4351 results about "Potassium hydroxide" patented technology

The invention provides a method for preparing lithium cobaltate by directly using an invalid lithium ion battery. The method comprises the following steps: crushing the invalid lithium ion battery or scraps generated when a lithium cobaltate battery is produced by a mechanical crusher at normal temperature; adding water and one or more of acetic acid, sulfuric acid, hydrochloric acid or nitric acid to produce mixed aqueous solution of the battery scraps and acid; filling the mixed aqueous solution into a hermetic pressure reactor, and controlling the temperature in the reactor to be between 50 and 150 DEG C; introducing or adding one leaching additive of sulfur dioxide or hydrogen, or adding hydrazine hydrate; stirring and leaching, cooling, and filtering; adding one precipitator of sodium carbonate, potassium carbonate and ammonium carbonate, or adding composite precipitator consisting of one of the sodium carbonate, the potassium carbonate and the ammonium carbonate and one of sodium hydroxide and potassium hydroxide to obtain mixture of lithium carbonate, cobalt carbonate and cobalt hydroxide; drying and calcining at high temperature to produce a lithium cobaltate product. The method is particularly suitable for the treatment scale of medium-sized and small enterprises, and is an effective method for directly materializing cobalt secondary resources.

A method and device for removing, deodorizing and purifying odor, smoke and harmful substances from exhaust gas or flue gas employs a water solution containing hypohalogen acid such as hypochlorous acid soda, an alkaline electrolyte such as potassium hydroxide or sodium hydroxide and a saline electrolyte such as sodium chloride, potassium chloride, sodium bromide or potassium bromide which is electrolyzed to produce an electrolytic water solution which is fed to a deodorizing tower and brought into contact with exhaust gas or flue gas to remove odor, smoke and harmful substances in the exhaust gas or flue gas.

Rare earth oxide material is dissolved in dense nitric acid, titrated with potassium hydroxide and made to pass through hydrothermal reaction at 100-250 deg.c inside one sealed container, so that monocrystal nanostring of RE hydroxide may be prepared. When the hydroxide is used as precursor, and through annealing at 400-500 deg.c, corresponding Re oxide nanostring may be prepared; and the hydroxide may be calcined at certain temperature to produce corresponding RE oxide nanopowder. When some other RE is doped, composite RE hydroxide, RE oxide nanostring or nanopowder may be prepared. The nanopowder has great specific surface area and the nanostring is anisotropic, so that they may find wide application in various fields.

A method for treating particulate biodegradable organic waste includes sizing the waste and adding a base prior to introducing the waste to a thermal hydrolysis reactor and hydrolyzing the waste at a temperature of about 130° C. or greater and a pressure greater than the saturated water vapor pressure to produce a slurry including solubilized organic material and residual solids. The solubilized organic material is separated from the residual solids using a liquid/solid separator and the solubilized organics are subjected to anaerobic digestion to produce a methane gas. The base is preferably potassium hydroxide (KOH) at a concentration of about 1%. The method may further include preheating the particulate biodegradable organic waste with latent heat of the separated solubilized organic material prior to thermal hydrolysis.

The invention discloses a method for preparing monopotassium phosphate by using wet-process phosphoric acid. The method comprises the following steps: reacting carbonyl diamide and wet-process phosphoric acid to obtain an intermediate; reacting the intermediate and potassium hydroxide to prepare a monopotassium phosphate product. The method has the advantages of short process route, low energy consumption, stable product quality, low production cost, convenience in operation and safety in production. A side product, namely, slurry can be recycled completely, an entire production process is environment-friendly, clean and free from pollution, and no waste gas, waste water or waste residues are discharged. A response is made to the policy calling of energy saving, emission reduction and clean production, the problems of complex process, instable product quality, high energy consumption and environmental pollution existing in the prior art are solved, and the purity of the obtained monopotassium phosphate product is more than or equal to 98 percent.

