50 results about "Potassium dichromate" patented technology

The present application belongs to the technical field of wastewater treatment, and discloses a method for treating electroplating wastewater by using bioreduction of biogas slurry and combined iron bio-oxidation, which is a secondary combined use technology for removing various heavy metals in electroplating wastewater by iron bio-oxidation, comprising the following steps: (1) collecting fermentation biogas slurry, and performing ultraviolet irradiation sterilization after aeration; (2) adding potassium dichromate solution and fresh nutrient solution to the sludge system, and culturing anaerobic sludge; (3) adding treated biogas slurry to the anaerobic sludge, and repeatedly domesticating chromium-reducing microorganisms; (4) configuring a mixed solution of comprehensive electroplating wastewater and biogas slurry according to a certain proportion; (5) building a primary treatment biological reactor, and reducing Cr(VI) in wastewater by anaerobic biological reduction under the promotion of pyrite; and (6) building a secondary biological reactor filled with straw biomass charcoal, and generating iron oxides under the action of functional bacteria to continue adsorbing Cd, Cu and Ni ions in wastewater.

The invention discloses a fluoride-salt-free and nitrate-free steel plate enamel high-temperature titanium creamy yellow cover glaze as well as a preparation method and application thereof, and belongs to the technical field of enamel. The cover glaze is prepared from quartz, anhydrous borax, rutile, potassium feldspar, trisodium phosphate, potassium carbonate, potassium dichromate and zinc oxide according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The overglaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are solved from the source, the fluorine content of the product is not detected through detection, the product meets the European Union REACH regulation limit value requirements, and meanwhile, the overglaze has good hue, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 840-880 DEG C and the firing time of 820-830 minutes, and has good application prospects. The method can be used for producing green and environment-friendly enamel products.

The invention relates to the technical field of slide processing. The invention discloses a slide treatment method for improving wall adhesion of 293T cells. The slide processing method comprises the following steps: preparing a cleaning solution; putting the slide into the cleaning solution, soaking, taking out the slide, washing the slide with deionized water, and putting the slide into a drying oven for drying; immersing the dried slide into PLL treatment liquid for 3-7 minutes, taking out and airing; wherein the cleaning solution is prepared from the following raw materials: potassium dichromate, water and concentrated sulfuric acid; the PLL treating fluid is poly-L-lysine with the mass concentration of 0.05%-0.15%, and the solvent is deionized water. The invention further discloses the slide prepared by the slide treatment method for improving the wall adhesion of the 293T cells. According to the slide treatment method, the adhesive force of the slide to 293T cells can be effectively improved, and the cell adherence is enhanced.

The application provides a method for detecting the titer of vitamin B12 in a fermentation liquor. The method comprises the following steps: preparing a potassium dichromate solution, a hydrochloric acid solution and a potassium dihydrogen phosphate solution, mixing the three solutions with the vitamin B12 fermentation liquor under certain conditions to generate cyanocobalamin, and then testing the titer of the cyanocobalamin by using a high performance liquid chromatography. The titer of the vitamin B12 detected by using the method is consistent with the titer detected by using a sodium cyanide method. The operation method greatly reduces the safety risk of an analyst caused by using the sodium cyanide, and the operation method is simple, easy to manage in a laboratory and can save the testing cost.

The invention belongs to the technical field of magnesium-aluminum magnesium alloy surface treatment, and particularly relates to a magnesium-aluminum alloy surface yellow ceramic film layer and a color control method thereof, and the method comprises the following steps: immersing a pretreated magnesium alloy into an electrolyte containing a coloring agent, and carrying out micro-arc oxidation to generate different yellow ceramic film layers on the surface of the magnesium-aluminum magnesium alloy; the coloring agent is one or two of potassium dichromate, potassium permanganate and anhydrous cupric sulfate; by adopting the method disclosed by the invention, uniform, smooth and compact ceramic film layers with different yellow colors can be generated on the surface of the magnesium-aluminum alloy. Six ceramic film layers with different yellow colors are prepared, the cost is low, the protection function and the decoration function can be achieved, and the requirements of different application scenes are met.

