44 results about "Iron(II) oxalate" patented technology

A method for treating red mud by utilizing oxalic acid solution comprises the steps of taking 0.5-1mol/L oxalic acid solution as a leaching agent, mixing air-dried red mud with the oxalic acid solution according to a proportion of 80-120g/L, stirring at 60-90 DEG C for 0.5-4h, and conducting solid-liquid separation to obtain the treated red mud and ferrum-containing oxalic acid solution. The ferric oxide content in the treated red mud is smaller than 1 percent, so that the red mud is applicable to manufacturing of refractory bricks, cement and the like. The ferrum-containing oxalic acid solution is subjected to photochemical reaction under irradiation of ultraviolet light or sunshine, thus being capable of forming ferrous oxalate sedimentation with better crystal. Ferric oxide content of filtrate after being separated from ferrous oxalate sedimentation is smaller than 1g/L, and the filtrate solution is continuously used for treating the red mud as supplement liquid of the leaching agent after being added with proper oxalic acid or being directly used.

The invention discloses a method for stripping an iron-loaded P2O4 organic phase and removing iron from strip liquor, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: (1) mixing an oxalic acid solution serving as a stripping agent with the iron-loaded P2O4 organic phase, and performing reverse-flow stripping at the temperature of 20-40 DEG C to obtain iron-rich strip liquor and a blank P2O4 organic phase; (2) performing photodecomposition on the iron-rich strip liquor by means of solar radiation to precipitate and remove iron, or adding iron powder into the iron-rich strip liquor under heating and stirring conditions to remove iron by means of reductive precipitation; (3) filtering precipitated and iron-removed materials to separate a solid phase and a liquid phase out; (4) replenishing oxalic acid into the separated liquid phase, namely, an iron-poor oxalic acid solution, returning to the step (1) for recycling, and recycling the solid phase in the form of a ferrous oxalate product. The method is free from acid mist pollution in the operating environment, and has the advantages of simple process, no discharge of waste residues or waste liquor, high efficiency, environmental friendliness and high practicability.

The invention provides a method for leaching vanadium, titanium and chromium from vanadium, titanium and chromium raw materials by hydrothermal organic acid, and belongs to the technical field of metallurgy. The method comprises the steps that vanadium slag, extracted vanadium tailings, vanadium slag-extracted vanadium tailing mixed slag and titanium concentrate are used as raw materials, and organic acid is used as a leaching agent for hydrothermal reaction in a reactor. The vanadium slag, the extracted vanadium tailings and the vanadium slag-extracted vanadium tailing mixed slag are correspondingly leached by the organic acid to obtain an element solution containing vanadium, titanium and chromium and ferrous oxalate; and the titanium concentrate is leached by the organic acid to obtaina solution contacting titanium and ferrous oxalate. According to the method, the acidity and the high complexing ability of the organic acid are utilized to destroy a phase containing vanadium, titanium and chromium, the complex reaction is generated to form a complex ion solution of [V(C2O4)3]3-, [Ti(C2O4)3]3- and [Cr(C2O4)3]3-, and the efficient leaching of vanadium, titanium and chromium elements is achieved; in addition, the method is simple in process and environment-friendly; the added value of the ferrous oxalate is high; and used equipment is common, the energy consumption is low, anda good application prospect is achieved.

The invention belongs to the technical field of a negative electrode material for a lithium-ion battery, and discloses a nitrogen-doped carbon-coated iron oxide negative electrode material for the lithium-ion battery and a preparation method of the nitrogen-doped carbon-coated iron oxide negative electrode material. The method comprises the following steps of adding ferrite to a mixed solution of water and ethanol, stirring, dissolving, adding oxalate and stirring to obtain a turbid liquid; heating the turbid liquid to 120-220 DEG C for reaction for 8-15 hours to obtain a ferrous oxalate precursor; heating the ferrous oxalate precursor to 500-600 DEG C and burning the ferrous oxalate precursor for 4-8 hours to obtain an iron oxide; dissolving an emulsifier into water, adding n-butyl methacrylate, acrylonitrile and styrene, heating the solution to 55-65 DEG C, adding an initiator, stirring for 4-10 hours to obtain an emulsion and carrying out demulsification to obtain a polymer; and dispersing the polymer into an organic solvent, adding the iron oxide, stirring for 12-36 hours, separating to obtain a solid, heating the solid to 500-600 DEG C and burning the solid for 2-4 hours to obtain the nitrogen-doped carbon-coated iron oxide negative electrode material with excellent cycle performance and rate capability.

