11results about "Chromium oxides/hydrates" patented technology

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.

The invention discloses a chromic oxide powder preparation method and device, and belongs to the technical field of chromic oxide powder preparation. According to the method, anhydrous sodium dichromate and powdered sulfur are used as raw materials and are mixed according to a molar ratio, and the mixture and a ball-milling medium are placed in a ball-milling tank together. After an inert protective atmosphere is formed through vacuum pumping and argon replacement, a mechanochemical reaction is carried out under the action of a high-energy ball mill, and a mixture of chromic oxide, sodium sulfate and powdered sulfur is directly generated. And washing the reaction product with water to remove soluble sodium sulfate and sulfur powder, and drying to obtain the superfine chromic oxide powder. The method is simple in process, mild in reaction condition, low in energy consumption and environmentally friendly, and the prepared chromium oxide powder is high in purity and fine and uniform in particle size and has a good application prospect.

A recovery treatment line and method for chromium-containing wastewater; the recovery treatment line comprises a recovery reactor, a reducing agent feeder, a lye feeder and a recovery filter pressing system; the output end of the recovery reactor is communicated with the recovery filter pressing system, and is used for outputting chromium hydroxide wastewater to the recovery filter pressing system; a primary filter press is used for receiving the chromium hydroxide wastewater of the recovery reactor, and performing filter pressing treatment on the chromium hydroxide wastewater, outputting filtrate to a liquid phase recovery device, and outputting chromium hydroxide to a filter crushing device; the filter crushing device is used for performing crushing treatment on the chromium hydroxide, and outputting the chromium hydroxide to a cleaning tank; the cleaning tank is used for cleaning the chromium hydroxide, and outputting the chromium hydroxide to a secondary filter press; the secondary filter press performs filter pressing treatment on the chromium hydroxide of the cleaning tank, and obtains chromium hydroxide. The scheme solves the problem of high treatment difficulty of chromium-containing wastewater.

Disclosed in the present invention are a composite positive electrode material for a lithium battery and a manufacturing method therefor. The method comprises: a grinding step: grinding CrO3 and FeS2 to a mixture having a uniform color; and a heating and sintering step: carrying out a heating reaction on the mixture to obtain a FeS2-doped Cr8O21 composite positive electrode material. The mass ratio of CrO3 to FeS2 is (10-20):1, the heating temperature is 260℃-270℃, and the constant-temperature duration is 8 h-18 h. The FeS2-doped Cr8O21 composite positive electrode material manufactured by the present invention has the characteristics such as small particle size, high purity, and low impurity content, and can effectively enhance discharge efficiency and electrochemical performance when applied to lithium batteries.

The invention provides a preparation method of a positive electrode substrate modified material and a zinc-manganese battery, and belongs to the field of battery materials. The invention provides a preparation method of a positive electrode material, which comprises the following steps: dipping carbon cloth in a chromium salt solution, and drying to obtain chromium salt-loaded carbon cloth; and heating the carbon cloth loaded with the chromium salt by using a Joule heat technology, and generating chromium oxide from the chromium salt to obtain the positive electrode material. According to the prepared positive electrode material, the conductivity and stability of the carbon cloth are improved, and the active sites of the carbon cloth are increased.

The invention relates to a method for preparing hydrated chromic oxide by reducing a hexavalent chromium salt solution, which comprises the following steps: (1) mixing the hexavalent chromium salt solution and a piezoelectric material in an inert atmosphere to obtain a precursor solution; (2) carrying out hydrothermal reaction on the precursor solution in a hydrogen atmosphere to obtain slurry containing hydrated chromic oxide; and (3) carrying out solid-liquid separation on the slurry containing the hydrated chromic oxide in an inert atmosphere to obtain the hydrated chromic oxide. Under the hydrothermal condition, efficient reduction of hexavalent chromium is achieved through the catalysis of the piezoelectric material and the synergistic effect of hydrogen, the reaction temperature and pressure of hexavalent chromium reduction through hydrogen are remarkably reduced, and a new method is provided for preparing hydrated chromic oxide through hexavalent chromium low-temperature reduction.

