8results about "Chromium halides" patented technology

The invention provides a high-purity ferrous chloride and chromic chloride mixed crystal and a preparation method and application thereof, and the preparation method comprises the following steps: dissolving carbon ferrochrome in a hydrochloric acid solution to obtain a strong acid dissolution solution; water is added for dilution, and the total concentration of iron and chromium is 100-200 g / L; adding a sodium dimethyl dithiocarbamate solution, stirring and reacting to generate sulfide precipitate, and filtering to remove the sulfide precipitate; concentrating the filtrate after impurity removal, arranging a permanent magnet outside or at the bottom of a crystallization container to ensure that a magnetic field generated by the permanent magnet can cover a main area of the solution, and carrying out magnetic field assisted crystallization; and after crystallization, carrying out solid-liquid separation, and drying to obtain the high-purity ferrous chloride and chromium chloride mixed crystal. The method has the advantages of being simple in technological process, high in impurity removal efficiency, low in target metal loss rate and good in safety, the ferrous chloride and chromium chloride mixed crystal with excellent purity can be prepared, and the method has good application prospects and large-scale popularization potential in the field of iron-chromium flow battery electrolyte.

A method of making an Fe—Cr electrolyte includes a) oxidizing a carbon-containing Fe—Cr alloy with Fe2O3 or FeO; and b) treating the oxidized carbon-containing Fe—Cr alloy with FeCl3 or HCl or any combination thereof to produce a FeCl2—CrCl3 electrolyte. The method may also include treating, under reducing conditions, a starting material, such as chromite ore, with a carbon source to produce the carbon-containing Fe—Cr alloy. Additionally or alternatively, the method may include removing a portion of the FeCl2 from the FeCl2—CrCl3 electrolyte to obtain a selected iron to chromium molar ratio for the Fe—Cr electrolyte.

This invention provides a method for preparing spherical and sheet-like CrF3·3H2O micro / nano powders and their crystalline transformation. An HF acid solution is slowly added to Cr2AlB2 powder, and the mixture is stirred at 25-40°C for 4-20 h; the HF acid solution has a mass fraction of 20-45%. After the reaction, the resulting solution is washed successively with deionized water and anhydrous ethanol by centrifugation until neutral. The precipitate is then freeze-dried to obtain spherical CrF3·3H2O powder, which is then ultrasonically treated in an ethanol solution to fully expand and form a two-dimensional sheet-like material. This invention prepares spherical CrF3·3H2O micro / nano powders based on the selective etching reaction of hydrofluoric acid on Cr2AlB2. By adjusting the reaction conditions, CrF3·3H2O micro / nano powders with uniform morphology and narrow particle size distribution can be obtained, and the crystalline transformation of CrF3·3H2O can be achieved through heat treatment.

A method of making an Fe-Cr electrolyte includes a) oxidizing a carbon- containing Fe-Cr alloy with Fe2O3 or FeO; and b) treating the oxidized carbon-containing Fe-Cr alloy with FeCl3 or HC1 or any combination thereof to produce a FeCl2-CrCl3 electrolyte. The method may also include treating, under reducing conditions, a starting material, such as chromite ore. with a carbon source to produce the carbon-containing Fe-Cr alloy. Additionally or alternatively, the method may include removing a portion of the FeCl2 from the FeCl2-CrCl3 electrolyte to obtain a selected iron to chromium molar ratio for the Fe-Cr electrolyte.

A method for producing an iron chromium electrolyte, the method comprising leaching iron and chromium from a ferrochrome alloy using hydrochloric acid at an elevated leaching temperature. A crude iron chromium electrolyte comprising dissolved iron and dissolved chromium is produced. The crude electrolyte is purified and conditioned to produce a functional iron chromium electrolyte.

The invention belongs to the technical field of inorganic chemical industry and material chemistry, and particularly relates to a method for preparing high-purity anhydrous chromium trichloride based on direct dehydration of solid acid. The method comprises the following steps: uniformly mixing pretreated chromium trichloride hexahydrate and solid superacid in proportion in an inert atmosphere; placing the mixture in a tubular reactor, and carrying out temperature programming stepped dehydration in a flowing dry inert gas or vacuum environment; and after the reaction is finished, cooling to room temperature in inert gas flow, extracting and separating by using an organic solvent or screening and separating, and drying in vacuum to obtain the anhydrous chromium trichloride. According to the method, the solid acid is directly used as the main dehydrating agent and the catalyst, the chromium trichloride hexahydrate is efficiently converted into the high-purity anhydrous chromium trichloride through the one-step method, the technological process is simple, the conditions are mild and safe, and the product is high in purity and environmentally friendly.

Disclosed are a preparation method and crystalline state transformation method for spherical and sheet-like CrF 3·3H 2O micro-nano powder. The preparation method comprises: slowly adding an HF acid solution to Cr2AlB2 powder, and stirring and reacting at 25-40ºC for 4-20 h, wherein the mass fraction of the HF acid solution is 20-45%; after the reaction is complete, centrifugally washing the obtained solution successively with deionized water and absolute ethanol to neutrality; and freeze-drying the obtained precipitate to obtain spherical CrF 33H2O powder and ultrasonically treating the powder in an ethanol solution until the powder is fully expanded to form a two-dimensional sheet-like material. In the present method, on the basis of a selective etching reaction of hydrofluoric acid for Cr2AlB 2, spherical CrF33H2O micro-nano powder is prepared. By adjusting the reaction conditions, CrF33H2O micro-nano powder having uniform morphology and relatively narrow particle size distribution can be obtained, and crystalline state transformation of CrF33H2O can be realized by means of heat treatment.

A process for producing an iron chromium electrolyte, the process includes leaching iron and chromium from a ferrochrome alloy at an elevated leaching temperature, using hydrochloric acid. A raw iron chromium electrolyte comprising dissolved iron and dissolved chromium is produced. The raw electrolyte is purified and adjusted to produce a functional iron chromium electrolyte.