38results about "Chromium oxides/hydrates" patented technology

The invention relates to the field of chromium-containing waste liquid recovery, in particular to a method and system for recovering chromium in leaching waste liquid, and the method comprises the following steps: S1, adding alkali into the chromium-containing leaching waste liquid to adjust the pH value to 8 or above, and then adding ozone for oxidation to oxidize trivalent chromium into hexavalent chromium to obtain alkali-adjusted oxidized waste liquid; s2, adding a flocculation precipitator into the alkali-adjusting oxidation waste liquid, and removing impurities in a precipitation form to obtain a flocculation precipitation waste liquid; s3, acid is added into the flocculent precipitation waste liquid to adjust the pH value to 6.5 or below, then a reducing agent is added, hexavalent chromium is reduced into trivalent chromium, and acid-adjusted reduction waste liquid is obtained; s4, alkali is added into the acid-adjusted reduction waste liquid, the pH is adjusted to 8.5-9.5, trivalent chromium is precipitated in the form of chromic hydroxide, and chromic hydroxide precipitate and supernate are obtained. The method can enrich and recover the chromium element in the leaching waste liquid, has a high recovery rate, and has the advantages of high treatment efficiency, strong treatment capability, simple operation, stable recovery and the like.

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 powder composition for thick-film resistor coating that can be calcined at 650°C or lower, or even at lower temperatures, has chemical resistance, and is substantially free of lead, and a glass paste for thick-film resistor coating.SOLUTION: A powder composition for thick-film resistor coating contains lead-free glass powder, and inorganic oxide powder. There is also provided a glass paste for thick-film resistor coating that contains lead-free glass powder, inorganic oxide powder, resin, and solvent.SELECTED DRAWING: None

The invention relates to a method for treating a residue obtained from the chloride process, wherein the residue comprises the components titanium dioxide, coke, an inert metal oxide, and an iron-containing component. Further, the invention refers to the use of this method to separate the components contained in said residue, and to the use of the separated components in the chloride process for obtaining titanium dioxide.

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.

The invention belongs to the technical field of solid waste recycling and wastewater treatment, and particularly relates to a method for treating chromium-containing wastewater by adopting organic amine flue gas desulfurization residues. According to the method, the organic amine flue gas desulfurization slag is adopted as a reducing agent, hexavalent chromium is reduced into trivalent chromium, the trivalent chromium is separated from water in a precipitate form, and the precipitate is roasted to obtain chromium sesquioxide powder with relatively high purity in supernate; hexavalent chromium and total chromium can reach the national standard. According to the method, the treatment cost of the hexavalent chromium wastewater and the flue gas desulfurization slag is remarkably reduced, and meanwhile, the resource utilization of the flue gas desulfurization waste in a waste-to-waste manner is also realized.

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.

A method for directly preparing a trivalent chromium compound by electrochemical oxidation of ferrochrome is provided. The method includes: putting ferrochrome as an anode, and placing the anode into an electrolyte solution containing a complexing agent together with a cathode, then turning on a power supply for electrolysis reaction so that chromium and iron in ferrochrome are directly converted into free Cr3+ and Fe3+ respectively, allowing one of Cr3+ and fe3+ to form a stable soluble metal complex together with the complexing agent, and allowing the other of Cr3+ and Fe3+ to form a metal hydroxide solid together with OH− generated by electrolysis reaction, so as to obtain an electrolysis completion slurry. Compared with the prior art, the present application has no hexavalent chromium salt stage, thereby shortening the process flow and avoiding the generation of chromium-containing waste residue.

The invention relates to the field of industrial wastewater treatment, in particular to a chromium-containing waste liquid harmless treatment process and device. The chromium-containing waste liquid harmless treatment process comprises the steps of S1, pretreatment; s2, carrying out photoelectrocatalytic reduction; s3, precipitation separation; s4, performing low-temperature pyrolysis; and S5, tail gas resourceful treatment is conducted, Cr (VI) high in toxicity is efficiently removed and converted into Cr (III) low in toxicity, finally, the Cr (III) low in toxicity is converted into a chromium oxide product with economic value, and waste resourceful treatment is achieved. Meanwhile, the process adopts a closed-loop design, ammonia gas generated by pyrolysis is recycled as a precipitant, the chemical consumption and the risk of secondary pollution are remarkably reduced, and both environmental benefits and economic benefits are achieved.