The invention relates to a manufacture method for water solubility fertilizer containing humus acid. It includes the following steps: adding water and raw material, and KOH as extracting agent, keeping temperature at 50-60 degree centigrade, distilling for 1-2 hours, taking centrifuging, filtering potassium humate, exhausting residue, dissolving N, P, K, and B, dissolving complex agent and adding Ca, Mg, Cu, Fe, Zn, and Mn, heating to dissolving; mixing the materials gained from the above steps, grinding for 3-4 hours under the effect of emulsification pump.

The invention relates to a watery zinc-aluminium heavy-duty coating in a compounding squama shape and a preparation method thereof. The watery zinc-aluminium heavy-duty coating belongs to a bi-component coating and is prepared from organic-inorganic modified base stock and pigment according to a certain proportion by weight, wherein the organic-inorganic modified base stock contains silica sol, potassium hydroxide, silicone-acrylate emulsion, a pigment dispersing agent, a film forming addition agent and an antifoaming agent, and the balance is deionized water or distilled water; the pigment comprises squama-shaped zinc powder and squama-shaped aluminium powder; and the weight ratio of the organic-inorganic modified base stock to the pigment is 5: 1-2. The watery zinc-aluminium heavy-duty coating contains no chrome, can be solidified at the normal temperature, has environmental protection and low energy consumption and can be used for preparing thin coatings with high corrosion resistance, and the like.

Cleaning compositions comprising (A) N-long-chain acyl neutral amino acid or a salt thereof, (B) N-long-chain acyl neutral amino acid dipeptide or a salt thereof, and (C) N-long-chain acyl neutral amino acid tripeptide or a salt thereof provide abundant foam, are excellent in foam retaining properties, and furnish a cleaned and dried body or hair with both a smooth feeling and a moist feeling. Compositions which further comprise (D) a higher fatty acid having 8 to 22 carbon atoms or a salt thereof exhibit enhanced creamy properties in foam quality. N-long-chain acyl neutral amino acids or salts thereof may be conveniently prepared by mixing a neutral amino acid, a long-chain fatty acid, and at least one of an alkaline substance selected from sodium hydroxide and potassium hydroxide, and maintaining the mixture with heating, while removing the water produced during the reaction, with no catalyst being employed.

The invention provides an environment-friendly silt curing agent, which is manufactured through the following steps: one or two among fly ash, calcium sulfate, sodium sulfate, sodium carbonate and potassium carbonate, one or two among slag, slag combination, potassium hydroxide, calcium oxide, sodium silicate or silicon dioxide, one or two among carbide slag, lime or gypsum, as well as one or two among triethanol amine surfactant, calcium lignosulfonate or sodium lignosulfonate form a plurality of optimal compound formulations according to respective attributes, are optimized, compounded, ground till the Brinell specific surface areas are between 300 and 900 m2/kg respectively and then mixed, wherein particle sizes are between 0.00040 and 0.5 mm. As a large amount of waste is utilized, the curing agent saves raw materials, solves the problems about waste discharge and environmental pollution, controls waste through waste, and has important significance to environmental protection. The invention aims to provide the environment-friendly silt curing agent which has strong adaptability to a plurality of types of silt and soil, is good in curing effect, good in durability after curing and capable of utilizing industrial waste, and can be widely applied to fill engineering, embanking or embankment reinforcement engineering, road engineering and other fields.

The present invention describes a process for converting vapor streams from sources containing at least one nitrogen-containing oxidizing agent therein to a liquid fertilizer composition comprising the steps of: a) directing a vapor stream containing at least one nitrogen-containing oxidizing agent to a first contact zone, b) contacting said vapor stream with water to form nitrogen oxide(s) from said at least one nitrogen-containing oxidizing agent, c) directing said acid(s) as a second stream to a second contact zone, d) exposing said second stream to hydrogen peroxide which is present within said second contact zone in a relative amount of at least 0.1% by weight of said second stream within said second contact zone to convert at least some of any nitrogen oxide species or ions other than in the nitrate form present within said second stream to nitrate ion, e) sampling said stream within said second contact zone to determine the relative amount of hydrogen peroxide within said second contact zone, f) adding hydrogen peroxide to said second contact zone when a level of hydrogen peroxide less than 0.1 % by weight in said second stream is determined by said sampling, g) adding a solution comprising potassium hydroxide to said second stream to maintain a pH between 6.0 and 11.0 within said second stream within said second contact zone to form a solution of potassium nitrate, and h) removing said solution of potassium nitrate from said second contact zone.