The invention discloses a method for removing iron ions in a trivalent chromium acid solution. The method includes the following steps that an additive is added into the trivalent chromium acid solution to reduce the trivalent ferric ions to bivalent ferric ions, then an oxalate solution is added, leached materials are subjected to liquid-solid separation, and the trivalent chromium acid solution obtained after iron removing is used for producing a chromium slat product; and ferrous oxalate obtained after iron removing is subjected to oxidation leaching in an alkali solution, iron in the ferrous oxalate is converted into ferroferric oxide, oxalate is leached into the solution liquid-solid separation is carried out, an oxalate leaching agent is obtained and used for cyclically removing iron, and the obtained ferroferric oxide becomes a black iron oxide pigment after being dried. According to the method, consumption of an iron removing agent is greatly reduced, iron is removed thoroughly through the trivalent chromium acid solution, the byproduct of black iron oxide can reach the pigment performance of domestic 722 black iron oxide and does not contain high-toxicity hexavalent chromium, and the method can be used in the industries of buildings, coatings and the like.

The invention discloses a nanocrystalline porous iron oxide and a preparation method thereof. The hydrothermal reaction is carried out with an aqueous solution containing ferrous ions and an aqueous solution containing oxalate, and the precursor ferrous oxalate is first prepared, and the ferrous oxalate is a micron-scale strip shape; then the precursor ferrous oxalate is heat-treated, Porous iron oxide structured by nanocrystals is obtained. The porous iron oxide constructed by nano crystals in the present invention is composed of uniform nanoparticles and has a large specific surface area, which provides excellent conditions for the application of iron oxide. The outstanding advantage of the present invention is that the porous iron oxide obtained by the synthesis method has a regular strip-shaped macroscopic appearance, and the secondary particles that construct the porous structure are nanoparticles, which can meet the requirements of the iron oxide materials in the application fields such as electrode materials and catalytic materials. Specific surface area requirements. Moreover, the method provided by the invention is simple and controllable, and is easy to realize industrial production.

The invention discloses an efficient composite Fenton reagent. Ferrous oxalate is used as a main catalyst; other metal salts which are one or several kinds of materials from copper metal salts, cobaltmetal salts, aluminum metal salts, manganese metal salts, nickel metal salts, cadmium metal salts, chromium metal salts, cerium metal salts and palladium metal salts, are added; The reagent has the advantages that the cost during the sewage treatment can be obviously reduced; a complicated device is not needed; the oxidization efficiency is obviously improved; meanwhile, the requirement on the use environment is reduced; good oxidization capability is realized under the acidic and basic conditions; meanwhile, the preparation method of the composite Fenton reagent is simple; the operation is convenient.

The invention discloses a method for modifying the performance of a sintered Mn-Cu damping alloy with ferrous oxalate. According to the method, sintering is promoted by high-activity iron produced by pyrolysis and hydrogen reduction of the ferrous oxalate, H2O, CO2 and other gases released during pyrolysis and hydrogen reduction of the ferrous oxalate can prevent a compact sealing layer from being formed on the surface of a sintered blank, and pyrolysis, reduction and sintering are performed under the action of hydrogen. Dehydration is performed at 180-240 DEG C with the heat preservation time of 1-4 h; pyrolysis is performed at 400-500 DEG C with the heat preservation time of 1-4 h; reduction is performed at 750-850 DEG C with the heat preservation time of 1-2 h; then a sintering process is finished at 850-950 DEG C with the heat preservation time of 2-4 h; and the heating speed is 5-10 DEG C/min. The sintered Mn-Cu damping alloy prepared according to the method reaches the diameter of 100 mm, the length of 200 mm, the density of 5.10-5.75 g/cm<3>, the hardness of 52-86 HRF and the bending strength of 128-184 MPa and has high uniformity.

