid is effectively recycled, rare and precious metals in the vanadium extraction converter sludge are efficiently and synergistically extracted, and the method has a relatively good popularization prospect.

To provide a new method in which zinc is collected from a steelmaking dust.SOLUTION: Halogen is removed from a steelmaking dust including zinc and halogen by washing the dust using a cleaning solution. A zinc solution containing the zinc and iron is obtained by dissolving the washed steelmaking dust using an acid. An impurity element contained in the zinc solution is deposited on the surface of the zinc metal by adding the zinc metal to the zinc solution. The iron contained in the zinc solution is deposited as an iron deposit. By electrolyzing the zinc solution with an electrode inside, the zinc contained in the zinc solution is deposited on the surface of the electrode.SELECTED DRAWING: Figure 1

The invention relates to a method for extracting rare earth elements based on a biological separation method, and relates to the technical field of rare earth element separation and extraction. In order to solve the problems of high pollution and poor selectivity of a traditional chemical method and low adsorption capacity, insufficient stability and the like of a biotechnology, the rare earth ion adsorbent is prepared by screening microbial strains or biomolecules with high affinity, utilizing the specific adsorption or metabolic acid production dissolution effect of surface functional groups of the microbial strains or biomolecules on rare earth ions and combining biological material modification and a combined process. And efficient enrichment and selective separation of target elements in low-grade rare earth ore, multi-metal complex ore and rare earth-containing wastewater are realized. According to the technology, key parameter regulation and control are optimized through a process kinetic model, energy consumption and environmental pollution are reduced, meanwhile, the rare earth recovery purity and process stability are improved, and an innovative solution is provided for green and sustainable development of rare earth resources.

The invention discloses a nickel-iron alloy dissolving method which comprises the following steps: feeding a copper sulfate solution into a mixed feed liquid containing a first nickel-iron alloy and copper sulfate, carrying out primary replacement reaction to obtain copper-containing slag and a reaction liquid, maintaining c (Fe < 2 + >) / c (Cu < 2 + >) in the reaction liquid to be 50-90, and overflowing to obtain a nickel-iron-copper solution; wherein c (Fe < 2 + >) and c (Cu < 2 + >) are mass concentrations of Fe < 2 + > and Cu < 2 + > respectively, and the unit is g / L; and carrying out secondary replacement reaction on the nickel-iron-copper solution and a second nickel-iron alloy until the concentration of Cu < 2 + > in a liquid phase is lower than 5ppm, and carrying out solid-liquid separation to obtain a nickel-iron solution product and second copper-containing slag. According to the dissolving method of the ferro-nickel alloy, the recovery process of ferro-nickel in the ferro-nickel alloy can be simplified, the quality of the ferro-nickel solution is improved, the gas production phenomenon caused by acid dissolution is avoided, and the safety is higher.

The invention provides a gold ore phase analysis method, and belongs to the field of mineral analys.The gold ore phase analysis method comprises the steps that a gold ore sample is prepared into ore pulp, the pH value is adjusted to 10-11, ultrasonic cavitation treatment is conducted after polyethylene glycol is added, and limonite turbid liquid and sedimentation bottom mud are obtained through separation; the turbid liquid is subjected to flocculation precipitation, drying, roasting, acid dissolution and impurity removal, and the limonite gold-loaded grade is obtained through the mass difference before and after dissolution and gold concentration determination; separating metal sulfide ore heavy minerals and gangue minerals from the settled bottom mud through artificial heavy elutriation, performing acid dissolution and impurity removal on the metal sulfide heavy minerals, and calculating the gold loading grade of the metal sulfide heavy minerals through mass difference and gold concentration determination; after gangue minerals are subjected to oxidizing roasting, the gold content is measured after concentrated acid dissolution; and calculating the distribution rate of gold based on the result. The gold loading grade and distribution of the limonite phase, the metal sulfide ore phase and the gangue mineral phase are measured in a split-phase mode, the method is highly matched with the gold ore development process, operation is easy and convenient, the result is reliable, and beneficiation and metallurgy technological process formulation and technical index pre-judgment can be effectively served.

