119 results about "NEODYMIUM OXIDE" patented technology

The invention discloses a method for recycling a waste lithium battery positive electrode material, and relates to the technical field of lithium battery positive electrode materials. When the lithium battery positive electrode material is prepared, the waste lithium iron phosphate battery is discharged and then disassembled, a current collector is separated through cyclic soaking in cold and hot water, lithium ions are selectively leached through sulfuric acid-hydrogen peroxide after calcination, and the recycled lithium carbonate is obtained through recycling; preparing a carbonic acid ternary precursor by using a coprecipitation method; mixing the carbonic acid ternary precursor, recycled lithium carbonate, silicon monoxide, lithium fluoride and neodymium oxide, and performing secondary calcination to obtain a doped modified ternary positive electrode material; compounding and coating lanthanum, aluminum and zinc on the surface of the doped modified ternary positive electrode material by using a potassium-sodium alloy reduction method to prepare a coated modified ternary positive electrode material; and mixing the coated modified ternary positive electrode material with a conductive agent and a binder, and coating a carbon-coated aluminum foil with the mixture to prepare the lithium battery positive electrode material. The lithium battery positive electrode material prepared by the invention has high charge-discharge specific capacity, long cycle life and good rate capability.

The invention relates to the technical field of wear-resistant materials, in particular to a nano wear-resistant composite material and a preparation method and application thereof, and the nano wear-resistant composite material comprises the following raw materials in parts by weight: 45-50 parts of nano tungsten carbide, 10-15 parts of cobalt powder, 7-11 parts of a modified nano titanium nitride agent, 5-7 parts of nano neodymium oxide, and 4-6 parts of a nano TaC-doped complexing agent. According to the nano wear-resistant composite material, the nano tungsten carbide is matched with the cobalt powder and the nano neodymium oxide, the modified nano titanium nitride agent, the doped nano TaC and the synergist are coordinated and matched, and the raw materials are coordinated and synergistic, so that the wear resistance, the yield strength performance and the fatigue resistance of the obtained nano wear-resistant composite material are coordinated and improved; meanwhile, the product is excellent in performance stability under different degrees of salt corrosion conditions.

The invention discloses a preparation method of an aperture-adjustable and metal-loaded graphite felt flow battery electrode, which comprises the following steps: (1) pretreatment and pore separation: mixing a graphite felt with an alkali solution, magnetically stirring, heating, cooling to room temperature, and treating again to obtain a pore separation material; (2) loading neodymium oxide: dipping the porous material in a solution containing neodymium salt and polyamino acid, heating, cleaning, and drying to obtain a neodymium oxide modified electrode material; (3) loading oxygen-deficient CoMnOx: coating the mixed slurry containing manganese and cobalt on an electrode plate, heating, cleaning and drying to obtain an oxygen-deficient CoMnOx loaded electrode; and (4) carrying out electro-deposition on the electrode loaded with the oxygen defect CoMnOx to obtain the novel bismuth-deposited graphite felt electrode. According to the electrode product obtained through the method, the energy efficiency is improved to 85% or above, and the stable cycle index for maintaining the energy efficiency can exceed 1440 times.

The invention relates to a manufacturing method of a novel high-temperature high-performance piezoelectric ceramic material, the manufacturing method is improved on the basis of a lead zirconate titanate piezoelectric ceramic material, the prepared ceramic material is suitable for a high-temperature environment through doping and process optimization, and the manufacturing method comprises the following steps: burdening and mixing, pre-sintering, secondary ball milling, granulating and forming, glue discharging and sintering. And machining, silver electrode firing and polarization testing are carried out. According to the manufacturing method of the piezoelectric ceramic material, components of the lead zirconate titanate piezoelectric ceramic are optimized, and neodymium oxide is doped into the lead zirconate titanate piezoelectric material, so that the performance of the ceramic is improved. By doping neodymium oxide, volatilization of the piezoelectric ceramic in lead can be effectively inhibited, deformation of the ceramic is reduced, and the piezoelectric ceramic is suitable for application and industrial production. Meanwhile, the Curie temperature of the ceramic is not obviously reduced, so that the preparation of the high-temperature piezoelectric ceramic is realized.