A polishing composition includes silicon dioxide, an alkaline compound, an anionic surfactant, and water. The silicon dioxide is, for example, colloidal silica, fumed silica, or precipitated silica. The alkaline compound is, for example, potassium hydroxide, sodium hydroxide, ammonia, tetramethylammonium hydroxide, piperazine anhydride, or piperazine hexahydrate. The anionic surfactant is at least one selected from a sulfonic acid surfactant, a carboxylic acid surfactant, and a sulfuric acid ester surfactant. The polishing composition can be suitably used in applications for polishing a silicon wafer.

An ink jet ink composition including from 40.0 to 99.0% by weight of water; from 0.1 to 20.0% by weight of a pigment dispersed with an oleoyl methyl taurine salt dispersant from 0 to 70.0% by weight of a water miscible co-solvent; and from 0.1 to 20.0% by weight of a water-reducible addition polymer; wherein the weight average molecular weight of the polymer is from 2,000 to 100,000; the acid number is from 50 to 400; and the acid group on the polymer is neutralized by an alkaline metal hydroxide such as lithium hydroxide, sodium hydroxide potassium hydroxide, or a mixture thereof; and wherein all weight percentages are based on the total weight of the ink composition. An ink jet printing method is also disclosed.

The invention relates to a preparation method of herbicide dicamba. The preparation method includes: (1) liquid potassium hydroxide and 2, 5-dichlorophenol are reacted according to molar ratio of 0.95:1-1:1 to obtain 2, 5-dichlorophenol potassium; (2) at the presence of anhydrous potassium carbonate and catalyst, the 2, 5-dichlorophenol potassium obtained in the step (1) is reacted with CO2 to generate 3, 6-dichlorosalicylic acid, pressure of CO2 is controlled to be 4-6MPa, reaction temperature ranges from 100 DEG C to 160 DEG C, and molar ratio of anhydrous potassium carbonate and 2, 5-dichlorophenol potassium is 1-2:1; and (3) in alkaline condition, at the temperature of 70-100 DEG C, the 3, 6-dichlorosalicylic acid obtained in the step (2) and chloromethane are reacted under the action of the catalyst through a tube fixed-bed reactor according to molar ratio 1:1-3.5, saponification and acidification are performed to obtain 3, 6-dichloro-2-methoxysalicylic acid, namely the dicamba. The process is high in reaction yield, simple in reaction condition, good in product quality, small in three wastes and low in energy consumption.

The invention relates to a gel plugging agent for deep profile control of a higher temperature oil reservoir, and a preparation method of the gel plugging agent. The gel plugging agent comprises 0.3-0.8 percent of nonionic polyacrylamide, 0.6-1.3 percent of a cross-linking agent A, 0.45-1.44 percent of a cross-linking agent B, 0.02-0.04 percent of a temperature stabilizer and 0.01-0.08 percent of a pH value regulator, wherein the cross-linking agent A is methenamine; the cross-ling agent B is hydroquinone or resorcinol; the temperature stabilizer is sodium thiosulfate, sodium bisulfite or sodium sulfite; and the pH regulator is sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate. The gel plugging agent disclosed by the invention has strong temperature resisting performance and can be used for the profile control operation of the high temperature oil reservoir with 100-160DEG C; the gel plugging agent has the characteristics of high strength after being gelatinized, stronger plugging capability for the stratum and favorable thermal stability; and in addition, after the gel plugging agent is stood at the temperature of 130 DEG C for 90 days, the strength change is little and gel breaking and hydration are avoided.

