9 results about "Iron(II) hydroxide" patented technology

At least one embodiment of the invention provides a preparation method of sponge titanium, which comprises the following steps: pretreating bauxite tailings to obtain a first mixture; carrying out acid treatment on the first mixture, and filtering to obtain a second mixture; putting the second mixture into a reaction kettle containing an alkaline substance to react so as to convert the ferric titanate into titanate and ferric oxide or ferrous hydroxide to obtain a third mixture; carrying out suction filtration treatment on the third mixture to obtain a first solid phase and a first liquid phase, and drying and grinding the first solid phase; roasting the dried and ground first solid phase to form an iron elementary substance, and carrying out magnetic separation to remove the iron elementary substance; adding an acidic material into the first liquid phase for reaction to obtain metatitanic acid colloid, and washing the metatitanic acid colloid; the metatitanic acid colloid is subjected to calcination, chlorination reaction and replacement reaction in sequence to obtain the sponge titanium. The sponge titanium obtained through the preparation method is high in purity.

The invention discloses a resourceful treatment method for stainless steel pickling waste liquid and waste water. The waste liquid is divided into high-concentration waste liquid and low-concentration waste liquid according to the acid concentration and the salt concentration to be treated respectively. Sequentially recovering gypsum, chromic hydroxide, nickel sulfide, ferrous hydroxide and manganese-rich slag from the low-concentration waste liquid through gradient precipitation; and neutralizing free acid from the high-concentration waste liquid by using ferrous hydroxide generated in a low-concentration section, cooling and crystallizing to recover ferrous sulfate, deeply removing nickel by using nickel sulfide generated in the low-concentration section, and precipitating to recover chromium hydroxide. In the whole process, generation of ferric iron is strictly controlled, and high-value productization recovery of free acid and all metals is achieved. The method has the advantages of low medicament consumption, high metal recovery rate, high product value, no secondary pollution and the like.

To provide a method for producing a new ferrite quantum dot different from a conventional one.SOLUTION: A method for producing ferrite quantum dots, the method comprising the steps of preparing a mixed solution in which at least ferrous hydroxide is present in water at 0 °C or higher and 30 °C or lower, preparing a green rust-containing suspension by oxidizing the mixed solution to form green rust crystals in the mixed solution, synthesizing ferrite quantum dots in the suspension by raising the temperature of the suspension to 50 °C or higher and 100 °C or lower in an oxygen-free stream, and collecting the ferrite quantum dots in the suspension.SELECTED DRAWING: None

To provide a new method for producing quantum dots of an iron-containing sulfide different from a conventional one.SOLUTION: A method for producing quantum dots of an iron-containing sulfide includes a step of preparing a mixed solution in which at least ferrous hydroxide is present in water at 0 °C or higher and 30 °C or lower, a step of preparing a green rust-containing suspension by oxidizing the mixed solution to form green rust crystals in the mixed solution, and a step of raising the temperature of the suspension to 50 °C or higher and 100 °C or lower in an oxygen-free stream. A method for producing iron-containing sulfide quantum dots, the method comprising: synthesizing the ferrite quantum dots in the slurry; collecting the ferrite quantum dots in the slurry; and treating the ferrite quantum dots with hydrogen sulfide gas at 110 °C. or more and 150 °C. or less to substitute sulfide ions O2 - for oxide ions S2 - in the ferrite, thereby producing iron-containing sulfide quantum dots.SELECTED DRAWING: Figure 1

The invention discloses a full-recycling process and system for pickling wastewater generated by rare earth ore hydrometallurgy, which comprises the following steps: feeding the pickling wastewater into a calcium sulfate pre-crystallization reactor to react with lime emulsion under a low pH condition to obtain calcium sulfate crystals, feeding sulfur removal wastewater into a calcium fluoride crystallization reactor to increase pH, and reacting with a lime solution to obtain calcium fluoride crystals; carrying out filter pressing on the fluorine-removed water to obtain silicon dioxide precipitate, enabling filter-pressed water to enter a ferrous hydroxide crystallization reactor to react with sodium hydroxide to obtain ferrous hydroxide crystals, enabling molten iron to enter a magnesium hydroxide crystallization reactor to react with sodium hydroxide to obtain magnesium hydroxide crystals, enabling magnesium-removed water to enter a neutralization regulating tank, adding acid for neutralization, and discharging after reaching the standard. According to the method, the pollution problem of the rare earth ore pickling wastewater is solved, resource recycling of multiple valuable components in the wastewater is achieved, particularly, the purity of the obtained calcium fluoride product is higher than 70%, the calcium fluoride product can be used in the fields of metallurgy and the like, and the value of the resource product is greatly improved.