The invention belongs to the field of hydrometallurgy, and particularly provides an ionic type rare earth ore leachate composite precipitation treatment method which comprises the steps that magnesium oxide is adopted for one-step precipitation of rare earth leachate, and rare earth and impurities are co-precipitated to form an enriched product; carrying out acid dissolution treatment on the rare earth enrichment, carrying out solid-liquid separation to obtain filter residues, using the filter residues for mining and covering soil, neutralizing and removing impurities from the filtrate by adopting magnesium oxide or the rare earth enrichment, adjusting the pH value of one part of the filtrate after impurity removal by adopting magnesium oxide, and sufficiently aging to serve as a precipitator for later use; the pH of the other part is adjusted by the precipitator, and then sodium bicarbonate or sodium hydroxide composite precipitation is adopted to recover the rare earth. The treatment method provided by the invention effectively solves the problems of high content of silicon, aluminum, sulfur and magnesium impurities and low total amount of rare earth in a rare earth enriched product when rare earth is recovered by a single precipitator, and poor crystallization, slow sedimentation, difficult filtration, high rare earth loss and the like of a rare earth carbonate product during traditional sodium bicarbonate precipitation, and realizes mining and smelting cyclic utilization of magnesium resources; and the overall development and utilization efficiency of the ionic rare earth ore is improved.

The invention discloses a precipitation separation and purification method for metals in gallium-containing wastes. The method comprises the following steps: firstly, dissolving the waste containing gallium, indium and tin with acid, then adding alkali liquor, and adjusting the pH value of the solution twice to respectively obtain a precipitate containing tin, a precipitate containing gallium and indium and a solution containing zinc; after the sediment stands for a period of time, slurry is added for filtering, obtained filter residues return to a slurry barrel, obtained tin-containing filtrate is used for preparing a high-purity tin product, obtained gallium and indium-containing filtrate is extracted with an extracting agent mainly comprising tributyl phosphate or trioctyl / decyl alkyl tertiary amine and the like, high-purity gallium is obtained in an organic phase, and high-purity indium is obtained in raffinate. According to the method, separation and purification of gallium, indium, tin and zinc are achieved through two-time precipitation and two-time filtration. Precipitation operation is simple, a precipitant is cheap and easy to obtain, and the separation method is low in cost.

The invention discloses a method for accurately measuring trace calcium in high-purity magnesium metal by combining membrane desolvation and triple quadrupole mass spectrometry, which comprises the following steps: (1) sequentially adding water to wet a high-purity magnesium sample and adding acid to dissolve the sample to obtain a digestion solution, and adding an internal standard solution into the digestion solution; (2) preparing calcium element solutions with multiple concentration gradients, adding the internal standard solution, fixing the volume, and shaking uniformly; (3) sequentially carrying out atomization treatment and membrane desolvation treatment on the prepared solution to respectively obtain dry aerosol of the to-be-detected solution and the standard solution; and (4) carrying out scanning determination on the dry aerosol of the solution to be detected and the standard solution in the step (3) by using a triple quadrupole mass spectrometer, and calculating to obtain the calcium content in the high-purity magnesium sample. According to the method, the 24Mg16O polyatomic interference brought by the matrix element and the mass spectrum interference of the working gas Ar on the to-be-detected element 40Ca are removed through membrane desolvation and triple quadrupole mass spectrometry, so that the trace calcium element in the high-purity magnesium sample can be accurately determined, and the lower determination limit can reach ppb level.