The invention relates to a high-gloss black decorative glass prepared from sludge incineration ash by an all-electric melting method. The high-gloss black decorative glass comprises the following raw material components in percentage by mass: 75-79% of fly ash, 5-7% of calcium carbonate, 9-10% of sodium carbonate, 5-6% of potassium alkali, 1-1.4% of boric acid, 0.03-0.04% of porous carbon, 0.06-0.08% of semi-coke powder, 0.16-0.22% of cobaltosic oxide, 0.1-0.2% of cerium dioxide, 0.04-0.06% of neodymium oxide, 0.5-0.7% of waste zircon brick powder and 0.03-0.05% of yttrium oxide. The dedusting ash is electrostatic dedusting ash collected by incineration of filtered sludge in a municipal sewage treatment plant, and belongs to hazardous waste; the porous carbon is rich in a hierarchical pore structure of sub-nano pores (0.5-1.0 nm). According to the method, a closed-loop production mode that waste is used for treating waste is constructed, high-added-value decorative materials are produced while energy consumption is reduced, and environmental protection investment is converted into economic benefits.

The invention relates to the technical field of rare earth metal separation, and particularly discloses a praseodymium neodymium oxide separation and purification process and a regeneration system. The process comprises the following steps: after H2S is subjected to impurity removal and filtration, carrying out multi-stage counter-current extraction by adopting a P507 / TRPO synergistic extraction organic phase, carrying out graded reverse extraction on praseodymium by HCl, and carrying out reverse extraction on neodymium by HNO3; the regeneration system comprises a wastewater treatment unit and an organic phase regeneration unit, wastewater is recycled through neutralization precipitation, precision filtration and reverse osmosis, and an organic phase is subjected to alkali washing, acid activation and 4A molecular sieve dehydration circulation. The praseodymium-neodymium separation coefficient reaches 2.0-2.2 through synergistic extraction, and the stage number is reduced by 40%; the double regeneration systems reduce the organic phase loss to be less than or equal to 2% and the wastewater reuse rate to be greater than or equal to 92%; the purity of the prepared neodymium oxide is greater than or equal to 99.99% and Fe is less than or equal to 10ppm. According to the method, the extraction efficiency is remarkably improved, the service life of an organic phase is multiplied, the product purity breaks through the limit, near-zero wastewater discharge is closed, the whole process stability is guaranteed, and the resource utilization rate is maximized.

The device comprises a device body, an inner cavity, a feeding hopper, a net plate, a pushing air cylinder, a discharging port and a liquid outlet pipe, a liquid distribution cavity is formed in the top of the inner cavity, the liquid distribution cavity and the inner cavity are separated through a partition plate, the feeding hopper is arranged on the side wall of the upper end of the inner cavity, and the net plate is arranged on the side wall of the lower end of the inner cavity. One side of the supporting block is hinged to the net plate through a hinge, the other side of the supporting block is connected with the bottom of the net plate through a tension spring, the discharging port is formed in the side wall of the inner cavity and the same side of the hinge, a side installation frame is arranged on the outer side of the discharging port, and a material blocking air cylinder is installed outside the side installation frame; by arranging the screen plate and the material pushing air cylinder structure, neodymium iron boron waste materials on the screen plate can be pushed up and down, the waste materials collide with the protruding blocks on the lower side of the partition plate, the material dispersing effect is achieved, coatings on the outer surfaces of the waste materials fully react with soaking liquid, the coatings are cleaned, the cleaned raw materials are conveyed to the next station from the discharging port, and praseodymium neodymium oxide is recycled; and the soaking liquid is discharged from the liquid outlet pipe.

