40 results about "Ammonium perrhenate" patented technology

The invention relates to nano W-Re-Y2O3 alloy powder with small particle size and a preparation method of the nano W-Re-Y2O3 alloy powder with small particle size, and the nano W-Re-Y2O3 alloy powder with small particle size comprises the following components in percentage by mass: 79-94 wt.% of W, 10-20 wt.% of Re and 1-5 wt.% of Y2O3, the small-particle-size nano W-Re-Y2O3 alloy powder is prepared through a sol-gel method and specifically comprises the steps that firstly, citric acid is dissolved in deionized water, then ammonium metatungstate, ammonium perrhenate and yttrium nitrate are added, water bath heating is conducted, and stirring is conducted till colloid is formed; drying and calcining the colloid to obtain nano oxide powder; and putting the nano oxide powder into a reaction furnace, and reducing the nano oxide powder by using hydrogen to obtain W-Re-Y2O3 powder. According to the method, W and Re are combined on the atomic scale through a sol-gel method, Y2O3 particles are generated in situ during calcination, the Y2O3 particles are evenly mixed in the powder, the average particle size of the prepared alloy powder particles is about 12 nm, and the reduced powder does not need to be subjected to follow-up treatment. The preparation method is simple, the raw material cost is low, and large-scale production is easy to realize.

The invention belongs to the technical field of synthesis of medium-chain glyceride, and particularly relates to a rhenium-loaded nano flaky pure silicon S-1 zeolite catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: by taking tetraethoxysilane as a silicon source, tetrapropylammonium hydroxide as a template agent and ammonia water and glucose as growth regulators, preparing by adopting a hydrothermal synthesis method, and drying and calcining to prepare a nano flaky pure silicon S-1 zeolite carrier; ammonium perrhenate is used as a rhenium source to prepare a rhenium precursor solution, the nanosheet-shaped pure silicon S-1 zeolite carrier is subjected to equivalent-volume impregnation, and the rhenium-loaded nanosheet-shaped pure silicon S-1 zeolite catalyst is obtained through aging, drying and calcination. The high-performance solid catalyst containing metal active sites on the surface is prepared, is applied to the esterification reaction of caprylic acid and glyceride to produce medium-chain glyceride, and has higher catalytic esterification activity.

The invention discloses an efficient preparation method of a small-grain-size rhenium-containing alloy, and relates to the technical field of refractory metal powder metallurgy. The preparation method mainly comprises the following steps: preparing oxide composite powder by adopting a combustion synthesis method and taking soluble transition metal salt, ammonium perrhenate, hydrogen peroxide or ammonium nitrate and fuel as raw materials, reducing the oxide composite powder through hydrogen to obtain nano alloy powder, and performing compression molding and high-temperature sintering through a hydraulic press to prepare the rhenium-containing alloy material. The material has the advantages of being high in purity, uniform in doping, excellent in mechanical performance, resistant to corrosion, long in service life and the like, and a new breakthrough is brought to the field of powder metallurgy of refractory metal.

The invention discloses a surfactant for selectively extracting perrhenate and an application method of the surfactant, the surfactant is a high-selectivity diamino surfactant, and ammonium perrhenate can be separated and enriched by the surfactant. The application method comprises the following steps: adjusting the pH value of a perrhenate-containing leachate, sequentially adding the diamino surfactant and the bubble dispersant, and introducing gas for flotation to obtain a rhenium-rich component; and after the rhenium-rich component is subjected to pH adjustment, a stripping agent is added for stripping, so that ammonium perrhenate with relatively high purity is obtained. The method is simple in technological process, low in operation cost, good in selective separation effect on ammonium perrhenate, capable of effectively overcoming the defects that a traditional solvent extraction process is tedious and high in extraction agent consumption, and suitable for selective separation of ammonium perrhenate under the low-concentration condition.

The invention discloses resin purification equipment for ammonium perrhenate production and an extraction method thereof, and relates to the field of non-ferrous metal smelting waste residue utilization, the resin purification equipment comprises a support, at least two columns are installed on the support, partition plates are used for separating resin particles, and multiple layers of partition plates are arranged in the height direction in the columns at intervals; the rotating shaft is coaxially and rotationally connected into the column body, the bottom end of the partition plate is rotationally connected with stirring rods used for stirring resin particles, liquid inlet flow at the top end of the column body can drive the rotating shaft to rotate, and the rotating shaft and all the stirring rods are provided with mutually-matched protruding block structures in a staggered mode. The rotating shaft can rise and fall in a reciprocating mode in the height direction while rotating. The rotating mechanism is driven by liquid inlet water flow in the ion exchange process to intermittently disturb the resin bed in each independent chamber, so that resin particles are in full contact with the material liquid in a transient suspension state, and the problems of crushing and shear desorption caused by long-term stirring are effectively avoided.

