734 results about "Ferrous sulphate" patented technology

The invention discloses a chitosan modified lithium iron phosphate and carbon composite positive electrode material and a preparation method thereof.The preparation method comprises the steps that 1, lithium hydroxide, phosphoric acid and ferrous sulfate heptahydrate are mixed to prepare a uniform and stable solution, and a lithium iron phosphate precursor is prepared through a solvothermal method; step 2, dissolving chitosan in an acetic acid aqueous solution, and magnetically stirring under a water bath condition until the chitosan is completely dissolved to prepare a chitosan solution; and 3, adding the lithium iron phosphate precursor into a chitosan solution, uniformly mixing, carrying out ball milling and freeze drying, and carrying out high-temperature carbonization treatment in an inert gas to obtain the chitosan modified lithium iron phosphate and carbon composite positive electrode material. The method is simple to operate, low in cost and uniform in product particle size distribution.

The invention provides lepidolite flotation wastewater treatment equipment and a flotation process, and relates to the technical field of wastewater treatment, the lepidolite flotation wastewater treatment equipment comprises a reaction tank, a stirring mechanism, a swing dosing mechanism and a spraying mechanism; the stirring mechanism comprises a mounting frame fixedly arranged at the top of the reaction tank, and a rotating shaft is vertically and rotatably connected to the inner side of the mounting frame. According to the scheme, a ferrous sulfate solution is finally added into the reaction tank through the spraying mechanism, then a diluted H2O2 solution is intermittently fed through the swing medicine feeding mechanism, the H2O2 solution generates strong oxidizing hydroxyl free radicals under the catalysis of the ferrous sulfate solution, and therefore hydrophobic chains and polar groups of residual medicine are destroyed, and the medicine is obtained. The lepidolite metallurgical flotation wastewater is degraded into small molecular organic matters or mineralized into CO2 and H2O, so that the phenomenon that the subsequent coagulating sedimentation or adsorption process is hindered by residual chemicals is avoided, the chemical oxygen demand and toxicity of the wastewater are reduced, the subsequent biological treatment on the wastewater is facilitated, and the treatment effect and efficiency of the lepidolite metallurgical flotation wastewater are effectively improved.

The invention relates to the technical field of water treatment agent preparation and environmental governance material processing, in particular to polymeric ferric sulfate and a preparation method thereof.The preparation method comprises the steps that steam condensation recycled water of a thermal power plant of an aluminum factory is mixed with ferrous sulfate and concentrated sulfuric acid to form a reaction solution, oxygen is introduced for an oxidative polymerization reaction, and a liquid intermediate is generated; gradient cooling is carried out on the liquid intermediate to control the molar ratio of ferric ions to hydroxyl, and a porous solid precursor is formed through concentration and closed aging; crushing the precursor, performing graded drying by adopting a rotary kiln and flash drying, and synchronously spraying a hydrophobic modifier to reduce the surface hydroxyl activity; the powdery product is secondarily dried in a nitrogen inert environment, and moisture absorption and agglomeration are inhibited. The invention solves the problems of mixed crystal forms, delayed release of effective components and secondary pollution in the traditional process. The obtained product is uniform in crystal form, concentrated in particle size distribution, remarkably improved in dissolution rate and storage stability, and suitable for black and odorous water body treatment and industrial sewage treatment.

The invention relates to the technical field of preparation of iron phosphate materials, in particular to a method for doping iron phosphate with titanium, which comprises the following steps: 1, dissolving a titanium dioxide by-product ferrous sulfate powder in water to prepare a titanium-containing iron source solution; 2, adding water into the reaction kettle, and stirring; 3, adding the titanium-containing iron source solution, the phosphorus source solution, ammonia water and an oxidizing agent into a reaction kettle to prepare primary slurry; 4, carrying out filter pressing on the primary slurry, washing until the conductivity is less than or equal to 2000us / cm, and then adding water to prepare secondary slurry; 5, phosphoric acid is added into the reaction kettle for bottoming, and the temperature is increased to 60-70 DEG C; 6, adding the secondary slurry into the reaction kettle, and carrying out heat preservation reaction on the secondary slurry and phosphoric acid; and 7, filtering the reaction product obtained in the step 6, washing until the conductivity is less than or equal to 500us / cm, and then drying and sintering. According to the method, the titanium doping technological process is simplified, and meanwhile the titanium element utilization rate in the titanium dioxide by-product and the purity of the titanium-doped iron phosphate product are improved.

