93 results about "Ferrous ammonium sulfate" patented technology

A corrosion-inhibited fire retardant composition is provided that comprises at least one ammonium polyphosphate, at least one suspending agent, at least one phosphonate selected from a group consisting of aminotri(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, hexamethylenediaminetetra(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), salts thereof, and mixtures thereof and a corrosion inhibiting system. The corrosion inhibiting system is comprised of at least one corrosion inhibiting compound selected from a group consisting of azoles, insoluble ferric pyrophosphate, soluble ferric pyrophosphate, ferrous oxalate, ferric citrate, ferrous sulfate, ferric ammonium citrate, insoluble ferric orthophosphate, soluble ferric orthophosphate, ferric ammonium oxalate, ferric ammonium sulfate, ferric bromide, ferric sodium oxalate, ferric stearate, ferric sulfate, ferrous acetate, ferrous ammonium sulfate, ferrous bromide, ferrous gluconate, ferrous iodide, ferric acetate, ferric fluoroborate, ferric hydroxide, ferric oleate, ferrous fumarate, ferrous oxalate, ferrous oxide, ferric lactate, ferric resinate, and any combination thereof. Methods of making and using the same are also described. In addition, agricultural plant nutrients comprising the same are provided.

Corrosion-inhibited fire retardant compositions and methods of making and using the same are provided. The corrosion-inhibited fire retardant compositions are comprised of at least one fire retardant component, at least one biopolymer having a particle size diameter of less than about 100 microns, and a corrosion inhibiting system. The corrosion inhibiting system is comprised of at least one corrosion inhibiting compound selected from a group of compounds including azoles, insoluble ferric pyrophosphate, soluble ferric pyrophosphate, ferrous oxalate, ferric citrate, ferrous sulfate, ferric ammonium citrate, soluble ferric orthophosphate, insoluble ferric orthophosphate, ferric ammonium oxalate, ferric ammonium sulfate, ferric bromide, ferric sodium oxalate, ferric stearate, ferric sulfate, ferrous acetate, ferrous ammonium sulfate, ferrous bromide, ferrous gluconate, ferrous iodide, ferric acetate, ferric fluoroborate, ferric hydroxide, ferric oleate, ferrous fumarate, ferrous oxide, ferric lactate, ferric resinate and any combination thereof. In a specific embodiment, the corrosion-inhibited fire retardant composition includes a xanthan biopolymer.

The invention relates to a method of mensurating the content of chrome in tungsten matrix which is added with the chrome and vanadium separately or synchronously. The method is characterized in that a sample is melted by sodium dioxide and is soaked in hot water; meanwhile, the sodium dioxide is also used as oxidant to oxidize the chrome into high valence chrome; ammonium bifluoride is used for complexing main body tungsten and avoiding tungstenic acid cementing out; the whole analysis process avoids the occurrence of precipitation and opacification; titration can be carried out under completely limpid and transparent state; and titration result is exact and reliable. The limpid and transparent solution during the titration is very important to the accuracy of titration analysis. The solution is always limpid and transparent during the whole mensuration process, thereby ensuring that the interference of the vanadium is eliminated exactly and quantitatively when the chrome is mensurated. After the interference of the vanadium is oxidized by potassium permanganate, ferrous ammonium sulphate standard solution is used for titrating to eliminate by a subtraction method. The mensurating method ensures that the mensuration is carried out under the completely limpid and transparent state, and the method eliminates the interference of the vanadium completely and quantitatively and improves the accuracy and the speed for detecting the content of the chrome in the tungsten matrix which is added with the chrome and the vanadium separately or synchronously.

The invention discloses a method for measuring the chemical oxygen demand of waste water, which comprises the following steps: preparing standard solution of potassium dichromate, ferroin indicator solution, standard solution of ammonium ferrous sulfate, solution of sulfuric acid-silver sulfate and mercuric sulfate; diluting the mercuric sulfate in a water sample, adding the standard solution of potassium dichromate and a plurality of cleaned glass balls in a certain proportion; adding the solution of sulfuric acid-silver sulfate; heating the solution into an autoclave; after keeping the solution at a certain temperature and under a certain pressure for a period of time, adding water to continuously cool to room temperature; adding the ferroin indicator solution, performing titration through the standard solution of ammonium ferrous sulfate; recording the dosage of the standard solution of ammonium ferrous sulfate according to color changes; performing a blank experiment through distilled water according to the same operating steps; and recording the dosage of the standard solution of ammonium ferrous sulfate in blank titration. The method has the advantages of time conservation, and simple requirements on test conditions.