The present invention relates to a reagent combination for determining the chemical oxygen demand (COD) in a liquid medium, wherein the reagent combination comprises a first reagent, wherein the first reagent is an acidic solution of mercuric sulfate (HgSO4); a second reagent, wherein the second reagent is an acidic solution containing potassium dichromate (K2Cr2O7); and a third reagent, wherein the third reagent is an acidic solution, characterized in that at least the second reagent or at least the third reagent also contains potassium aluminum sulfate (KAl(SO4)2·12H2O).

The application discloses a kind of aluminum lithium alloy passivation methods, the passivation aluminum lithium alloy is successively included from inside to outside, aluminum lithium alloy core, passivation layer growth film, passivation layer coating film;The sum thickness of the passivation layer growth film and the passivation layer coating film film is 1~1.5 μm;Specifically using potassium dichromate, using magnetic stirrer, forms the passivation film on the surface of aluminum lithium alloy;Aluminum lithium alloy can be added into solid propellant after passivation of the application.The application forms dense passivation film on the surface of aluminum lithium alloy, effectively prevents and insulates the influence of external water vapor on aluminum lithium alloy, maintains the stability of aluminum lithium alloy during storage and use.

The application discloses a testing method for the content of divalent iron ions in EDTA chemical cleaning solution, and aims at the problem that the existing titration method cannot accurately determine the content of divalent iron ions due to the interference of EDTA. Instead of adopting a complex separation step, the method eliminates the interference through two steps. First, the to-be-tested solution is adjusted to be acidic to weaken the complexing capacity of EDTA, and then a sulfur-phosphorus mixed acid solution is added. The strong acidity of sulfuric acid is used to inhibit the complexing reaction and avoid hindering titration. The whole process is based on the principle of titration method, and does not need expensive instruments and reagents, and is low in cost. The operation is simple and does not need professional skills. The application adopts the high-stability potassium dichromate standard solution, reduces the calibration frequency, realizes rapid, convenient, accurate and low-cost determination, and is suitable for on-site detection requirements.

The invention relates to the technical field of determination of chemical oxygen demand (COD) of a catalyst, in particular to a rapid COD determination method for an improved catalyst system, chemical oxygen demand (COD) serves as a key index for measuring the content of reducing substances in a water body, and the content of the reducing substances in the water body is determined through oxidation treatment of potassium dichromate. The amount of potassium dichromate consumed by the oxidized reducing pollutants in the water sample corresponds to the mass concentration of oxygen, and the measurement result directly reflects the pollution degree of the water body. COD is one of core parameters for water environment monitoring and treatment, a traditional COD determination method takes a potassium dichromate oxidation method as a reference, but has the problems of low reaction efficiency, long time consumption, incomplete oxidation caused by a single catalyst, weak anti-interference capability and the like, depends on manual operation, and is inconvenient to operate. In the prior art, the requirements of modern environment monitoring on rapidness, accuracy and automation are difficult to meet due to large reagent dosage and high secondary pollution risk, and for a complex water sample, a traditional method is easy to cause determination deviation and insufficient in data sharing and remote monitoring capability, so that the intelligent development of water environment monitoring is restricted.

The application discloses a steel plate enamel high-temperature titanium milk yellow face glaze free of fluorinated salt and nitrate, a preparation method and application thereof, and belongs to the technical field of enamel. The face glaze is prepared from quartz, zero-water borax, rutile, potassium feldspar, trisodium phosphate, potassium carbonate, potassium dichromate and zinc oxide according to specific mass proportions. The preparation comprises raw material mixing, smelting at 1300+ / -10 DEG C under a pure oxygen environment, and rapid cooling after wire drawing detection of the smelting state. The face glaze completely avoids the use of fluorinated salt and nitrate, eliminates fluorine emission and environmental protection equipment blockage problems from the source, the fluorine content of the product is not detected through detection, meets the limit value requirements of the EU REACH regulation, has good color, gloss and firing adaptability, is suitable for a steel plate substrate, has a firing temperature of 840-880 DEG C, and can be used for the production of green and environmentally-friendly enamel products.

