659 results about "Hydrogen oxidation" patented technology

The invention discloses a magnesium-based cobalt precipitation agent and a preparation method and application thereof, and relates to the technical field of composite materials. The method comprises the following steps: performing calcination dissociation, enhanced leaching, carbonization separation, efficient pyrolysis, solid-liquid separation, drying and calcination on first magnesium ore to obtain active magnesium oxide; the second magnesium ore is subjected to calcination dissociation, hydration impurity removal, solid-liquid separation and low-temperature calcination, and then high-purity magnesium oxide is obtained; performing series-parallel modification on active magnesium oxide and high-purity magnesium oxide to obtain a magnesium-based cobalt precipitation agent; the mass ratio of the active magnesium oxide to the high-purity magnesium oxide is 1: (2-10), the modifier is quaternary ammonium salt organic powder, and the addition amount of the modifier is 0.02-1% of the total mass of the magnesium oxide. The magnesium-based cobalt precipitation agent prepared through the method is high in activity, has the advantages of being high in efficiency, low in price, low in unit consumption, environmentally friendly and the like in the aspect of nickel and cobalt precipitation through copper-cobalt ore and laterite-nickel ore wet smelting, and can greatly reduce the material cost in the nickel cobalt hydroxide production process.

The invention provides a dump leaching method for improving the leaching rate of gold ore, and belongs to the technical field of mineral processing. The method comprises the following steps: firstly, separating minerals into oversize products and undersize products; mixing sodium carboxymethyl cellulose, bentonite and ferrous sulfate to obtain a mixture, and granulating the undersize product by using the mixture as a binder; and mixing the undersize product particles with the oversize product, and carrying out cyanide-free dump leaching. According to the method, through graded granulation and heap building, the problem that heap building permeability is poor due to the fact that the gold ore contains many clay minerals is solved. In the granulation stage, ferrous hydroxide colloid generated by hydrolysis of ferrous sulfate in the binder can assist ore particle agglomeration, and particle stability is enhanced; during subsequent cyanide-free dump leaching, ferrous sulfate can be used as an auxiliary reducing agent and a catalyst in a thiourea gold leaching system to promote oxidation and dissolution of gold; meanwhile, ferrous ions can adjust the oxidation-reduction potential of a system, so that the thiourea gold leaching reaction is in a more favorable potential interval, the oxidation efficiency of thiourea is improved, invalid decomposition of thiourea is reduced, and therefore the use amount of thiourea and the use amount of agents are reduced.

The invention discloses a method for controlling ion concentration and volume balance in an electrolyte by using nickel hydroxide. The method comprises the following steps: preparing a reaction base solution containing a first complexing agent and a first alkali; the first anolyte, a second complexing agent solution and a second alkali solution are simultaneously added to the bottom of the reaction base solution for stirring reaction, solid-liquid separation is performed after nickel hydroxide reaches the target particle size, and filtrate and a filter cake are obtained; washing the filter cake, and slurrying the filter cake by using a second anolyte to obtain a nickel hydroxide slurrying material; and adjusting the sodium ion concentration, pH and nickel ion concentration of the third anolyte by adopting a sodium hydroxide solution, a nickel hydroxide slurrying material and a nickel sulfate solution to obtain the catholyte. According to the invention, a feeding mode of feeding at the bottom is adopted, and a complexing agent is matched, so that crystals can stably grow and are convenient to filter; in the preparation process, aging and too high pH conditions are not needed, operation is simpler, labor intensity is small, the reaction rate is higher, and continuous treatment of the anolyte can be achieved.

The invention relates to the technical field of thallium recovery and treatment, in particular to a method for efficiently recovering thallium from a complex solution. The invention discloses a method for efficiently recovering thallium in a complex solution. The method comprises the following steps: S1, multi-stage replacement; a metal displacer is added into the thallium-containing feed liquid, a multi-stage displacement reaction is carried out, and the pH value during the multi-stage displacement reaction is 3-5; after the reaction is finished, separating to obtain thallium-removed feed liquid and thallium-containing solid; s2, dissolving; dissolving the thallium-containing solid with an inorganic acid to form a thallium-containing solution; s3, oxidizing and precipitating; and adding an oxidizing agent into the thallium-containing solution, adjusting the pH value of the solution to 1-3 after the oxidation is finished, generating a precipitate, and separating to obtain a thallium hydroxide solid. The method disclosed by the invention is wide in application range, can be used for treating thallium-containing wastewater with various concentrations, is simple in process and easy to implement, and meanwhile, thallium and other valuable metals can be recycled, so that efficient recovery and utilization of resources are realized.