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 discloses a carbon nanotube material filled with inorganic salt, a preparation method and a suction filtration device. The preparation method comprises the following steps: S1, pretreating a carbon nanotube to obtain a carbon nanotube with an opened tip; s2, adding a carbon nanotube with an opened tip into a solution containing metal salt ions, and uniformly stirring to obtain a suspension; s3, carrying out primary suction filtration on the suspension by using an internal filling suction filtration device, gradually adjusting the suction filtration pressure from normal pressure to 10 <-7 > mbar in the primary suction filtration process, and determining the secondary suction filtration pressure according to a liquid drop dropping vibration frequency curve; s4, carrying out secondary suction filtration on the suspension, and obtaining a precursor by adopting the secondary suction filtration pressure determined in the step S3; and S5, calcining the precursor in a protective atmosphere to obtain the carbon nanotube material filled with inorganic salt, the outer surface cleanliness and the product uniformity of the carbon nanotube material are obviously improved, and the carbon nanotube material has relatively high rate capability and cycling stability when being applied to a negative electrode of a lithium ion battery.

The present invention relates to a preparation method of a chromium / manganese bimetallic sulfur cathode composite material, belonging to the technical field of lithium-sulfur battery cathodes. In the present invention, a MIL-101(Cr) precursor is prepared by a hydrothermal method; the MIL-101(Cr) precursor is dispersed in deionized water to obtain a suspension C, KMnO4 is added to the suspension C and stirred for 2-3 h, then a dilute H2O2 solution is added and stirred for 2-3 h, solid-liquid separation is carried out, the solid is washed with deionized water more than three times, and then uniformly heated to a temperature of 900-950 °C in an argon atmosphere and thermally decomposed at a constant temperature for 2-3 h to obtain Cr2O 3 / MnO x -C; Cr2O 3 / MnO x -C and sublimed sulfur powder are ground and mixed evenly, and uniformly heated to a temperature of 155-165 °C in an inert gas and reacted at a constant temperature for 18-20 h, and cooled to room temperature to obtain a chromium / manganese bimetallic sulfur cathode composite material S / Cr2O 3 / MnO x -C. The chromium / manganese bimetallic sulfur cathode composite material S / Cr2O 3 / MnO x -C has excellent electrochemical performance. Compared with the sulfur cathode prepared from the original MOF material MIL-101(Cr), the initial specific capacity at 0.1C is increased by 43%, the 100-cycle performance is increased by 27%, and the rate performance and Coulomb efficiency are improved.

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.

The invention relates to a method for recycling chlorine in the production of titanium tetrachloride. Further, the invention refers to the use of this method in the chloride process to produce titanium dioxide.

The invention discloses a method for preparing chromium trioxide and vanadium pentoxide by using chromium-containing vanadium slag, comprising: calcifying and roasting the chromium-containing vanadium slag to extract vanadium by acid leaching to obtain a vanadium-containing solution, then sodiumizing and roasting the separated solid to extract chromium by water to obtain a chromium-containing solution, adding ammonium carbonate to adjust the pH value and temperature of the vanadium-containing solution to precipitate vanadium, filtering and separating to obtain ammonium metavanadate, and roasting the ammonium metavanadate to obtain vanadium pentoxide; adding a reducing agent to the chromium-containing leaching solution, adjusting the pH to precipitate chromium, filtering to obtain chromium hydroxide precipitate, and precipitating and roasting to obtain chromium trioxide. The vanadium-chromium waste liquid can be recycled. The invention selects different roasting temperatures at the front end to achieve efficient separation of vanadium and chromium, avoids the complex separation process of vanadium and chromium at the back end, shortens the vanadium-chromium separation process, and the purity of the vanadium pentoxide and chromium trioxide obtained respectively is relatively high. At the same time, the vanadium-chromium waste liquid can be returned for recycling, thereby avoiding water pollution and effectively saving production costs.

Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.