The present invention discloses a repairing agent of a saline alkali land for planting cotton. The components in the formula of the repairing agent comprise, by weight, 28-44 parts of desulfuration gypsum, 20-35 parts of a microbial agent, 5-11 parts of polyacrylate potassium, 25-45 parts of silica, 16-32 parts of sodium-based bentonite, 3-7 parts of sulfur, 8-19 parts of soluble humic acid, 4-12 parts of ferrous ammonium sulfate, and 8-17 parts of amino acid powder. According to the present invention, with the added soluble humic acid, the added ferrous ammonium sulfate and the added amino acid powder, the soil can be further improved, the growth environment of the cotton can be improved, the salt rejection rate of the soil can be increased, and the growth of the cotton can be promoted; and the rich raw materials are used to replace the single raw material in the traditional repairing agent, such that the repairing time of the saline alkali land can be substantially shortened, and the repairing agent and the repairing method can be widely promoted and used.

The invention provides a method for preparing micaceous iron oxide, which has the advantages of controllable grain size and color change, high purity, complete and reliable production process, easy operation and high resource utilization rate, by a molten salt growth method. In the method, ammonium ferrous sulfate or ferrous sulfate or a mixture of ammonium ferrous sulfate and ferrous sulfate serving as an iron source and sulfates or chlorides or a mixture of sulfates and chlorides serving as a fluxing agent are mixed and melted to form the micaceous iron oxide, wherein the main component of the micaceous iron oxide is a-Fe2O3. The method has the advantages of low cost, easy operation, complete process, no toxicity, high chemical stability, high purity, high crystallinity, high heat resistance, easy realization of industrialization and the like.

The invention relates to a water gel modified anti-protein pollution ultrafiltration membrane and a preparation method thereof. Vinyl materials (CH2=CH(CONH2)n, wherein n is greater than 1 but smaller5) containing multiamides groups at the lateral chain are used as monomers; ferrous ammonium sulphate are used as polymerization inhibitors; water and methanol are used as solvents; through ultraviolet radiation grafting, a gel layer with hydrophilicity is obtained on the surface of the PVDF ultrafiltration membrane. The initial contact angle of the modified membrane surface is reduced to 55 degrees from the initial 120 degrees, and can reach 0 degree in 10 to 12s; the water flux restoration rate can reach 90 to 99 percent. The surface of the prepared separation membrane has excellent anti-protein pollution capability; the biocompatibility is relatively good. Compared with a conventional method of coating water gel onto the surface of the membrane, the method has the advantages that the gel layer grafted onto the surface of the membrane has more excellent stability; the preparation method is simple; the addition of chemical crosslinking agents is not needed; the performance is stable;the cleaning is easy.

The invention relates to a method for measuring COD in high-chlorinated water by a chlorine oxygen consumption curve correction-sealed digestion method. The method comprises the following steps: (1) preparing sodium chloride solutions of different concentrations; (2) adding the sodium chloride solution to In the pressure dissolution bomb, add MnSO4, potassium dichromate solution, and concentrated sulfuric acid in sequence, and digest it together with the distilled water blank in a drying oven at a constant temperature; (3) Take out the pressure dissolution bomb, and after cooling, titrate with ferrous ammonium sulfate solution to calculate the COD (4) take Cl-concentration as the abscissa and COD (Cl) as the ordinate, draw the chlorine oxygen consumption curve; (5) process the high chlorine water sample to be tested according to step (2) and step (3) successively , to obtain the apparent COD value; according to the Cl- content in the high-chlorinated water sample to be tested, the COD(Cl) value is obtained from the chlorine oxygen consumption curve, and the apparent COD value is subtracted from the COD(Cl) value to obtain the high-chlorinated water sample to be tested. The actual COD value of the water sample. The invention has the advantages of simple operation, good reproducibility, good accuracy, saves time, reduces pollution, and is easy to realize batch measurement.