The invention provides ruthenium dioxide powder as well as a preparation method and application thereof, and belongs to the technical field of inorganic materials. The preparation method of the ruthenium dioxide powder provided by the invention comprises the following steps: carrying out ball milling on ruthenium hydroxide, and then carrying out freeze drying to obtain the ruthenium dioxide powder; the ball milling comprises first ball milling and second ball milling which are carried out in sequence; the diameter of a ball-milling bead of the second ball mill is smaller than that of a ball-milling bead of the first ball mill, and the rotating speed of the second ball mill is higher than that of the first ball mill. By controlling the rotating speed of two times of ball milling and the diameter of ball milling beads, the kinetic energy of the second ball milling is higher than that of the first ball milling, agglomeration of ruthenium hydroxide precipitates is broken, small and uniform particle size distribution is obtained, and the specific surface area is increased; ruthenium hydroxide is dehydrated through freeze drying to obtain ruthenium dioxide powder, dense tiny holes are formed in the ruthenium dioxide powder, thermal collapse caused by traditional high-temperature drying of the powder is avoided, and the specific surface area of the ruthenium dioxide powder is greatly increased.

The invention relates to a preparation method of a multi-site silver (Ag) and nickel hydroxide (Ni (OH) 2) modified copper (Cu) nanowire catalyst (Ag-Ni (OH) 2) / Cu NW) and application of the multi-site silver (Ag) and nickel hydroxide (Ni (OH) 2) modified copper (Cu) nanowire catalyst. A cation exchange and electrodeposition method is adopted to prepare an electrocatalytic nitrate reduction reaction NO3-RR series catalyst with three sites of Ag, Ni (OH) 2 and Cu. Based on the synergistic effect of three sites, Ag in the catalyst promotes conversion from nitrate NO3 <-> to nitrite NO2 <->, Ni (OH) 2 promotes dissociation of water H2O to generate free hydrogen * H, Cu atoms near Ni (OH) 2 accelerate conversion from NO2 <-> to ammonia NH3, and the efficient series catalytic process is achieved. Under the condition of-0.1 V vs. Reversible hydrogen electrode RHE in a 1M potassium hydroxide solution containing 50 mM of potassium nitrate, the NH3 yield of 4.01 mgh <-1 > cm <-2 > and the NH3 Faraday efficiency of 97.3% are obtained, under the condition of 0V vs. RHE, the excellent energy efficiency of 46.5% is achieved, the excellent catalytic activity is kept in a NO3 <-> solution with the wide concentration, and the good sewage treatment capacity is achieved. The invention provides a new design thought for tandem catalysis, and has a wide application prospect in the field of NO3-RR.

The invention belongs to the technical field of electrochemistry, and provides a monatomic iridium-based alloy cluster catalyst and a preparation method and electrocatalysis application thereof, and the preparation method comprises the following steps: low-pressure gas-phase capillary filling: mixing an iridium organic metal precursor, a dopant metal organic precursor, a microporous carrier material and a solvent, and drying to obtain mixed powder, the mixed powder is placed in an ampoule bottle with a certain vacuum degree and sealed, then the ampoule bottle is placed in a rotary drying oven for high-temperature heat treatment, and powder a is obtained; temperature-controlled acid etching: mixing the powder a and an acid solution for reaction in the environment of protective gas to obtain black powder; the black powder is placed in H2 / Ar mixed gas for programmed heat treatment, and the monatomic iridium-based alloy cluster catalyst is obtained. The monatomic iridium-based alloy cluster catalyst prepared by the method provided by the invention shows mass activity and catalytic durability which are obviously superior to those of commercial platinum carbon in alkaline hydroxide catalysis, and has a practical application prospect.