The invention relates to the technical field of ammonium rhenate purification, and particularly discloses a method for removing Tl impurities in ammonium rhenate. The method specifically comprises the following steps: dissolving ammonium rhenate in deionized water, adding an oxidant, carrying out an oxidation reaction while stirring, filtering, carrying out ion exchange, evaporation and concentration, adding ammonia water / ammonia gas to obtain an ammonium rhenate solution, freezing, crystallizing, and drying to obtain a high-purity ammonium rhenate solid. The method is simple to operate and ingenious in process, the oxidizing agent is added to oxidize and adsorb the Tl, impurities are not introduced, and the Tl which is not easily removed by ion exchange is removed, so that the high-purity ammonium rhenate is obtained. The Tl content is smaller than 0.9 ppm, and the purity of ammonium rhenate is larger than 99.999%.

This invention belongs to the field of metal ingot preparation technology, specifically relating to a high-purity rhenium ingot and its preparation method. Using ammonium perrhenate solution as raw material, this invention directly generates elemental rhenium and rhenium oxides of different valence states through electrodeposition without complex pretreatment. The mixture is then crushed and fed into a transferred arc hydrogen plasma reaction zone, where the rhenium oxides of different valence states are rapidly reduced to rhenium powder under the high temperature and high energy environment of the hydrogen plasma. The rhenium powder and elemental rhenium fall into a water-cooled copper crucible, where they are continuously heated and melted by the transferred arc hydrogen plasma to form liquid rhenium. Unreacted rhenium oxides continue to be reduced in the liquid rhenium pool to ensure complete reduction. Finally, the liquid rhenium is cooled and solidified to obtain a high-purity rhenium ingot. This invention integrates the reduction and melting processes, resulting in a simple and efficient process that effectively avoids the introduction of impurities. The prepared rhenium ingot has a purity ≥99.99%, high density, and uniform composition, making it widely applicable in high-end fields such as aerospace, nuclear energy, and electronics.

The invention belongs to the technical field of preparation of scattered metal oxides, and particularly relates to a preparation device and method of 5N-grade rhenium heptoxide and application of the 5N-grade rhenium heptoxide. In the prior art, two methods are generally adopted when 5N-grade rhenium heptoxide is prepared: 1, an ammonium perrhenate crude product is adsorbed and separated by ion exchange resin to obtain 5N-grade ammonium perrhenate, and the 5N-grade ammonium perrhenate is heated and decomposed to form 5N-grade rhenium heptoxide; and 2, heating and decomposing the ammonium perrhenate crude product to form rhenium heptoxide, and separating and purifying the rhenium heptoxide to form 5N-grade rhenium heptoxide. The invention discloses a preparation device, method and application of rhenium heptoxide formed by heating and decomposing an ammonium perrhenate crude product as a raw material and separating and purifying the rhenium heptoxide, and compared with the prior art, the preparation device and method have the advantages of simple technological process, high purification efficiency, stable product quality, low cost and the like. And the purification rate is high.

The present invention provides a preparation method of a chelating resin and its application in the purification of ammonium perrhenate. By setting the ratio of the oil-phase mixture and the water-phase mixture and precise temperature control, a chelating resin with excellent performance is prepared. This chelating resin not only has a uniform dispersion of the extractant, a strong binding force with the resin, but also is not easily lost. When using this chelating resin to purify ammonium perrhenate solution in a chromatography column, by controlling the solution concentration and flow rate, ammonium perrhenate with a purity greater than 99.99% can be obtained. The chelating resin prepared by the method provided by the present invention can not only improve the purification efficiency and purity of ammonium perrhenate, but also reduce the generation of organic waste liquid, reduce the impact on the environment, and at the same time simplify the resin synthesis and regeneration process, so as to enhance the economy and environmental protection of the ammonium perrhenate refining technology, and provide a high-quality rhenium metal resource guarantee for the development of China's aerospace industry.