The invention provides a dump leaching method for improving the leaching rate of gold ore, and belongs to the technical field of mineral processing. The method comprises the following steps: firstly, separating minerals into oversize products and undersize products; mixing sodium carboxymethyl cellulose, bentonite and ferrous sulfate to obtain a mixture, and granulating the undersize product by using the mixture as a binder; and mixing the undersize product particles with the oversize product, and carrying out cyanide-free dump leaching. According to the method, through graded granulation and heap building, the problem that heap building permeability is poor due to the fact that the gold ore contains many clay minerals is solved. In the granulation stage, ferrous hydroxide colloid generated by hydrolysis of ferrous sulfate in the binder can assist ore particle agglomeration, and particle stability is enhanced; during subsequent cyanide-free dump leaching, ferrous sulfate can be used as an auxiliary reducing agent and a catalyst in a thiourea gold leaching system to promote oxidation and dissolution of gold; meanwhile, ferrous ions can adjust the oxidation-reduction potential of a system, so that the thiourea gold leaching reaction is in a more favorable potential interval, the oxidation efficiency of thiourea is improved, invalid decomposition of thiourea is reduced, and therefore the use amount of thiourea and the use amount of agents are reduced.

The invention belongs to the field of solid waste recycling, and relates to a hematite modified rice hull-based biochar material as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out ultrasonic treatment on rice husks in an ethanol solution, then soaking the treated rice husks in a mixed solution of methanol and formalin for activation, carrying out vacuum filtration and drying, and carrying out anaerobic calcination under the protection of a nitrogen atmosphere to obtain rice husk-based biochar; the method comprises the following steps: soaking rice husk-based biochar in an acid solution, and carrying out microwave digestion on the acid-modified rice husk-based biochar to obtain chemically-modified rice husk-based biochar; adding into a solution containing ferrous sulfate, fully stirring, and then carrying out hydrothermal treatment to obtain the hematite modified rice hull based biochar material. The method can significantly improve the conversion rate of organic matters in the sludge, increase the accumulated yield of biogas, effectively reduce the biotoxicity of heavy metals in the sludge, facilitate the resource utilization of the sludge, and have important significance for solving the environmental risk problem of the sludge.

The invention belongs to the field of lithium ion battery material preparation, and provides a preparation method of low-impurity battery grade iron phosphate, which comprises the following steps: dissolving titanium dioxide ferrous sulfate in water to obtain a solution A, adjusting the pH value of the solution A to 3.0-4.0, reacting, and carrying out solid-liquid separation to obtain a clear liquid; adjusting the pH value of the clear liquid, and then mixing the clear liquid with sodium nitrite to obtain a solution B; adding the solution B into a reaction kettle, introducing compressed oxygen until the pressure in the kettle body is 5-15 bar, reacting until the pressure in the kettle body is reduced to a constant value, and carrying out solid-liquid separation to obtain a purified iron source solution; preparing iron phosphate dihydrate by taking the purified iron source solution and a phosphorus source as raw materials through a precipitation method; and calcining the iron phosphate dihydrate to obtain the low-impurity battery-grade iron phosphate. The preparation method is simple and feasible in process, low in cost, wide in source of required raw materials, good in safety, low in cost, easy to realize large-scale production, good in impurity removal effect and low in iron loss, and the Mn content of the battery-grade iron phosphate prepared from the impurity-removed ferrous sulfate can be as low as 10 ppm or below.