The invention relates to a dephosphorization material, a preparation method thereof and a dephosphorization method, belongs to the field of water treatment, and solves at least one of the problems of contradiction between adsorption capacity and structural stability, fast capacity fading, short service life, difficult recovery, higher cost and the like of the existing lanthanum-based dephosphorization material. The phosphorus removal material is a nano-porous carbon-supported lanthanum composite material, and comprises an amorphous nano-porous carbon matrix, an amorphous nano-porous carbon carrier, an amorphous nano-porous carbon carrier, and an amorphous nano-porous carbon carrier, and an active component embedded in situ in the nanoporous carbon matrix; wherein the active component comprises lanthanum oxide and / or lanthanum hydroxide. According to the invention, the adsorption capacity is high, the structure is stable, the attenuation of the adsorption capacity is delayed, the service life is prolonged, the cost is reduced, and the adsorbent can be recycled.

The invention provides a production method and application of niobium hydroxide in tantalum-niobium hydrometallurgy, and relates to the technical field of tantalum-niobium hydrometallurgy. Tantalum-niobium ore is ground to obtain tantalum-niobium particles; hydrofluoric acid and sulfuric acid are added into the tantalum-niobium particles for a decomposition reaction, and decomposition liquid containing tantalum and niobium is obtained; carrying out acid regulation on the decomposition liquid containing tantalum and niobium, and then extracting with MIBK (Methyl Isobutyl Ketone) to obtain a loaded organic phase containing tantalum and niobium; carrying out acid pickling on the tantalum-niobium loaded organic phase to obtain a tantalum-niobium loaded phase; extracting the tantalum-niobium load phase by using an anti-niobium solution to obtain a fluoroniobic acid solution; adding urea into the fluoroniobic acid solution to carry out neutralization reaction, and filtering to obtain a niobium hydroxide crude product; leaching the niobium hydroxide crude product, and drying after leaching to obtain a niobium hydroxide product; the urea is used as the neutralizer for neutralization, liquid ammonia is not used any more, the production risk is greatly reduced, and the safety production cost is reduced.

Provided are a cathode active material having a suitable particle size and high uniformity, and a nickel composite hydroxide as a precursor of the cathode active material. When obtaining nickel composite hydroxide by a crystallization reaction, nucleation is performed by controlling a nucleation aqueous solution that includes a metal compound, which includes nickel, and an ammonium ion donor so that the pH value at a standard solution temperature of 25° C. becomes 12.0 to 14.0, after which, particles are grown by controlling a particle growth aqueous solution that includes the formed nuclei so that the pH value at a standard solution temperature of 25° C. becomes 10.5 to 12.0, and so that the pH value is lower than the pH value during nucleation. The crystallization reaction is performed in a non-oxidizing atmosphere at least in a range after the processing time exceeds at least 40% of the total time of the particle growth process from the start of the particle growth process where the oxygen concentration is 1 volume % or less, and with controlling an agitation power requirement per unit volume into a range of 0.5 kW / m3 to 4 kW / m3 at least during the nucleation process.

The invention discloses a method for preparing a sulfur-doped nickel hydroxide-based self-supporting electrolyzed water anode, and belongs to the technical field of preparation of electrolyzed water catalytic electrodes, and the method comprises the following steps: S1, preparing strong oxidizing salt, thiourea and transition metal salt into an active solution; s2, pretreating the nickel-containing metal substrate to obtain a precursor; and S3, immersing the precursor in an active solution for ultrasonic impregnation, and performing in-situ oxidation to prepare the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode. According to the method for preparing the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode, an oxidizing agent-thiourea-transition metal salt synergistic reaction system is adopted, an ultrasonic-assisted technology is combined, and a high-performance catalytic layer is directly grown on the surface of the metal substrate in situ at room temperature; the invention aims to synchronously realize high catalytic activity, excellent stability and macro preparation of the electrode and fundamentally solve the core pain points of long process, high energy consumption, difficulty in amplification and the like in the prior art.

