321 results about "Ammonium ferrous sulfate" patented technology

The invention discloses a saline-alkali soil amendment, and relates to a soil amendment. The soil amendment of the invention solves the problem of the waste of land resources caused by a condition that saline-alkali soil is wasted and can not be used throughout the year because only artemisia anethifolia can grow in the saline-alkali soil at present, while other plants can not grow thereon. Besides, the existing saline-alkali soil amendment is mainly prepared from alum which has high cost and poor soil amendment effect. The saline-alkali soil amendment of the invention is prepared by weight percent from aluminum sulfate, ammonium ferrous sulfate and magnesium sulfate, which are mixed, and the weight ratio of the three materials is 1-1.8:1-2:0.2-0.5. The saline-alkali soil amendment of the invention can ensure that crop plants can be planted in the saline-alkali soil; thus, the saline-alkali soil, a wide land resource, can be made good use of. In addition, the saline-alkali soil amendment of the invention has the advantages of low cost and obvious effect of soil amendment.

The invention discloses a method for preparing a ferroferric oxide / carbon nano tube composite material, which is used for solving the technical problem that the nano Fe3O4 particle diameter of the coating prepared by the conventional method for preparing the ferroferric oxide / carbon nano tube composite material is not uniform. According to the technical scheme, multi-wall carbon nano tubes, ammonium ferrous sulfate, ferric chloride and sodium hydroxide are used as raw materials, polyvinyl alcohol is used as a surfactant, the ferroferric oxide / carbon nano tube magnetic nano composite material is obtained by adopting a reverse co-precipitation method, and nano Fe3O4 coatings with different particle diameters are obtained by changing the reaction temperature and the concentration of the reaction solution. The nano Fe3O4 particle diameter of the coating of the ferroferric oxide / carbon nano tube composite material prepared by the method is uniform, the average nano particle diameter is less than 10 nanometers, and the synthesis process and the production equipment are simple.

The invention provides a passivator for repairing mercury polluted soil. The passivator is prepared from a sulfur-containing reagent and an iron-containing reagent which are stored separately in a mass ratio of 1:5-5:1, wherein the sulfur-containing reagent is one or more of sulfur, sulfide, hydrosulfide, polysulfide and thiosulfate, and the iron-containing reagent is one or more of zero-valent iron, ferrous sulfate and hydrate thereof, ammonium ferrous sulfate and hydrate thereof, ferric sulfate, ferrous chloride and hydrate thereof, ferric chloride and hydrate thereof, polyferric chloride, poly ferrous sulfate, ferroferric oxide and ferric oxide. The sulfur-containing reagent and the iron-containing reagent in the passivator for repairing mercury polluted soil are stored separately, so that invalidation of effective ingredients of mercury in soil caused by reactions generated by mixing can be avoided. The passivator is wide in raw material source and low in cost. The repairing method is simple and feasible, is not sensitive to the soil type, has a remarkable repairing effect for various forms of mercury, does not have secondary pollution, and can be used for repairing cadmium, lead, zinc, copper or nickel heavy metal polluted soil.

The invention relates to a filtrate loss reducer for high-temperature-resistant oil field drilling fluid, a preparation method of the filtrate loss reducer, and application of a treatment agent. A novel high-temperature-resistant filtrate loss reducer is synthesized by implementing the following steps: adopting lignin, acrylamide and 2-acrylamide-2-methyl propanesulfonate as synthetic monomers; enabling the synthetic monomers to perform graft copolymerization under the initiation of potassium peroxodisulfate, ammonium ferrous sulfate hexahydrate and hydrogen peroxide respectively; adding a crosslinking agent, namely N,N-methylene bisacrylamide to enhance the stabilizing force of the synthetic monomers under high temperature condition. The filtrate loss reducer disclosed by the invention adopts waste materials of a paper-making factory, is extensive in source and low in cost, and can be used for absorbing the excellent viscosity reduction capacity of lignin; the introduced acrylamide and 2-acrylamide-2-methyl propanesulfonate can be used for improving the precipitation capacity at a high temperature; N,N-methylene bisacrylamide is added as the crosslinking agent to ensure that a network structure is formed, the high temperature resistance can be improved, an oil and gas layer can be protected from collapsing, and the service life of an oil well can be prolonged. A product disclosed by the invention is applied to the oil field drilling fluid.