A method for determining chromium content in a tungsten matrix with singly or simultaneously added chromium and vanadium, characterized in that a test sample is subjected to melting with sodium peroxide and hot water leaching; meanwhile said sodium peroxide is also used as an oxidizing agent to oxidize all the chromium to high valences; the main body of tungsten is coordinated by ammonium hydrogen fluoride to prevent tungstic acid from precipitating; precipitation and turbidity are avoided throughout the analysis, titration can be carried out in a quite clear condition with accurate and reliable results. In this invention, the clearness of the solution when titrating is very important for the accuracy of titrimetric analysis; the solution is always clear throughout the determination, ensuring that the interference with determination of chromium from vanadium is accurately and quantitatively eliminated; the interference from vanadium is eliminated by subtraction method, by means of titrating with ferrous ammonium sulfate standard solution after oxidation with potassium permanganate. In this invention, the determination method allows the determination to be carried out in the quite clear condition, and eliminates the interference from vanadium completely and quantitatively, thus the accuracy and speed of the determination of chromium content in a tungsten matrix with singly or simultaneously added chromium and vanadium are improved.

The invention discloses an adhesive for a corrugated cardboard and a preparation method, and belongs to the technical field of cardboard manufacturing. The adhesive for the corrugated cardboard comprises, by weight: 30-40% of plant starch, 1-2% of an epoxy resin, 0.1-0.5% of a toughening agent, 0.4-0.8% of a sodium hydroxide solution, 0.5-0.8% of carboxymethyl cellulose, 0.5-1% of an antiseptic, and 0.01-0.02% of ammonium ferrous sulfate, with the balance being water. The adhesive for the corrugated cardboard has advantages of high bonding speed, firm bonding, quick drying, gelation simplicity, and easy and uniform application. The adhesive is simple to prepare and convenient to use; the manufacturing efficiency is high; and the cost is low. The adhesive does not precipitate and mould, and is stable in quality and long in service life. The firmness of the prepared corrugated cardboard can reach 5-6 kg / cm. The invention also discloses a preparation method of the adhesive for the corrugated cardboard.

The invention discloses magnetic meso-porous silicon. A preparation method of the magnetic meso-porous silicon comprises the steps of reacting by taking tetraethoxysilane as a silicon source, ammonium ferrous sulfate as an iron source and an F-127 block polymer as a template, separating to obtain a meso-porous compound, adding an oxidant, reacting, filtering, drying and firing to obtain the magnetic meso-porous silicon which is even in magnetic distribution. The invention also provides a magnetic meso-porous silicon adsorbent. A preparation method of the magnetic meso-porous silicon adsorbent comprises the steps of performing polymeric oxidizing reaction through the magnetic meso-porous silicon, ammonium persulfate and phenylamine under an acid condition, then washing, filtering and drying to obtain the magnetic meso-porous silicon adsorbent; and the preparation method is simple and saves the reaction time. The invention also provides an application of the magnetic meso-porous silicon adsorbent in removal of heavy metal ions in water; and the magnetic meso-porous silicon adsorbent is strong in adsorption force of heavy metals and large in adsorption capacity.

The invention relates to a determination method for the content of silicon in a high strength aluminum welding wire. The content of silicon in the high strength aluminum welding wire is determined by a spectrophotometric method. The determination method comprises the following steps: (1) sampling; (2) adding water and sodium hydroxide, heating until the sample is completely and clearly dissolved, and cooling; (3) acidizing; (4) heating to boil, removing nitrogen oxides, cooling, and diluting; (5) dividing the sample solution into colorimetric tubes, adding nitric acid and ammonium molybdate solution, and performing water bath; (6) cooling by running water, adding sulfuric acid-ammonium oxalate solution and ferrous ammonium sulphate solution, diluting with water to the mark, and shaking uniformly; (7) preparing a reagent blank along with the experiment; and (8) drawing a standard curve; determining an absorbance, and calculating a numerical value by the standard curve. A spectrophotometer is used for successfully determining the mass content of silicon in the high strength aluminum welding wire, a determining range of the mass content is 1.00% to 7.00%, and the accuracy is comparable to that of a gravimetric measurement method. The method saves a lot of analysis time and also increases silicon measurement method types.

