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

The invention relates to a method for producing high-purity battery grade iron oxalate by utilizing pickle liquor, comprising the following steps: the pickle liquor is pre-treated for lowering spent acid content, thus leading the pickle liquor to generate ferrite solution with a certain concentration; then after strict filtering and magnetic separation, the ferrite solution is transported into a reaction kettle, then industry ammonia is added and the solution is stirred for reaction to generate ferrous hydroxide gelatin; the soluble oxalic acid solution is slowly added in and stirred, and then the mixture is stirred by a conversion reaction kettle and heat preservation is carried out, thus obtaining iron oxalate slurry after reaction; iron oxalate mother solution is separated in the iron oxalate slurry, and the separated iron oxalate is washed, dried and crashed for obtaining high-purity superfine iron oxalate products. The method has the beneficial effects that: the pickle liquor in industrial production is fully utilized; a two-step liquid phase method of oxidation and conversion is adopted for leading the reaction to be more fully, so that the reaction rate is greatly improved,the grain diameter of the finished products iron oxalate is fine and uniform, D50 is less than or equal to 5mum, and the content of the iron oxalate is more than or equal to 95.5 percent; furthermore, the pickle liquor is used as raw material, and cyclic utilization and environmental protection of the industrial waste are utilized, thus changing waste into valuable and greatly lowering the production cost.

The invention provides a method for leaching vanadium in ferrovanadium spinel vanadium-containing minerals through complexing of hydrothermal oxalic acid, and belongs to the field of leaching of vanadium in ferrovanadium spinel vanadium-containing minerals through a hydrothermal method. According to the method, the ferrovanadium spinel vanadium-containing minerals are used as raw materials, ferrumpowder is used as a reducing agent, an oxalic acid solution is used as a leaching agent, and the ferrovanadium spinel vanadium-containing minerals, the ferrum powder and the oxalic acid are mixed into slurry to react under a hydrothermal condition; and solid-liquid separation is conducted on the slurry obtained after the reaction, so that clean vanadium-containing leachate and a ferrous oxalate by-product are obtained. According to the method, oxalate ions with a the strong complexing effect react with vanadium and ferrum in ferrovanadium spinel to form [V(C2O4)3]<3-> and [Fe(C2O3]<3-> to enter the solution; and the formed [Fe(C2O3]<3-> reacts with the Fe powder to form ferrous oxalate sediment, so that proceeding of the reaction is facilitated, and the leaching reaction rate is increased. By adoption of the method, vanadium in the ferrovanadium spinel vanadium-containing minerals can be effectively extracted, vanadium and ferrum are separated in the leaching process, the process steps are simplified, and the by-product, namely the ferrous oxalate, with high added value is obtained.

The invention belongs to the technical field of industrial waste recycling and specifically relates to a method for synchronously and efficiently extracting high-value rare earth and iron from NdFeB waste for reuse. The method of the present invention reacts the oxidation product obtained after oxidizing and roasting the NdFeB waste with the oxalic acid solution to obtain the leach solution containing iron oxalate and the solid precipitate mainly composed of rare earth oxalate, and then only the leach solution and the precipitate Iron reduction and molten salt electrolysis treatment can be carried out respectively to obtain rare earth alloys for the production of NdFeB materials and ferrous oxalate for the production of lithium battery materials. The method only uses oxalic acid solution as a leaching agent and a precipitating agent, and can complete the leaching of iron and the transformation of rare earths in one step, thereby achieving the purpose of simultaneously realizing the efficient extraction and high-value recycling of iron and rare earths. The method of the invention has a short extraction process, is environmentally friendly, can effectively recover and obtain high-value products, and has extremely high process operability.

The invention relates to a preparation method for a hydrous salt crystal of ferrous oxalate. The method comprises a contact reaction between water solution of oxalate and water solution of ferrous salt, which is carried out in the presence of mixed solvent of organic solvent and water; the organic solvent and water are totally soluble. The hydrous salt crystal of ferrous oxalate prepared by the method provided by the invention has small average grain size, as small as 1-5 micron, has good reactivity, and is suitable for being as compound raw material of lithium iron phosphate, an active substrate of anode of lithium-ion secondary batteries.

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 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 separating and extracting iron and nickel from an iron and nickel leaching solution. In the method, after adjusting the pH of the waste water, oxalic acid precipitation is used to remove iron to obtain ferrous oxalate and nickel sulfate solutions. Ferrous oxalate After calcination, iron oxide is obtained; the nickel sulfate solution is further ion-exchanged to remove iron, and then nickel electrowinning is carried out to obtain a nickel plate. After the solution produced by nickel electrowinning is treated by electrodialysis, fresh water is reused; , The problem of deep separation of nickel leaching solution, the whole process constitutes a closed loop, sulfuric acid and water resources are recycled, the process operation cost is low, iron extraction production can obtain ferrous oxide with a purity >99.5%, and nickel extraction production can obtain nickel plate with a purity greater than 99.995% , high resource utilization rate, good product purity, excellent economic benefits, no waste gas, waste water and waste residue discharge in the whole process, and no secondary pollution.