The invention belongs to the technical field of new energy battery materials, and particularly relates to coated asphalt for a negative electrode of a new energy battery as well as a preparation method and application of the coated asphalt. The method comprises the following steps: mixing an ethylene tar raw material and a cross-linking agent, and carrying out a first hydroxide cross-linking reaction in an oxygen-containing atmosphere to obtain a reaction liquid after the first hydroxide cross-linking reaction; transferring the reaction liquid after the first hydroxide cross-linking reaction into a protective gas atmosphere, and carrying out a second hydroxide cross-linking reaction to obtain a reaction liquid after a second hydroxide cross-linking reaction; and cooling the reaction liquid after the second hydroxide cross-linking reaction to room temperature, and performing liquid phase volatilization, so that the obtained coated asphalt has the characteristics of high softening point, low quinoline insoluble content, low coating thickness, high integrity, high compactness and high yield, is easy to realize industrial application, and can solve the recycling problem of ethylene tar.

The invention discloses a p-region metal introduced palladium-based intermetallic compound catalyst and a preparation method and application thereof in the field of electrocatalysts, and the preparation method comprises the following steps: introducing a p-region metal element into metal palladium through a colloid synthesis method to prepare a palladium-based intermetallic compound precursor; and calcining the precursor in a reducing atmosphere to obtain the p-region metal-introduced palladium-based intermetallic compound, which shows significantly improved alkaline HOR performance. The introduction of the p-region metal in the catalyst promotes d-p orbital hybridization and electron interaction, and the catalyst can be used as an electrocatalyst in alkaline hydroxide reaction, and is beneficial to optimization of binding energy of catalytic surface reaction intermediates, so that the alkaline HOR activity is improved, the cost is reduced, and the catalyst variety is widened.

The invention relates to an anode catalyst capable of being updated in situ in an electrolytic bath as well as a preparation method and application of the anode catalyst. The anode catalyst capable of being updated in situ in the electrolytic bath comprises a nickel-based self-supporting carrier and a NiFe-LDH nanosheet array S-NiFe-LDH which is loaded on the nickel-based self-supporting carrier and formed by alternately combining S element doped nickel hydroxide and ferric hydroxide.

The invention provides a waste molybdenum-based catalyst regeneration method which comprises the following steps: crushing and grinding a waste molybdenum-based catalyst to obtain catalyst powder; adding a liquid caustic soda solution into the obtained catalyst powder, and placing in a reaction kettle for hydrothermal reaction to obtain molybdenum hydroxide and sodium sulfate; the obtained molybdenum hydroxide is sequentially subjected to drying treatment, forming treatment and calcining treatment, and the regenerated catalyst is obtained. According to the present invention, the poisoning catalyst is regenerated by mainly using the hydrothermal reaction principle, such that the catalyst cost can be reduced, and the operation cost caused by other waste catalyst recovery methods can be avoided, such that the regeneration of the catalyst active component is achieved through the multi-stage staged treatment so as to significantly improve the regeneration efficiency and the regeneration frequency; and a new technical path is provided for resource utilization of the waste molybdenum-based catalyst.

The invention belongs to the field of PET (polyethylene glycol terephthalate) plastic waste treatment, and particularly relates to preparation of a copper oxide-nickel hydroxide core-shell structure catalytic material and application of the copper oxide-nickel hydroxide core-shell structure catalytic material to preparation of high-added-value formic acid by upgrading electro-catalysis PET plastics, and the preparation method comprises the following steps: (1) placing a copper conductive substrate in an alkali etching mixed solution for alkali etching treatment, obtaining a conductive substrate on which a Cu (OH) 2 precursor grows; (2) placing the conductive substrate on which the Cu (OH) 2 precursor grows in a muffle furnace for heat treatment to obtain a conductive substrate on which CuO nanowires grow; and (3) placing the conductive substrate on which the CuO nanowire grows in a hydrothermal kettle, and obtaining the CuO-coated Ni (OH) 2-x core-shell structure catalyst through a hydrothermal method.

A hybrid electrochemical device configuration that comprises a first electrode that includes a redox reactive material or an alloy based on a transition metal, a second electrode that includes a multi-functional catalyst to catalyze hydrogen evolution reaction, hydrogen oxidation reaction, and water oxidation reaction at the second electrode, a separator disposed between the first and second electrode, an electrolyte disposed between the first electrode and the second electrode, and a conduit which provides the means to compensate for water loss in the electrolyte during electrochemical device operation. At least one valve is included that connects the electrolyte management system to the conduit system and a valve to connect the gas formed in the electrode to the gas management system. The electrochemical device configurations include several individual devices stacked on top of each other and separated from each other using separation plates.