The invention relates to a remedy method for the mistakes in vanadium content determination with ammonium ferrous sulfate volumetric analysis, which comprises the following steps: the vanadium in the solution to be test that is over-titrated or is titrated insufficiently is oxidized to be V5+ with potassium permanganate, while the chromium in the solution is not oxidized; the excessive potassium permanganate is deoxidized with sodium nitrite with the existence of urea; meanwhile, the excessive sodium nitrite is also decomposed with the existence of urea, thus the interference of excessive sodium nitrite to titration is eliminated; then n-phenylanthranilic acid is used as indicator and the vanadium is re-titrated with ammonium ferrous sulfate standard solution. The invention corrects the titration mistakes in vanadium content analysis operation, wherein, the mistakes results from the concentration of the chosen ammonium ferrous sulfate titrating solution does not matched with the vanadium content in the sample, or titration end-point is judged inaccurately, or other reasons. Compared with the prior international standard, the invention has the advantages of enlarged determination range, reduced reworking rate in operation, and better service for scientific research and production. The invention is suitable for vanadium content determination in sample of total vanadium content more than 1.00% and chromium content less than 1.00%.

The invention discloses a cultivation method for pleurotus eryngii and belongs to the cultivation field of pleurotus eryngii. The method comprises the following parts: straw, bean dregs, coal ashes, lime, ammonium ferrous sulfate, cottonseed casing, wood chips, cinnamyl acetate, orange peel powders, biogas residues and water. The method comprises the following preparation steps: A, adding straw, bean dregs, wood chips, orange peel powders and biogas residues into water, stirring and standing the mixture to obtain a mixed solution; B, adding coal ashes, lime, cottonseed casing, cinnamyl acetate and ammonium ferrous sulfate into the mixed solution obtained in the step A, and stirring the solution to make the solution to be pasty; C, machining the pasty solution into a cylinder and drying the cylinder at the temperature of 100-120 DEG C to obtain a pleurotus eryngii medium. According to the technical scheme of the invention, the compositions of the medium are extensive in source, low in cost and easily obtained. Cultivated pleurotus eryngii is good in growth vigor and obviously shortened in cultivation period. Therefore, the method is suitable for large-scale production.

The invention discloses a method capable of accurately measuring chemical oxygen demand in water. Accurately absorb 10.00mL of potassium dichromate standard solution into a 500mL conical flask, add water to dilute to about 110mL, slowly add 30mL of concentrated sulfuric acid, and add 3 drops of test Ferrous spirit indicator solution, titrate with ferrous ammonium sulfate solution, the color of the solution changes from yellow to blue-green to reddish brown as the end point; add 5g of silver sulfate to 500mL of concentrated sulfuric acid; take 20.00mL of uniformly mixed water sample and place it in 250mL Accurately add 10.00mL potassium dichromate standard solution and a few small glass beads or zeolite to the ground-mouth reflux conical flask, connect the ground-mouth reflux condenser, and slowly add 30mL sulfuric acid-silver sulfate solution from the top of the condenser Get 20.00mL double distilled water, do blank test according to the same operation steps, record the consumption of ferrous ammonium sulfate standard solution when titrating the blank, you can get the chemical oxygen demand in the water. The method can accurately measure the chemical oxygen demand in water, determine whether it meets the requirements of environmental protection, and avoid direct discharge into the environment to cause environmental pollution.