The invention relates to an acid-soluble water-swelling gel plugging agent as well as a preparation method and application thereof. The acid-soluble and water-swelling gel plugging agent disclosed by the invention is prepared by polymerizing the following raw materials in parts by weight: 15 to 25 parts of carboxymethyl cellulose, 20 to 40 parts of N, N-dimethylacrylamide, 15 to 30 parts of dimethyl diallyl ammonium chloride and 10 to 35 parts of sodium p-styrenesulfonate. The plugging agent disclosed by the invention can resist high temperature and high pressure, also has high water absorption and salt resistance, is high in acid solubility, fully ensures smooth proceeding of plugging work, avoids damage to a stratum, and is beneficial to proceeding of plugging removal work in the later period. The invention further provides a preparation method and application of the acid-soluble water-absorbing expansible gel plugging agent, the preparation process is simple, the requirement for professional knowledge of operators is low, no special requirement for use equipment exists, the production stability is good, all the raw materials are commercially available, the source is wide, the price is low, and large-scale industrial production is easy to achieve.

The invention discloses a steel cylinder cleaning method. The method comprises the steps that ethyl alcohol is injected into a steel cylinder; rolling the steel cylinder filled with the ethanol for multiple times to rinse the inner wall of the steel cylinder, and then emptying the ethanol in the steel cylinder; injecting ultrapure water into the steel cylinder cleaned by the ethanol; rolling the steel cylinder filled with the ultrapure water for multiple times, rinsing the inner wall of the steel cylinder, and then emptying the ultrapure water in the steel cylinder; nitric acid is injected into the steel cylinder cleaned by the ultrapure water, metal ions in the steel cylinder are dissolved, and then the nitric acid in the steel cylinder is emptied; injecting ultrapure water into the steel cylinder to rinse the steel cylinder, and emptying the ultrapure water in the steel cylinder; taking the discharged ultrapure water as a sample, and detecting the content of residual metal ions in the steel cylinder; according to the obtained metal ion content, whether the steel cylinder meets the cleanliness requirement or not is judged, if the cleanliness requirement is met, a small amount of nitric acid is added into the steel cylinder, sampling detection is conducted after the steel cylinder is moistened and washed, and if the test result is consistent with the previous metal ion content, the steel cylinder is clean. According to the steel cylinder cleaning method, external source introduction is avoided while metal ion impurities in the steel cylinder are treated.

The invention belongs to the technical field of geological sample analysis and detection, and particularly discloses a method for measuring the amount of each element of lithium ore in a closed acid-soluble system, and the method comprises the following steps: pretreating the lithium ore; the pretreated lithium ore is weighed and put into a closed sample dissolving device, hydrofluoric acid and purified nitric acid are sequentially added, and the closed sample dissolving device is closed; carrying out heat preservation on the closed sample dissolving device twice to obtain a test solution; and measuring the test solution by using an inductively coupled plasma mass spectrometer to obtain a working curve, and calculating the content of the analysis element in the sample solution by using the working curve. The method for determining the amount of each element in the lithium ore by adopting the closed acid-soluble system has the characteristics of simplicity in operation, high efficiency and good stability, realizes simultaneous determination of the amount of lithium, rubidium, cesium, beryllium, strontium, niobium, tantalum, zirconium, hafnium and rare earth elements in the large-batch lithium ore, and further provides a reference for determination of main trace elements in the lithium ore.

The invention provides a method for preparing a low-aluminum titanium-doped iron phosphate material by utilizing ferrophosphorus slag, which comprises the following steps: S1, crushing the ferrophosphorus slag, and dissolving the crushed ferrophosphorus slag in an acid solution to prepare a primary leaching solution; s2, acid is continuously added into the leaching residues for dissolution, and secondary leaching liquid is prepared; s3, adding an alkaline substance into the primary leachate to obtain an iron-phosphorus mixture; s4, mixing the secondary leachate with an iron-phosphorus mixture; s5, preparing a yellow material; s6, pulping the yellow material, and adding a phosphoric acid solution to obtain the yellow material; s7, the yellow material is heated and then subjected to heat preservation; s8, naturally cooling, filtering, washing and dehydrating to obtain iron phosphate dihydrate; and S9, drying the dehydrated iron phosphate dihydrate in a drying oven, and calcining to obtain the low-aluminum titanium-doped anhydrous iron phosphate. The titanium element in the iron-phosphorus adjusting liquid is doped into the iron phosphate material, so that the crystal structure and the performance of the iron phosphate material are optimized, the preparation process is simplified, and the titanium doping cost is reduced.