The invention belongs to the technical field of environmental barrier coatings, and particularly relates to an environmental barrier coating for an outer ring block of an engine and a preparation method of the environmental barrier coating. The environmental barrier coating sequentially comprises a silicon layer, a double-ytterbium silicate layer, a single-ytterbium silicate layer, a transition layer and an abradable layer from inside to outside, and each of the transition layer and the abradable layer comprises a mixed oxide containing aluminum oxide, lanthanum oxide, magnesium oxide and neodymium oxide. The mass ratio of aluminum oxide to lanthanum oxide to magnesium oxide to neodymium oxide in the transition layer is (50-70): (15-25): (10-15): (8-10), and the mass ratio of lanthanum oxide to magnesium oxide to neodymium oxide in the abradable layer is (40-60): (20-30): (15-20): (5-8). The environmental barrier coating has significantly improved abradability, corrosion resistance, life in high temperature service environments.

The present invention discloses a method for preparing a pore-adjustable and metal-loaded graphite felt flow battery electrode, comprising the following steps: (1) pretreatment and pore separation: mixing graphite felt with an alkaline solution, magnetically stirring, heating, cooling to room temperature, and re-treating to obtain a pore-separated material; (2) loading neodymium oxide: immersing the pore-separated material in a solution containing a neodymium salt and a polyamino acid, heating, cleaning, and drying to obtain a neodymium oxide-modified electrode material; (3) loading oxygen-deficient CoMnOx: applying a mixed slurry containing manganese and cobalt to an electrode sheet, heating, cleaning, and drying to obtain an oxygen-deficient CoMnOx-loaded electrode; and (4) electrodepositing the oxygen-deficient CoMnOx-loaded electrode to obtain a novel graphite felt electrode with bismuth deposition. The electrode product obtained by the method of the present invention has an energy efficiency of more than 85%, and the number of stable cycles at which the energy efficiency is maintained can exceed 1440 times.

The invention belongs to the technical field of alumina ceramic preparation, and particularly relates to microcrystalline wear-resistant alumina ceramic and a preparation method thereof. The microcrystal wear-resistant aluminum oxide ceramic is prepared from the following raw materials: fused corundum powder, gibbsite, diopside, calcium fluosilicate, neodymium oxide, nickel aluminate, strontium oxide and sodium tripolyphosphate. According to the microcrystal wear-resistant aluminum oxide ceramic disclosed by the invention, the fused corundum powder and the gibbsite are used as main raw materials, so that the mechanical property of the prepared aluminum oxide ceramic is fundamentally ensured; diopside and calcium fluosilicate are used as fluxing agents, so that the firing temperature of the aluminum oxide ceramic is reduced, and the compactness is improved; neodymium trioxide, nickel aluminate and strontium oxide are used as wear-resistant assistants, and the wear resistance of the aluminum oxide ceramic is improved by improving the microstructure of the aluminum oxide ceramic, avoiding stress concentration at a grain boundary and generating a second reinforcement phase under the synergistic effect of the three assistants. Therefore, it is ensured that the prepared aluminum oxide ceramic has excellent wear resistance.

The invention belongs to the technical field of high-entropy materials, and discloses high-entropy pyrochlore ceramic as well as a preparation method and application thereof. The chemical formula of the high-entropy pyrochlore ceramic is (La0. 2Nd0. 2Sm0. 2Gd0. 2Er0. 2) 2M2O7, M is Zr, Hf, Ti or Sn, lanthanum oxide, neodymium oxide, samarium oxide, gadolinium oxide, erbium oxide and zirconium oxide or hafnium oxide or titanium oxide or tin oxide are sintered at the temperature of 1400-1600 DEG C to synthesize high-entropy pyrochlore powder, the high-entropy pyrochlore powder is mixed with tin chloride, ball-milled and dried to obtain mixed powder, the mixed powder is mixed with a surfactant, the mixed powder is mixed at the temperature of 200-400 DEG C, ball-milled and dried, and the high-entropy pyrochlore ceramic is obtained. And carrying out cold sintering under the pressure of 200-500MPa, and then carrying out vacuum sintering at the temperature of 1300-1600 DEG C, thereby obtaining the The high-entropy pyrochlore ceramic disclosed by the invention is high in purity, high in density, excellent in mechanical property and leaching resistance, low in sintering temperature and short in heat preservation time, and has an application prospect in the field of nuclear waste curing.