The invention belongs to the technical field of powder metallurgy, and particularly relates to a preparation method of nano molybdenum-rhenium alloy powder. The most common preparation method of the nano molybdenum-rhenium alloy powder comprises the following steps: firstly, dissolving ammonium perrhenate and ammonium molybdate in a calculated amount in hot water; cooling and separating out mixed crystals; and finally, the nanometer molybdenum-rhenium alloy powder is generated through hydrogen reduction. The preparation method has the problems that mixed crystallization of ammonium perrhenate and ammonium molybdate is not uniform, and the particle size of alloy powder cannot be controlled. The invention discloses a preparation method of nano molybdenum-rhenium alloy powder. The preparation method comprises the following steps: in an organic solvent, carrying out rapid crystallization on a mixed solution of ammonium perrhenate and ammonium molybdate to generate high-uniformity mixed crystals; and the high-uniformity mixed crystals are reduced through hydrogen, and nano molybdenum-rhenium alloy powder is generated. The nanometer molybdenum-rhenium alloy powder prepared through the preparation method has the beneficial effects that metal rhenium is evenly distributed, and the particle size of the alloy powder can be effectively controlled.

The application relates to the field of photocatalysis, in particular to a composite material for photocatalytic degradation of PFOA and a preparation method thereof. The composite material comprises the following steps: step one: using titanium foil as an anode and a nickel sheet as a cathode, carrying out anodic oxidation, and then annealing to obtain TiO2-NT; step two: first, acid pickling TiO2-NT, and then preparing TiO2-NT suspension liquid; adding chloroplatinic acid, a dispersing agent and potassium borohydride into the TiO2-NT suspension liquid to prepare a Pt / TiO2-NT composite material; step three: coating ammonium perrhenate on the Pt / TiO2-NT composite material, and then sintering, repeating 1-2 times to obtain a modified Pt / TiO2-NT composite material; and step four: preparing a MIP-Pt / TiO2-NT composite material through a molecular imprinting technology.

The invention provides a method for recovering ammonium perrhenate and removing molybdenum from molybdenum ore, which comprises the following steps: carrying out water heating saturation primary redissolution on a high-molybdenum ammonium perrhenate product needing molybdenum reduction to obtain a high-molybdenum liquid; then hydrogen peroxide and ammonia water are added, the temperature is kept at 70-75 DEG C, the pH value of the high-molybdenum liquid is larger than 10, then nanoscale cross-flow filtration is conducted, and concentrated liquid is returned to be redissolved; performing freezing crystallization on the filtered high-molybdenum clear liquid at the final temperature of 0-3 DEG C, and returning crystallization mother liquor for re-dissolution; carrying out negative pressure suction filtration on the obtained primary crystallized ammonium perrhenate by using 200-mesh filter cloth to obtain a primary crystallized ammonium perrhenate filter cake; and carrying out water saturation secondary redissolution on the obtained primary crystallized ammonium perrhenate filter cake, then adding ammonia water, carrying out freezing crystallization, and carrying out suction filtration and drying after crystallization to obtain a low-molybdenum ammonium perrhenate product. According to the method, two redissolution separation stages are set in the molybdenum and rhenium separation process, and the molybdenum removal efficiency is further guaranteed.

The invention belongs to the technical field of scattered metal, and particularly relates to a preparation method of 5N-grade high-purity rhenium powder. In the prior art, industrial-grade ammonium perrhenate is generally used as a raw material, and 5N-grade high-purity ammonium perrhenate is obtained through ion exchange resin adsorption separation. And the 5N-grade high-purity ammonium perrhenate is subjected to hydrogen reduction to prepare the 5N-grade high-purity rhenium powder. The preparation method has the problems of complex purification process, low purification efficiency and low purification rate. The invention discloses a preparation method of 5N-grade high-purity rhenium powder, which is characterized in that industrial ammonium perrhenate with the content of 99.9% is subjected to precision filtration and two times of recrystallization to prepare 5N-grade high-purity ammonium perrhenate. And reducing the 5N-grade high-purity ammonium perrhenate with hydrogen to prepare the 5N-grade high-purity rhenium powder. The preparation method of the 5N-grade high-purity rhenium powder has the advantages of being simple in preparation process, high in purification efficiency and high in purification rate.