The invention provides a method for treating waste water containing fluorine and aluminum, which comprises the following steps: S1, first treatment: reacting a first mixed solution, and carrying out solid-liquid separation to obtain a first treated solution and first treated slag; wherein the first mixed solution comprises waste water containing fluorine and aluminum and ammonia water, and the pH value of the first mixed solution is 7-8; s2, second treatment, wherein the second treatment comprises the steps S2'and S2 ''; s2 ', the first treatment slag and a hydrofluoric acid solution are mixed for acid dissolution, and an acid solution is obtained; mixing an acid solution and sodium fluoride, and carrying out precipitation treatment to obtain cryolite; s2 '', mixing the first treatment liquid with calcium chloride, performing defluorination treatment, and performing solid-liquid separation to obtain calcium fluoride and defluorination waste liquid. By the treatment method, cryolite with high yield and high purity can be prepared, and meanwhile, the low-aluminum and low-fluorine discharge requirements can be met.

The invention discloses a method for treating red mud by using waste sulfuric acid, which comprises the following steps: mixing waste sulfuric acid and red mud, placing the mixture in a double-chamber electrochemical reaction system, breaking the silicate structure of the red mud in an anode chamber through 0.8-1.0 V voltage, and introducing acidithiobacillus acidophilus for metabolism to generate oxalic acid and citric acid to dissolve iron and aluminum oxides; the extracellular polymer fixes heavy metal ions to reduce the leaching toxicity by 90%, a cathode chamber is blocked by an ion exchange membrane to recycle more than 85% of waste acid, step-by-step precipitation of Fe < 3 + >, Al < 3 + > and Ca < 2 + > is realized by regulating and controlling the pH gradient in stages, goethite with the magnetic separation purity being greater than or equal to 95% and aluminum gel are used as functional materials, and 99% high-purity gypsum is generated through induction of nanocrystalline seeds. According to the method, 95% of iron recovery rate and heavy metal stabilization in the red mud are achieved, the waste acid recycling rate reaches 85%, the method has the advantages of low energy consumption and recycling, the treatment cost is reduced by 50% or above compared with a traditional method, and an efficient solution is provided for cooperative treatment of the red mud and the waste acid.

The invention provides a method for recovering scandium from scandium-containing lithium slag and a pretreatment method of the scandium-containing lithium slag. The method for recovering scandium from the scandium-containing lithium slag comprises the following steps: mixing the scandium-containing lithium slag with concentrated sulfuric acid, and heating and roasting to obtain a roasted product; the roasted product is subjected to water leaching, and scandium-containing leaching liquid and leaching residues are obtained; the scandium-containing leachate is extracted, and a scandium-containing organic phase and raffinate are obtained; washing the scandium-containing organic phase to obtain a purified scandium-containing organic phase and a washing solution; carrying out reverse extraction on the purified scandium-containing organic phase, and filtering to obtain a reverse extract; the reverse extract is subjected to acid dissolution, and a scandium-containing acid solution is obtained; adding oxalic acid into the scandium-containing acid solution for precipitation, filtering to obtain scandium oxalate precipitation, and roasting to obtain scandium oxide.

The invention discloses a preparation method of a modified red-mud-based chlorobenzene catalyst, which comprises the following steps: taking solid waste red mud as a main component, adding a certain amount of acid for dissolving, dropwise adding alkali liquor to enable the pH value of red mud suspension to reach 8-9, washing to be neutral, drying, grinding, passing through a molecular sieve, and roasting to obtain red-mud-based catalyst carrier powder; the red-mud-based catalyst carrier powder is mixed with a nitrate solution, it is guaranteed that the active component loading content in the mixed solution is 10-20%, and a filter cake loaded with the active component is roasted and then ground to obtain the red-mud-based catalyst. According to the method, the solid waste red mud is subjected to resource utilization, the red mud is modified into the efficient and low-cost catalyst to be applied to catalytic oxidation of volatile organic compounds, volatile organic compound waste gas is eliminated, the atmospheric environment quality is improved, waste is turned into wealth, and pollution is treated with waste.