The invention discloses a chromium oxyhydroxide adsorbent for selective bromine extraction and a preparation method thereof. The preparation method comprises the following steps: carrying out first hydrothermal reaction on a mixed system comprising soluble chromium salt, a reducing agent, a mineralizing agent and water to obtain a hydrated chromic oxide precursor; and carrying out a second hydrothermal reaction on the hydrated chromic oxide precursor in a strong acid solution with the pH value of less than or equal to 3 to prepare the hydroxyl chromic oxide adsorbent. The synthesized chromium oxyhydroxide is pure trilateral phase alpha-CrOOH, has developed microporous and mesoporous structures and is rich in surface active sites and functional groups, the polyhydroxy structure on the surface of a matrix of the chromium oxyhydroxide can selectively adsorb bromide ions, and the chromium oxyhydroxide can be used as a stable inorganic skeleton to load various effective active substances in the later period; the efficient application in the fields of concentrated seawater / brine bromine extraction, underground water bromine removal and the like is realized.

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 utility model discloses a retrogradation system for chromium resources in hexavalent chromium-containing wastewater. The retrogradation system comprises an impurity removal mechanism, an acidification mechanism, an ion exchange mechanism and a crystallization mechanism, chromium-containing wastewater and alkali liquor are introduced into the impurity removal mechanism, so that impurity metal ions in the chromium-containing wastewater are precipitated; the acidification mechanism is communicated with the impurity removal mechanism, and is used for introducing acid liquor into the supernate so as to adjust the pH value of the supernate; the ion exchange mechanism is communicated with the acidification mechanism, the ion exchange mechanism can adsorb hexavalent chromium ions in the supernate, and an alkali desorption solution can be introduced into the ion exchange mechanism so as to desorb and regenerate the adsorbed hexavalent chromium ions into a chromium salt solution; the crystallization mechanism is communicated with the ion exchange mechanism, the chromium salt solution can be introduced into the crystallization mechanism, and the crystallization mechanism can concentrate and dry the chromium salt solution to obtain crystallized chromium salt. According to the chromium resource retrogradation system in the hexavalent chromium-containing wastewater, provided by the utility model, the recovery content of hexavalent chromium is increased.

The invention relates to a method for selectively and efficiently separating and recovering chromium from vanadium and chromium slag leaching liquid. According to the technical scheme, the method comprises the steps that vanadium and chromium slag sub-molten salt is subjected to alkaline leaching, and vanadium and chromium slag leaching liquid is obtained; and the vanadium and chromium slag leaching solution is put into an evaporation device to be evaporated and concentrated, and the vanadium and chromium slag alkaline leaching concentrated solution is obtained. Putting the vanadium and chromium slag alkaline leaching concentrated solution into a crystallizer, adding a potassium-containing additive into the vanadium and chromium slag alkaline leaching concentrated solution, and carrying out reaction, solid-liquid separation and washing under a first stirring condition to obtain potassium sodium chromate crystals and a post-crystallization solution; dissolving the potassium sodium chromate crystal to obtain a potassium sodium chromate solution, and adjusting the pH value with sulfuric acid; and adding sodium sulfite into the potassium sodium chromate solution, reacting under a second stirring condition, and carrying out solid-liquid separation to obtain a chromium hydroxide solid. And calcining the chromium hydroxide solid to obtain chromium sesquioxide. The method has the characteristics of simple process, low cost, strong adaptability and environmental friendliness, is suitable for the vanadium-chromium-containing solution with high strong alkalinity, and is good in vanadium-chromium separation effect and high in chromium recovery rate.

The invention discloses a comprehensive utilization technology of sodium thiosulfate wastewater and chromium-containing wastewater resources, which comprises the following steps: uniformly mixing sodium thiosulfate wastewater and hexavalent chromium wastewater in proportion, adding sulfuric acid to adjust the pH value, heating to a certain temperature through steam, and keeping the temperature for reduction reaction; adding caustic soda flakes into the completely reacted materials to adjust the pH value, then stirring and precipitating, and carrying out heat preservation for curing reaction; and carrying out plate-frame pressure filtration on the completely cured material, and washing to obtain a chromium hydroxide product, wherein the hexavalent chromium in the filtered water reaches the specified index. The method has the beneficial effects that the comprehensive value cost of two kinds of wastewater is fully utilized, comprehensive utilization of resources is realized, and the treatment cost is greatly reduced; the generated chromium hydroxide is used for calcining to produce 99% metallurgical grade chromium oxide green products, so that chromium resources in the wastewater are completely recovered and productized; a dispersing agent is added in the precipitation process, microwave and ultrasonic dispersion treatment is carried out at the same time to prevent precipitation from gathering, a calcined product is ground, and the nanoscale chromium oxide green is obtained.

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.