The invention discloses a fermentation medium for regulating and controlling a clostridium aerovorans target product and a fermentation method of the clostridium aerovorans target product. The medium comprises a basic component and a regulating component, the basic components comprise ammonium chloride, potassium chloride, magnesium sulfate heptahydrate, sodium chloride, monopotassium phosphate, yeast powder, calcium chloride dihydrate, sodium selenite, nickel chloride hexahydrate, biotin, folic acid, pyridoxine hydrochloride, thiamine, riboflavin, nicotinic acid, D-calcium pantothenate, cobalamin, para aminobenzoic acid and lipoic acid; the adjusting component comprises sodium tungstate, ferrous sulfate and sodium molybdate, sodium tungstate and ferrous sulfate have a forward adjusting effect on increasing the yield of acetic acid, ethanol and butanol in the target product, and sodium molybdate has a reverse adjusting effect on the target product. By optimizing the proportion of trace elements in the culture medium, the clostridium metabolism efficiency is improved, synthesis of a target product is regulated and controlled, and the method is particularly suitable for industrial production of acetic acid, ethanol, butanol and the like.

The invention relates to a fluorine-containing binder for a sulfide all-solid-state battery and a preparation method and application thereof.The binder is formed by copolymerizing isoprene and lithium perfluorovinyl ether sulfonate, specifically, the lithium perfluorovinyl ether sulfonate, a chelating agent, an emulsifying agent, ferrous sulfate, a reducing agent and an acid-base buffering agent are dissolved in water, cooling is conducted in the inert atmosphere, and the fluorine-containing binder for the sulfide all-solid-state battery is obtained. And adding isoprene, an initiator and a molecular weight regulator, and carrying out polymerization reaction to obtain the fluorine-containing binder. The isoprene can enhance the solubility of the lithium perfluorovinyl ether sulfonate fragment in the non-polar solvent, so that the whole polymer is dissolved in the non-polar solvent; the perfluorovinyl ether lithium sulfonate has a large space proportion of fluorocarbon groups, and has a shielding effect on hydrocarbon groups on isoprene, so that the stability of the whole polymer can be improved. The fluorine-containing binder prepared by the preparation method disclosed by the invention is a binder with high elasticity, high ionic conductivity and high stability.

The invention relates to a special fertilizer suitable for saline-alkali soil and a preparation method thereof. The fertilizer is granular and has a multi-layer structure which is sequentially arranged from inside to outside: a nutrition core layer, a controlled release film layer, a soil improvement fast exchange layer and a microorganism attaching layer. The nutrition core layer contains nitrogen, phosphorus, potassium and medium trace elements, and meets the basic nutrient requirements of crops; the controlled release film layer is self-assembled layer by layer by adopting alginate / chitosan, a humic acid-ferrous complex and a breakable cross-linking point are inserted into the film, and starch is sprayed on the outer layer, so that an ionic strength / alkalinity dual-response controlled release system is formed; the soil improvement quick exchange layer contains microcrystalline gypsum and ferrous sulfate; the microbial epiphytic layer fixes salt-tolerant phosphate solubilizing bacteria, potassium bacteria and exopolysaccharide-producing bacillus by using a charcoal-zeolite carrier, and the bacteria are distributed on the surfaces of the particles in a dotted manner. The fertilizer realizes organic combination of soil improvement, fertilizer supply and microbial regulation and control, can significantly reduce the soil salinity and alkalinity in a saline-alkali soil environment, and improves the fertilizer utilization rate and the crop growth performance.

The invention relates to the field of organic fertilizer manufacturing, in particular to a preparation method of a humic acid-containing water-soluble organic fertilizer with chelated medium trace elements for synergism, and the preparation method comprises the following steps: S1, adding modified humic acid into deionized water, heating to 40-50 DEG C, stirring for 25-35 minutes, adding hydrated ferrous sulfate, introducing compressed air, and stirring for reaction for 30-50 minutes to obtain a chelating solution and the like; according to the invention, the environmental adaptability of humic acid is improved through molecular structure modification, a composite chelation system is constructed to enhance element stability, a multistage chelation sequence is optimized to prevent ion antagonism, and a physical barrier is innovated to realize a core process path of intelligent controlled release. The functional limitation of a traditional fertilizer in a complex agricultural ecological system is effectively broken through, the nutrient utilization efficiency and agricultural sustainability are remarkably improved, and the fertilizer has wide application prospects in soil remediation, precision agriculture and resource-saving planting systems.