The invention relates to the technical field of building material synthesis and particularly discloses a synthetic method of polycarboxylic acid type highly slump loss resistant water-reducing agent. The method comprises the following steps: 1, water treatment agent and acrylic acid-maleic anhydride copolymer are added into tap water until the content of acrylic acid-maleic anhydride copolymer is 3-8mg / L so as to obtain treating water; and 2, backing material formed by unsaturated polyoxyethylene ether, maleic anhydride, functional small monomer, and treating water is added into a polyreactor, the temperature is increased to be 40 DEG C and stirring is performed till the mixture is completely dissolved resolution, NaOH solution is used for adjusting pH to 4, then a proper amount of hydrogen peroxide is added, and mixed solution composed of acrylic acid, ammonium ferrous sulfate, a cross-linking agent, a chain transfer agent and treating water well prepared in advance is dripped; dripping is finished within 2.5 to 4 h, thermal insulation is continuously performed for 0.5 to 1 h after dripping, and NaOH solution is used for neutralization to pH 5-6. The method provided by the invention has the advantages that the process is simple, the conditions are mild, the feedstock conversion rate is high, tap water can be used as raw materials, the cost is greatly reduced, and the slump loss resistance of products is obviously superior to that in the prior art.

The invention discloses a sepiolite modification method and application of modified sepiolite to wastewater treatment. Cellulose and molysite are jointly adopted for modification of sepiolite, and the method particularly includes acid treatment of the sepiolite and joint hydrothermal reaction of acid-modified sepiolite, the cellulose and the molysite. The preparation method is quite simple, mild in preparation condition, low in related reaction temperature and low in energy consumption. The cellulose for modification is low in cost, the molysite can be combined with the sepiolite to improve adsorption effects and also plays a role in catalysis in a hydrothermal synthesis process to enhance catalysis effects, and utilization of toxic catalysts such as ammonium ferrous sulfate hexahydrate is avoided. The modified sepiolite prepared according to the method is excellent in performance and high in adsorption rate of heavy metals and organic pollutants such as phenol.

The invention provides a method for detecting the silicon content in a vanadium-aluminum alloy. The method comprises the steps of: establishing a silicon standard solution concentration-absorbance working curve; decomposing a sample to be detected with hydrochloric acid and nitric acid; adding sodium sulfite into the obtained solution to be detected so as to reduce the solution to blue, conducting cooling, and setting the constant volume of the solution in a standard volumetric flask; getting two solutions of certain amount from the standard volumetric flask for detecting, with one solution used as a color developing solution and the other solution used as a reference solution; adjusting the color developing solution to chromogenic acidity, adding excess ammonium molybdate, and disposing the solution for 5-30min so as to generate silicomolybdenum yellow heteropoly acid, then adding a mixed acid of oxalic acid and sulfuric acid, and adding ammonium ferrous sulfate immediately to reduce the silicomolybdenum yellow heteropoly acid generated during reaction to silicomolybdenum blue heteropoly acid, and carrying out dilution to a scale; adjusting the reference solution to chromogenic acidity, adding a mixed acid of oxalic acid and sulfuric acid, ammonium molybdate and ammonium ferrous sulfate, and carrying out dilution to the scale; measuring absorbance at a position of 680nm at a spectrophotometer, looking up the working curve according to the obtained absorbance value of the color developing solution, and calculating the silicon content in the vanadium-aluminum alloy.