The invention relates to a method for preparing an electrode material of a lithium-ion-mixed capacitor. The method comprises: a water solution having ammonium ferrous sulfate and iminodiacetic acid is placed in a reaction still, reaction is carried out under a certain temperature, and a precursor Fe-IDA is generated; the precursor Fe-IDA is cleaned and dried and then is placed in a tube furnace with argon protection, an annealing experiment is carried out to obtain a negative electrode material Fe3O4@C; the negative electrode material is corroded in a dilute acid solution, thereby obtaining positive-material porous carbon; and the positive electrode, the negative electrode, and a diaphragm are arranged in a button battery, the button battery is placed into a lithium hexafluorophosphate solution as an electrolyte, and packaging is carried out to obtain a lithium-ion-mixed capacitor. According to the invention, the negative electrode material and the positive electrode material of the lithium-ion-mixed capacitor are prepared by one way, so that problems of long preparation time, high cost, and compatibility of capacities and volumes of the positive electrode and negative electrode can be solved. The prepared lithium-ion-mixed capacitor has advantages of wide operating voltage range, excellent performances, high energy density, and ultra-high power density.

The invention provides a soil curing method for a saline and alkaline land by using a polyvinyl alcohol soil scarification agent. The soil curing method comprises a step of applying the soil scarification agent, wherein the soil scarification agent comprises the following components in parts by weight: 7-10 parts of polyvinyl alcohol, 2-4 parts of a bacillus licheniformis liquid, 12-19 parts of potato powder, 8-12 parts of modified starch, 6-8 parts of vermiculite, 14-18 parts of medical stones, 5-7 parts of ammonium ferrous sulfate, 2.5-3.5 parts of carboxymethylcellulose, 4-7 parts of gypsum and 6-9 parts of humic acid. The modified starch comprises 60% of acrylic acid modified starch and 40% of acetic acid modified starch. The viable content of the bacillus licheniformis liquid is 0.8 billion / ml. By adopting the soil curing method for curing the land for 4 months, the total porosity of the soil is 54-56% and the volume weight of the soil is 1.35-1.44 g / cm3.

A high molecular weight cationic polyacrylamide chemical polymerization method, the weight of each polymerization component is: solid acrylamide monomer: 490-520kg; DAC cationic monomer: 104-124kg; deionized water: 1356-1956kg; : 1.6-2.0kg; ammonium persulfate: 10-14g; ferrous ammonium sulfate: 6-10g. Ammonium ferrous sulfate with a stable chemical structure is selected as an auxiliary agent for reducing the activation energy of the polymerization reaction. Make the polymerization reaction occur in a large amount at a relatively low temperature, even in the case of low temperature in winter, the polymerization reaction can be completed in about 4 hours, the production is smooth, the molecular weight of the product is stable, and the product has good solubility in water.

The invention discloses a preparation method of a FeNiP / C@ MXene composite negative electrode material for a lithium ion battery. The method comprises the following steps: dissolving nickel acetylacetonate and ammonium ferrous sulfate in ethanol, adding the solution into a solution of N, N-dimethylformamide dissolved with a surfactant and an organic ligand, strongly and magnetically stirring, and transferring the solution into a high-pressure reaction kettle for reacting; carrying out centrifugal separation and vacuum drying to obtain a mixed metal organic framework template; mixing and stirring a template and a pretreated MXene material, and centrifuging to obtain a Fe / Ni-MOF@ MXene precursor; and phosphating and calcining the precursor in a protective atmosphere to obtain the FeNiP / C@ MXene composite material. According to the invention, phosphide is crystallized and nucleated in MOF, the hollow carbon shell provides a sufficient space for the volume change of the internal phosphide, and the MXene at the outermost layer can limit the side reaction of the electrolyte and the phosphide so that initial coulombic efficiency is improved.

The present invention is a kind of preparation method of oil well cement filtrate reducer, comprising the following steps: (1) dissolving lignin in deionized water, adding redox initiator ferrous ammonium sulfate and hydrogen peroxide, feeding nitrogen to initiate; ( 2) Weigh two anionic monomers of acrylic acid and sodium p-vinylbenzenesulfonate, dissolve them in water and adjust the pH to 6-7, add potassium persulfate as an initiator, and feed nitrogen to initiate; (3) Mix the lignin monomer and two kinds of anionic monomers, add aluminum citrate cross-linking agent and continuously feed nitrogen to carry out graft modification; (4) after the reaction is completely finished, add absolute ethanol, demulsify and filter, A solid product was obtained. In the present invention, lignin macromolecules and modified monomers are respectively initiated to increase the grafting rate of the polymerization reaction, and aluminum citrate is used as a crosslinking agent, which is stable and conducive to the production of high-quality products. The method of the present invention is simple and can For a variety of grafting monomers, the feasibility is very high.