The invention discloses a gradient chelation-free radical activation synergistic eucalyptus chemithermomechanical pulp wastewater composite coagulant and a preparation method thereof, and belongs to the technical field of eucalyptus chemithermomechanical pulp wastewater treatment. Ferrous sulfate heptahydrate, aluminum hydroxide and magnesium sulfate are used as raw materials, and the water purifying agent with the viscosity of 35-45 mPa.s is prepared through gradient chelation reaction, free radical activating treatment, functional component composite reaction, pH and specific gravity regulation and control and curing treatment. By utilizing the synergistic effect of the polydimethyldiallylammonium chloride and the formaldehyde dicyandiamide resin, the electric neutralization capability on macromolecular colloidal substances in the wastewater is remarkably enhanced, and macromolecular substances which are difficult to biodegrade in the water are effectively removed; when the compound coagulant is used for treating the eucalyptus chemithermomechanical pulp wastewater, the addition amount of the compound coagulant is small, and the compound coagulant has excellent COD (Chemical Oxygen Demand) reduction and decolorization effects.

The invention provides high-performance silver powder suitable for TOPCon battery fine grid silver paste, a preparation method of the high-performance silver powder and the silver paste, and belongs to the technical field of photovoltaic materials. The preparation method comprises the steps that a silver salt solution and a composite reducing agent are mixed, a first-stage hydrothermal reaction is carried out at the first temperature, a second-stage hydrothermal reaction is carried out at the second temperature, and silver powder is obtained after centrifugation, washing and drying; wherein the composite reducing agent is selected from a mixture of two of potassium tartrate, sodium sulfite and ferrous sulfate. According to the method, gradual growth and crystallinity improvement of silver crystal nucleuses are achieved through two-stage heating, particle aggregation or uneven morphology caused by rapid reduction is avoided, in addition, the adopted composite reducing agent combination is remarkably superior to a single reducing agent (such as ascorbic acid), and the morphology and particle size distribution of the silver powder can be more accurately regulated and controlled.

The invention belongs to the technical field of coal combustion, and particularly relates to an environment-friendly rare earth catalyst as well as a preparation method and application thereof in promoting coal combustion. The catalyst is prepared from composite rare earth oxide, calcium oxide, potassium carbonate, ferrous sulfate, kaolin, diatomite and a multi-component composite assistant component in a specific proportion through the steps of slurry ultrasonic activation, rare earth coating, assistant step-by-step doping, microwave drying, protective atmosphere roasting and the like. The catalyst is unique in structure and good in dispersity, the coal combustion efficiency can be remarkably improved, the burnout temperature and the carbon content of fly ash are reduced, emission of flue gas pollutants such as CO, NOx and SO2 is effectively reduced, and the catalyst is suitable for the fields of energy conservation, carbon reduction and environment-friendly treatment of coal-fired power plants and industrial boilers.

The invention provides a leaching method and a recycling method of metal in a nickel cobalt lithium manganate positive plate. The leaching method comprises the following steps: pre-treating a nickel cobalt lithium manganate positive plate disassembled from a waste battery to obtain positive powder; preparing a gluconic acid leaching agent containing gluconobacter oxydans, and electrolyzing the positive electrode powder at the voltage of 2.0-2.5 V by adopting a double-chamber electrochemical electrolytic tank to obtain a leaching solution containing Li < + >, Ni < 2 + >, Co < 2 + > and Mn < 2 + >. Positive electrode powder, a gluconic acid leaching agent and a ferrous sulfate aqueous solution are put into a cathode chamber of a double-chamber electrochemical electrolytic tank, and an inorganic alkali aqueous solution is contained in an anode chamber of the double-chamber electrochemical electrolytic tank; the leaching efficiency can be improved and the leaching rate is high through the effects of dissolution of gluconic acid, electrolysis for hydrogen release and auxiliary reduction of Fe < 2 + >.