The application discloses a preparation method of 4N high-purity rhenium powder and belongs to the field of metal processing. The method uses common 3N high-purity ammonium perrhenate as raw material, and after pretreatment, the target product of 4N can be obtained through specific pickling. The method has simple operation steps, low equipment requirement and low dependence on human operation, and can guarantee the stability of product quality in the process of industrialized scale production.

The invention belongs to the technical field of scattered metal salt purification, and particularly relates to a preparation method of 5N-grade ammonium perrhenate. In the prior art, two methods are generally adopted when 5N-grade ammonium perrhenate is prepared: 1, an ammonium perrhenate crude product is adsorbed and separated by ion exchange resin to obtain 5N-grade ammonium perrhenate; and 2, heating and decomposing the ammonium perrhenate crude product to form rhenium heptoxide, separating and purifying the rhenium heptoxide to obtain 5N-grade rhenium heptoxide, and absorbing the 5N-grade rhenium heptoxide by ammonia water to obtain 5N-grade ammonium perrhenate. Wherein the method 1 is wider in application, but the preparation process has the following problems: 1, the purification process is complicated and the efficiency is low; 2, the loss of ammonium perrhenate is large, and the purification rate is low; the invention discloses a preparation method of 5N-grade ammonium perrhenate. The 5N-grade ammonium perrhenate is prepared by separating and purifying an ammonium perrhenate crude product by adopting macroporous adsorption resin. The preparation method provided by the invention has the characteristics of simple process and high purification rate.

The invention discloses a rhenium recovery functional material and a preparation method thereof. The preparation method comprises the following steps: weighing 10-50g of chlorine balls in a 100ml beaker, then adding 10-40g of N, N-dimethylformamide, ensuring that the chlorine balls are completely immersed, and immersing for 2-4 hours; weighing an N-ethyl thiourea aminating agent according to a preset proportion of the available chlorine content to amine, and putting the N-ethyl thiourea aminating agent into a constant-pressure separating funnel; heating the reaction system in a water bath, dropwise adding an N-ethyl thiourea aminating agent within 2-3 hours, dropwise adding a sodium hydroxide solution into the reaction bottle after the aminating agent is dropwise added, adjusting the pH value of the reaction system to 5-12, and continuing to react for 6-14 hours; after the reaction is finished, repeatedly cleaning the resin by using deionized water until the cleaned solution is neutral, and removing residual impurities and reaction byproducts; drying in a vacuum environment to obtain a dried rhenium recovery functional material; the method can solve the problem of insufficient desorption capability when ammonium perrhenate is recovered by using ammonia water.

This invention belongs to the field of metallurgical technology, and specifically relates to a method for efficiently extracting rhenium from rhenium-containing waste. The method includes the following steps: pulverizing and sieving the raw material, adding a purification reagent to remove impurities, followed by electrolytic dissolution, evaporating and concentrating the resulting solution, separating it by resin adsorption, eluting with an eluent, purifying by recrystallization, and finally obtaining high-purity rhenium powder by hydrogen reduction. The method provided by this invention effectively removes impurity ions from the waste by introducing a purification reagent, and further utilizes a cation exchange resin to adsorb and separate residual trace metal ions in the solution, thereby avoiding the impact of impurities on the purity of subsequent ammonium perrhenate and rhenium powder. This method has a simple process flow, is highly operable, has a wide range of applications, and has minimal environmental impact, showing promising application prospects.

The application discloses a hollow multi-shell nanosphere loaded with CoP / Re heterojunction and a preparation method and application thereof. A precursor solution is prepared by dissolving a cobalt salt and ammonium perrhenate in a mixed ethyl alcohol aqueous solution containing polyvinylpyrrolidone (PVP) and nitric acid; the precursor solution is subjected to an electrostatic spraying technology to obtain solid nanoparticles; the solid nanoparticles are pyrolyzed at high temperature in an air atmosphere, and are further subjected to phosphating treatment, and are naturally cooled to obtain the hollow multi-shell nanosphere material loaded with the CoP / Re heterojunction. The preparation method is low in cost and simple in operation; the prepared material has a hollow multi-shell spherical structure, a relatively large effective specific surface area, can provide more active sites, is favorable for gas diffusion, and maintains structural stability. Meanwhile, the establishment of the CoP / Re heterostructure can significantly change the electronic configuration of the active sites, improve the conductivity, and thus improve the electrochemical activity.