The invention relates to a kit and a detection method for rapid outdoor detection of residual oxidant in water. The kit comprises the following components: six ferrous ammonium sulfate hexahydrate centrifugal pipes, each containing 0.392 g of ferrous ammonium sulfate hexahydrate, six hollow centrifugal pipes, six H2SO4 reagent bottles, each containing 5 mL of 6mol / L H2SO4, six potassium permanganate reagent bottles, each containing 10 mL of 0.1 mol / L KMnO4 solution, six disposable filters, each containing a 0.45 mu m filter membrane, six injectors, 24 pasteur pipets, six of which are on standby, and six hollow transparent glass bottles, wherein all the components are put in a box. The kit disclosed by the invention has simple arrangement and low cost, and is convenient to carry; the method is simple, and displays rapid and high-efficiency monitoring effect due to the use of ferrous ammonium sulfate as the reducing agent and potassium permanganate as the oxidant, and the results can be directly read during real-time determination; and the kit is convenient to use, and the kit and the detection method are especially applied to rapid outdoor detection of residual oxidants in water.

The invention discloses a Pleurotus eryngii medium and a preparation method thereof, and belongs to the field of mushroom cultivation. The medium comprises, by mass, stalks, bean dregs, coal ash, lime, ammonium ferrous sulfate, cottonseed shells, sawdust, cinnamyl acetate, orange peel powder, biogas residues and water. The preparation method comprises the following steps: 1, selecting the stalks, the bean dregs, the sawdust, the orange peel powder and the biogas residues, adding the stalks, the bean dregs, the sawdust, the orange peel powder and the biogas residues to water, stirring obtained water, and standing the obtained water to obtain a mixed solution; 2, adding the coal ash, the cottonseed shells, cinnamyl acetate and ammonium ferrous sulfate to the mixed solution obtained in step 1, and stirring the obtained solution to form a paste; and 3, processing the paste obtained in step 2 to form cylinders, and drying the cylinders at 100-120DEG C to obtain the Pleurotus eryngii medium. Composition components of the Pleurotus eryngii medium have wide sources, and are cheap and easily available, and Pleurotus eryngii cultured by using the medium has good growth vigor and obviously shortened cultivation period, so the medium is suitable for large-scale production.

Ferrous sulfate and ferrous ammonium sulfate are known to kill moss and liverwort. They impart acidity in the lawn. Moss grows better in an acidic pH. The current invention proposes a formulation of ferrous sulfate or ferrous ammonium sulfate and zero valent iron with lime. Lime neutralizes the acidity produced by the ferrous salt and keeps the pH of the soil at 7 to 7.5. The formulation produces an immediate effect to eradicate moss and also provides a sustained effect over a long period. Another embodiment contains an addition of antimicrobial agents such as benzalkonium chloride, dichlorophen, and didecyldimethyl ammonium chloride to the ferrous sulfate-lime formulation.

The invention discloses a preparation method of doped lithium iron oxide, and belongs to the technical field of new energy. The preparation method comprises following steps: a lithium hydrogencarbonate solution, an ammonium ferrous sulfate solution, a titanyl sulfate solution, and an acidifying or alkalizing agent are mixed, and are added into a base solution, wherein in the adding process, the pHvalue is maintained to be 7 to 7.5, the temperature is controlled to be 50 to 60 DEG C, and the stirring speed is controlled to be 300 to 400r / min; after material adding, the temperature is increasedto 90 to 95 DEG C, stirring reaction is carried out for 30 to 60min, and filtering washing are carried out to obtain a precipitate; the precipitate is subjected to drying, is introduced into a rotarykiln for calcining at 700 to 900 DEG C for 8 to 10h to obtain a calcined product, wherein air is introduced in calcining; and the calcined product is subjected to crushing, sieving, and removing of iron to obtain the doped lithium iron oxide. According to the preparation method, preparation of the doped lithium iron oxide can be realized, the surface area is large, the activity is high, and the surface is of a porous structure.

