12 results about "Ferric hydroxide oxide" patented technology

To provide a method for suppressing red heat embrittlement cracking in the production of a steel containing Cu and Ni, particularly in a hot rolling stage, and also suppressing the generation of scale indentation flaws caused by the degradation in descaling properties.SOLUTION: A method for suppressing red heat embrittlement cracking and scale indentation when producing a steel containing Cu and Ni, the Cu-containing steel having a Cu equivalence CCuEq (mass%) of a base metal of 0.15% or more and 3.00% or less and a Ni concentration CNi (mass%) of 0.05% or more and half or less of the Cu equivalence CCuEq (mass%), the method comprising: mixing a Si-containing material having a Si amount per surface area of the steel of 200 to 1200g / m2 with an iron oxide or iron hydroxide having a Fe amount of 0.3 to 20.0% of the Si amount to obtain a mixture; The mixture is disposed on a steel material surface of the steel material, the steel material is heated in a temperature range of 1170 °C or higher, descaling is performed, and then hot rolling is performed.SELECTED DRAWING: None

According to the present invention, a reducing agent and a slag-forming agent having a mass ratio (CaO / SiO2) of 0.50 or less are added to an oxide to produce an oxide-containing mixture, the oxide comprising: at least one valuable element selected from the group consisting of Ni, Co, and Mn; impurity elements copper and iron; and a quasi-valuable element Li. The oxide is reduced by heating the oxide-containing mixture to produce a slag that contains metal and the quasi-valuable element. The metal is brought into contact with an acid solution to produce a leachate that contains a valuable element and an impurity element. A sulfiding agent is added to the leachate to precipitate copper in the form of copper sulfide, thereby producing a copper-depleted solution. An oxidizing agent is added to the copper-depleted solution to precipitate iron in the form of iron hydroxide, thereby producing a valuable element solution that contains a valuable element. The valuable element solution, a complexing agent, and an alkaline aqueous solution are introduced into a liquid in a reaction tank to produce a precipitate that contains a valuable element.

The invention discloses a chlorination process waste acid resource reutilization method which comprises the following steps: S1, firstly neutralizing chlorination process waste acid, and controlling the neutralization pH value to be 2.5-3.5; s2, then adding iron oxide black seed crystals; s3, carrying out oxidation treatment on the system added with the seed crystal, further neutralizing the system, and controlling the neutralization pH to generate large-particle-size iron black; and S4, carrying out separation to separate the large-particle-size iron black from other precipitates so as to obtain an iron black product. The waste acid is neutralized firstly, the pH of the waste acid is increased, and iron oxide black is prevented from being dissolved again during subsequent iron oxide black seed crystal. And then iron black crystal seeds are added, so that ferric hydroxide which is neutralized and separated out during subsequent oxidation treatment is promoted to be converted into large-particle-size iron black crystals, the particle size of the iron black crystals is obviously larger than that of precipitates of other metal ions, the iron black crystals can be effectively separated from the other precipitates, and the purity of the iron black product is greatly improved.

To provide: a reducing agent composition for iron oxide and / or iron hydroxide that can quickly produce dithionous acid as a reduction active species from thiourea dioxide and can minimize the inactivation of reduction species due to dissolved oxygen in water to exhibit a sufficient reduction rate of iron oxide and / or iron hydroxide; and a method for reducing iron oxide and / or iron hydroxide using the same.SOLUTION: Provided are: a reducing agent composition for iron oxide and / or iron hydroxide, comprising components (A)-(C) and having a pH in a range of 7-11, wherein a redox potential when component (A) is dissolved in an aqueous solution containing components (B) and (C) reaches -600 mV or lower within 20 minutes after start of dissolution of component (A), and a rate of change in redox potential reaches a value of 0 mV / min or greater within 60 minutes; and a method for reducing iron oxide and / or iron hydroxide by bringing the reducing agent composition into contact with iron oxide and / or iron hydroxide. (A) Reducing agent, (B) water-soluble metal chelating agent, and (C) amine compound.SELECTED DRAWING: None

TITLE OF THE INVENTION: DEVICE, KIT AND METHOD FOR PURIFYING A GAS COMPRISING MAJORITY IN METHANE. A device for purifying a gas containing methane comprising: - a methanation reactor (101) comprising: - an oxygen inlet (104), - a means for regulating the oxygen flow rate (105) and - a gas outlet (107), - a purification reactor (111) comprising: - an iron hydroxide bed (112), - a gas inlet (110) connected to the outlet of the methanation reactor and - a purified gas outlet (115), - a sensor (108) for the oxygen concentration of the gas; - a control unit (118) sending a command to regulate the oxygen flow rate according to the oxygen concentration detected. Figure for the abstract: Figure 1

The present invention discloses a method for extracting carbides from wear-resistant steel, belonging to the field of metal electrochemistry technology. The present invention achieves the purpose of extracting pure and complete carbides from steel by improving the electrolyte and method. An electrolyte containing tartaric acid is selected to react with metal ions in the solution to inhibit the formation of iron hydroxide. The acidic environment can effectively dissolve sulfide inclusions and reduce the impact of impurities on the purity of carbides. An H-type electrolytic cell is used, and a filter membrane is used to physically separate the cathode and the anode, effectively preventing the iron precipitated on the cathode from mixing into the carbides and affecting the analysis of the carbides. The method can successfully obtain carbides from the wear-resistant steel matrix by selecting a suitable electrolyte and an electrolytic extraction device. The extraction device is simple, and the obtained carbides are purer and more complete, which can realize the analysis of the phase, morphology and particle size distribution of the carbides.