The present invention relates to the technical field of ammonium rhenate preparation, and particularly relates to a drying device for preparing high-purity ammonium rhenate, which includes a drying inner barrel fixedly installed inside a drying outer barrel. The bottom of the drying outer barrel is fixedly communicated with a discharge funnel, and the bottom of the drying inner barrel is fixedly communicated with a water outlet funnel that penetrates the discharge funnel. A drying mechanism for grading and screening ammonium rhenate particles and uniformly drying them respectively is arranged inside the drying inner barrel. A feeding mechanism for dispersedly adding ammonium rhenate particles into the drying inner barrel is arranged at the top of the drying outer barrel. The drying mechanism includes a supporting vertical pipe arranged inside the drying inner barrel and having its bottom fixed to the water outlet funnel. The present invention can make the ammonium rhenate particles more evenly distributed during drying, can quickly and effectively remove moisture, shorten the drying time of ammonium rhenate, improve the drying efficiency of ammonium rhenate, effectively prevent the situation that ammonium rhenate particles agglomerate and are difficult to disperse, affecting the drying effect, and improve the product quality of high-purity ammonium rhenate.

The invention discloses a method for efficiently separating platinum and rhenium in a waste aluminum-based platinum-rhenium catalyst and recovering metal aluminum by using a microwave technology, and relates to the technical field of comprehensive utilization of metallurgical solid waste resources and recovery of rare and noble metals. The method comprises the following steps: carrying out microwave alkali fusion roasting on the waste aluminum-based platinum-rhenium catalyst, cooling a reaction product, and adding water for leaching to obtain a leachate 1 and leaching residues; dissolving the leaching residues by using aqua regia, centrifuging, precipitating platinum by using ammonium chloride, finally reducing platinum-containing precipitates to obtain platinum powder, promoting meta-aluminate radical hydrolysis of the leaching solution 1 by using an acid adding method, filtering to obtain aluminum hydroxide precipitates and a leaching solution 2, carrying out alkaline anion resin adsorption exchange on the leaching solution 2, and desorbing by using a desorbent to obtain a rhenium-containing solution; and concentrating and crystallizing to obtain ammonium rhenate. The method realizes efficient separation of platinum and rhenium in the waste aluminum-based catalyst and recovery of metal aluminum, has the remarkable advantages of small slag amount, high efficiency and the like, and provides a solution for solving the problem of treatment of the waste aluminum-based catalyst.

The invention discloses a preparation method of rhenium trioxide and rhenium dioxide, which comprises the following steps of: 1, dissolving ammonium perrhenate in deionized water to prepare an ammonium perrhenate solution, and enabling the ammonium perrhenate solution to flow through an exchange column filled with H + type C160 cationic resin to obtain a perrhenic acid solution; 2, ammonium perrhenate is subjected to hydrogen reduction, and active rhenium powder is obtained; 3, mixing and drying the perrhenic acid solution and the active rhenium powder to obtain a rhenium oxide precursor; and 4, thermally decomposing the rhenium oxide precursor in an inert atmosphere to obtain a rhenium trioxide or rhenium dioxide solid. According to the method, ammonium perrhenate is subjected to cationic resin ion exchange and hydrogen reduction treatment to obtain a perrhenic acid solution and active rhenium powder respectively, then the perrhenic acid solution and the active rhenium powder are evenly mixed, dried and subjected to thermal decomposition, and cubic-crystal-form rhenium trioxide or orthorhombic-crystal-form rhenium dioxide solids are obtained; the crystal form of rhenium dioxide is effectively controlled, the raw materials are easier to obtain and store, the difficulty of the preparation process is reduced, and the method is suitable for large-scale production.

The invention belongs to the field of powder metallurgy, and particularly discloses a method for preparing nano molybdenum-rhenium alloy powder through liquid-phase in-situ precipitation. According to the method, ammonium heptamolybdate and ammonium perrhenate serve as raw materials and are dissolved in an ammonia water solvent, then a dispersing agent, a complexing agent and a surface active agent are added, the pH is adjusted to be within the acidic range, so that molybdenum-rhenium precursors are rapidly separated out from the solution in situ, and atomic-scale mixed ammonium dimolybdate-ammonium perrhenate mixed crystals are formed. And then low-temperature calcination dehydration is conducted in the argon atmosphere, gradual reduction and alloying of oxides are sequentially achieved through a three-stage hydrogen reduction technology, and finally the nanometer molybdenum-rhenium alloy powder which is uniform in component, good in dispersity and about 160 nm in average particle size is obtained. The method is simple in process, and the prepared powder is small in particle size and concentrated in distribution, has high sintering activity and is suitable for preparing a high-performance molybdenum-rhenium alloy material.