The invention discloses a fast and accurate detection method for silicon dioxide content in limestone, kalk and dolomite. The detection method comprises the following steps: crushing samples, and drying for 1.5-2.5 h under thea temperature of 105-110 DEG C; mixing 0.1000 g samples and 3.0-4.0 g mixed fluxing agent of sodium carbonate and boric acid evenly, liquating for 18-20 min under athe temperature of 890-910 DEG C, dissolving frits by a 45-55 ml hydrochloric acid and 25-35 ml water, and placing the test solution in a 250-ml volumetric flask; taking and adding 5.00 ml test solution in a 100-ml volumetric flask, adding 18-22 ml ammonium molybdate and still standing for 18-22 min, and adding 45-55 ml mixed acid of oxalic acid and sulfuric acid, 4.80-5.20 ml ascorbic acid-ammonium ferrous sulfate mixed solution; measuring the absorbency of a color development solution at the wavelength of 680 nm through a spectrophotometer, and using blank as a reference; preparing a silicon dioxide standard sample with the concentration of 40 ug / ml, moving and taking 0.00 ml, 2.00 ml, 4.00ml, 6.00 ml, 8.00 ml and 10.00 ml silicon dioxide standard samples, and placing the standard samples in 100-ml volumetric flasks respectively, adding 5.00 ml blank test solution in the volumetric flasks respectively, after color-developing, measuring the absorbency at the same conditions, and then drawing a working curve. The silicon dioxide content in the samples is calculated according to the following formula (shown in the specification). The detection method is fast and efficient, excellent in accuracy, reproducibility and stability, and particularly suitable for detection of samples with silicon dioxide content equal to or higher than 4 %.

The invention provides preparation of a Prussian blue photo-Fenton catalyst; ferric trichloride, ferric nitrate, ferric sulfate or ammonium ferrous sulfate, potassium ferricyanide, and potassium ferrocyanide are used as raw materials, and are dissolved in ultrapure water respectively to prepare a solution containing iron ions and ferricyanide ions; molecular sieve, kaolin or construction waste are used as carriers, and Prussian blue is fixed on the carriers to obtain fixed Prussian blue photo-Fenton catalyst. The invention also provides a method for degrading organic pollutants by the Prussian blue photo-Fenton catalyst, which comprises mixing of the prepared photo-Fenton catalyst with hydrogen peroxide under a light condition to degrade organic simulated pollutants. The method of the invention is simple and practical; the catalyst is suitable for recycle, can both effectively remove chroma of polluted water, and reduce COD of the polluted water.

The invention relates to a method for preparing lithium ion battery membrane via radiation grafting modification by using a polypropylene film, belonging to the technical field of high polymer material modification. The method comprises the main processes of: (1) preparing a grafting reaction reagent system and using methacrylic acid shrinkage glyceride with the volume ratio of 15 percent, solvent N,N-dimethylformamide with the volume ratio of 85 percent and a proper amount of inhibitor ammonium ferrous sulfate to form the reagent system; (2) placing a polypropylene film to be processed in a polyethylene bag, filling with nitrogen and placing in an electron irradiation room after being sealed for irradiation, wherein the electron beam intensity is 2mA and the irradiation dose is 100kGy; and (3) placing the irradiated polypropylene film in the mixed solution of the reaction reagent system, performing grafting reaction for 2 hours under the condition of constant-temperature water bath at 50 DEG C, washing and drying to obtain the polypropylene battery membrane via grafting modification. The membrane has favorable electrochemistry property via constant-current charging and discharging test in the lithium ion battery.

The invention relates to a method used for quantitative analysis on vanadium in high-chromium alloy, in particular to the method used for the quantitative analysis on vanadium in hydrogen storage alloy, belonging to the analytical chemistry field. The technical problem to be solved is that the interference of vanadium is eliminated and the content of the vanadium in the high-chromium alloy is exactly and quantitatively analyzed. The analysis method adopts solution mixed by sulfuric acid, nitric acid and hydrochloric acid to dissolve the high-chromium alloy, then takes ethanol as a masking agent and uses ammonium ferrous sulfate to carry out titration analysis on the content of the vanadium; wherein, the proportion of the mixed solution of sulfuric acid, nitric acid, hydrochloric acid and water is 4-6:2-3:4-6:10-15. The analysis method has simple and convenient operation, is easy to be handled, eliminates the chromium interference, enlarges the applicable range of the existing method used for measuring the content of vanadium by the ammonium ferrous sulfate volumetric method, and provides a new method for quantitatively analyzing the content of the vanadium in the high-chromium alloy, especially in the hydrogen storage alloy.