The utility model relates to the technical field of praseodymium neodymium oxide processing, in particular to a firing mechanism for praseodymium neodymium oxide processing, which comprises a base, the upper end face of the base is fixedly connected with a heat insulation shell, a plurality of first firing cylinders and second firing cylinders which are distributed in a staggered manner are respectively arranged in the heat insulation shell, the three first firing cylinders rotate clockwise, and the three second firing cylinders rotate clockwise. The two second firing barrels rotate anticlockwise, praseodymium neodymium oxide is brought to the upper end of the interior of the first firing barrel through a plurality of baffles and then slips off from the baffles, the praseodymium neodymium oxide is scattered and falls into the second firing barrel on the left side, then the praseodymium neodymium oxide is scattered again through the baffles in the second firing barrel on the left side, the praseodymium neodymium oxide is evenly heated, and the praseodymium neodymium oxide is evenly fired. Meanwhile, the praseodymium-neodymium oxide is moved into the first firing barrel on the right side through mutual cooperation of the three first firing barrels and the two second firing barrels and then discharged through a discharging pipe, and then the praseodymium-neodymium oxide is continuously fired, so that the working efficiency is improved.

The invention belongs to the technical field of castable, and relates to a refractory castable and a preparation method thereof. The invention provides a refractory castable taking a rare earth compound as a base material. The refractory castable comprises a first composite refractory material, a second composite refractory material, a binding agent, a water reducing agent and water, the first composite refractory material is composed of a first refractory framework and a first auxiliary agent; the first fireproof framework comprises rare earth compound powder; the second composite refractory material is composed of a second refractory framework and a second auxiliary agent; the second fireproof framework comprises rare earth compound powder; the rare earth compound powder is selected from one or more of cerium oxide, lanthanum oxide, neodymium oxide and yttrium oxide; the stability and corrosion resistance of the high-temperature industrial equipment can be improved.

The invention discloses a series of high-stability negative temperature coefficient heat-sensitive materials based on seven-principal-element high-entropy rare earth stannate and application, and aims to solve the problem that existing stannate heat-sensitive materials with pyrochlore structures cannot meet long-term application in high-temperature environments. The series of heat-sensitive materials are prepared by mixing lanthanum trioxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide, dysprosium oxide and tin dioxide with erbium oxide or ytterbium oxide respectively, and the preparation process comprises the steps of wet three-dimensional vibration ball milling, powder calcination, cold isostatic pressing, high-temperature sintering and the like. And finally obtaining the negative temperature coefficient heat-sensitive material with the pyrochlore structure. The electrical property parameters of the series of materials are as follows: B is equal to 13914-14067 + / -1.89% K, and rho 1500 DEG C is equal to 180.26-204.09 + / -1.38% omega.cm. The negative temperature coefficient heat-sensitive material has the negative temperature coefficient characteristic in the wide temperature range of 400-1500 DEG C and shows excellent high-temperature aging stability under the high-temperature condition of 1500 DEG C, and the resistance drift rate of the negative temperature coefficient heat-sensitive material is only 0.7% after an aging test for 500 hours.

This application discloses a heterogeneous catalyst for the selective hydrogenation of nitrile rubber and its application. The heterogeneous catalyst, by weight percentage, consists of 1–10% noble metal particles and 90–99% support, wherein the support is alumina, cerium oxide, titanium dioxide, zirconium oxide, or neodymium oxide. The content of positively valence noble metal in the catalyst accounts for 20–80% of the total noble metal element content, and the noble metal is uniformly loaded on the support. The noble metal is Rh, Os, Ir, Pt, Ru, or Pd, and the particle size of the noble metal particles is 1–20 nm. The heterogeneous catalyst of this invention can carry out hydrogenation reactions at room temperature and pressure, and its hydrogenation selectivity is as high as 100%, with a hydrogenation activity >99%.