The invention relates to an anti-pollution and high-flux modified polymer separation membrane and a preparation method thereof. The preparation method comprises the following steps of adding an acrylic monomer into an ammonium ferrous sulfate aqueous solution to prepare a grafting solution, and putting a polymer separation membrane into the grafting solution, introducing inert gas to remove oxygen, and carrying out electron beam radiation grafting to prepare the modified polymer separation membrane. The acrylic monomer is grafted on the polymer separation membrane through radiation, so that the hydrophilicity of the membrane is obviously improved, and the water content exceeds 3-5 times of that before modification; when the modified polymer separation membrane is used for filtering a BSA solution, the water flux is improved by 20-50% compared with the water flux when pure water is filtered, the flux decline rate is remarkably reduced, and the pollution resistance of the membrane is remarkably improved. The preparation method provided by the invention is simple to operate, low in cost and easy to realize industrial application, and has important significance in promoting the application of the separation membrane.

The invention discloses a method for preparing a graphene / ferric oxide composite material. The method comprises the following steps: (1) putting a mixed solution of deionized water and ethanol amine into graphene oxide, and performing ultrasonic dispersion; (2) dissolving PEG-10000, ammonium ferrous sulfate and hexamethylenetetramine into the mixed solution; (3) placing the mixed solution in a sealed environment, and keeping the temperature of 180-200 DEG C for 15-20 hours; and (4) washing and drying a reactant, thereby obtaining ferric oxide magnetic nano particles. The ferric oxide nano particles prepared by using the method are uniformly dispersed on a graphene layer, so that agglomeration of graphene is effectively avoided, and the prepared graphene / ferric oxide composite material is excellent in photocatalytic degradation activity under radiation of ultraviolet radiation, is good in stability, has ferromagnetic behaviors, and can be effectively separated from dyes under the action of external magnetic fields.

The invention relates to the technical field of chemical analysis. The invention particularly relates to a method for detecting the chromium content of a high-chromium-content aluminum alloy. The method comprises the steps of: dissolving the to-be-detected substance by adopting sodium hydroxide-hydrogen peroxide to form an alkaline mixed solution; acidifying the alkaline mixed solution; then adding a sulfuric acid-phosphoric acid mixed medium into the acidified mixed solution; dissolving chromium chloride in a mixed solution to enable trivalent chromium ions in the mixed solution to be in a stable state, adding an oxidizing agent into the mixed solution to oxidize trivalent chromium into hexavalent chromium, titrating hexavalent chromium through an ammonium ferrous sulfate standard solution, and calculating the chromium content in a to-be-detected substance according to the volume of the consumed ammonium ferrous sulfate standard solution. The method is high in chemical reaction speedand stable in reaction. When a large instrument condition is not provided and the mass fraction of the chromium element in the aluminum alloy is greater than 0.60%, the detection method is the simplest, most practical, rapider and safer detection method.

The invention provides a composition for on-line silicon meter detection, a preparation method thereof and an on-line silicon meter detection method. The composition for on-line silicon surface detection comprises a color developing agent, a masking agent and a reducing agent, wherein the color developing agent is an acidic ammonium molybdate solution which comprises ammonium molybdate with the concentration of 49.8-50.2 g / L, H2SO4 with the concentration of 79.5-81.2 g / L and the balance of water; the masking agent is an oxalic acid solution which comprises oxalic acid with the concentration of39.8-40.2 g / L and the balance of water; the reducing agent is a ferrous ammonium sulfate solution which comprises ferrous ammonium sulfate with the concentration of 19.8-20.2 g / L, H2SO4 with the concentration of 22.1-22.6 g / L and the balance of water. The composition is used for replacing an outsourcing medicament for on-line silicon meter detection, has higher accuracy, effectively solves the problem of high cost of the outsourcing medicament, can ensure the normal operation of the silicon meter, and improves the efficiency of water quality detection of a thermal power plant and the continuity of related production.