The invention relates to a method for preparing aluminum-coated anode materials of lithium-ion batteries, which is characterized in that: firstly, soluble nickel salts, cobalt salts, and manganese salts are formulated into salt solutions, and then mixed with ammonia-water-mixed sodium hydroxide or potassium hydroxide solutions React to form precursor particles, wash and dry; add water to the dried precursor particles to prepare a flowable slurry, stir, and add trivalent aluminum salt solution and sodium hydroxide or potassium hydroxide solution dropwise to the slurry at the same time , to obtain the precursor of nickel hydroxide cobalt manganese coated with aluminum; then mix the precursor with lithium source, and then sinter to obtain the positive electrode material of lithium ion battery coated with aluminum. The present invention has the following obvious advantages: raw materials are easy to obtain; coated The process conditions are easy to control, and it is easy to obtain a relatively uniform coating body; the prepared positive electrode material can make the lithium ion battery have superior high temperature stability and better cycle characteristics.

The invention relates to a method for preparing activated carbon with humic acid as a raw material and an application of the activated carbon. The method comprises the steps of mixing industrial humic acid with an activating agent which is potassium hydroxide, sodium hydroxide, zinc chloride, potassium carbonate or phosphoric acid uniformly to react under inert atmosphere protection for 1-5 hours; then cooling the product, washing the product in an acid solution until the pH value is 6-7 and drying the product, thus obtaining the activated carbon. The method is convenient to operate, is relatively low in energy consumption and is suitable for large-scale industrial production. The humic acid porous activated carbon material obtained by the method has a rich porous structure and a relatively big specific surface area, is used for preparing water purifiers or electrode materials of supercapacitors, and has methylene blue dye adsorption value of 600mg/g. Besides, the humic acid porous activated carbon material is used as the electrode material of a supercapacitor to assemble a high-performance supercapacitor. The specific capacitance of the activated carbon single electrode is 351Fg<-1>. Various test results show that the activated carbon is microporous-mesoporous composite carbon and has specific surface area of about 3200m<2>/g, the pore size distribution of the activated carbon is 1-5nm, and the pore volume of the activated carbon is about 2cm<3>/g.

The invention relates to a method for preparing hollow zeolite socony mobil-5 (ZSM-5) nanometer zeolite. The method is characterized by comprising the following steps of: mixing single-dispersion ZSM-5 nanometer zeolite of which the silicon-aluminum molar ratio of SiO2/Al2O3 is over 20 and the partical size ranges from 100 to 400 nanometers with 0.05 to 0.5 mol/L of an aqueous solution of alkaline substances, wherein the alkaline substances are selected from a mixture in which a molar ratio of quaternary ammonium salt to sodium hydroxide is 1:1, a mixture in which a molar ratio of the quaternary ammonium salt to potassium hydroxide is 1:1, n-butylamine and quaternary ammonium base; and stirring at the temperature of between 80 and 200 DEG C for 10 to 200 hours, and separating. By the method, a regular cavity structure is formed, so that reactants and products are easy to transfer, and the crystallinity is high; and the method is simple, low in cost and high in yield, and can be used for mass production. The hollow ZSM-5 nanometer zeolite with different silicon-aluminum ratios can be obtained by using different matrixes or under different treatment conditions, and the sizes of cavities of hollow ZSM-5 nanometer zeolite can be regulated by changing the treatment condition.