The invention relates to the field of solid waste resource recovery, in particular to a method for recovering iron, calcium and rare elements in red mud through cooperation of magnetic separation and oxalic acid. The method comprises the following steps: mixing red mud with a reducing agent, then carrying out reduction roasting at 600-900 DEG C, grinding the roasted clinker, then carrying out water leaching, carrying out solid-liquid separation, and washing; magnetic separation is conducted on the water leaching residues, and iron ore concentrate and non-magnetic residues are obtained; carrying out sulfuric acid leaching on the non-magnetic slag, filtering to remove impurities to obtain neodymium-rich leachate, treating the leaching residues with hydrochloric acid, and roasting to recover calcium; and oxalic acid is added into the neodymium-rich lixivium for precipitation, a neodymium oxalate product is obtained, and neodymium oxalate is roasted to obtain a neodymium oxide product. The method is simple in process and low in medicament consumption, and realizes efficient separation and comprehensive utilization of iron, calcium and rare elements.

The application discloses a kind of waste lithium battery positive electrode material recycling method, it is related to lithium battery positive electrode material technical field.The application is in preparation lithium battery positive electrode material, first waste lithium iron phosphate battery is discharged and disassembled, and in cold hot water circulation immersion separation current collector, after calcination, with sulfuric acid-hydrogen peroxide selection leaching lithium ion is recovered to obtain recycled lithium carbonate;Carbonate ternary precursor is prepared by coprecipitation method;Carbonate ternary precursor, recycled lithium carbonate, silicon monoxide, lithium fluoride, neodymium oxide are mixed and secondly calcined to obtain doped modified ternary positive electrode material;Lanthanum, aluminum and zinc are coated on the surface of doped modified ternary positive electrode material by potassium-sodium alloy reduction method to obtain coated modified ternary positive electrode material;Coated modified ternary positive electrode material is mixed with conductive agent and binder, and then coated on carbon-coated aluminum foil to obtain lithium battery positive electrode material.The lithium battery positive electrode material prepared by the application has high charge-discharge specific capacity, high cycle life and good rate performance.

The utility model provides a praseodymium neodymium oxide preparation stock solution firing device, which belongs to the technical field of praseodymium neodymium oxide preparation, and comprises a conveyor belt and a firing furnace, the front surface of the conveyor belt is fixedly connected with the firing furnace, the back surface of the firing furnace is connected with a baffle plate in an embedded manner, the top of the firing furnace is fixedly connected with a servo screw rod, and the servo screw rod is fixedly connected with a motor. The output end of the servo lead screw is fixedly connected with a transmission plate, and the inner side of the firing furnace is fixedly connected with an electric heating pipe. The ventilating fan, the water tank, the conveying pump and the output head are additionally arranged through the fixing frame, the ventilating fan conveys air to the outer surface of the container, the air flow speed of the surface of the container is increased, primary cooling is conducted on stock solution in the container, meanwhile, the conveying pump generates suction force on water in the water tank, and the water is conveyed into the output head; at the moment, the output head atomizes and conveys the water to the outer surface of the container, and further cooling of the stock solution and the container is completed.

The present invention relates to a method for preparing a transuranium nuclide glass solid body. The method for preparing a transuranium nuclide glass solid body of the present invention comprises the following steps: 1) mixing granite powder and boron oxide powder and calcining to obtain granite glass powder; 2) uniformly mixing cerium oxide and neodymium oxide to obtain cerium-neodymium oxide; 3) mixing the cerium-neodymium oxide with the granite glass powder as a base material, adding transuranium nuclides, adding a mixing medium and mixing uniformly, and then pressing and molding to obtain a molded body; 4) calcining the molded body at 1200°C-1400°C for 1-3 hours under an inert atmosphere to obtain a transuranium nuclide glass solid body. The preparation method of the present invention utilizes cerium-neodymium oxide in conjunction with granite glass powder to solidify transuranium nuclides under relatively mild conditions, thereby solving the problem of adhesion between the crucible and the solid body during solidification and sintering, and obtaining a transuranium nuclide glass solid body with good chemical stability.