The present invention relates to a reagent combination for determining chemical oxygen demand (COD) in a liquid medium, the reagent combination comprising a first reagent wherein the first reagent is an acidic solution of mercury sulfate (HgSO4); a second reagent, wherein the second reagent is an acidic solution comprising potassium dichromate (K2Cr2O7); and a third reagent, where the third reagent is an acidic solution, characterized in that at least the second reagent or at least the third reagent further comprises potassium aluminum sulfate (KAl (SO4) 212H2O).

The invention provides a method for determining the resultant amount of elements in an iron-based sodium electric precursor based on the total iron content, and the method comprises the following steps: dissolving the iron-based sodium electric precursor by using an acid, then adjusting the pH value by using an alkali to precipitate iron ions so as to obtain an iron precipitate, and then dissolving the iron precipitate by using an acid so as to obtain an iron-containing solution; ferric ions in the iron-containing solution are reduced, and a solution containing ferrous ions is obtained; the method comprises the following steps: removing redundant reducing agents, adding an indicator into a solution containing ferrous ions, titrating by adopting a potassium dichromate standard solution until the solution is colorless and mutates into purple, measuring the total iron content, and calculating the element sum according to the total iron content and the molar ratio of elements in the iron-based sodium electric precursor measured by adopting an ICP (Inductively Coupled Plasma) method. The method comprises the following steps: firstly reducing all Fe < 3 + > in a sample into Fe < 2 + >, then titrating and testing the total iron content by adopting a potassium dichromate standard solution, and then converting the resultant of the elements according to the molar ratio of the elements.

The invention relates to the technical field of phosphogypsum harmlessness, in particular to a formula and method for curing soluble phosphorus, eutectic phosphorus, soluble fluorine and ammonia nitrogen in fresh phosphogypsum of a rotary table type vacuum filter. Comprising the following components: ardealite, calcium hydroxide, anionic polyacrylamide, magnesium chloride, aluminum chloride, deacetylated chitin, potassium dichromate and deionized water. Agents adopted by the invention are common industrial agents which are convenient to purchase on a large scale. The medicament is low in cost and has no special requirements for storage and transportation. The agent cost for harmlessly treating each ton of fresh phosphogypsum of the large rotary table type vacuum filter is lower than 30 yuan. According to the method, the concentration of fluoride in the phosphogypsum leachate can be effectively controlled to be 4 mg / L or below.

The invention discloses fluoride-salt-free and nitrate-free low-temperature titanium creamy yellow surface glaze for steel plate enamel as well as a preparation method and application of the surface glaze, and belongs to the technical field of enamel. The cover glaze is prepared from quartz, borax anhydrous, trisodium phosphate, titanium dioxide, potassium feldspar, magnesium carbonate, potassium carbonate, potassium dichromate and zinc oxide according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The overglaze completely avoids the use of fluoride salt and nitrate, the problems of fluoride emission and environmental protection equipment blockage are solved from the source, the fluorine content of the product is not detected through detection, the limit value requirement of the European Union REACH regulation is met, meanwhile, the overglaze has good hue, luster and firing adaptability and is suitable for a steel plate matrix, the firing temperature is 760-800 DEG C, and the firing time is 2-3 hours. The method can be used for producing green and environment-friendly enamel products.

The invention discloses a method for quickly testing chemical oxygen demand, which comprises the following steps of: 1, preparing a test solution which comprises the following components: A, a potassium dichromate solution (c is equal to 0.0250 mol / L); b, a mercury sulfate solution (100g / L); c, a silver sulfate-sulfuric acid solution (10g / L); 2, preparing a standard water sample; step 3, preparing a comparison reference sample, sequentially adding the standard water sample, the reagent B and the reagent A into the colorimetric tube, uniformly shaking, adding the reagent C into the colorimetric tube by using a pipette, uniformly shaking, and standing until the reaction is finished; 4, developing the water sample to be detected, sequentially adding the water sample to be detected, the reagent B and the reagent A into the colorimetric tube, uniformly shaking, adding the reagent C into the colorimetric tube by using the pipette, uniformly shaking, and standing until the reaction is finished; and 5, carrying out color comparison on the to-be-detected water sample obtained in the step 4 and a comparison reference sample.