The invention relates to high-adsorptivity modified activated carbon which is prepared from the following raw materials in parts by weight: 30-40 parts of grape vine, 40-50 parts of sawdust, 100-120 parts of activated carbon, 30-40 parts of corn cob, 6-9 parts of potassium hydroxide, 7-10 parts of sodium lauryl sulfate or polyethylene glycol, 7-10 parts of urea, 2-5 parts of zinc nitrate, 2-5 parts of nickel nitrate, 10-14 parts of Arabic gum or sodium alginate, 7-10 parts of modified attapulgite and a right amount of water. According to the invention, the grape vine, sawdust and corn cob are subjected to high-temperature heat treatment, and the prepared activated carbon has large specific surface area, realizes new application of wastes and achieves the effects of convenient carbonization activation process and less pollutant discharge; and by using the potassium hydroxide, urea, zinc nitrate and nickel nitrate substances for modification, the activated carbon increases the gap and enhances the adsorption capacity. Besides, the high-adsorptivity modified activated carbon is accessible in raw materials, simple in process, low in cost and suitable for industrial production, causes no generation of harmful substances and has favorable application prospects.

The present invention concerns a preparation method of an activated carbon fiber. A preparation method of a fiber column of a plant activated carbon is characterized in that the method contains the following steps: (1) After the fruit of a plane tower gourd is dried naturally or artificially, a coat and seeds are removed and a plant fiber column can be obtained. (2) The plant fiber column is dipped into a chemical solvent which is a phosphoric acid, a zinc chloride liquor, a sodium hydroxide, or a potassium hydroxide liquor. (3) The dipped plant fiber column is dried at a temperature between 100 DEG C and 108 DEG C. (14) The dried plant fiber column is put into a carbonization and activation crucible, of which a cover is sealed by a sealing silica gel. (5) The crucible containing the plant fiber column is put into a muffle and carbonized and activated 0.1-1.0h at the temperature between 200 DEG C and 800 DEG C. (6) After the carbonization and activation are finished, the sealed crucible is taken out and cooled in a drying bison and then the product is obtained. The technology of the method is simple. The obtained fiber column of the plant activated carbon has the characteristics of good adsorption performance, large adsorption capability and lost cost.

The invention discloses a preparation method of biomass pomelo peel derived activated carbon serving as an electrode material of a super capacitor. The preparation method comprises the following steps: a pomelo peel is subjected to hydrothermal treatment for mild carbonization firstly, a pomelo peel adopting a porous structure is obtained, a hydrothermal product of the pomelo peel and potassium hydroxide are mixed for soaking, so that potassium hydroxide sufficiently diffuses into the pomelo peel, a mixture is calcined at a high temperature finally, carbon balls are activated by potassium hydroxide, and a honeycomb activated carbon material adopting leveled hole structures is prepared. Honeycomb activated carbon prepared with the method has rich leveled hole structures and larger specific surface area, the electrode capacity is as high as 300 F/g when the activated carbon serves as the electrode material of the super capacitor, and the method has the characteristics of simplicity in process operation, high repeatability and low cost.

Disclosed herein is a self-rechargeable alkaline battery. The battery comprises a cathode and an anode, at least one of which is constructed of a metallic plate, an electrode receptor equipped to the cathode, an electrode donor equipped to the anode, a separator provided between the electrode donor and the electrode receptor, an electrolyte comprising an aqueous potassium hydroxide solution and an aqueous sodium hydroxide solution and having at least one powdered material selected from the group consisting of aluminum oxide, manganese oxide, and silicon oxide. The battery has a self-rechargeable ability, stable output characteristics, and a remarkably increased life span.

The invention relates to a method for preparing hollow cavity type ZSM-5 modified zeolite molecular sieve, and aims to solve the problems that the microcellular structure diffusion admittance is narrow, the modified zeolite molecular sieve has lower relative degree of crystallinity, and the adjustable range of apertures inside molecular sieve is small, thereby facilitating macromolecule reaction limited by diffusion. The invention adopts at least one 0.1-8.5 mol/L acid solution of hydrochloric acid, nitric acid, sulphuric acid or acetic acid to treat ZSM-5 molecular sieve raw powder with the silica alumina ratio SiO2/Al2O3 being 20-1000 and the particle size being 0.4-10 Mum for 1-8 h; then at least one 0.1-5.0 mol/L aqueous alkali of sodium hydroxide, magnesium hydrate, potassium hydroxide, sodium carbonate or sodium bicarbonate is used for treatment for 1-48 h at 20-90 DEG C; and at least one 0.1-8.5 mol/L acid solution of hydrochloric acid, nitric acid, sulphuric acid or acetic acid is used for treatment for 1-48 h at 20-90 DEG C to obtain the modified ZSM-5 molecular sieve. The problems are well solved, and the invention can be used in industrial production of macromolecule catalysis and transformation catalysts.