The present invention discloses a nanometer dual-phase high-entropy zirconate material with nearly equal proportions, and a preparation method and application thereof, belonging to the technical field of thermal barrier coating materials. The present invention obtains five single rare earth metal salt solutions by dissolving lanthanum oxide, neodymium oxide, gadolinium oxide, dysprosium oxide and ytterbium oxide in acid solution respectively; the five single rare earth metal salt solutions are sequentially added to the zirconium salt solution in the order of ion radius from large to small to form a mixed solution with a uniform and stable tetramer structure, and then a precipitant is added to carry out precipitation reaction to obtain a gel-like precursor precipitate; the gel-like precursor precipitate is subjected to aging, ball milling and high-temperature calcination to obtain a high-entropy zirconate material. The zirconate material of the present invention exhibits extremely low thermal conductivity, extremely high thermal expansion coefficient, good mechanical properties and high-temperature stability through the synergistic effect of alloy components and nearly equal dual phases.

The present invention relates to the technical field of wear-resistant materials, and more particularly to a nano-wear-resistant composite material, a preparation method thereof, and an application thereof. The composite material comprises the following raw materials in parts by weight: 45-50 parts of nano-tungsten carbide, 10-15 parts of cobalt powder, 7-11 parts of modified nano-titanium nitride, 5-7 parts of nano-neodymium oxide, and 4-6 parts of a synergistic agent doped with nano-TaC. The nano-wear-resistant composite material of the present invention utilizes nano-tungsten carbide in combination with cobalt powder and nano-neodymium oxide, and is further coordinated with the modified nano-titanium nitride and the synergistic agent doped with nano-TaC. Through the coordinated coordination and synergistic effect between the raw materials, the resulting nano-wear-resistant composite material achieves coordinated improvements in wear resistance, yield strength, and fatigue resistance. Furthermore, the product exhibits excellent performance stability under varying degrees of salt corrosion conditions.

The invention relates to the technical field of environment-friendly materials, and provides an environment-friendly deplating agent for neodymium-iron-boron materials and a preparation method and a using method thereof.The deplating agent comprises, by weight, 1%-5% of ammonium carbonate, 5%-10% of sodium dihydrogen phosphate or trisodium phosphate, 1%-5% of sodium hydroxide, 10%-15% of potassium citrate and the balance deionized water. The cleaning agent comprises the following components in percentage by weight: 40-50% of a cleaning agent, 5-10% of amino triethanol, 15-20% of hexamethylenetetramine or ethylenediamine, 40-50% of deionized water, and 0.1-1% of a chelating agent and a surface repairing agent; wherein the surface repairing agent is a composition comprising 0.1-1% by weight of nanoparticles and 0.1-0.5% by weight of a rare earth element compound; the nanoparticles and the rare earth element compound are used for forming a complex for repairing small surface defects; the rare earth element compound comprises one or more of a dysprosium compound, a praseodymium compound and / or a samarium compound; the nano particles comprise nano neodymium oxide and nano iron oxide, and the mass ratio of the nano neodymium oxide to the nano iron oxide is (1: 1)-(2: 3).

The invention relates to a polycrystalline fused product of formula (Sc2O3)yAx(ZrO2 + HfO2)1-x-y, with 0.030 ≤ y ≤ 0.150, and 0.000 ≤ x ≤ 0.070, and x ≤ y, A denoting an additive selected from Y2O3, Al2O3, CeO2, Yb2O3, Gd2O3, MnO, Bi2O3, La2O3, Pr2O3, Nd2O5, Sm2O3, Eu2O3, Tb4O7, Ta2O5, Nb2O5 and mixtures thereof, ZrO2 + HfO2 + Sc2O3 + A representing more than 98% of the mass of the fused product, MnO expressing the total content of manganese oxides expressed in the form MnO, Pr2O3 expressing the total content of praseodymium oxides expressed in the form Pr2O3, Nd2O5 expressing the total content of neodymium oxides expressed in the form Nd2O5, Tb4O7 expressing the total content of terbium oxides expressed as Tb4O7, Ta2O5 expressing the total content of tantalum oxides expressed as Ta2O5, and Nb2O5 expressing the total content of niobium oxides expressed as Nb2O5.