The present invention involves obtaining a mixed oxide by adding a reducing agent (a carbon-containing substance and an iron-containing substance) to an oxide including valuable elements that are Mn and at least one selected from the group consisting of Ni and Co and impurity elements that are copper and iron. The iron-containing substance is at least one selected from the group consisting of metallic iron and iron oxide, and the total addition amount of the carbon-containing substance and the iron-containing substance is 1.0-1.6 equivalents. A metal is obtained by heating the mixed oxide to reduce the oxide. A leachate containing the valuable elements and the impurity elements is obtained by bringing the metal into contact with an acid solution. A copper-depleted solution is obtained by adding a sulfurizing agent to the leachate to precipitate copper as copper sulfide. A valuable-element solution containing the valuable elements is obtained by adding an oxidizing agent to the copper-depleted solution to precipitate iron as iron hydroxide. A precipitate including the valuable elements is obtained by introducing the valuable-element solution, a complexing agent, and an alkaline aqueous solution into a liquid in a reaction chamber.

According to the present invention, a reducing agent is added to an oxide to produce an oxide-containing mixture, the oxide comprising: at least one valuable element selected from the group consisting of Ni and Co; a valuable element Mn; and impurity elements copper and iron. The oxide is reduced by heating the oxide-containing mixture to produce metal. The metal is brought into contact with an acid solution to produce a leachate that contains a valuable element and an impurity element. A sulfiding agent is added to the leachate to precipitate copper in the form of copper sulfide, thereby producing a copper-depleted solution. An oxidizing agent is added to the copper-depleted solution to precipitate iron in the form of iron hydroxide, thereby producing a valuable element solution that contains a valuable element. The valuable element solution, a complexing agent, and an alkaline aqueous solution are introduced into a liquid in a reaction tank to produce a precipitate that contains a valuable elements. The reducing agent comprises at least one agent selected from the group consisting of a C-based reducing agent, an Si-based reducing agent, and an Al-based reducing agent. The reducing agent is added in an amount R that satisfies the specific formula shown in Formula (1).

The present application relates to the technical field of iron phosphate preparation, in particular to a process for preparing battery-grade iron phosphate from carbon-containing crude iron phosphate. Specifically, the carbon-containing crude iron phosphate is ground into fine powder, and then deionized water is added to form a slurry, which is reacted in an alkaline environment to obtain carbon-containing iron hydroxide. The iron hydroxide is calcined in an inert atmosphere and then subjected to magnetic separation to obtain iron powder. The iron powder is dissolved in acid, and then passed through a membrane separator of a homogeneous cation exchange membrane to remove metal impurity ions. Sodium phosphate solution and hydrogen peroxide are added to obtain basic iron phosphate. The basic iron phosphate is aged with phosphoric acid, and then calcined to obtain anhydrous iron phosphate. The modified homogeneous cation exchange membrane has high selectivity and adsorption capacity. The metal impurity ions are removed from the iron phosphate solution by forming complexes with the metal impurity ions through coordination bonds. The method significantly improves the purity of the battery-grade iron phosphate.

The present invention discloses a method for preparing iron vanadate by an isophasic pH precipitation method and using the same to produce vanadium dioxide, which relates to the technical field of hydrometallurgy for vanadium extraction. The method comprises the following steps: 1) heating a vanadium-containing acid solution to a set temperature and oxidizing it; 2) simultaneously adding the vanadium-containing acid solution, an iron salt solution and dilute alkali into the system at a certain flow rate respectively, and keeping the pH of the slurry unchanged; 3) separating the solid and liquid of the above slurry, washing the precipitate with hot dilute alkali to obtain an iron hydroxide precipitate and a vanadate alkaline solution; 4) adjusting the above alkaline solution to be acidic and adding a reducing agent; 5) adjusting the pH of the above vanadium-containing acidic solution to neutral to obtain a vanadium hydroxide precipitate, and calcining the precipitate without oxygen to obtain vanadium dioxide. The present invention provides a method for preparing iron vanadate by an isophasic pH precipitation method and using the same to produce vanadium dioxide, which can realize the recovery of vanadium in the vanadium-containing acid solution and the preparation of vanadium dioxide, and has the advantages of short production process, high vanadium precipitation rate, high recovery rate and pure vanadium dioxide.

To provide a recovery method of precious elements capable of removing impurity elements and selectively recovering Ni and Co.SOLUTION: An oxide containing at least one valuable element selected from the group consisting of Ni and Co, as well as Mn, and impurity elements such as Cu and Fe, is mixed with a reducing agent to obtain a mixed oxide. By heating the mixed oxide, the oxide is reduced to obtain the metal. The metal is contacted with an acid solution to obtain a leach solution containing valuable elements and impurity elements. A sulfidizing agent is added to the leach solution to precipitate copper as copper sulfide, thereby obtaining a copper-depleted leach solution as a copper removal solution. An oxidizing agent is added to the copper removal solution to precipitate iron as iron hydroxide, thereby obtaining a copper removal solution depleted of iron as a valuable element solution containing valuable elements. The reducing agent contains at least one selected from the group consisting of C-based reducing agents, Si-based reducing agents, and Al-based reducing agents, and the amount of reducing agent added, R, satisfies a specific formula (1).SELECTED DRAWING: Figure 1

This invention relates to an intermediate red effect pigment having high saturation and high brightness, using a metal coated with a colored absorbent layer of iron oxide or iron oxide hydroxide as a flake-shaped substrate.