12results about "Chromium halides" patented technology

The invention provides a one-step method for preparing ferrochromium leachate and application, and the method comprises the following steps: mixing a ferrochromium-containing material with a hydrochloric acid solution and a chromium-containing oxidizing agent to carry out leaching reaction, and after the reaction is finished, carrying out solid-liquid separation to obtain the ferrochromium leachate. According to the method provided by the invention, the chromium-containing oxidizing agent and the hydrochloric acid are used for synergistically leaching the ferrochromium metal raw material, so that the ferrochromium leaching rate is improved, no hydrogen is produced, the reaction safety is improved, the leachate with high chromium concentration is obtained, and the leachate can be directly used for preparing the ferrochromium flow battery.

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 present invention discloses a production and purification process for food-grade hydrated chromium trichloride, comprising: S1, cleaning a reactor, adding chromium chloride and pure water into the reactor and introducing protective gas, heating to dissolve, and insulating the reaction; S2, adding an antidote and hydrochloric acid during the insulating reaction process to carry out a detoxification reaction, and removing the antidote after the reaction; S3, filtering the reaction material, and collecting the filtrate for crystallization; S4, centrifuging after crystallization; S5, low-temperature vacuum drying to obtain food-grade hydrated chromium trichloride. The process of the present invention mainly obtains food-grade chromium trichloride hexahydrate through processes such as dissolution, inert gas protection detoxification, charge reduction filter bag detoxification filtration, recrystallization, centrifugation, and low-temperature rotary vacuum drying, thereby solving the problems of unstable quality, foreign matter impurities, elemental impurities, uneven particle size distribution, inconsistent product appearance color, and the possible presence of highly toxic hexavalent chromium in the current industrialized production of health products, food and drug additives.

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.

The invention discloses a preparation method of an MX2 / CrCl3 heterojunction, which comprises the following steps of: cleaning a SiO2 / Si substrate to obtain a clean surface, adhering a block sample by using a 3M adhesive tape, obtaining a dense and uniformly distributed thick-layer material on the adhesive tape in a manner of repeatedly adhering and tearing two adhesive tapes, and then stripping a two-dimensional material from the surface of the thick-layer material on the adhesive tape by using PDMS (Polydimethylsiloxane) to obtain the MX2 / CrCl3 heterojunction. Single-layer MX2 and few-layer CrCl3 are identified by means of an optical microscope or a photoluminescence spectrum; the method comprises the following steps: sequentially stacking a few layers of CrCl3 and a single layer of MX2 on a cleaned SiO2 / Si substrate by virtue of a two-dimensional transfer platform so as to construct an MX2 / CrCl3 two-dimensional Van der Waals heterostructure; performing vacuum annealing treatment on the prepared MX2 / CrCl3 sample to enhance the interface coupling of the MX2 / CrCl3 sample so as to obtain an MX2 / CrCl3 two-dimensional Van der Waals heterojunction sample with relatively high quality; and the circularly polarized laser excites the MX2 / CrCl3 heterojunction to induce out-field-free room temperature valley polarization of MX2, and finally, non-resonant excited room temperature valley polarization under the action of no external field is realized.

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.

The invention provides a method for preparing a ferrochromium leaching solution and application, the method comprises the following steps: mixing a ferrochromium-containing raw material with a hydrochloric acid solution, carrying out at least one-stage leaching, and carrying out solid-liquid separation to finally obtain the leaching solution and leaching residues; and the leachate, the leaching residues and ferric trichloride are mixed to be subjected to a hydrothermal reaction, solid-liquid separation is conducted after the reaction is finished, and the ferrochromium leachate is obtained. According to the method, deep extraction of chromium and iron in the ferrochrome raw material is achieved through the two steps of leaching and oxidation, the chromium leaching rate and the iron leaching rate are high and can both reach 99.0% or above, the acidity of the obtained leachate is low, ferrochrome proportion blending is achieved at the same time, the iron-chromium flow battery electrolyte can be directly prepared, and the method has important value for industrial production.