The invention provides a preparation method of a fiber carrier-based western blotting calcium alginate hybrid gel membrane. The preparation method comprises the following steps: putting fibers in an aqueous solution of acrylic acid, adding a polymerization inhibitor ammonium ferrous sulfate, letting nitrogen in, irradiating with an ultraviolet lamp for 0.2-1h to obtain polyacrylic acid grafted fibers, and neutralizing with an aqueous solution of sodium hydroxide to obtain sodium polyacrylate grafted fibers; preparing a mixed aqueous solution containing proteins with the mass percentage concentration of 0.1-5%, sodium alginate with the mass percentage concentration of 2-5% and a water-soluble additive with the mass percentage concentration of 0.05-5%, and simultaneously preparing an aqueous solution of calcium chloride with the mass percentage concentration of 1-10%; and immersing the sodium polyacrylate grafted fibers in the mixed aqueous solution of the proteins, the water-soluble additive and sodium alginate, then immediately putting the fibers in the aqueous solution of calcium chloride to make the fibers crosslink for 0.5-2h, and washing off the template proteins to obtain the fiber carrier-based western blotting calcium alginate hybrid gel membrane.

The invention provides a multifunctional palygorskite base adsorbing material, which takes palygorskite clay as a carrier, a compound of cane sugar, beta-cyclodextrin and chitosan as a carbon source, and ammonium ferrous sulfate hexahydrate as a catalyst, and is prepared by a direct roasting method. Proven by experiments, the composite material has the efficacy of efficiently removing organic matters, heavy metal ions, colors and odors. Thus, the composite material has great application potential in the aspects of treating wastewater, such as toxic organic matters, heavy metal ions, dyes and the like.

The invention belongs to a measuring method of divalent cobalt content in lithium cobalt oxide in the metallic ion quantitative detection field; the measuring method is characterized in that: total cobalt content and trivalent cobalt ion content in the lithium cobalt oxide are respectively measured, and then the total cobalt content subtracts the trivalent cobalt ion content for obtaining the divalent cobalt content in lithium cobalt oxide; wherein, the measuring method of the total cobalt content in the lithium cobalt oxide adopts ethylenediamine tetraacetic acid (EDTA) chelatometrie volumetric method, an iodometry method or a potassium ferricyanide oxidimetry method, and the measuring method of the trivalent cobalt ion content in the lithium cobalt oxide adopts an ammonium ferrous sulfate oxidimetry method. The measuring method in the invention makes up the disadvantage that the prior art has no measuring method of divalent cobalt content in lithium cobalt oxide and provides a measuring method of divalent cobalt content in lithium cobalt oxide in the metallic, wherein the method has simple operation, easy judgment of a finishing point and accurate measuring result, thereby providing powerful reference for judging the purity of the lithium cobalt oxide products and ensuring the lithium cobalt oxide products to have good electro-chemical performance.

The invention discloses a method for measuring silicon dioxide content in solution. The method comprises the following steps of: preparing a series of standard solution of silicon dioxide with the concentration of below 5ppm in colorimetric tubes respectively; diluting the solution to a scale by using distilled water; adding sulfuric acid to regulate the pH of the solution to be measured to be 1.2; adding excessive solution of ammonium molybdate; shaking uniformly and standing for 20 to 30 minutes; adding excessive solution of oxalic acid; immediately adding excessive solution of ammonium ferrous sulfate; shaking uniformly and standing for 15 minutes; taking blank solution into which SiO2 is not added as reference solution, measuring the absorbance on a spectrophotometer and drawing a silicon dioxide standard curve; adding a proper amount of solution to be measured into a colorimetric tube; adding the sulfuric acid to regulate the pH to be 1.2; adding the excessive solution of ammonium molybdate; shaking and standing for 20 to 30 minutes; adding the excessive solution of oxalic acid, and immediately adding the excessive solution of ammonium ferrous sulfate; shaking uniformly and standing for 15 minutes; taking the same blank solution as the reference solution and measuring the absorbance on the spectrophotometer; and calculating the silicon dioxide content in the solution according to the drawn silicon dioxide standard curve and the measured absorbance of the solution to be measured.