The invention belongs to the technical field of powder metallurgy, and particularly relates to a preparation process of molybdenum-rhenium alloy. An existing molybdenum-rhenium alloy preparation process mainly comprises a dry method and a wet method, in the dry method, metal molybdenum powder and metal rhenium powder are mixed and ball-milled in a ball mill to form molybdenum-rhenium mixed powder, and the molybdenum-rhenium mixed powder is subjected to hydrogen reduction, isostatic pressing and sintering to form the molybdenum-rhenium alloy; the wet method comprises the following steps: dissolving ammonium metamolybdate and ammonium perrhenate in water to form a mixed solution; and the mixed solution is subjected to evaporation dehydration, hydrogen reduction, isostatic pressing and sintering to form the molybdenum-rhenium alloy. The preparation method has the problem of non-uniform distribution of metal rhenium in the molybdenum-rhenium alloy. The invention discloses a preparation process of a molybdenum-rhenium alloy, which comprises the following steps: mixing and ball-milling an ammonium perrhenate aqueous solution and molybdenum powder in a ball mill to form high-uniformity mixed powder; and the high-uniformity mixed powder is subjected to hydrogen reduction, isostatic pressing and sintering to form the molybdenum-rhenium alloy, and the preparation method has the characteristic that metal rhenium in the molybdenum-rhenium alloy is evenly distributed.

The utility model discloses an ultrasonic-assisted ammonium perrhenate crystallization device which comprises a support, a crystallization tank is installed on the support, an ultrasonic generator is transversely arranged on the inner side wall of the vertical middle of the crystallization tank, and the tail end of the ultrasonic generator extends out of the side wall of the crystallization tank and is provided with an end cover. The ultrasonic generator which is transversely arranged is arranged on the inner side wall of the vertical middle part of the crystallizing tank for assisting crystallization, so that the contact area of the ultrasonic generator and liquid is maximized, the crystallizing speed is greatly increased, the granularity of a crystallized product is smaller, and meanwhile, the end cover is arranged at the tail end of the ultrasonic generator, so that the crystallization effect is better. The ultrasonic generator can be conveniently taken out of the crystallizing tank and is convenient to clean and maintain; the ultrasonic frequency of the ammonium perrhenate crystallization rate ultrasonic generator can be adjusted, the ammonium perrhenate crystallization rate ultrasonic generator can be suitable for different working conditions, and the ultrasonic generator is convenient to detach and convenient to clean and maintain. The technical problem that in the prior art, an ammonium perrhenate crystallization device is not high in efficiency is solved.

The application discloses a rhenium disulfide-nitrogen doped porous carbon composite material and a preparation method and application thereof. The preparation method of the rhenium disulfide-nitrogen doped porous carbon composite material comprises the following steps: (1) adding a rhenium source, thiourea and sodium chloride into a folic acid solution and uniformly mixing to obtain a mixed solution, wherein the rhenium source is at least one of ammonium perrhenate and potassium perrhenate; (2) performing freeze drying on the mixed solution to obtain a mixed dry powder; (3) performing heat treatment and sulfuration treatment on the mixed dry powder under an inert atmosphere and at a certain temperature; and (4) performing washing and freeze drying on the product obtained in the step (3) to obtain the rhenium disulfide-nitrogen doped porous carbon composite material. The rhenium disulfide-nitrogen doped porous carbon composite material prepared by the method has good conductivity and low volume expansion effect, and is not prone to agglomeration or accumulation.

The invention discloses a method for extracting high-purity rhenium from copper smelting waste acid, which is characterized by comprising the following steps: (1) filtering to remove solid particles in the waste acid; (2) carrying out ion exchange on the filtered waste acid to obtain crude ammonium rhenate; (3) pouring the crude ammonium rhenate into a recrystallization kettle for recrystallization to form an ammonium rhenate crude product; and (4) adding hydrogen peroxide into the ammonium rhenate crude product, and recrystallizing to obtain ammonium rhenate crystals. Through a large number of experimental studies, it is found that high-purity ammonium rhenate can be obtained by adding a small amount of hydrogen peroxide and N, N-dimethylformamide in the recrystallization process, and meanwhile the recovery rate of rhenium is also remarkably increased.