The utility model discloses a ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration, comprising a drying drum and a combustion chamber, wherein the head of the drying drum is higher than the tail and can rotate, the drying drum is formed by connecting a first drying drum and a second drying drum, the tail of the first drying drum is connected to the head of the second drying drum by a connecting assembly and the connecting assembly cannot rotate, the combustion chamber comprises a first combustion chamber and a second combustion chamber, the first combustion chamber feeds high-temperature flue gas into the first drying drum through the connecting assembly, and the second combustion chamber is close to the tail of the second drying drum and feeds high-temperature flue gas into the second drying drum. The utility model feeds high-temperature flue gas into the two drying drums through two combustion chambers respectively, so as to facilitate segmented temperature control to achieve segmented dehydration of raw materials, obtain ferrous sulfate monohydrate with higher purity, and finally achieve the purpose of easy temperature control, high product purity and high production efficiency.

The invention provides an alloying modification method of a platinum catalyst, and relates to the field of electrochemical catalysis, and the alloying modification method specifically comprises the following steps: uniformly mixing a 5% platinum-carbon catalyst and a phytic acid solution, carrying out freeze-drying treatment, carrying out primary pyrolysis, sulfuric acid treatment, ultrapure water cleaning and suction filtration, and drying to obtain powder, adding ferrous sulfate and 1, 10-phenanthroline, and uniformly stirring to obtain the platinum-carbon alloy. And carrying out secondary pyrolysis, sulfuric acid treatment, ultrapure water cleaning, suction filtration and drying to obtain the alloying modified carbon-based catalyst. According to the method, the metal platinum and the transition metal are alloyed, so that the activity and the stability of the catalyst are effectively improved, the usage amount of the noble metal platinum is reduced, and the manufacturing cost of the catalyst is effectively reduced; the alloying modified carbon-based catalyst obtained by the method can be used for preparing primary zinc-air batteries, rechargeable zinc-air batteries and other batteries.

The invention discloses an iron-based layered silicate material for efficiently removing variable-valence heavy metals and water treatment application of the iron-based layered silicate material, and belongs to the technical field of water treatment.The preparation method of iron-containing layered silicate minerals comprises the following steps that ferrous sulfate heptahydrate is dissolved in water, sodium dithionite and sodium orthosilicate are sequentially added, stirring is conducted, and a mixture is obtained; stirring, homogenizing and aging for two hours; the hydrothermal reaction kettle is used for reacting in a high-temperature and high-pressure environment; according to the iron-containing layered silicate mineral material, a unique layered structure similar to natural iron-containing layered silicate minerals and high adsorption performance are reserved, variable-valence heavy metal arsenic in a wastewater solution is synergistically and efficiently removed by means of the oxidation-reduction activity of the iron-containing layered silicate mineral material and induction of generation of Fenton-like reaction, and the iron-containing layered silicate mineral material is obtained. The method disclosed by the invention shows high treatment efficiency, environmental friendliness and remarkable economic benefits, and is expected to exert remarkable environmental benefits in the field of water treatment.

The invention provides a recovery method of a sodium ferrous sulfate waste pole piece and a sodium ferrous sulfate positive electrode material, and belongs to the technical field of sodium ion batteries. The recovery method of the sodium ferrous sulfate waste pole piece comprises the following steps: separating a positive electrode material and carbon from the sodium ferrous sulfate waste pole piece to prepare a first mixed solution containing FeSO4.xH2O, Na2SO4.yH2O and carbon; wherein 1 < = x < = 7, 1 < = y < = 10; adding an antioxidant and a pH value regulator into the first mixed solution to obtain a second mixed solution; carrying out pulpifying treatment on the second mixed solution to obtain slurry; drying the slurry to obtain a precursor; and sintering the precursor to obtain the sodium ferrous sulfate positive electrode material. The sodium ferrous sulfate positive electrode material comprises sodium ferrous sulfate and a carbon net which is coated on the surface of the sodium ferrous sulfate and is of a porous structure, can enhance infiltration of an electrolyte and shorten a sodium ion transmission path, and has excellent electrochemical performance.