The invention relates to the field of preparation of nano materials, in particular to a preparation method of a metal-oxide cluster electro-catalytic material based on an ammonia-mediated electrostatic adsorption principle, and aims to solve the problem that a metal-oxide cluster heterogeneous interface is difficult to accurately construct by an existing method. The preparation method comprises the following steps: dispersing a carbon carrier, a soluble inorganic compound containing platinum, ruthenium and rhodium, a soluble metal complex anion salt and dopamine hydrochloride in a water-alcohol mixed solution, adding ammonia water, and preparing a metal-oxide heterogeneous cluster precursor through an ammonia-mediated electrostatic adsorption effect; and pyrolyzing the precursor in a reducing atmosphere to prepare the metal-oxide cluster electro-catalytic material. The prepared electro-catalytic material has a definite heterogeneous cluster interface and has excellent performance in alkaline hydroxide reaction. The method is simple and convenient to operate, low in cost and low in energy consumption, can be popularized to various metal-oxide cluster electro-catalytic materials, and has application potential.

The invention discloses iridium-cobalt oxide nanoparticles as well as a preparation method and application thereof. The iridium-cobalt oxide nanoparticles comprise a cobaltosic oxide carrier and supported iridium oxide. The preparation method comprises the following steps: 1) preparing an iridium salt-cobalt salt aqueous solution; 2) preparing a reaction solution of a complex containing iridium ammonium salt and cobalt; (3) preparing an iridium hydroxide-cobalt complex compound; and 4) grinding the iridium hydroxide-cobalt complex compound, placing the ground complex compound in an oxygen-containing atmosphere for heat treatment, and then carrying out water washing and drying. The iridium-cobalt oxide nano-particles are low in iridium content, small and uniform in particle size and simple in preparation method, have the advantages of being high in electrochemical activity, good in electrochemical stability and the like when being used as an OER reaction catalyst, and are suitable for large-scale industrial application in the field of hydrogen production through water electrolysis.

The invention relates to the technical field of electro-catalysis, in particular to a Cu-In2O3 nanoparticle catalyst as well as a preparation method and application thereof. The method comprises the following steps: dissolving a soluble copper salt and a soluble indium salt in water together, mixing with an alkali solution, carrying out a precipitation reaction, and combining copper ions and indium ions with OH <-> ions in alkali in the precipitation reaction process to generate copper hydroxide and indium hydroxide so as to obtain a precipitate; freeze-drying the precipitate to obtain a precursor; and calcining the precursor in a mixed atmosphere of hydrogen and inert gas to obtain the Cu-In2O3 nanoparticle catalyst. The Cu-In2O3 nanoparticle catalyst disclosed by the invention not only has excellent catalytic activity and high selectivity to formic acid, but also has good stability and reusability. When the Cu-In2O3 nano-particle catalyst is applied to the electrocatalytic carbon dioxide reduction reaction, the energy consumption can be effectively reduced, and the production efficiency and the product quality of formic acid can be improved.

The invention belongs to the technical field of anion exchange membrane fuel cells, and discloses a high-stability ruthenium-based hydroxide electrocatalyst used as an anode of an anion exchange membrane fuel cell and a preparation method of the high-stability ruthenium-based hydroxide electrocatalyst. The catalyst is prepared by taking ruthenium as a unique active component, fullerene (C60) as a carbon substrate and polydopamine (PDA) as an additive through argon heat treatment. The preparation method disclosed by the invention is simple and easy to implement, and through the design scheme that C60 with high electron affinity is used as a carrier, the electronic structure of a ruthenium active site is effectively adjusted, and excessive adsorption of a ruthenium-based catalyst to hydroxyl species in a hydrogen oxidation reaction (HOR) process is weakened, so that the ruthenium reaction active site is greatly reserved for hydrogen adsorption, and the hydrogen adsorption efficiency is improved. Therefore, the stability of ruthenium-based electro-catalysis in hydrogen oxidation reaction can be greatly improved.

