737 results about "Mischmetal" patented technology

The invention belongs to the technical field of rare earth functional materials, and particularly relates to a rare earth aluminate low-temperature magnetic refrigeration material and a preparation method and application thereof.The preparation method comprises the following steps that 1, rare earth metal nitrate and aluminum nitrate are added into water to be mixed, and a mixed solution is prepared; adding ammonia water into the mixed solution to prepare a precipitate; (2) carrying out annealing treatment on the precipitate to prepare a metal oxide; and (3) calcining the metal oxide to obtain the rare earth aluminate low-temperature magnetic refrigeration material. The rare earth aluminate which has the characteristics of stable structure, low preparation cost, strong mechanical property, high magnetic density and the like and is prepared by adopting a coprecipitation method and combining a high-temperature sintering technology has more excellent magnetocaloric properties in a low-temperature region.

The invention relates to the technical field of rare earth metal electrolysis cathode protection coatings, in particular to a high-temperature-corrosion-resistant yttrium-stabilized zirconia gradient coating on the surface of a tungsten cathode. A metallurgically bonded strong bonding bottom layer is constructed on a tungsten substrate through surface pretreatment and reactive sintering, then an atmosphere plasma technology is adopted to spray a creep-resistant gradient layer with continuous components to buffer thermal stress, and finally a sol-gel technology is utilized to construct an extremely compact corrosion-resistant surface layer in a superposition mode. The high-temperature-corrosion-resistant yttrium-stabilized zirconia gradient coating is constructed through a multi-scale and multi-mechanism synergistic effect, the problems that a tungsten cathode coating is insufficient in binding force and poor in thermal shock resistance are fundamentally solved, molten salt permeation can be blocked, and the service life of a tungsten cathode in a severe environment is remarkably prolonged.

The invention belongs to the technical field of magnetic functional materials, and particularly relates to a nanocrystalline magnetically soft alloy and a preparation method and application thereof. The invention provides a nanocrystalline soft magnetic alloy which comprises the following chemical components: Fe, Si, B, Nb, Cu, P and rare earth metal, and the rare earth metal is selected from at least one of Nd and Sm. According to the nanocrystalline magnetically soft alloy, a proper amount of rare earth metal is added, the ferromagnetic coupling exchange effect between ordered phases of the nanocrystalline magnetically soft alloy is improved, so that the magnetic induction intensity and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy are both improved, the magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above, and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above. Meanwhile, the saturation flux density reaches up to 1.75 T or above, and the coercive force is as low as 0.8 A / m.

A preparation and diffusion treatment method for a high-performance diffusion coating used for a sintered neodymium-iron-boron magnet. The method comprises the following steps: the preparation of alloy powders, the preparation of glue, the preparation of a diffusion coating, a pretreatment, coating with the coating, surface drying, and a heat treatment. By controlling the components and particle size of the alloy powders, the compounding of the glue, an anti-bonding powder and an auxiliary agent ensures that under the condition of a relatively small usage amount of a diffusion heavy rare earth metal, the coercive force is greatly improved, the residual magnetism is almost not reduced or is slightly reduced, and the phenomena of the shedding of the coating and the bonding of magnetic sheets after diffusion are avoided.

The invention relates to the technical field of glass, in particular to microcrystalline glass and a preparation method thereof, reinforced microcrystalline glass and a preparation method thereof, and a glass product. The invention provides microcrystalline glass which comprises the following components in percentage by mass based on the total mass of 100%: 58.21-70.63% of SiO2; the content of Al2O3 is 6.46 to 7.83 percent; zrO2: 3.23% to 3.92%; 1.86%-2.3% of P2O5 (P2O5); 0.4 to 0.5 percent of B2O3; 1.9 to 14.4% of a rare earth metal oxide; an alkali metal oxide: 10.86 to 12.99%; wherein the rare earth metal oxide is prepared from Y2O3 and La2O3; the alkali metal oxide comprises Na2O and Li2O. According to the microcrystalline glass disclosed by the invention, the link of a glass network is enhanced by utilizing the rare earth metal oxide and Al2O3 together to form a high-density network structure, uniform nucleation is induced through the nucleating agent, fine grains are generated, grain boundary defects are reduced according to a multi-step nucleation-crystallization system, and the mechanical property is remarkably improved.