The invention discloses a method for producing mRNA (messenger ribonucleic acid) template plasmids by fermenting escherichia coli. When the recombinant escherichia coli is fermented and cultured, a seed solution of the recombinant escherichia coli is inoculated into a basic culture medium to be fermented and cultured until the OD600 value of fermentation liquor is 18-22, then a fed-batch culture medium is continuously added at the feeding rate of 5-15 mL / L / h to be subjected to continuous fed-batch fermentation culture, the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate, and the basic culture medium contains 0.05-0.2 mmoL / L of ferric salt compound and 0.05-0.2 mmoL / L of copper chloride dihydrate. The basal culture medium contains 10-15 g / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the basal culture medium contains 0.1-0.3 mmoL / L of a ferric salt compound, 0.1-0.3 mmoL / L of copper chloride dihydrate and 100-300 mg / L of p-hydroxybenzoic acid, the carbon source of the fed-batch culture medium contains 360-480 g / L of glycerol, and the ferric salt compound is one or more of ferrous citrate, ferric ammonium citrate or ferrous sulfate heptahydrate. According to the method, the yield and superhelix content of the mRNA template plasmids are improved by optimizing the culture medium formula and culture conditions, and large-scale production of the high-quality target mRNA template plasmids is facilitated.

The invention relates to the technical field of soil improvement, in particular to a saline-alkali soil improver prepared by compounding ferrous sulfate and fly ash as well as a preparation method and application of the saline-alkali soil improver. By scientifically compounding the ferrous sulfate, the active fly ash, the beer fermentation residues, the attapulgite and the microbial agent, the proportion of all the components is optimized, the synergistic effect of all the components is fully exerted, the improvement effect of the saline-alkali soil is remarkably improved, and multi-dimensional improvement of the saline-alkali soil is achieved. The saline-alkali soil improver can effectively reduce the pH value and salt content of soil, improve the soil structure, improve the soil fertility and biological activity and promote plant growth. Compared with the prior art, the saline-alkali soil improver has the advantages of being good in improvement effect, lasting in effect, low in cost, environmentally friendly and the like, is suitable for large-area saline-alkali soil improvement and agricultural production, and has good application and popularization prospects.

The invention discloses a magnetic porous microsphere for in-vitro diagnosis and a preparation method of the magnetic porous microsphere, and belongs to the technical field of preparation of micro-nano materials. According to the invention, styrene is used as a polymerization monomer, and a dispersion polymerization method is adopted to prepare monodisperse polystyrene microspheres; ferric chloride and ferrous sulfate are selected as precursors, magnetic nanoparticles are synthesized through a coprecipitation method under the alkaline condition, the initial loading capacity is changed, the magnetic nanoparticles are loaded on the surfaces and in pore channels of polymer porous microspheres through a multi-step seed growth method, and the magnetic nanoparticles are prepared. The composite magnetic polystyrene microspheres with high magnetic content, good magnetic responsiveness and superparamagnetism are synthesized; finally, functional groups are introduced to the surfaces of the magnetic spheres by monomers containing the functional groups through a monomer swelling polymerization method, and the prepared magnetic porous microspheres have the advantages of uniform particle size, small coefficient of variation and large specific surface area, and can be better combined with antigens and antibodies, so that in-vitro diagnostic function detection such as nucleic acid extraction and chemiluminescence is carried out.

The invention provides a method for reducing the content of magnesium, manganese and zinc impurity elements in iron phosphate, which comprises the following steps: (1) preparing a 1.2 mol / L ferrous sulfate solution, adding 25% ammonia water into the ferrous sulfate solution, adjusting the pH value, heating, stirring and reacting for 30 minutes, and filtering to obtain a purified ferrous sulfate solution; (2) preparing a 1 mol / L ammonium dihydrogen phosphate solution, and filtering to obtain a purified phosphorus salt solution; (3) dropwise adding 25% hydrogen peroxide into the purified ferrous sulfate solution to obtain a ferric sulfate solution; (4) dropwise adding a purified phosphorus salt solution into the oxidized ferric sulfate solution; (5) after the phosphorus salt solution is dropwise added, supplementing the purified ferrous sulfate solution according to the amount; (6) rapidly heating the solution and continuously reacting until the material turns white from yellow; and (7) washing the iron phosphate dihydrate precipitate until the conductivity is less than or equal to 200 us / cm, carrying out flash evaporation drying on the iron phosphate dihydrate filter cake, and calcining to obtain the battery-grade iron phosphate. The method can be widely applied to industrial production of iron phosphate.