The invention provides a method for measuring the vanadium content of silicon ferrovanadium, which includes the steps: (a) mixing silicon ferrovanadium and nitric acid, adding hydrofluoric acid into mixture, heating the mixture to completely dissolve the silicon ferrovanadium, adding sulfuric acid into the mixture, heating the mixture until the moment of smoking, and afterwards cooling the mixture; (b) adding phosphoric acid into the mixture, heating the mixture until smoking, keeping smoking for a period of time and cooling the mixture; (c) adding sulfuric acid into the mixture, cooling the mixture, adding potassium permanganate solution into the mixture until appearing of stable red and allowing the mixture to stand for a period of time; (d) adding urea solution into the mixture, dripping sodium nitrite solution into the mixture to reduce excessive potassium permanganate, excessively adding 1-3 drops of sodium nitrite solution and then allowing the mixture to stand for a period of time; (e) adding N-phenyl o-aminobenzoic acid indicators into the mixture and then dripping ammonium ferrous sulfate standard solution into the mixture to obtain a titration endpoint when the mixture is light green; and (f) computing the vanadium content according to the formula.

The invention discloses a treatment agent for treating heavy metal sewage, and a preparation method and an application thereof, and belongs to the field of sewage treatment. The preparation method comprises the following steps: 1, grinding bentonite and active carbon, and taking 90 mesh particles for later use; 2, dissolving polyaluminum chloride, iron trichloride and sodium dihydrogen phosphate in deionized water, and stirring; 3, adding a stabilizer to a mixed solution obtained in step 2, uniformly stirring the obtained solution, adding ammonium ferrous sulfate and sodium carbonate, stirring the obtained solution, carrying out water bath heating until the temperature of the stirred solution is 35DEG C, adding polyurethane, carboxymethylcellulose sodium and acrylamide, stirring the obtained solution, and standing the stirred solution; and 4, adding a solid mixture obtained in step 1 to a mixed solution obtained in step 3, stirring, the obtained solution, and drying the stirred solution to prepare particles which are the treatment agent for treating the heavy metal sewage. The sewage treatment agent prepared in the invention has the advantages of good stability, very strong adsorption effect on heavy metal ions, no secondary pollution, good purification effect, and suitableness for industrial production.

The invention discloses a preparation method of a magnetic mesoporous carbon nitride adsorbent and a method for removing perfluorooctane compounds in water. The method comprises the following steps of: based on mesoporous carbon nitride as a matrix, and ammonium ferrous sulfate and ammonium ferric sulfate as an iron source, adjusting the alkaline environment of the liquid by ammonia water; and performing co-precipitin reaction in water bath condition. The saturation magnetization of the magnetic mesoporous carbon nitride prepared is 6.37emu / g. The magnetic mesoporous carbon nitride is used for removing perfluorooctane compounds [PFOS (Perfluorooctane sulfonates)] and [PFOA (Perfluorooctanoic acid)] in water, so that a good removal effect is obtained and adsorption equilibrium is quickly realized. Meanwhile, the magnetic mesoporous carbon nitride adsorbent provided by the invention can be recovered by additionally applying a magnetic field to the benefit of repeated use. The adsorbent provided by the invention has an important meaning for adsorption removal of perfluorooctane compounds, and has a good application prospect in wastewater treatment.

A combined determination method for main components in high-carbon ferrochrome slag. The method is characterized by comprising the steps of: melting a high-carbon ferrochrome sample by a iron crucible; carrying out high-temperature melting decomposition by sodium peroxide; leaching in a 250ml plastic cup filled with water; acidifying and clarifying with sulfuric acid; placing at room temperature to obtain a high-carbon ferrochrome sample mother liquor; conducting constant volume analysis on the high-carbon ferrochrome mother liquor; decomposing the sample at one time; and respectively measuring the chemical composition of SiO2, Al2O3, MgO, CaO and Cr2O3 by 1) determination of Cr2O3 by potassium permanganate oxidation and ammonium ferrous sulfate titration method, 2) determination of SiO2 by a silicon molybdenum blue spectrophotometric method, and 3) determination of Al2O3, MgO and CaO by an EDTA volumetric method. The method greatly reduces the analysis time (determination of SiO2, Al2O3, MgO, CaO and Cr2O3 within four hours), while omits weighing and analysis of Al2O3 by a nickel crucible, and saves a lot of cost analysis.