The present invention discloses a pretreatment method and application of an alumina-supported copper oxide-rare earth metal oxide catalyst. The pretreatment method is as follows: adding the alumina-supported copper oxide-rare earth metal oxide catalyst used for the reaction of ethanol to higher alcohols into a mixture of one or several C1-C8 alcohols, impregnating at 10-90 °C for 1-24 h, filtering to remove the excess alcohol after impregnation is completed, and then drying in an oven at 40-200 °C for 1-24 h to complete the pretreatment of the catalyst. The present invention provides the application of the alumina-supported copper oxide-rare earth metal oxide catalyst pretreated by the pretreatment method in the reaction of ethanol to higher alcohols. The pretreatment method of the present invention significantly increases the selectivity of the product higher alcohols and keeps the conversion rate of ethanol unchanged or slightly improved, thus solving the problem that it is difficult to balance both the conversion rate and selectivity in the prior art.

The invention relates to a diffusion source for a neodymium-iron-boron magnet and a preparation method and application of the diffusion source. The invention discloses a rare-earth metal catalyst which comprises the following components in percentage by mass: 46%-49% of an organic solvent, 0.1%-2% of an adhesive, 0.1%-5% of a metal oxide and 46%-49% of rare-earth metal, and the melting point of the metal oxide is higher than that of the neodymium-iron-boron magnet. The specific organic solvent, the adhesive, the metal oxide and the rare earth metal are matched for use according to a specific matching relation, so that the diffusion source is more stable, the diffusion effect is improved, and when the magnet attached with the diffusion source is subjected to thermal diffusion treatment, the rare earth metal can be diffused into the magnet so as to improve the coercive force and other properties of the magnet. In the process, the high-melting-point metal oxide is adhered to the surface of the magnet and then serves as a spacer, the adhesion phenomenon of the magnet in the high-temperature sintering diffusion process is reduced or avoided, grain boundary diffusion is further promoted, and the performance of the magnet is improved.

The invention belongs to the technical field of porous silicon nitride ceramics, and discloses a porous silicon nitride ceramic material and a preparation method thereof. The preparation method comprises the following steps: mixing silicon nitride ceramic powder, metal oxide powder and rare earth metal oxide powder, adding a pore forming agent and a grinding medium, mixing, and carrying out ball milling, drying, grinding and sieving to obtain ceramic powder; carrying out dry pressing molding on the ceramic powder to obtain a ceramic green body; carrying out glue discharging treatment on the ceramic green body to obtain a precursor; the precursor is subjected to ultrahigh-temperature rapid sintering treatment, and the porous silicon nitride ceramic is obtained; wherein the sintering temperature ranges from 1600 DEG C to 1900 DEG C. According to the porous silicon nitride ceramic prepared by the method, the porosity is wide and adjustable in range, and the porous silicon nitride ceramic with closed spherical pore morphology can be prepared.

The invention discloses a grain boundary diffusion method of a sintered neodymium-iron-boron magnet. The grain boundary diffusion method comprises the following steps: providing a magnet to be diffused; coating the surface of the magnet to be diffused with coating slurry containing heavy rare earth metal powder, and performing grain boundary diffusion after vacuum heat preservation and dehydrogenation; the vacuum heat preservation dehydrogenation process comprises the steps that under the vacuum condition, the temperature is increased to 220-250 DEG C from the normal temperature after 1-1.5 h, heat preservation is conducted for 2-3 h, then the temperature is increased to 520-560 DEG C after 1-2 h, and heat preservation is conducted for 1-2 h; the grain boundary diffusion process comprises the following steps: heating to 650-750 DEG C after 1-1.5 hours, and preserving heat for 24-30 hours for permeation; and finally, the temperature is increased to 970-1000 DEG C after 1-1.5 h, and heat preservation is conducted for 2-3 h. According to the grain boundary diffusion method, the coercive force of the center part of the sintered neodymium-iron-boron magnet with the high permeation thickness can be remarkably improved, and the intrinsic coercive force gradient difference of the surface layer and the center part of the magnet is reduced.