This electroconductive member comprises a substrate and a polycrystal film. The substrate contains chromium. The polycrystal film contains a plurality of chromic oxide particles, and is disposed on the substrate. The polycrystal film contains a first element. The first element is disposed between chromic oxide particles, and has a smaller first ionization energy and a smaller free energy of oxide formation per mol of oxygen than chromium.

The present disclosure reports compositions of matter, methods of synthesis, and methods of catalyzing chemical reactions - all relating to metal (oxy)hydroxide nanoparticles having all size dimensions less than about 20 nm. Unlike conventional approaches, the methods of the present disclosure utilize a stoichiometry-controlled base- addition protocol, optionally in the presence of an ambidentate ligand. By: (i) selecting a suitable base and optionally a suitable ambidentate ligand; and (ii) tuning the reaction stoichiometry appropriately, the methods of the present disclosure may provide sufficient control over the nucleation and growth processes to encourage the formation of metal (oxy)hydroxide nanoparticles at the low end of the nanoparticle size spectrum.

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.

The invention provides a fluorine-molybdenum double-doped chromium metal oxide positive electrode material and a preparation method thereof, the chemical formula of the fluorine-molybdenum double-doped chromium metal oxide positive electrode material is Cr < 8-x > Mo < x > O < 21-y > F < y >, x is less than or equal to 5, and y is less than or equal to 12; the fluorine-molybdenum double-doped chromium metal oxide positive electrode material is prepared from the following raw materials in parts by mass: 1 part of fluorine-molybdenum compound and 6-15 parts of chromium metal oxide; the chromium metal oxide at least comprises Cr8O21; the fluorine molybdenum compound at least comprises molybdenum hexafluoride gas. The fluorine element and the molybdenum element are introduced into the chromium metal oxide, so that the interlayer spacing, the structural stability and the conductivity of the chromium metal oxide are improved, and the rate capability, the storage performance and the safety of the chromium metal oxide are further improved.

This invention relates to the field of industrial wastewater treatment, specifically to a process and apparatus for the harmless treatment of chromium-containing wastewater. The process, provided by this invention, involves S1 pretreatment; S2 photoelectrocatalytic reduction; S3 precipitation separation; S4 low-temperature pyrolysis; and S5 tail gas resource recovery treatment. This not only efficiently removes highly toxic Cr(VI) and converts it into less toxic Cr(III), ultimately transforming it into economically valuable chromium oxide, thus achieving waste resource recovery. Simultaneously, the closed-loop process design recovers ammonia generated during pyrolysis as a precipitant, significantly reducing chemical consumption and the risk of secondary pollution, thus achieving both environmental and economic benefits.

To provide novel electromagnetic wave absorbing particles.SOLUTION: Provided are electromagnetic wave absorbing particles containing a composite oxide, wherein: the composite oxide contains element A, which is one or more elements selected from H, alkali metals, Mg, and alkali earth metals, and element B, which is one or more elements selected from Cr and Mo; and when the mole number of the element A and the mole number of the element B contained in the composite oxide are denoted by x and y, respectively, the following relation is satisfied: 0.001≤x / y≤1.5.SELECTED DRAWING: None

The invention relates to a chromium-iridium solid solution oxide electrocatalyst with a three-dimensional ordered macroporous structure as well as preparation and application of the chromium-iridium solid solution oxide electrocatalyst. The preparation method comprises the following steps: (1) preparing a highly-monodispersed polymethyl methacrylate (PMMA) colloidal crystal template by adopting an emulsion polymerization method; (2) introducing a chromium precursor and an iridium precursor into the PMMA suspension, and carrying out mixing and heat treatment to obtain a three-dimensional ordered macroporous skeleton; the three-dimensional ordered macroporous skeleton is composed of highly dispersed nanoscale (1-2nm) chromium-iridium solid solution oxide particles; and (3) the obtained catalyst is subjected to pre-acid leaching treatment, soluble heteroatoms are removed, and the structural stability and the metal leaching resistance are enhanced. The obtained catalyst 3DOM H-Cr0. 75Ir0. 25Ox (3DOM represents a three-dimensional ordered macroporous structure, and H-represents an acid treatment step) shows higher electrocatalytic activity and durability than a traditional iridium-based catalyst under an acidic condition, and the use amount of noble metal is remarkably reduced, so that the cost of a membrane electrode is effectively reduced.