The invention discloses a method for reducing nitrogen loss during the composting process, which belongs to the field of aerobic composting of solid organic wastes. The method comprises the following steps: initially mixing livestock and poultry feces and accessories as raw materials for composting; adding sulfur powder and ferrous sulfate as mixed stacking materials, and using a stirring machinefor evenly stirring the mixed stacking materials; spraying thiobacillus thioparus bacterial liquid during the stirring process of the mixed stacking materials; and carrying out composting and fermentation treatment when water content of the mixed stacking materials is controlled between 50% and 55%. The method reduces the nitrogen loss during the high-temperature composting process of the livestock and poultry feces, reduces odor generated by volatilization of ammonia and hydrogen sulfide, increases content of available nutrients of a composting finished product, further obtains an organic-inorganic compound fertilizer containing an ammonium ferrous sulfate complex salt, improves the quality of agricultural composting and is conductive to absorption of crops.

The invention relates to a compound plugging agent for oil well water control and a preparation method of the compound plugging agent. The preparation method comprises the following steps: adding water into a reactor, adding one or two of acrylic acid, N, N-methylenebisacrylamide and polyethylene glycol diacrylate while stirring until complete dissolution is achieved, slowly adding micron-sized granular montmorillonite or / and kaolin, after montmorillonite or / and kaolin is uniformly dispersed, dropwise adding ammonium ferrous sulfate and hydrogen peroxide, reacting for 1 hour at room temperature, finally adding sodium hydroxide for neutralizing to be neutral to obtain floccules and carrying out centrifugal drying on the floccules to obtain a nano(micro)-sized water-control compound temporary plugging agent. The temporary plugging agent can be used as a water-control temporary plugging agent in refracturing, plug removal and acidizing measures of old oilfields subjected to waterflooding development, the temporary plugging agent is injected from the oil well of which the moisture content is 20-40% to plug dominant waterflooding channels in medium-moisture-content and high-moisture-content oil wells and thus the purpose of measure water control in the medium-moisture-content and high-moisture-content oil wells is achieved.

The invention relates to a method for cleanly extracting vanadium pentexide from a vanadium containing material. The method is characterized in that: the vanadium containing material is milled by the wet method, and then mixed with a certain weight amount of sulfuric acid, vanadic acid, water, sulfuric acid or phosphoric acid salt having certain association; under conditions of set temperature and set time, performing three-stage reflux leaching reaction of the mixture; adding ammonia sulfate and reducing iron powder to reaction leach solution in sequence to obtain aluminum ammonium sulfate crystals and ammonium ferrous sulfate crystals respectively; adding sulfuric acid to the solution in which aluminum and iron are separated out, cooling the solution for crystallization to obtain vanadium sulfate acyl crystals, and returning the mother liquor to extract vanadium ores; performing the neutralization reaction of the vanadium sulfate acyl crystals and ammonia water to obtain a precipitate of vanadium hydroxide, and returning the solution of ammonia sulfate to precipitate the aluminum and iron; and calcining the vanadium hydroxide and oxygen gas at a high temperature of over 300 DEG C to obtain the vanadium pentexide. The method has the advantages of short process flow, less energy consumption, high vanadium yield, low production cost, environmental protection, and comprehensive utilization of valuable metallic elements in ores.