The invention belongs to the technical field of battery materials, and particularly discloses a pretreatment process of PAN-based carbon fibers and application of the PAN-based carbon fibers in preparation of a high-activity flow battery electrode material. The method comprises the following steps: soaking a polyacrylonitrile (PAN) precursor in an aqueous solution containing a pretreating agent such as potassium dichromate, and carrying out chemical pretreatment, so that the surface of the PAN fiber is subjected to primary structural transformation; and respectively carrying out pre-oxidation and carbonization treatment on the obtained material to obtain the PAN-based carbon fiber electrode material with the catalyst on the surface. When the obtained carbon fiber material is used as an electrode material of the all-vanadium redox flow battery, the electrode reaction kinetics of the positive electrode and the negative electrode of the battery can be effectively improved, and the energy conversion efficiency and the rate capability of the battery are improved. The method is easy to operate, compared with a traditional electrode preparation technology, energy consumption is low, the process is simple, large-scale production is easy to achieve, and the method has good application prospects in the field of vanadium battery electrode materials.

The invention discloses a visible-light-responsive ternary Z-type semiconductor composite material and a preparation method and application thereof. According to the composite material, a heterojunction is formed by nesting an Al2O3 / Cr2O3 compound and protonated C3N4. The specific preparation method comprises the following steps: preparing potassium dichromate into an aqueous solution, adding concentrated sulfuric acid to react, and adding an organic solvent and alkali to adjust the pH value; heating the solution of which the pH is adjusted, adding aluminum chloride and ammonia water to react, and filtering, drying, roasting and grinding a solid product to obtain Al2O3 / Cr2O3 compound powder; calcining urea, and then carrying out acid pickling and drying treatment to obtain porous graphite phase carbon nitride powder; al2O3 / Cr2O3 compound powder and porous graphite phase carbon nitride powder are mixed in proportion and suspended with water, and then the ternary Z-type semiconductor composite material is prepared through ultrasonic stirring, centrifugation and drying. Under the irradiation of visible light, the degradation rate of the composite material on ibuprofen in 6 hours reaches 97.58%, the degradation rate constant is 15 times that of pure C3N4, and the composite material still keeps high efficiency under the condition of alkalescence, namely pH = 7.9. The degradation rate of the composite material still reaches 80.44% after four times of circulation.

This invention discloses a method for degreasing ceramic packing, relating to the field of degreasing technology. The method involves preparing a degreasing solution, injecting it into the packed tower, and circulating it using a reflux pump. The degreasing solution includes sulfuric acid, potassium dichromate, and hydrogen peroxide. This invention employs an innovative degreasing solution that effectively removes siloxanes from the surface of the ceramic packing, significantly improving clogging and eliminating clogging issues after a period of use, thus meeting production requirements.

The invention discloses a photoelectrocatalysis COD (Chemical Oxygen Demand) water quality on-line monitoring system and a detection method, and belongs to the technical field of water quality analysis. Aiming at the pain points that a traditional potassium dichromate method needs a strong acid high-temperature toxic reagent, the detection time is long, the maintenance cost is high, a UV method is poor in interference resistance, and an existing photoelectrocatalysis method is unstable in light source, insufficient in automation and the like, the system adopts a composite photoelectrode and an integrated thin-layer electrolytic tank integrating three electrodes and is matched with a UV-LED light source; a miniature shading shutter is introduced to eliminate the influence of unstable current at the moment when a light source is turned on; meanwhile, a miniature constant potential rectifier (for controlling the potential of a working electrode and collecting light current), a multi-way valve, a two-position three-way valve, a peristaltic pump, a water sample-electrolyte mixer and a bubble sensor (for preventing bubble interference and realizing metering liquid inlet) are integrated, so that a miniaturized and full-automatic integrated structure is formed. The detection method sequentially comprises the following steps of: rinsing the system, stabilizing a light source, uniformly mixing a water sample and electrolyte, pumping into a thin-layer pool, opening a shutter to carry out photoelectrocatalysis detection (applying bias voltage by a constant potential rectifier and recording photocurrent), calculating a COD value by combining photocurrent integration with a calibration curve, and carrying out waste discharge reset. Meanwhile, a standard liquid calibration process and a quality inspection process are matched. The device is researched and developed on the basis of the photoelectrochemical degradation principle, does not need strong acid, high temperature and toxic chemical reagents, is short in detection time, low in detection lower limit, high in anti-interference capability and low in maintenance cost, and can realize high-precision monitoring of water quality COD.