The invention relates to the technical field of metallurgy, in particular to a rare earth neodymium iron boron waste recovery device and process. The rare earth neodymium iron boron waste recovery device comprises a metallurgical furnace and a feeding port formed in the metallurgical furnace, a flat hopper is arranged above the feeding port, a water shell is arranged behind the flat hopper, the front end of the water shell extends to form a shell, and the shell penetrates through the interior of the flat hopper; the front end face of the outer shell and the rear end face of the interior of the flat hopper are coplanar, a magnetic plate is embedded in the outer shell, the front end face of the magnetic plate and the front end face of the outer shell are coplanar, the upper end of the water shell is fixedly communicated with a water outlet pipe, the lower end of the water shell is fixedly communicated with a water inlet pipe, and a flow control swing part is arranged in the water shell in a penetrating mode. The proportion of neodymium-containing oxide in waste is guaranteed, stable reaction with a continuously and quantitatively fed reducing agent is guaranteed, the phenomenon of high-temperature demagnetization of the magnetic plate is avoided, and meanwhile crushed iron adsorbed on the magnetic plate can be automatically cleaned and discharged.

The utility model belongs to the technical field of praseodymium neodymium oxide powder processing, and particularly relates to a screening device for praseodymium neodymium oxide powder processing, which comprises a mounting seat, the left side of the mounting seat is in contact with a box body, the interior of the box body is in sliding connection with a screen, the upper end of the screen is fixedly connected with a baffle plate, and the baffle plate is in contact with the box body. A sliding rod is fixedly connected to the side, close to the mounting base, of the box body, the sliding rod is slidably connected with the mounting base, a limiting ring is fixedly connected to the interior of the mounting base, a spring is arranged on the outer side of the sliding rod, and a motor is fixedly mounted at the lower end of the mounting base. According to the screening device for praseodymium and neodymium oxide powder processing, the motor, the cam, the spring and other components are arranged, the motor can be started to drive the box body and the filter screen to shake, so that materials are effectively screened, and the problems that the screening device for praseodymium and neodymium oxide powder processing is poor in screening effect and inconvenient to use during use are solved.

The invention belongs to the technical field of high-entropy materials, and discloses a Cr2O3 coated high-entropy pyrochlore composite ceramic as well as a preparation method and application thereof, the composite ceramic is xCr2O3. (1-x) (La0. 2Nd0. 2Sm0. 2Gd0. 2Sc0. 2) 2Zr2O7, x is 5-20wt.%, Sb0. 2Sb0. 2Gd0. 2Sc0. 2) 2Zr2O7, Sb0. 2Sb0. 2Gd0. The preparation method comprises the following steps: sintering lanthanum oxide, neodymium oxide, samarium oxide, gadolinium oxide and zirconium oxide at 1400-1700 DEG C to obtain high-entropy pyrochlore powder, adding the high-entropy pyrochlore powder into a CrCl3 solution after ball milling, stirring, drying to obtain CrCl3 coated high-entropy pyrochlore powder, pressing the CrCl3 coated high-entropy pyrochlore powder into blocks, carrying out cold sintering at 200-400 DEG C and 200-500 MPa, carrying out heat preservation at 800-900 DEG C, heating to 1500-1700 DEG C, and carrying out pressureless sintering. The composite ceramic is high in density, excellent in radiation resistance and leaching resistance and capable of being applied to the field of nuclear waste solidified bodies.