The application relates to a method for one-step synthesis of strong magnetic hydrophobic Fe3O4 nanoparticles at low temperature and the Fe3O4 nanoparticles and application, and belongs to the technical field of nano material preparation. The method comprises the following steps: adding a ferrous sulfate solution into a mixed solution of sodium hydroxide and sodium nitrate, heating and stirring to react, adding oleic acid in the reaction process, and obtaining black Fe3O4 crystals after the reaction is completed. The saturation magnetization of the obtained strong magnetic hydrophobic Fe3O4 nanoparticles can reach 85.69 emu / g at most, and the water contact angle can reach 148.95 DEG. The one-step synthesis reaction only needs to use oleic acid as a regulator, avoids an extreme high-temperature and high-pressure environment, does not need to use a toxic chemical solvent, the condition is mild, the process is simple, the operation condition is easy to control, and the method has a wide application prospect.

The invention provides a method for removing nitrate in water by using a modified zero-valent iron aerogel electrocatalyst, which comprises the following steps: preparing a mixed solution of ferrous sulfate and sodium sulfide, preparing a sodium borohydride solution, mixing and magnetically stirring the mixed solution and the sodium borohydride solution to obtain black colloid, and finally obtaining vulcanized zero-valent iron aerogel, dispersing the obtained sulfurized zero-valent iron aerogel and a Nafion solution in absolute ethyl alcohol to prepare a catalyst mixed solution; potassium nitrate and potassium hydroxide are dissolved in a pure water solution to serve as electrolyte, a sulfurized zero-valent iron aerogel electrode is used as a cathode, a platinum sheet is used as an anode, a mercuric oxide electrode is used as a reference electrode, and an electrocatalytic reduction reaction is carried out by using a three-electrode system. The technology not only can improve the efficiency of water nitrate pollution treatment, but also conforms to the concept of green and low-carbon development, and has a wide environment application prospect.

The invention provides a preparation method for preparing a high-compaction lithium iron phosphate positive electrode material by utilizing double-iron-source composite grade matching. The preparation method comprises the following steps: adding ferrous sulfate and phosphoric acid into pure water, and fully mixing to obtain a solution; dividing the solution into a solution A and a solution B; adding a certain amount of a metal doping source material, an oxidizing agent and phosphoric acid into the solution A, and controlling the pH to be 1-3 to obtain iron phosphate; adding a certain amount of metal doped source material and ammonia water into the solution B, and controlling the pH to be 5-6 to obtain ferrous phosphate; the preparation method comprises the following steps: respectively sanding and spraying iron phosphate and ferrous phosphate with a lithium source, a carbon source and pure water according to a molar ratio to obtain a lithium iron phosphate yellow material A and a lithium iron phosphate yellow material B; calcining the yellow material A in a furnace to obtain a precursor A, calcining the yellow material B in the furnace to obtain a precursor B, mixing the precursor A and the precursor B according to a certain mass ratio, and calcining to obtain a finished product. The method is simple in technological process, can be combined with actual production, and is very effective for improving the compaction density and the electrical property.