The invention discloses a lithium iron phosphate nanorod/graphene composite material as well as a preparation method and an application thereof; the preparation method comprises the following steps offirstly, providing ferrous oxalate/graphene oxide composite material and then carrying out mixing on the ferrous oxalate/graphene oxide composite material and ammonium dihydrogen phosphate and lithium acetate dihydrate according to a certain molar ratio, and carrying out grinding and drying, and next, carrying out high-temperature reaction under the protection of inert gas to obtain the compositematerial. The lithium iron phosphate nanorod/graphene composite material prepared by adopting a two-step solid phase reaction method is small in particle size and uniform in particle size distribution, and has a one-dimensional nanorod-shaped structure, so that the transmission rate of ions can be effectively increased, and the capacity in large-current discharge is not attenuated; graphene is added, so that the surface conductivity of the material is further improved, and meanwhile, the rate performance and the cycling performance of the material are remarkably improved; and in the preparation process of the lithium iron phosphate nanorod/graphene composite material, the reaction conditions are easy to control, the operation is simple, the production cost is low, and industrial production is easy to realize.

The invention discloses a method for extracting Fe, Zn and Pb from electric furnace fly ash and utilizing Fe, Zn and Pb in a high-value mode. A large amount of dangerous waste electric furnace fly ash is used as a raw material, oxalic acid is used as a leaching agent, and a complex reaction is performed under the reaction conditions of low temperature and normal pressure, so that the purpose of stepwise separating iron and zinc resources is achieved. Under the conditions that the concentration of the oxalic acid is 5-30%, the liquid-solid ratio is 10:1-50:1, the reaction temperature is 30-90 DEG C and the reaction time is 0.5-4 h, the leaching rate of Fe in the electric furnace fly ash can reach 92% or above, the content of Zn (in terms of ZnO) in leaching residues can reach 36% or above, and the purity of finally obtained ferrous oxalate can reach 97% or above. The method is simple in process, low in energy consumption and low in reaction cost; and the obtained ferrous oxalate and zinc-rich residues have higher additional value, meanwhile, the influence on the environment is smaller, and the method has good market application prospects.

The invention discloses a method for preparing fulvic acid calcium magnesium fertilizers. The method includes the steps that 1, raw humic acid powder or sodium humate is added into gulonic acid mother liquor, the mixture is sufficiently stirred for 1 hour and centrifugally filtered, and filter liquor is collected; 2, ferrous sulfate is added into the filter liquor to be stirred, the mixture and oxalic acid generate ferrous oxalate, and filter liquor is collected after filtering is carried out; 3, the pH value of the obtained filter liquor is adjusted through calcium oxide to 2 to 4, the filter liquor is neutralized through magnesium hydrate till the pH value of the filter liquor ranges from 4 to 5, filtering is carried out, and filter liquor is collected; 4, the collected filter liquor is neutralized through potassium hydroxide till the pH value of the collected filter liquor ranges from 6 to 6.5, and fulvic acid calcium magnesium fertilizer intermediate products are obtained; 5, nutrients are added into the intermediate products, the mixture is mixed, dissolved and filtered, and filter liquor is prepared into the fulvic acid calcium magnesium fertilizers. According to the method, fulvic acid which can be conveniently absorbed by plants is generated after scientific harmless treatment is carried out on the gulonic acid mother liquor, the functional fulvic acid calcium magnesium fertilizers are prepared through the chelation performance of the fulvic acid, and the fulvic acid calcium magnesium fertilizers have the effects of resisting drought and diseases, promoting growth of crops and improving soil.

The invention discloses a method for preparing nano ferroferric oxide. According to the method, ferrous oxalate is subjected to thermal decomposition at 500-520 DEG C in the presence of an inert gas, thus obtaining the nano ferroferric oxide. The method is simple in process and convenient to operate; moreover, a thermal decomposition technology used in the method has low requirement on equipment because of low temperature; in addition, the cost is low due to the adopted ferrous oxalate, so that the method can be used for effectively realizing mass production.

The invention discloses a method for leaching gold hematite wrapped in second-stage calcine through using oxalic acid. The method comprises the steps that firstly, the oxalic acid is added into a leaching tank; the second-stage calcine and water are added into the leaching tank added with the oxalic acid, agitation leaching is carried out, and liquid-solid separation is carried out after the leaching process is ended so as to obtain a leachate and leaching residues; illumination treatment is carried out on the leachate to obtain a faint yellow precipitate and an illuminated solution; and cyaniding leaching is conducted on the leaching residues, liquid-solid separation is conducted after the leaching process is finished, and accordingly gold-containing pregnant solution is obtained. According to the method, the oxalic acid is added, the strong complexing effect of C2O4<2-> on Fe<3+> is utilized, the hematite in the second-stage calcine is leached in the form of an iron oxalate complex,the iron leaching speed is high, the iron leaching rate is high, the energy consumption in the leaching process is low, and industrialization is easy; the leachate is subjected to illumination treatment to obtain ferrous oxalate, part of the oxalic acid is re-used, and recovering of iron, recycling of part of leaching agent oxalic acid and re-using of the system water are achieved; and cyaniding is conducted on iron removal slag for gold extraction, and the leaching rate of gold is effectively increased.

