3 results about "Chromium product" patented technology

This application provides a method for selectively separating vanadium and chromium from chromium-vanadium slag leachate, relating to the field of solid waste recycling. The method includes: diluting a hydrophobic eutectic solvent with a diluent to obtain an extractant; mixing the extractant with the chromium-vanadium slag leachate, performing shake extraction, allowing the mixture to stand and separate phases to obtain a vanadium-loaded organic phase and a raffinate; washing and back-extracting the organic phase to obtain a vanadium-poor organic phase and a vanadium-rich back-extract; then subjecting the vanadium-rich back-extract to vanadium precipitation treatment and a first calcination to obtain vanadium pentoxide; the hydrophobic eutectic solvent is obtained by heating and stirring a mixture of a hydrogen bond donor and a hydrogen bond acceptor, wherein the hydrogen bond acceptor is composed of a neutral phosphorus-containing organic compound and a hydrophobic quaternary ammonium salt. This method can achieve selective separation of vanadium and chromium, effectively solving the problem of vanadium and chromium separation from chromium-vanadium slag leachate, and has good application prospects in the field of selective separation of vanadium and chromium to prepare high-purity vanadium and chromium products.

The invention discloses a method for repairing chromium-contaminated soil through cooperation of microorganisms and natural iron-containing minerals, and the method comprises the following steps: mixing the natural iron-containing minerals into the chromium-contaminated soil, standing for several days, then adding mixed bacteria into the obtained system, standing for a reduction reaction, reducing high-valence iron and high-valence sulfur in the system into ferrous iron and ferrous sulfur, and then removing the ferrous iron and the ferrous sulfur in the system. A low oxidation-reduction potential environment is formed in the system; the method comprises the following steps: adding chromium reducing bacteria into a system in a low oxidation-reduction potential environment, standing and reducing hexavalent chromium to obtain trivalent chromium, and carrying out mineralization reaction on the trivalent chromium and ferrous iron to obtain a chromite-like product, thereby realizing the remediation of the chromium-polluted soil. According to the method provided by the invention, the natural iron-containing minerals, the mixed bacteria and the chromium reducing bacteria synergistically reduce and mineralize the hexavalent chromium, mineralization stable repair of the hexavalent chromium is realized, the problems of instability, easy re-dissolution and re-pollution and the like of a chromium product after traditional repair are solved, and the method has the advantages of short repair period, low construction cost and long-acting and stable effect, and is suitable for large-scale popularization and application. And the problem of secondary pollution in the treatment process is avoided.

The invention discloses a method for preparing chromium metal nitride by a carbon reduction sintering method, which comprises the following steps of: adding chromium green powder, an additive and an adhesive into a mixer, uniformly mixing, pressing into honeycomb briquette-shaped blocks by adopting a compression molding device, and drying in a drying furnace; putting the dried honeycomb briquette-shaped block into an intermediate frequency furnace, and sintering in a vacuum environment to obtain metal chromium; and after metal chromium sintering preparation is completed, the temperature in the intermediate frequency furnace is adjusted, a certain flow of nitrogen is introduced for nitridation, after cooling, crushing is conducted through a shaping machine, and nitrided metal chromium is obtained. The mixer is adopted for mixing materials, a three-dimensional and crushing mode is utilized, the mixing efficiency can be effectively improved, the production time is shortened, the production energy consumption is reduced, and meanwhile, the process is simple, parameters are easy to control, and the method is environmentally friendly and suitable for industrial production. And the obtained nitrided metal chromium product has the advantages of low impurity element content, strong metal luster, high density and good uniformity.