The invention discloses dedicated chemical fertilizer for grape. The dedicated chemical fertilizer is prepared from the following components in parts by weight: 25 to 30 parts of nitrogen fertilizer, 10 to 15 parts of phosphate fertilizer, 20 to 25 parts of potash fertilizer, 8 to 10 parts of magnesium sulfate, 20 to 30 parts of straw, 8 to 10 parts of sugar beet pulp, 5 to 10 parts of boron-magnesia fertilizer, 3 to 5 parts of zinc sulfate, 1 to 3 parts of chelate zinc, 3 to 5 parts of copper amino acid chelate, 3 to 5 parts of ammonium ferrous sulfate, 3 to 5 parts of humic acid, 3 to 5 parts of manganous sulfate, 3 to 5 parts of ammonium molybdate, 3 to 5 parts of amino acid, 1 to 3 parts of cnidium lactone and the like. The invention belongs to the technical field of agricultural fertilizer, and particularly provides the dedicated chemical fertilizer for the grape, which is comprehensive and balanced in nutrient, high in pertinence, and capable of effectively improving the structure of soil, increasing the yield of the grape, preventing and controlling plant diseases and insect pests and improving freezing resistance of grape plants, and a preparation method of the dedicated chemical fertilizer.

The invention provides a preparation method of FeWO4 nanowire. The method comprises the following steps: adding ammonium ferrous sulfate into distilled water to obtain ammonium ferrous sulfate solution; adding PVPK30 (polyvinyl pyrrolidone 30) into the ammonium ferrous sulfate solution to obtain a solution A; adding sodium tungstate and dimethyl formamide into distilled water to obtain a mixed solution B; dropwise adding the solution B into the solution A and pouring into a hydrothermal reaction kettle after uniform magnetic stirring, and the filling degree is controlled in the range of 60-80%; then sealing the hydrothermal reaction kettle, controlling the hydrothermal temperature at 160-190 DEG C, and reacting for 14-36 hours; naturally cooling to room temperature after finishing the reaction; filtering and collecting the product, and then washing the product with deionized water and anhydrous ethanol respectively; and drying at 40-80 DEG C to obtain the final product FeWO4 nanowire. The preparation method provided by the invention adopts a simple hydrothermal synthesis process to prepare FeWO4 nanowire by adding the template agent PVPK30. Not only is the preparation cost greatly reduced, but also the process is simple, the operation is convenient and the raw material is easy to get. The prepared FeWO4 nanowire has good crystallization and repeatability, with the diameter all about 10 nanometers and the length several hundred nanometers.

The invention discloses an efficient compound on-tree preservative agent for glorious oranges and a preparation method thereof, and the preservative agent comprises the following components in parts by weight: 0.7-2.0 parts of 2,4-sodium dichlorophenoxy acetate, 0.3-1.0 part of sodium bicarbonate, 28-40 parts of compound amino acid powder, 15-26 parts of boric acid, 4-12 parts of zinc sulfate, 7-18 parts of ammonium ferrous sulfate and 6-40 parts of potassium sulfate. The preparation method comprises the following steps: a) weighing the components; b) premixing the 2,4-sodium dichlorophenoxy acetate and the sodium bicarbonate in parts by weight; c) premixing the remaining components in parts by weight; d) mixing the mixtures obtained in the steps b and c again; and e) baking the mixture obtained in the step d in a baking oven at 50-60 DEG C, enabling the moisture content of the mixture to be less than or equal to 5 percent, crushing, sieving, inspecting, packaging, and obtaining the product. The on-tree preservative agent has good effect, convenient use, simple preparation method, low cost, no pollution to the environment and long shelf life.

The invention relates to a method for measuring iron content in inorganic mineral, particularly relates to a method for measuring iron content in kaolin through using a spectrophotometer, and the method is simple and convenient in operation, and rapid and accurate. The method comprises the following steps: melting a test sample with sodium hydroxide at a high temperature, and acidifying with hydrochloric acid to obtain a sample solution; placing ammonium ferrous sulfate hexahydrate in a beaker, adding hydrochloric acid and water, dissolving, placing into a volumetric flask, adding water to a constant volume to obtain a standard iron storage solution, and diluting to obtain a standard iron solution; transferring standard iron solutions of different volumes into a set of 50mL volumetric flasks, diluting with water to about 15mL, adding a mixed color development solution, adding water to a constant volume, transferring into an absorption vessel after 15min, measuring absorbance with a spectrophotometer at a wavelength of 510nm, and calculating the slope of a standard iron working curve; and measuring absorbance and blank absorbance of the sample solution, and then calculating the iron content in kaolin.