The invention relates to the technical field of rare earth and iron recovery, in particular to a method for comprehensively recovering rare earth and iron from neodymium iron boron oil sludge. According to the method, oil in the neodymium iron boron oil sludge is removed through a detergent, then oxidizing roasting is conducted, the rare earth and the iron can be converted into corresponding oxides, it is avoided that indissolvable NdFeO3 is generated due to high-temperature roasting, hydrochloric acid is used for leaching the rare earth and the iron obtained after oxidizing roasting at the low temperature, the rare earth and the iron are almost completely dissolved, and through fractional precipitation, the rare earth and the iron are recovered by the aid of rare earth oxalate and ferrous oxalate respectively. The method has the characteristics of easiness in operation, low oxidizing roasting temperature, high rare earth and iron recovery rate and high comprehensive utilization rate of resources.

The invention relates to a preparation method of a lithium ferrous oxalate ion battery negative electrode material with exposed specific oriented crystal faces. An iron hydroxide precursor is added into a mixed solution composed of additives such as ascorbic acid and oxalic acid in a specific proportion, and synthesis of a ferrous oxalate nano-material exposing different oriented crystal faces is achieved by controlling the reduction dissolution rate of iron hydroxide in the solution and coordinating the nucleation growth process of the ferrous oxalate material. According to the invention, ascorbic acid is adopted to strengthen reduction dissolution of an acidic oxalic acid solution on ferric hydroxide and regulate and control atomic coordination and an initial crystal stacking rate of ferrous oxalate; meanwhile, the atomic coordination environment and the surface energy of ferrous oxalate crystal particles are interfered by using an organic solvent; therefore, the preparation of the ferrous oxalate material with exposed specific oriented crystal faces is achieved. The ferrous oxalate material with the exposed specific oriented crystal face growth can give full play to the advantages of different types of electrochemical reaction ion diffusion microchannels constructed by arrangement of different crystal face atoms and the characteristic of close arrangement of different oriented crystal face atoms to adjust material stress distribution and energy storage catalytic sites, and the lithium storage performance of the ferrous oxalate material is enhanced.

The invention discloses a method for modification preparation of a composite electrode micropowder material by using vanillic acid. The method comprises the steps: according to the atomic ratio of Li1-xYxFePO4, taking a proper amount of lithium acetate, ferrous oxalate, ammonium dihydrogen phosphate and a Pr powder, mixing, then grinding the mixed raw material with an agate mortar, grinding fullyto obtain a precursor powder, then adding a proper amount of vanillic acid, continuing to grind, after being uniform, carrying out heat treatment under the protection of an inert gas atmosphere, naturally cooling to room temperature, and thus obtaining the prepared composite electrode micropowder material modified by vanilla acid.

The invention relates to a lithium ion composite electrode material doped with citric acid and a process thereof. The process comprises the steps: firstly, taking lithium acetate (CH3COOLi.2H2O, analytically pure), ferrous oxalate (FeC2O4.2H2O, analytically pure), ammonium dihydrogen phosphate (NH4H2PO4, analytically pure), and an Nd powder according to the ratio of Li1-xNdxFePO4 and proportioning, placing in an agate pot, carrying out mixed grinding, grinding to become a pale yellow powder, then adding citric acid, mixing evenly, carrying out heat treatment for a period of time under the protection of an inert gas atmosphere and in the condition of the temperature of 300-400 DEG C firstly, and then carrying out isothermal heat treatment at the temperature of 500-550 DEG C for a period oftime, naturally cooling the obtained product to room temperature under the protection of an inert gas atmosphere, and thus obtaining the lithium ion composite electrode material powder doped with citric acid. The method has the advantages of simple process and low production cost, and the electric conduction and charge and discharge performance of the prepared electrode material powder is good.