The invention provides a control operation method for a discharge robot of a rare earth metal electrolytic furnace, which comprises the following steps: the discharge robot acquires the electrolytic state of the electrolytic furnace through a visual sensor, and judges whether the electrolytic state reaches a discharge standard or not; after it is judged that the discharging standard is met, a discharging robot grabs a discharging tool, the discharging tool is preheated, and the discharging tool is moved to the discharging position to prepare for discharging; the discharging robot moves along the planned path, the contact force between the robot and the electrolytic furnace is monitored through a force sensing system, the track of the robot is corrected according to the contact force, and the discharging process is executed; after the discharging process is finished, whether discharging continues or not is judged, and if not, the process is finished. The molten metal discharging standard is judged in real time through the visual sensor, the position of the furnace opening is dynamically calibrated, tool deformation is monitored, flexible control over the tail end is achieved through the force sensor, damage to the furnace body in the digging operation is avoided, manual participation is reduced, and the operation efficiency is greatly improved.

The invention relates to a hollow mesoporous carbon sphere prepared based on a confinement polymerization method and a preparation method of a platinum alloy catalyst loaded by the hollow mesoporous carbon sphere and doped with rare earth metal. The method comprises the following steps: by taking mesoporous silica as a template, introducing an initiator and a small molecular organic matter precursor into mesopores, and carrying out confinement polymerization in the mesopores to obtain a silica / polymer composite; carrying out high-temperature calcination and etching treatment on the complex to obtain hollow mesoporous carbon spheres; the carbon sphere is used as a carrier to load a platinum alloy doped with rare earth metal. The hollow mesoporous carbon spheres prepared by the method have good spherical morphology and mesoporous channels and high specific surface area, and the problems of non-uniform morphology, unobvious mesopores and the like in a traditional method are solved. After platinum alloy particles doped with rare earth metal are loaded on the carbon spheres, the problems of agglomeration, wide particle size distribution, poor performance and the like of the platinum alloy particles are solved.

The invention discloses a rare earth metal ceramic and a preparation method thereof, and belongs to the technical field of metal ceramic preparation, the rare earth metal ceramic comprises, by mass, 45-65% of a ceramic phase, 30-50% of a metal binding phase and 3-8% of a rare earth additive, the ceramic phase is composed of one of TiC and WC and one of Al2O3 and ZrO2, the metal binding phase is composed of a Ni-Co alloy and Mo or Cr, and the rare earth additive is composed of one of Al2O3 and ZrO2. The rare earth additive is composed of mixed rare earth oxide and nano rare earth fluoride. The invention further provides a preparation method of the rare earth additive. Through the synergistic effect of oxide grain boundary purification and fluoride liquid phase sintering in a two-phase rare earth system, the problem that traditional single rare earth is difficult to add and disperse is solved, through staged hot pressing sintering, dual optimization of grain refinement and density improvement is achieved, and the high-temperature oxidation resistance and interface bonding strength of metal ceramic are enhanced.