The invention discloses a fluoride-salt-free and nitrate-free medium-temperature titanium creamy yellow overglaze for steel plate enamel as well as a preparation method and application of the overglaze, and belongs to the technical field of enamel. The cover glaze is prepared from quartz, anhydrous borax, rutile, potassium feldspar, magnesium carbonate, trisodium phosphate, calcium carbonate, potassium dichromate and zinc oxide according to a specific mass ratio. The preparation method comprises the following steps: mixing the raw materials, melting at 1300 + / -10 DEG C in a pure oxygen environment, and quenching after wiredrawing to detect a molten state. The overglaze completely avoids the use of fluoride salt and nitrate, eliminates the problems of fluoride emission and environmental protection equipment blockage from the source, the fluorine content of the product is not detected through detection, the product meets the European Union REACH regulation limit value requirements, has good hue, luster and firing adaptability, is suitable for a steel plate matrix, has the firing temperature of 800-840 DEG C and the firing time of 20-30 minutes, and can be widely applied to the production of steel plates. The method can be used for producing green and environment-friendly enamel products.

The application provides a potassium dichromate titration determination method based on a multi-modal fusion attention mechanism. The method obtains the initial volume and concentration of a standard solution and performs titration analysis in a multi-stage speed mode; collects a state image of a to-be-measured solution and performs pretreatment operation; inputs the state image after the pretreatment operation into a multi-attention mechanism network of a fused GoogLeNet for processing, and outputs a state image feature matrix; collects a spectrum and obtains a spectrum data matrix of the to-be-measured solution; fuses the state image feature matrix and the spectrum data matrix in a multi-modal mode, and outputs a color feature value; determines whether titration analysis reaches a titration endpoint according to the color feature value; if the titration analysis does not reach the titration endpoint, the titration analysis is continued; if the titration analysis reaches the titration endpoint, the titration analysis is stopped; and the content of the to-be-measured solution is calculated and output. The method can improve the speed and efficiency of automatic titration, can identify a slight color change, can accurately extract a color feature value, and can improve the precision of potassium dichromate titration.

The application provides a kind of hot-pressed iron block water yield determination method, to solve the problem of low accuracy of hot-pressed iron block water yield determination method in prior art.The application provides a kind of hot-pressed iron block water yield determination method, comprising the following steps: (1) hot-pressed iron block is subjected to slag-iron separation treatment to obtain separated iron block and separated slag particles; (2) the first iron content determination treatment is carried out on the separated iron block by using a direct-reading spectrometer to obtain the iron content of the separated iron block; the second iron content determination treatment is carried out on the separated slag particles by potassium dichromate titration method to obtain the iron content of the separated slag particles; according to the mass of the hot-pressed iron block, the mass of the separated iron block, the iron content of the separated iron block and the iron content of the separated slag particles, the water yield of the hot-pressed iron block is obtained; the determination method has high accuracy and simple operation process.

The invention discloses a FeO content determination method suitable for multi-lithologic rock, and relates to the technical field of geological analytical chemistry and rock geochemistry. The method comprises the following steps: step 1, sample pretreatment: wetting a rock powder sample with water, adding hydrofluoric acid (HF) and a near-boiling dilute sulphuric acid solution, and covering and sealing; step 2, heating and decomposing: heating and decomposing the mixture in the step 1 at 200 + / -10 DEG C for 10-20 minutes; step 3, complexing and cooling with mixed acid: adding sulfur-phosphorus mixed acid into the heated solution, and then immediately cooling to room temperature in a water bath; and step 4, titration determination: adding a sodium diphenylaminesulfonate indicator into the cooled solution, titrating with a potassium dichromate standard solution until the solution presents stable light purple, and recording the consumed volume V1. The optimized HF-near-boiling H2SO4 system can efficiently decompose various rocks from acidity to super-basic property, the problem that indissolvable samples such as peridotite and the like cannot be completely decomposed by a traditional method is solved, and the sample applicability is wide.