This disclosure provides at least one embodiment of a method for preparing sponge titanium, comprising: pretreating bauxite tailings to obtain a first mixture; acid-treating the first mixture and filtering it to obtain a second mixture; placing the second mixture in a reaction vessel containing an alkaline substance to react, thereby converting ferrous titanate into titanate and ferric oxide or ferrous hydroxide to obtain a third mixture; filtration of the third mixture to obtain a first solid phase and a first liquid phase, and drying and grinding the first solid phase; calcining the dried and ground first solid phase to form elemental iron, and performing magnetic separation to remove the elemental iron; adding an acidic substance to the first liquid phase to react and obtain metatitanic acid colloid, and washing the metatitanic acid colloid; and sequentially subjecting the metatitanic acid colloid to calcination, chlorination, and displacement reactions to obtain sponge titanium. The sponge titanium obtained by this preparation method has high purity.

The invention discloses a method for removing magnesium and calcium impurities in titanium dioxide byproduct ferrous sulfate, and belongs to the technical field of battery material precursor purification. The method comprises the following steps: dissolving the titanium dioxide byproduct ferrous sulfate, and removing titanium by reducing iron powder to obtain a ferrous sulfate pretreatment solution; independently preparing and deeply washing to obtain a pure ferrous hydroxide wet filter cake of which the sodium content is lower than 100 ppm; adding a fluorine ion source into the ferrous sulfate pretreatment solution to obtain a fluorine-containing mixed solution; adding the wet filter cake into the fluorine-containing mixed solution to enable magnesium and calcium ions to form fluoride precipitates, and carrying out solid-liquid separation to obtain a ferrous sulfate purified solution; and finally, adding acid to stabilize the pH to obtain the high-purity ferrous sulfate solution. According to the method, pure ferrous hydroxide is used for replacing traditional alkali liquor, introduction of new impurities such as sodium, potassium and ammonium is avoided in principle while magnesium and calcium impurities are efficiently and synergistically removed, the technological process is simple, the cost is low, and the product purity is high.

The present application relates to the technical field of pendimethalin wastewater treatment, and particularly relates to a pendimethalin wastewater treatment method, which comprises the following steps: step 1, adding ferrous oxide or ferrous hydroxide to the wastewater to adjust the pH of the wastewater to neutral; step 2, adjusting the pH of the primary filtrate to 2-5 by using inorganic acid, and adding an iron-carbon mixture with a mass ratio of 1:0.5-2 to perform a redox reaction; and step 3, introducing the secondary filtrate into 2-5 reaction kettles in series, and adding hydrogen peroxide in 1-3 portions according to a mass ratio of 15-25:1 between the hydrogen peroxide and COD. The pendimethalin wastewater treatment method can quickly reduce nitrate into nitrogen oxide or ammonia gas through the original cell effect of the iron-carbon mixture in the solution, and can efficiently and quickly treat the nitrate, and finally the iron ions and ferrous ions can generate corresponding hydroxides.

The present invention provides a method and apparatus (2a) for producing at least one of calcium oxide, magnesium oxide and an iron oxide from an ore comprising a carbonate mineral of at least one of calcium, magnesium and iron, such as limestone and siderite ores. The method comprises producing liquid sodium and chlorine gas by electrolysis. The liquid sodium is oxidised to sodium oxide and the chlorine is used to make hydrochloric acid. The sodium oxide may be produced in a redox reaction with an oxide of another metal to produce the other metal in elemental form as well. The ore is added to the hydrochloric acid to dissolve the carbonate mineral therein, which produces gaseous carbon dioxide and an aqueous solution respectively comprising at least one of calcium chloride, magnesium chloride and ferrous chloride. The carbonate mineral is dissolved in the hydrochloric acid closed off from their surrounding environment and the carbon dioxide is captured. The aqueous solution is reacted with at least some of the sodium oxide, or sodium hydroxide derived therefrom, to produce an aqueous solution of sodium chloride and a precipitate respectively comprising at least one of calcium hydroxide, magnesium hydroxide and ferrous hydroxide. The precipitate is then phase separated from the aqueous solution of sodium chloride and the hydroxide(s) in the separated precipitate are thermally decomposed to produce water vapour and a solid end-product comprising the desired oxide(s). Sufficient heat for this thermal decomposition is transferred to the separated precipitate from at least one of the electrolysis products, the exothermic processes by which the precipitate is produced, their respective products and the products of the thermal decomposition itself. Thus the invention consumes no carbonaceous fuel, including any fossil fuel, and has electricity as its only energy requirement. If the electricity is produced from a source of renewable energy, it produces no greenhouse gas emissions. The apparatus (2a) comprises an electrolytic subassembly (10), a sodium oxide or hydroxide-producing subassembly (13), a hydrochloric acid-producing subassembly (12), a reaction subassembly (14), a solid-aqueous phase separator (16), a kiln (20), and a heat transfer pathway (23) for transferring enough heat to the precipitate in the kiln (20) to cause the thermal decomposition from at least one of: a product of the electrolytic subassembly (10), the other subassemblies (12, 13, 14) and their respective products, and a product of the thermal decomposition. The invention is intended to replace the traditional calcination process, including for the production of cement clinker, and can also be used to convert siderite ores into one or more iron oxides suitable for ironmaking. The captured carbon dioxide may be reacted with a second portion of the sodium oxide, or with sodium hydroxide derived therefrom, to produce sodium carbonate, thereby also providing a replacement for the Solvay process. In some embodiments, the method can even have a negative carbon footprint overall.