This invention discloses a combined pyrometallurgical-hydrometallurgical cascade separation method for arsenic-containing sludge from copper smelting, relating to the field of solid waste treatment technology. The method first involves low-temperature roasting of the arsenic-containing sludge at 300-600℃ in a reducing atmosphere to achieve preferential volatilization and recovery of arsenic, while copper and rhenium are retained in the roasted sludge. Next, the roasted sludge is subjected to pressure oxidative leaching, with copper and rhenium entering the leachate, and sulfur being enriched and recovered as elemental. Subsequently, arsenic is precipitated as stable arsenic crystals through ternary coupling control of redox potential, pH, and temperature. After deep removal of residual arsenic using barium / lead salts, rhenium is extracted using a co-extraction system to prepare ammonium perrhenate. Finally, copper is recovered from the raffinate by displacement or electrodeposition. This method can efficiently separate arsenic, sulfur, copper, and rhenium, with a sulfur recovery rate ≥92%, arsenic resource recovery rate ≥99%, rhenium recovery rate ≥92%, copper recovery rate ≥95%, solid waste reduction ≥80%, and no secondary pollution. It is suitable for the resource-based treatment of arsenic-containing sludge from copper smelting.

The invention relates to a rhenium powder preparation method, which comprises: mixing ammonium perrhenate and an organic antioxidant, carrying out heating reduction under a protective atmosphere, and naturally cooling to obtain rhenium powder, the organic antioxidant is selected from one or a combination of two or more of a benzotriazole compound, ascorbic acid, butylated hydroxytoluene and alkyl imidazoline; the protective atmosphere contains an inert atmosphere, and the volume fraction of the inert atmosphere in the protective atmosphere is not lower than 90%. According to the method, dangerous strong reducing atmospheres such as high-concentration hydrogen and carbon monoxide do not need to be used, the specific organic antioxidant is selected as a protective agent and a reducing agent of ammonium perrhenate, the rhenium powder with high purity and low oxygen content can be prepared through heating reduction, and the production safety risk is remarkably reduced. The organic antioxidant improves antioxidant protection at low temperature while pyrolyzing and reducing ammonium perrhenate, and decomposition products of the organic antioxidant can form a complex protective layer on the surface of the rhenium powder and effectively isolate oxygen at high temperature, so that the oxidation resistance of the rhenium powder is remarkably improved.

This invention discloses a method for recovering tungsten and rhenium from tungsten-rhenium alloy waste, belonging to the field of waste metal recycling technology. The method includes: leaching pretreated tungsten-rhenium alloy waste by heating and stirring with a mixed solution of dilute hydrochloric acid and hydrogen peroxide, converting tungsten and rhenium into tungstate ions and perrhenate ions respectively into the solution; then, rapid acidification by quantitatively adding concentrated hydrochloric acid, causing tungsten to precipitate as crystalline tungstic acid; filtering to obtain a crystalline tungstic acid filter cake and a rhenium-containing filtrate; adsorbing the rhenium-containing filtrate through an anion exchange resin to load perrhenate ions onto the resin; subsequently eluting with an ammonia solution to obtain an ammonium perrhenate solution; evaporating, concentrating, and crystallizing to obtain ammonium perrhenate crystals; simultaneously washing and drying the tungstic acid filter cake to obtain the tungstic acid product. This invention features a simple process flow, thorough tungsten-rhenium separation, high recovery rate, is green and economical, and can obtain high-purity tungsten and rhenium products.

The invention provides low-oxygen-content superfine rhenium powder and a preparation method thereof, and relates to the field of metal powder preparation. Mixing the ammonium rhenate solution, citric acid and polyethylene glycol, and performing ultrasonic treatment and spray drying on the obtained mixture to obtain solid powder; in reducing gas, the solid powder is subjected to reduction roasting, and reduced powder is obtained; and in a vacuum environment, the reduced powder is subjected to deoxidation treatment, and the low-oxygen-content superfine rhenium powder is obtained. The method is simple and convenient to operate, good in economical efficiency and convenient for industrial batch production.