The application discloses a steel plate enamel medium-temperature titanium milk yellow face glaze free of fluorinated salt and nitrate, a preparation method and application thereof, and belongs to the technical field of enamel. The face glaze is prepared from quartz, zero-water borax, rutile, potassium feldspar, magnesium carbonate, trisodium phosphate, calcium carbonate, potassium dichromate and zinc oxide according to specific mass proportions. The preparation comprises raw material mixing, smelting at 1300+ / -10 DEG C under a pure oxygen environment, and rapid cooling after wire drawing detection of the smelting state. The face glaze completely avoids the use of fluorinated salt and nitrate, eliminates fluorine emission and environmental protection equipment blockage problems from the source, the fluorine content of the product is not detected through detection, meets the limit value requirements of the EU REACH regulation, has good color, gloss and firing adaptability, is suitable for a steel plate substrate, has a firing temperature of 800-840 DEG C, and can be used for the production of green and environmentally-friendly enamel products.

The invention relates to the technical field of packaging, and particularly discloses a production process of a pre-coloring transfer laser film. The invention relates to a production process of a pre-coloring transfer laser film, which comprises the following specific process steps of: dissolving and dispersing a dye in a water-based acrylate modified polyurethane transfer coating in advance to form a transfer color layer coating, coating the transfer color layer coating on a base film, carrying out mold pressing, carrying out mold pressing, plate making and passivating treatment by using protein powder, and drying to obtain the pre-coloring transfer laser film. And finally, vacuum aluminum plating is performed to prepare the pre-coloring transfer laser film. According to the method, the dye is directly dissolved in the transfer color layer coating, pre-coloring is achieved, the subsequent coloring procedure is reduced, the protein powder is used for replacing potassium dichromate needed by a die-pressing plate-making process and a passivating treatment process, the method is green and environmentally friendly, abrasion of the color layer coating to textures during die pressing is reduced, adhesion is reduced, and the coloring effect of the laser film is improved.

This invention relates to the field of engineering component technology, specifically to a method for manufacturing a check valve core. The invention employs multi-process synergistic optimization, selecting raw materials containing 70-80% stainless steel powder and 10-15% alumina ceramic particles. A blank is prepared using powder metallurgy, and a cobalt-based alloy is clad onto the sealing surface using a 2000-2500W laser. After vacuum heat treatment at 1050℃ and cryogenic treatment at -196℃, the irregular flow channel is milled with a precision of ±0.01mm using five-axis CNC machining, combined with electrolytic polishing at 25-30℃ and potassium dichromate passivation treatment. Finally, the two blanks are sealed and welded, and the finished product is obtained after passing a 1.5MPa pressure holding test. This method gives the valve core high strength, high wear resistance, and corrosion resistance. The flow channel precision meets the requirements of high-pressure systems, and the surface finish and corrosion resistance are significantly improved. Testing shows that the wear life is more than three times that of traditional processes, effectively solving the problems of sealing failure and wear under complex operating conditions, and ensuring the reliability of the check valve.

The invention relates to a kit and a method suitable for Golgi staining of large animals. The kit comprises: 1) an impregnation liquid, wherein the impregnation liquid is an AB liquid, and the AB liquid is an isovolumetric mixed liquid of 5 wt% potassium dichromate (liquid A) and 5 wt% mercuric chloride (liquid B); the solution C is 1.4 wt% potassium chromate solution, the color developing solution is a mixed solution of a solution D, a solution E and flushing fluid in a volume ratio of 1: 1: 1.8-1: 1: 2.5, and the solution D is a mixed solution of 25vol% stronger ammonia water and Milli-Q water; the solution E is a sodium thiosulfate pentahydrate aqueous solution; and the flushing fluid is Milli-Q water. Methods of Golgi staining of large animal brain tissue are also provided. According to the method, high-definition and quantitative-analysis staining results are provided for neuroscience research of the domestic dogs, and reference is provided for optimization of Golgi staining technologies of other large animals.