The invention belongs to the technical field of solid waste resource utilization, and particularly relates to a red mud-based multifunctional water treatment agent and a preparation method thereof. The method comprises the steps of red mud dealkalization, drying and crushing, acid dissolution reaction, pH regulation and control, function enhancement, slow-release carrier forming and the like, and by introducing a modified polyacrylamide functional additive and a compound flocculant, the removal capacity of the treatment agent on heavy metal ions, organic pollutants and high-hardness ions is effectively improved; sodium alginate-polyvinyl alcohol is adopted to construct an ionic crosslinking type slow release system, so that the combination of long-acting release and broad-spectrum purification functions is realized. Compared with the prior art, the method has the advantages that resource utilization of the red mud waste is achieved, and the prepared water treatment agent has the remarkable advantages of being stable in structure, high in adaptability, high in treatment efficiency and the like.

The invention discloses a method for preparing iron phosphate through hydrogen-based micro-reduction roasting reinforced iron ore acid dissolution. The method comprises the following steps that (1) iron ore is pretreated into iron ore powder with D90 smaller than 74 micrometers; (2) hydrogen is introduced into the iron ore powder within the temperature range of 700-900 DEG C for micro-reduction roasting, the hydrogen flux of each kilogram of iron ore is 10-60 L / min, the roasting time is 5-30 min, and micro-reduction iron ore powder is obtained after cooling; (3) adding the micro-reduced iron ore powder into a mixed acid solution, adding a proper amount of a hydrogen peroxide solution, stirring and leaching at a set temperature to obtain a leaching mixed solution, and carrying out solid-liquid separation on the leaching mixed solution to obtain leaching residues and a leaching solution; (4) adjusting the pH value of the leachate, heating to a preset temperature, carrying out auxiliary stirring reaction, aging and filtering to obtain crude iron phosphate; and (5) calcining the crude iron phosphate, and cooling to obtain the battery-grade iron phosphate. By means of the method, the acid dissolution efficiency of the iron ore can be effectively improved, acid consumption and energy consumption are reduced, meanwhile, green production can be achieved, and the requirement for sustainable development is met.

The invention belongs to the technical field of waste resource treatment and recovery, and provides a hematite type waste residue treatment method which comprises the steps that hematite type waste residues are sequentially pulpified and washed, and washed residues are obtained; the washing slag is leached, and a leaching solution is obtained; mixing the leachate with iron powder and sulfur, and carrying out reduction reaction to obtain reduced liquid and reducing slag; mixing the reduced liquid with a precipitant, and carrying out an aluminum precipitation reaction to obtain a purified liquid and aluminum slag; and the purified liquid is electrolyzed, and the electrolytic iron powder is obtained. According to the method, the waste residues are subjected to acid dissolution through the hydrometallurgy technology and then are prepared into the electrolytic iron powder through the electrolysis technology, iron and impurities such as aluminum and silicon can be fully separated, a high-value iron powder product is obtained, meanwhile, the impurities can be further fully utilized, and by-products of nickel and aluminum are obtained.