The invention relates to an electrode material for an electrochemical super capacitor, more particularly to an active carbon for the super capacitor and a preparation method thereof. The inventive active carbon for the super capacitor is obtained by the steps of drying, carbonizing and activating starch that is taken as raw material. The preparation method thereof comprises the following steps of: 1) drying moisture in the starch; 2) putting the dried starch in an electric resistance furnace to be heated up to 350-550 DEG C under the protection of an inert gas, keeping constant temperature for 1-4 hours, and taking out after cooling to obtain a carbonizing material; 3) grinding and mixing the carbonizing material with potassium hydroxide saturated solution uniformly, drying the moisture and putting the mixture in the electric resistance furnace to be heated up to 750-850 DEG C under the protection of the inert gas, keeping constant temperature for 1-4 hours, and taking out the mixture after cooling to be ground, washing to a neutral state and drying to obtain the active carbon; the proportion by weight of the carbonizing material to potassium hydroxide solid is 1:4-8. The invention has extensive source of the raw materials, high specific surface area of the prepared active carbon and low production cost.

The invention discloses a hierarchical pore ZSM-5 molecular sieve and a synthetic method thereof. The hierarchical pore ZSM-5 molecular sieve is formed by the accumulation of crystalline grains with order nano-layered structures and is integrally structured. The synthetic method comprises the following steps of: with quaternary ammonium salt as a structure-directing agent (SDA), tetraethoxysilane (TEOS) as a silicon source, aluminium isopropoxide (AIP) as an aluminum source, and potassium hydroxide (KOH) as an alkali source, adding a cationic surface active agent (CSF) to prepare a synthetic liquid with the molar ratio of (20-100) SiO2: (1-3) Al2O3: (10-30) SDA: (10-50) KOH: (1,000-3,000) H2O: (1-10) CSF; adding 10 to 20% of Silicalite-1 molecular sieve seed crystal gel; performing hydrothermal crystallization according to the conventional method; processing a product by washing, drying and roasting to obtain the ZSM-5 molecular sieve. The molecular sieve is an agglomeration which is formed by the self-assembly under mutual effect of CSF, seed crystal gel and an inorganic species and is of a lamella and hierarchical zeolite structure; the molecular sieve is relatively high in specific surface area, relatively short in a diffusion path and relatively high in stability. The preparation method also has the advantages of high degree of crystallinity, high yield and simple operation steps, and is easy to separate.

The invention discloses an ammonia-free chemical nickel plating bath which adopts an ammonia-free pH modifying agent to regulate the pH value of the bath. Each liter of the bath contains the components that nickel salt is 24 to 30g, reducing agent is 24 to 33g, buffering agent is 10 to 18g, complexing agent is 20 to 30g, stabilizing agent is 0.5 to 1.5mL, brightener is 1.5 to 3.0mL, and others are water. In the ammonia-free chemical nickel plating bath, the ammonia-free pH modifying agent is selected from one or the mixture of sodium hydroxide, and potassium hydroxide or potassium carbonate. All materials in the ammonia-free chemical nickel plating bath do not contain heavy metal, ammonia water is not utilized to regulate the pH value, the problems of environment pollution, invalidation caused by overlong storing time of the bath, etc. are not caused, and the obtained chemical plating bath is friendly to the environment, in addition, the luminance brightness of the made plating layer can be full-bright. The bath has wide application prospect.