The invention discloses a casing tubular reactor for preparing chlorine by oxidizing hydrogen chloride, which comprises a main body, and a lower seal head and an upper seal head which are respectively arranged at the bottom end and the top end of the main body, a casing reaction tube is arranged in the main body, and the casing reaction tube comprises a central tube and a jacket which is arranged on the outer wall of the central tube in a surrounding manner. A heating medium flows through the central pipe and the jacket, so that the heat exchange area is increased, and the heating medium is timely moved away from the reactor to take away heat generated by heat release of oxidation reaction, so that excessive concentration of bed reaction heat is avoided; and the obvious defect of traditional reaction equipment in the aspect of heat removal is overcome, the problems that the reaction efficiency is limited and the energy consumption is high are solved, and the reaction efficiency can be greatly improved. The invention also provides a system and a method for preparing chlorine by oxidizing hydrogen chloride, which realize recycling of reaction heat, reduction of energy consumption, recycling of tail gas discharged from an absorption tower after treatment, improvement of the utilization rate of raw materials, closed-loop operation of chlorine elements and reduction of the production cost.

The invention discloses a method for deeply removing arsenic from a nickel sulfate solution, which comprises the following steps: adjusting the pH value by using nickel hydroxide to form colloid to preliminarily remove arsenic, oxidizing by using sodium sulfate, and adding polyferric sulfate to form ferric hydroxide colloid to deeply adsorb and remove arsenic, and is simple in process, convenient to implement in the production process, capable of greatly reducing the cost and reducing the environmental pollution, and suitable for industrial production. The method comprises the following steps: adjusting the pH value of a low-pH leaching solution / anolyte / crude nickel sulfate dissolving solution to 4.0 or more by using nickel hydroxide, carrying out filter pressing to remove slag, adding arsenic ions in a sodium persulfate oxidation solution, reacting for 30 minutes, adding polyferric sulfate, reacting for 30 minutes, and carrying out filter pressing to obtain a nickel sulfate solution which is almost free of arsenic, and the method is efficient, safe and environment-friendly.

The invention provides a method for improving main components in a cobalt nickel hydroxide intermediate product. The lifting method comprises the following steps: step S100, carrying out first activation on cobalt nickel hydroxide intermediate product slurry by adopting an alkaline substance to obtain first activated product slurry; step S200, adjusting the solid content of the first activated product slurry; s300, activating the first activated product slurry for the second time by adopting a reducing agent to obtain second activated product slurry; step S400, adjusting the solid content of the second activated product slurry; and step S500, adding the second activated product slurry into a nickel-cobalt-containing solution for conversion reaction to obtain nickel cobalt hydroxide and a converted solution. According to the method disclosed by the invention, the total content of nickel and cobalt in cobalt nickel hydroxide can be remarkably increased and reaches a level exceeding 50%. The problems that the content of impurities such as magnesium and manganese in the nickel cobalt hydroxide intermediate product is too high, the content of sulfate radicals is too high, and consequently the subsequent refining production cost is increased are solved.

The invention discloses a method for synthesizing high-purity or battery-grade manganous-manganic oxide, and belongs to the technical field of chemical synthesis. The invention relates to a method for synthesizing high-purity or battery-grade manganous-manganic oxide. The method comprises the following steps: S1, preparing a manganese hydroxide slurry suspension by using high-purity manganese hydroxide as a raw material and pure water; s2, adding ammonium salt into the reaction device as a catalyst; s3, introducing hot air at 25-90 DEG C into the reaction device, and reacting to obtain solid manganous-manganic oxide; and S4, filtering and drying the solid manganous-manganic oxide to obtain a high-purity manganous-manganic oxide product, and recycling filtrate to prepare slurry.

Methods and apparatuses for converting carbon dioxide to useful compounds are disclosed. The method involves reducing bicarbonate solution in an electrolyzer. Bicarbonate solution is supplied to the cathode. The direct reduction of bicarbonate at the cathode may be coupled with an oxidation reaction at the anode. The oxidation reaction may provide a source of protons (H+) to cathode for the reduction of bicarbonate. The oxidation reaction may be a hydrogen oxidation reaction (HOR). Hydrogen gas (H2) may be supplied to the anode. In some embodiments, a source of gas may be supplied to the bicarbonate solution to form a pressurized solution before supplying the solution to the cathode.