A method for obtaining a stable suspension of graphene oxide nanoparticles and carbon nanotubes. The method comprises: preparing graphene nanoparticles of size 70-150 nm, graphene oxide nanoparticles, in the process 0.7 g of potassium dichromate is added to 2 g of 96-98% sulfuric acid, 1 g of graphene nanoparticles is introduced, washed with water to a pH of 5.5; the graphene oxide nanoparticle suspension is dispersed in an ultrasonic disperser for 1 minute, 0.5 ml of ethanol is added to the carbon nanotubes, the resulting mixture is introduced into the graphene oxide nanoparticle suspension and dispersed for 5 minutes. In the method, the suspension contains graphene oxide nanoparticles at a concentration of 0.02 g / L or 0.03 g / L; the mixture containing 0.75 g of carbon nanotubes is introduced into the graphene oxide nanoparticle suspension at a concentration of 0.02 g / L, and the mixture containing 0.5-1 g of carbon nanotubes is introduced into the graphene oxide nanoparticle suspension at a concentration of 0.03 g / L.

The invention discloses a method for detecting manganese dithionate in a pyrolusite desulfurization solution, and belongs to the technical field of environmental hydrometallurgy. Drying potassium dichromate to constant weight, and preparing a potassium dichromate standard solution; filtering the desulfurized solution, transferring the filtrate into a COD (Chemical Oxygen Demand) digestion tube, adding a sulfuric acid solution and a potassium dichromate standard solution, and uniformly shaking to construct a reaction system; putting the digestion tube into a COD digestion instrument, setting temperature and time for digestion, transferring the solution into a conical flask, washing the digestion tube with water, and merging the washing solution into the conical flask to obtain a mixed solution; cooling the mixed solution to room temperature, titrating with an ammonium ferrous sulfate solution, dropwise adding an indicator, judging an end point according to color change, and recording solution consumption; calculating the content of residual potassium dichromate according to the concentration and consumption of the ammonium ferrous sulfate solution, and calculating the content of manganous dithionate in the desulfurization solution according to the difference between the initial amount and the residual amount of the potassium dichromate and the reaction stoichiometric ratio of the manganous dithionate to the potassium dichromate. The method is accurate and efficient in determination, simple and convenient to operate and low in reagent cost, and has remarkable industrial popularization value.

The invention discloses a chloride ion-free esterified fiber micro-smoke firecracker medicament and a preparation method thereof. Comprising sodium bicarbonate, potassium hydroxide or sodium hydroxide, castor oil, methyl acetate, ethyl formate, ferrocene, manganese dioxide, potassium dichromate and corncob powder fibers. The invention relates to an environment-friendly environment-friendly detergent, which is characterized by comprising 15-25 parts by weight of sodium bicarbonate, 4-10 parts by weight of potassium hydroxide or 8-12 parts by weight of sodium hydroxide, 12-22 parts by weight of castor oil, 25-35 parts by weight of methyl acetate, 25-35 parts by weight of ethyl formate, 6-8 parts by weight of potassium dichromate, 10-22 parts by weight of ferrocene, 2-5 parts by weight of manganese dioxide, 100-200 parts by weight of corncob fiber, and 6-8 cubic meters of water. The preparation method comprises the following steps: crushing a fiber coarse material, soaking in a pool, boiling, rinsing, carrying out centrifugal spin-drying, air-drying, squeezing, distilling, carrying out esterification reaction, adding elements such as potassium, sodium, iron, manganese and the like, sieving, mixing and the like to prepare a finished product. The invention has the advantages of no chlorine salt and sulfide, slight smoke, no toxicity, no pungent smell, no harm to human body, safety, environmental protection and the like.