The invention relates to an analysis method of chromium content in a chromium additive for an aluminum alloy, solving the problems of an existing detection method of the chromium content in the chromium additive that the cost is high, the detected result is not accurate and the efficiency is low. The analysis method comprises the following steps of: titrating a potassium dichromate standard solution by an ammonium ferrous sulfate standard solution by consuming the ammonium ferrous sulfate standard solution with the volume of V1; utilizing the ammonium ferrous sulfate standard solution to titrate a chromium element in a chromium additive sample by consuming the ammonium ferrous sulfate standard solution with the volume of V; and calculating to obtain the chromium content by using a formula W%=C*V*M / 3m, wherein C is the concentration of the ammonium ferrous sulfate standard solution, M is the molar mass of the chromium, and m is the mass of the chromium-powder additive sample. According to the invention, by utilizing a titration method, the analysis method has the advantages of simplicity in operation, capabilities of saving cost and improving efficiency, less interference and accurate detected result, and can solve the problems that the existing detection method is high in cost, inaccurate in the detected result and low in efficiency, thereby meeting the requirements of the modern industry production.

The invention discloses a reagent for measuring chemical oxygen demand (COD) and a method for preparing digestion solutions of the reagent. The reagent comprises an H reagent silver sulfate and a J reagent, wherein the mass fraction of potassium dichromate in the J reagent is 28.0%-36.0% and the mass fraction of mercury sulfate in the J reagent is 64.0%-72.0%. The preparation method of the digestion solutions of the reagent comprises the following steps: adding 1g of silver sulfate into 100ml of concentrated sulfuric acid to prepare the digestion solution of the H reagent; the preparation method of the digestion solution of the J reagent comprises the steps of dissolving the J reagent into 80mL-100mL of distilled water, adding 6.00mL-10.00mL of concentrated sulfuric acid, cooling until the temperature reaches a room temperature after dissolving, and then diluting by use of water until 120mL of solution is achieved. The dosage of the digestion solutions prepared by use of the J reagent and the H reagent of the reagent for measuring COD is greatly reduced so that the analysis cost can be greatly reduced. Compared with the national recommended standards, an ammonium ferrous sulfate standard titration solution does not need to be prepared for titration, and the analysis steps are simplified, and the reagent for measuring COD is simple, convenient and quick, and meets the requirements of an enterprise on fast detection.

The invention discloses a modified Teflon fiber metal complex catalyst and a preparation method thereof. According to the method, teflon fiber is graft-modified with a mixed water solution of crylic acid with the volume concentration of 300-500g / L and ammonium ferrous sulfate with the volume concentration of 15-50g / L, and then the modified fiber reacts with 0.025-0.075mol / L ferric ion and 0.025-0.07mol / LCu ion to generate a complex which is the catalyst, wherein the content of the ferric ion is 46.43-125.1mg / g, and the content of the Cu ion is 78.54-110.2mg / g; and the crack intensities of thecatalyst in dry state and wet state are respectively 91.25-92.56N and 91.11-91.79N. The preparation method comprises the following steps: 1. pre-treating the fiber; 2. graft-modifying the fiber; 3. preparing a metal ion mixed water solution; and 4. carrying out complexing reaction on the graft-modified fiber and the metal ion.

The invention relates to a method for determining the content of silicon dioxide in rubber through a spectrophotometer. The method comprises the steps as follows: subjecting a rubber sample to ashing treatment; adding potassium hydroxide into the ashed sample for treatment so as to convert silicon in the sample into soluble silicate; then reacting a silicon-containing solution with ammonium molybdate in a hydrochloric acid medium; then using ammonium ferrous sulfate for reducing a reaction product in the last step to silicon molybdenum blue, and measuring the absorbance of the silicon molybdenum blue in a position with a set wavelength of 700-880 nm. The method is applied to all rubber except silicon-containing rubber.