The invention relates to a preparation method of high specific surface area graphene with well-developed mesopores. The method comprises the steps of mixing graphene oxide and an activating agent under a protective atmosphere; passing through an activating gas to active the mixture; and finally obtaining the high specific surface area graphene with the well-developed mesopores through processes of washing, filtering and drying. The activating agent is selected any one from potassium hydroxide, sodium hydroxide, phosphoric acid and zinc chloride or a combination of at least two of the above materials. The method is simple in equipment and low in cost, is safe and reliable, has small pollutions and high production efficiency, and is suitable for large-scale production. The obtained graphene has high specific surface area, and is more suitable for migration of electrolyte ions.

A method of preparing a bis(thio-hydrazide amide) disalt includes the steps of combining a neutral bis(thio-hydrazide amide), an organic solvent and a base to form a bis(thio-hydrazide amide) solution; and combining the solution and methyl tert-butyl ether, thereby precipitating a disalt of the bis(thio-hydrazide amide). In some embodiments, a method of preparing a bis(thio-hydrazide amide) disalt includes the steps of combining a neutral bis(thio-hydrazide amide) and an organic solvent selected from methanol, ethanol, acetone, and methyl ethyl ketone to make a mixture; adding at least two equivalents of a base selected from sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, sodium ethoxide and potassium ethoxide to the mixture, thereby forming a solution; and combining the solution and methyl tert-butyl ether to precipitate the disalt of the bis(thio-hydrazide amide). The disclosed methods do not require lyophylization and the solvents used in the process can be more readily removed to low levels consistent with pharmaceutically acceptable preparation.

The invention provides a method for preparing a silver/graphene antimicrobial composite material, and the method provided by the invention comprises the following steps: a) providing a reductive graphene oxide-sodium polystyrene sulfate composite solution; b) heating the composite solution obtained in the step a) to 50-70 DEG C; and c) adding a silver nitrate solution into the heated composited solution obtained in the step b) for reaction, thus obtaining the silver/graphene antimicrobial composite material. The invention provides the method for preparing the silver/graphene antimicrobial composite material; and in the method, a reductive graphene oxide tablet is taken as a reducing agent for carrying out reduction on silver ions under a neutral pH condition so as to generate silver nano particles. In the method provided by the invention, no sodium borohydride is taken as a reducing agent, and in the whole preparation process, no potassium hydroxide is adopted, therefore, when the composite material prepared by the method is subjected to later application, no large biological irritant is caused. In addition, antibacterial experiments show that the silver/graphene antimicrobial composite material provided by the invention has a better antibacterial effect.

The invention relates to a method for decomposing vanadium slag with solution of potassium hydroxide under normal pressure, which comprises the following steps: adding the vanadium slag or pre-treated vanadium slag, water and KOH into a reactor, controlling the mass ratio of the KOH to the vanadium slag and the concentration of solution of KOH, performing oxidation reaction in the presence of oxidizing gas, and controlling the reaction temperature and reaction time in the reaction process; diluting the obtained reaction slurry with a diluting agent to obtain mixed slurry which contains potassium hydroxide, potassium vanadium, potassium chromate and tailings; and performing filtering separation on the mixed slurry to obtain the tailings and vanadium and chromium-containing aqueous solution. The method is only operated under normal pressure, is easy to perform and has high safety; the operation temperature is far lower than the traditional vanadium extraction temperature; the extraction rate of vanadium is high; and synchronous extraction of chromium in the vanadium slag can be realized. The total amount of the vanadium in the tailings is 0.2-1 weight percent (based on the amount of V2O5) and the total amount of the chromium is 0.2-1 percent (based on the amount of Cr2O3).

A process for preparing fertilizer from the black liquid generated during making paper by KOH method features that said black liquid is used to treat vegetable material to obtain fertilizer, which can be further processed to obtain different kinds of organic fertilizer, composite inorganic-organic fertilizer and biologic organic fertilizer.