The invention relates to a method for high-value utilization of waste lithium iron phosphate battery lithium extraction slag, and belongs to the technical field of waste lithium ion battery resource utilization. The method comprises the following steps: S1, mixing the lithium iron phosphate lithium extraction slag with a low-concentration sulfuric acid solution in proportion, carrying out countercurrent washing, carrying out solid-liquid separation, carrying out acid dissolution on a solid, carrying out gradient recycling on a washing solution, and carrying out resin adsorption and reverse osmosis treatment on a high-impurity washing solution for recycling; s2, reacting the pretreated solid with medium-concentration sulfuric acid, reducing a dissolved solution by using iron powder, then carrying out solid-liquid separation to obtain a first batch of ferrous sulfate heptahydrate, adding concentrated sulfuric acid into mother liquor, carrying out secondary crystallization, then carrying out solid-liquid separation, and recrystallizing the obtained solid by using washing wastewater to obtain a second batch of ferrous sulfate heptahydrate; s3, recovering sulfuric acid by adopting a membrane treatment method, and recovering phosphoric acid from residual mother liquor by adopting an extraction method; or directly treating the lithium iron phosphate waste residue. According to the method, efficient separation and recovery of iron and phosphorus resources and full-component high-value utilization of the lithium iron phosphate lithium extraction slag are realized.

The invention relates to the technical field of detection, and particularly provides a method for determining the quality and purity of silver in a silver-gold-plated product. The determination method comprises the following steps: dissolving a surface gold plating layer of a silver-plated product with aqua regia, and then dissolving a silver chloride protective film on the surface of silver with ammonia water, so that the problem that the mass of silver cannot be accurately weighed after the gold plating layer in the product is removed is solved, and the problem that the silver chloride protective film hinders the dissolution of pure silver with nitric acid to influence the determination is also solved. Thiourea is further adopted to dissolve a complex of diamine and silver, the situation that when silver is dissolved, added nitric acid reacts with the complex of diamine and silver to generate silver chloride precipitates is prevented, an ammonium nitrate solution is used for washing thiourea, a flame atomic absorption spectrometry method is adopted for conducting mass correction on silver in the solution obtained after aqua regia gold is dissolved, and the total silver mass is obtained through calculation. According to the determination method, the quality and the purity of the silver in the silver-plated product can be relatively accurately obtained.

The invention discloses a method and a system for adding a 3N electrolytic manganese metal additive. The method comprises the steps that S1, a manganese sulfate neutral solution is prepared, after manganese carbonate ore powder is subjected to acid dissolution, sodium dimethyl dithiocarbamate and a barium sulfide purifying agent are added to conduct impurity removal, purification and acid collection on the manganese sulfate solution, then air is introduced to remove iron, the manganese sulfate solution obtained after filter pressing is neutralized with ammonia water, the pH value of the solution is adjusted, and the qualified manganese sulfate electrolyte is prepared. According to the 3N electrolytic manganese metal additive adding method and system, an ammonium sulfite adding method is changed from adding in a manganese sulfate neutral liquid tank to dropwise adding an ammonium sulfite aqueous solution at a liquid inlet port of an electrolytic bath, and the concentration and the liquid inlet speed of the ammonium sulfite aqueous solution are controlled, so that the content of ammonium sulfite in the electrolytic bath is stable, and the condition of the electrolytic bath is stable; the addition amount of the additive is reduced, introduction of impurities is avoided, and meanwhile, oxidation-reduction reaction caused by too long retention time of ammonium sulfite in the liquid is reduced.

This invention discloses a method for resolving isomers of methylfenacin ester, comprising: firstly, dissolving methylfenacin ester in a first solvent and adding L-tartaric acid, dissolving until clear; then adjusting the system temperature to 40℃-53℃ and adding L-tartaric acid seed crystals of the target isomer; subsequently, cooling the system to 20℃-30℃, filtering the precipitated product, and obtaining the L-tartaric acid seed crystals of the target isomer as the filter cake; dissociating the L-tartaric acid seed crystals of the target isomer using an alkaline resin, collecting the filtrate, and drying the filtrate to obtain the target isomer of methylfenacin ester. This invention achieves the resolution of isomers of methylfenacin ester by using L-tartaric acid, and through optimization of conditions, achieves a yield of not less than 74.1% and an ee of 91.1% for the target isomer of methylfenacin ester. The resolution method provided by this invention is simple to operate, easy to control, suitable for large-scale production, and meets industrial needs.