The invention discloses a method for recovering rare earth from neodymium iron boron waste through low-temperature chlorination and water leaching, which adopts the principle that rare earth elements and compounds thereof are easy to react with ammonium chloride at low temperature to form rare earth chloride ions, and iron and oxides thereof are not easy to chloridize, so that the rare earth is selectively chlorinated; the rare earth ions enter the water solution to complete separation of the rare earth and the iron. The main process comprises the following steps: firstly, carrying out chloridizing roasting reaction on ammonium chloride and rare earth in the neodymium iron boron waste material at a certain temperature; the method comprises the following steps: firstly, carrying out water leaching on rare earth chloride to obtain rare earth ions, finally, carrying out iron removal and oxalic acid precipitation on the leached rare earth ions, and then firing the precipitate to obtain mixed rare earth oxides such as neodymium oxide and praseodymium oxide.

The invention provides a preparation method of a biomass platform molecule angelica lactone isomerization catalyst. The catalyst comprises one of the following solid metal oxides and one of potassium assistants: eight metal oxides (m-zirconium oxide, t-zirconium oxide, c-zirconium oxide, aluminum oxide, magnesium oxide, barium oxide, lanthanum oxide and neodymium oxide) and seven potassium sources (potassium nitrate, potassium carbonate, potassium acetate, potassium hydroxide, potassium chloride, potassium oxalate and potassium oxide). By designing the preparation method of the metal oxide, the high-specific-surface-area pure-crystalline-phase metal oxide is obtained; by introducing the potassium aid, the surface alkalinity of the catalyst is effectively regulated and controlled, so that the alpha-angelica lactone is simply and efficiently isomerized into the beta-angelica lactone. The catalyst provided by the invention has the characteristics of high activity, high selectivity, high stability and easy recovery, and provides a feasible technical approach for biomass platform molecule angelica lactone isomerization.

The invention discloses a thin-wall honeycomb ceramic with thermal shock resistance and mechanical property and a preparation method thereof. The thin-wall honeycomb ceramic comprises basic powder and a composite additive, the composite additive comprises vanadium pentoxide and neodymium oxide, wherein the addition amount of the vanadium pentoxide is 2-4wt% of that of the basic powder, and the addition amount of the neodymium oxide is 1-9wt% of that of the basic powder. The thermal expansion coefficient of the ceramic is reduced by adding vanadium pentoxide, and the sintering compactness of the ceramic is improved by combining neodymium oxide, so that the thin-wall high-strength honeycomb ceramic is obtained. The 2 wt%-4 wt% of vanadium pentoxide and 1 wt%-9 wt% of neodymium oxide interact with each other to achieve synergistic interaction, so that the low expansion coefficient is achieved. And the prepared sample is relatively small in deformation degree and relatively low in thermal expansion coefficient.

Catalytic converter, comprehensive: a substrate with a cellular structure through which exhaust gas flows; and a catalyst layer formed on a cell wall surface of the substrate, wherein the catalyst layer comprises a lower catalyst layer and an upper catalyst layer, wherein the lower catalyst layer is formed on a surface of the substrate and the upper catalyst layer is formed on a surface of the lower catalyst layer. the upper catalyst layer includes: a zirconia compound support with rhodium supported thereon, wherein the zirconia compound support contains zirconia, lanthanum oxide and yttrium oxide, an aluminum oxide compound without rhodium carried on it, wherein the aluminum oxide compound contains aluminum oxide and lanthanum oxide, and a cerium oxide-zirconium oxide-based composite oxide containing cerium oxide, zirconium oxide, lanthanum oxide and neodymium oxide, and the lower catalyst layer includes: an aluminum oxide compound support with platinum supported thereon, wherein the aluminum oxide compound support contains aluminum oxide and lanthanum oxide, which are the same materials as those of the aluminum oxide compound of the upper catalyst layer, and a cerium oxide-zirconium oxide-based composite oxide without platinum supported thereon, wherein the cerium oxide-zirconium oxide-based composite oxide contains cerium oxide, zirconia, lanthanum oxide and neodymium oxide, which are the same materials as those of the cerium oxide-zirconium oxide-based composite oxide of the upper catalyst layer.