The invention provides iron phosphate as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. Specifically, the method comprises the following steps: preparing a raw material solution from a ferrous sulfate crude salt of a titanium dioxide production by-product, heating the raw material solution to boil, and cooling to obtain a mixed solution; then carrying out solid-liquid separation to obtain recrystallized ferric salt and preparing into a ferric salt solution; adjusting the pH value of the ferric salt solution to be lower than 1.80, repeatedly boiling, cooling and crystallizing to obtain secondary crystallized ferric salt, and preparing into a second ferric salt solution; preparing a phosphorus salt solution from monoammonium phosphate and ammonia water; mixing the second ferric salt solution, the phosphorus salt solution and hydrogen peroxide, reacting, and separating to obtain an iron phosphate precursor; and preparing the iron phosphate precursor into slurry, adjusting the pH value, and sequentially carrying out heating reaction, solid-liquid separation and calcination after the slurry becomes white to obtain iron phosphate. According to the method, resource utilization of the ferrous sulfate crude salt byproduct is realized, and meanwhile, the defects of high impurity content and low product purity during resource product preparation are overcome.

The invention relates to the technical field of brake materials, in particular to a high-thermal-conductivity ablation-resistant carbon ceramic brake disc and a preparation process thereof. The carbon-ceramic brake disc overcomes the defects that an existing carbon-ceramic brake disc is poor in mechanical property and ablation resistance. The preparation method comprises the following steps: preparing modified polyacrylonitrile-based carbon fibers by taking polyacrylonitrile-based short carbon fibers, gamma-aminopropyltriethoxysilane, multiwalled carbon nanotubes, nickel sulfate hexahydrate and ferrous sulfate heptahydrate as raw materials; the preparation method comprises the following steps: preparing modified asphalt-based carbon fibers by taking asphalt-based short carbon fibers, nano silicon carbide and gamma-aminopropyltriethoxysilane as raw materials; preparing modified viscose-based carbon fibers by taking viscose-based chopped carbon fibers and tantalum carbide as raw materials; three modified fibers are used as raw materials of the enhancement layer, the heat conduction layer and the ablation layer; the carbon-ceramic brake disc is prepared through raw material mold pressing, two-stage high-pressure dipping, densification treatment, interface treatment, heat treatment and chemical vapor deposition, and the carbon-ceramic brake disc has the advantages of being high in mechanical property and ablation resistance.

The invention provides a manganese-doped ferrocobalt oxide nano particle-coated carbon-nitrogen cubic composite material as well as a preparation method and application of the manganese-doped ferrocobalt oxide nano particle-coated carbon-nitrogen cubic composite material. The preparation method comprises the following steps: firstly doping ferrous sulfate and manganese chloride into ZIF-8, then mixing the ZIF-8 with cobalt nitrate and 2-methylimidazole in methanol, carrying out centrifugal separation to obtain a product, and finally carrying out one-step calcination to realize carbonitriding of the composite material, doping of manganese and generation of nano particles from ferrocobalt oxide. And finally, the manganese-doped ferrocobalt oxide nanoparticle-coated carbon-nitrogen cubic composite material is obtained. Compared with the traditional preparation method, the method disclosed by the invention is simple, mild in reaction condition and high in yield, and the prepared composite material is uniform in morphology and has excellent electro-catalytic performance on the water electrolysis oxygen evolution reaction.

The invention discloses an advanced treatment method of tungsten beneficiation wastewater, which is characterized in that a composite flocculant is adopted to flocculate the tungsten beneficiation wastewater, and the composite flocculant is mainly composed of cationic polyacrylamide, a flocculant A and lignocellulose, the flocculant A comprises at least one of polyferric sulfate, polyaluminum chloride, polyaluminum ferric chloride, polyaluminum ferric sulfate, ferric sulfate, ferrous sulfate and aluminum chloride. According to the advanced treatment method for the tungsten beneficiation wastewater, under the action of the composite flocculant, the cost of a treatment agent can be reduced to about 0.16-0.20 yuan / m < 3 >, the cost reduction amplitude is as high as 80% or above, the treatment time can be shortened to be within 10 min, the precipitation time is greatly shortened, meanwhile, suspended solids in the wastewater can be effectively removed, actual production requirements are met, and the method is suitable for industrial production. The method has the advantages of low treatment cost, high treatment efficiency, good removal effect, good adaptability and the like, can realize advanced treatment of the tungsten beneficiation wastewater, and is high in use value and good in application prospect.