The present invention proposes an Al / La 2 O 3 The invention discloses a catalyst and a preparation method and application thereof, belonging to the field of organic synthesis catalytic materials, and is used to solve the technical problem of low yield of enone compounds. 2 O 3 The catalyst preparation comprises the following steps: dissolving lanthanum salt in water to prepare lanthanum salt solution, adding precipitant to prepare lanthanum hydroxide gel; adding aluminum hydroxide to lanthanum hydroxide gel and mixing to prepare mixed gel, washing and drying the mixed gel to obtain precursor; calcining the precursor to obtain Al / La 2 O 3 Catalyst. Al / La 2 O 3 The preparation method of the catalyst is simple and suitable for large-scale preparation. The material surface is rich in oxygen vacancies and divalent lanthanum ions, and has the characteristics of stable structure, high catalytic efficiency and stable cycle activity. 2 O 3 The catalyst can specifically catalyze the condensation of cyclopropyl methyl ketone molecules, effectively activate the chemical bonds in the reactants to enhance the catalytic efficiency, and achieve a higher yield at a lower reaction temperature.

The invention provides a method for extracting tantalum and niobium from tungsten tailings, and belongs to the technical field of rare metal recovery, and the method comprises the following steps: adding a reducing agent, a fluxing agent, a covering agent and a slag former into the tungsten tailings, and heating and smelting under the protection of inert gas to obtain an alloy ingot; the alloy ingot is crushed and then leached through hydrochloric acid, and acid leaching residues containing tantalum, niobium and tungsten are obtained; the acid leaching residues are subjected to alkaline leaching, and alkaline leaching residues containing tantalum and niobium are obtained; the alkaline leaching residues are leached through hydrofluoric acid and sulfuric acid, and decomposition liquid is obtained; and extracting and separating the decomposition liquid to obtain tantalum hydroxide and niobium hydroxide, and respectively calcining the tantalum hydroxide and niobium hydroxide to obtain tantalum oxide and niobium oxide. The method is simple in technological process, convenient to operate, low in cost and suitable for industrial production, tantalum and niobium can be efficiently extracted from tungsten tailings, and good economic benefits and environmental benefits are achieved.

Provided here are methods for producing a shaped metal-supported catalyst. One such method includes the steps of mixing a support hydroxide with an aqueous mixture of an active metal compound to form a malleable mixture of an active metal incorporated support hydroxide, passing the malleable mixture through a molding device to produce a shaped metal-supported wet catalyst; and drying and calcining the shaped metal-supported wet catalyst. The support hydroxide contains one or more of aluminium hydroxide, silica hydroxide, zirconia hydroxide, cerium hydroxide, titanium hydroxide, lanthanum hydroxide, gallium hydroxide, or niobium hydroxide. The active metal compound can be one or more of vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, and rhenium.

The invention relates to the technical field of metal recovery, in particular to a method for recovering metal from coarse nickel cobalt hydroxide. The method for recycling the metal from the coarse nickel cobalt hydroxide comprises the following steps that S1, after the coarse nickel cobalt hydroxide is subjected to ammonia complexing leaching and oxidation in sequence, leachate and manganese slag are obtained; s2, after the leachate is separated through an extraction method, raffinate, a nickel-containing solution and a copper-containing solution are obtained; s3, the raffinate is subjected to ammonia distillation treatment, and cobalt-zinc slag is obtained; s4, the cobalt-zinc slag is subjected to acid leaching, and a zinc-containing solution and cobalt slag are obtained; and S5, the cobalt slag is subjected to reduction leaching, and a cobalt-containing solution is obtained. According to the method for recovering the metal from the crude nickel cobalt hydroxide, the metal in the crude nickel cobalt hydroxide can be fully extracted, and a nickel product, a cobalt product, a copper product, a zinc product and manganese slag which can be sold as a manganese smelting raw material are obtained.