Disclosed is a catalyst composition for production of alkyl phenols. The catalyst composition comprises of an active phase such as an iron oxide (Fe2O3), one or more promoters and a binder component. This catalyst offers several benefits, including high selectivity for alkyl phenols and reduced decomposition of the alkylating agent, and controlling mechanical integrity and stability of catalyst composition in the reaction. The conversion efficiency of catalyst is particularly enhanced when modified with binder component. Furthermore, the catalyst simplifies operations, enabling precise control over both conversion and selectivity.

The present application relates to a kind of metallurgical grade chrome green and its preparation method and application.The preparation method of metallurgical grade chrome green includes the following steps: the pH value of hexavalent chromium salt solution is adjusted to acidic, and solution A is obtained;Reducing agent, seed crystal and alkali are mixed and then added to water, and high-dispersion mixed slurry B is obtained;High-dispersion mixed slurry B is heated to boiling, then solution A is added to high-dispersion mixed slurry B, to form fluid microelement, so that solution A and high-dispersion mixed slurry B react at the interface of fluid microelement, continue to react after feeding, so that the product is deposited, crystallized and grown, and intermediate product C is obtained;Intermediate product C is washed and calcined, and high-quality metallurgical grade chrome green product is obtained.The present application also provides a kind of metallurgical grade chrome green prepared by the preparation method as described in the present application.The present application solves the problem that the chromium green produced by the existing process has high impurity content and small particle size, which is difficult to meet the requirements of high-quality metallurgical grade chrome green.

The invention discloses an artificial pre-constructed interface layer modified chromium oxide positive electrode material and a preparation method thereof.The method comprises the steps that oxalate, a metal compound or a mixture of the oxalate and the metal compound is evenly deposited and coated on the surface of chromium oxide through an atomic layer deposition technology, and then heating is conducted in a deposition reaction chamber in an inert atmosphere to obtain the modified chromium oxide positive electrode material. And the esters and the metal compounds are decomposed and reacted on the surface of the chromium oxide, so that an organic amorphous, metal oxide, metal nitride or metal elementary substance and multi-component mixed interface coating layer is constructed. The surface modification of the chromium oxide is completed in the inert atmosphere, so that the side reaction between the high-oxidability surface of the material and an environmental medium is avoided; meanwhile, the structural stability, the electronic conductivity and the electrolyte wettability of the material are remarkably improved, the ion diffusivity is accelerated, and the dissolution phenomenon of the chromium element in the electrolyte is avoided, so that the cycling stability, the storage characteristic and the rate characteristic of the chromium oxide are remarkably improved.

This invention discloses a power-type chromium oxide, its preparation method, and its application. The method includes: S1, adding an acid solution to a dichromate solution, evaporating and crystallizing the reaction solution to obtain an evaporated chromium trioxide component; dissolving the evaporated component in water to obtain a chromium-containing solution, heating it to 80℃~200℃ and holding it at that temperature for a period of time, then cooling it to 0~20℃ at a certain cooling rate, and obtaining porous spherical chromium trioxide through low-temperature crystallization; S2, subjecting the porous spherical chromium trioxide to a first heat treatment in an oxygen environment to obtain a chromium oxide mixture powder; S3, adding the aforementioned powder to deionized water, ultrasonicating, filtering and drying the mixture, then subjecting it to a second heat treatment in an oxygen environment, and obtaining a power-type chromium oxide after cooling and grinding. The chromium oxide obtained by this invention has high power characteristics and low rate capacity characteristics, which is beneficial for the preparation of high specific energy and high power primary batteries. Furthermore, the preparation method is simple and suitable for large-scale industrial production and widespread application.

To provide a sulfuric acid corrosion-resistant coating member that is superior in both of resistance to heat and resistance to corrosion due to sulfuric acid.SOLUTION: A sulfuric acid corrosion-resistant coating member includes a steel substrate, and a complex oxide coat provided on the surface of the substrate. The complex oxide coat includes a first coat including aluminum oxide particles, chromium oxide particles and silicon oxide particles, and a chromium oxide phase that fills the gaps among the particles. The chromium oxide phase further includes at least one compound selected from phosphate compounds, borate compounds, and silicate compounds.SELECTED DRAWING: Figure 1