The invention relates to a method for measuring and analyzing nickel, silicon and phosphorus in nickel-containing pig iron, in particular to the technical field of detection and analys.The measuring and analyzing method comprises the steps that a nickel-containing pig iron sample is drilled, sampled and separated through a hard alloy drill bit, and a test sample is obtained; sequentially carrying out acid dissolution, solid-liquid separation and constant volume on the obtained test sample to obtain a test solution; measuring the contents of nickel, silicon and phosphorus in the obtained test solution by adopting a full-spectrum direct-reading inductively coupled plasma emission spectrum; a standard curve used in the full-spectrum direct-reading inductively coupled plasma emission spectrum measurement is obtained by dissolving a gradient nickel-containing pig iron standard sample to a constant volume. According to the determination and analysis method provided by the invention, the detection process is designed, so that the nickel, silicon and phosphorus elements in the nickel-containing pig iron with the nickel content of 8-15% can be jointly determined, and a scientific data basis is provided for production management and control.

Provided herein are compositions and methods for removing a coating, such as an environmental barrier coating (EBC), from a substrate. By some approaches, a method for removing a coating from a substrate comprises contacting the coating with a salt, the salt being a solid. The method also involves heating the coating and the salt to a temperature at or above the melting point of the salt to convert the coating to a dissolvable reaction product by fusion of the coating with the salt. After forming the dissolvable reaction product, the product is then dissolved using an acid to remove at least a portion of the coating from the substrate.

The invention discloses a method for preparing ultra-fine nano white carbon black from waste silicone rubber cracking residues. The method for preparing the ultra-fine nano white carbon black from the waste silicon rubber cracking residues comprises the following steps: A1, a conversion step: taking the waste silicon rubber cracking residues as raw materials, and sequentially crushing, sieving with a 200-1000-mesh sieve and calcining to obtain a faint yellow solid; a2, a purification step: sequentially carrying out acid dissolution, filtration, washing and drying on the faint yellow solid to obtain the nanoscale white carbon black. Compared with the prior art, the preparation method disclosed by the invention is simple in process, low in emission of three wastes, high in product yield and suitable for industrialization; the obtained ultra-fine nano white carbon black prepared from the waste silicon rubber cracking residues has the advantages of high whiteness, relatively high specific surface area and high physical and chemical properties.

The present invention provides a method for treating oily wastewater. The method relates to the field of oily wastewater treatment. A solid-oil-water slurry phase obtained by mixing a hydrophobic ZIF material with oily wastewater and allowing it to stand is placed in an acidic environment. The oil-containing hydrophobic ZIF material is dissolved with acid, and a ligand corresponding to the hydrophobic ZIF material is added to the aqueous phase after acid hydrolysis to recover the hydrophobic ZIF material and the oil. Through acid hydrolysis, the hydrophobic ZIF material is decomposed into its constituent components in an acidic environment, and oil substances can be completely released, avoiding the situation where oil substances remain on the solid material, thereby improving the oil recovery rate and recycling the hydrophobic ZIF material, reducing material consumption and waste generation.

The application provides a method for recovering valuable metals in waste lithium battery black powder based on a eutectic solvent, uses a green solvent system composed of a choline / guanidine compound A containing a quaternary ammonium salt structure and an organic carboxylic acid compound B containing two or more carboxyl groups to recover valuable metals in waste lithium battery black powder, realizes preliminary and efficient separation of lithium cobalt manganese and nickel and graphite, recovers cobalt, manganese and lithium from the leaching solution through a step-by-step precipitation method after the lithium cobalt manganese enters the leaching solution, recovers nickel and graphite through acid dissolution separation of the mixture containing nickel and graphite, separates and recovers the mixture of nickel and graphite through subsequent treatment, the leaching conditions are mild, the pollution is small, the cost is low, and the method has good social and economic benefits; the method provided by the application can produce a plurality of high-value products, has the advantages of strong adjustability, high precipitation efficiency, green environmental protection and low cost, and has wide application value in the separation and recovery of valuable metals and graphite resources in battery black powder.