The invention belongs to the technical field of ceramic materials, and relates to high-thermal-conductivity silicon nitride ceramic and a preparation method thereof. The invention discloses a preparation method of high-thermal-conductivity silicon nitride ceramic, which comprises the following steps: (1) uniformly mixing silicon powder and a sintering aid to obtain mixed powder, and carrying out compression molding on the mixed powder to obtain a silicon blank; the sintering aid is a rare earth metal oxide; (2) placing the silicon blank in a nitrogen-containing reducing atmosphere environment, pre-treating at 600-1180 DEG C, heating to 1350-1700 DEG C, and carrying out nitriding treatment to obtain a silicon nitride blank; and (3) placing the silicon nitride green body in an inert atmosphere, and sintering at 1800-2200 DEG C to obtain the silicon nitride ceramic. The pretreatment step is added before the nitridation reaction, so that silicon dioxide impurities wrapped on the surface of the silicon powder are effectively eliminated, and the oxygen content in a liquid phase is reduced on the basis of not reducing the total content of a sintering aid, so that a silicon nitride blank with low lattice oxygen content is more easily prepared, and the heat conductivity of the silicon nitride ceramic is improved.

The invention provides an aluminum alloy material for brazing, a preparation method of the aluminum alloy material and a brazing process of the aluminum alloy material for brazing. The aluminum alloy material for brazing comprises, by mass, 3.0%-12.0% of rare earth metal element RE, 0.06%-0.85% of Fe, 0.5%-1.2% of Mn, 0.1%-0.5% of Cr, 0.02%-0.5% of Mg, 0.1%-0.2% of Ti, 0.02%-0.2% of V, 0.02%-0.1% of B, smaller than or equal to 0.15% of Si, smaller than or equal to 0.02% of Cu and the balance Al and inevitable impurities, and the content of a single impurity element is smaller than or equal to 0.05%. Wherein the solidus temperature of the aluminum alloy material for brazing is larger than or equal to 625 DEG C. The problem that in the prior art, aluminum alloy is poor in casting performance and brazing quality is solved.

The invention relates to the technical field of rare earth metal hydrometallurgy, in particular to a rare earth molten salt electrolysis truss type multifunctional metal output system and a control method.The system comprises a main body supporting and moving frame, an integrated function execution module set, a bottom cleaning function module, an electrolytic bath station unit and an intelligent control system; wherein the integrated function execution module group, the bottom cleaning function module, the electrolytic tank station unit and the intelligent control system are respectively arranged in the main body support and motion frame, and the main body support and motion frame is arranged in a gantry truss structure; the four functions of pot lifting, casting, cooling and bottom cleaning in rare earth electrolysis are integrated on the integrated bearing platform of the same gantry truss type rack, and through multi-sensing information fusion and intelligent control, the system can automatically complete the whole process operation of crucible extraction, molten metal casting, cooling forming and electrolytic bath bottom cleaning; and the exposure of workers in high-temperature and high-risk environments is obviously reduced, and the production safety and efficiency are improved.

The invention relates to a dual-rare earth metal catalytic nano material, a diaphragm and a preparation method and application thereof. The preparation method comprises the following steps: carrying out hydrothermal reaction on an aqueous solution containing a carbon source, a hard template, a graphene oxide dispersion liquid, a nitrogen source, a phosphorus source, cerium salt and neodymium salt; then carrying out centrifugal separation to obtain a precipitate, and generating a precursor containing Ce and Nd rare earth bimetallic modified nitrogen and phosphorus doped graphene coated microspheres; and carrying out chemical etching on the precipitate after heat treatment to obtain the dual-rare earth metal catalytic nano material (HCS-coated NPrGO / CeNd). The HCS-coated NPrGO / CeNd can be used as a modification material of a lithium-sulfur battery diaphragm, not only can catalyze the conversion of polysulfide, but also can inhibit the shuttle effect of the polysulfide, so that the lithium-sulfur battery has relatively high capacity under high-rate charge and discharge, and has relatively low capacity fading rate in a high-rate long-cycle test.

The invention provides a reaction state recognition method and monitoring system for a rare earth metal electrolytic furnace. The method comprises the steps that the electrolyzed time of the electrolytic furnace and a plurality of in-furnace flame video frame sequences are obtained; the electrolyzed time is processed, and a time feature vector is generated; extracting local spatial-temporal features of adjacent frames from the plurality of in-furnace flame video frame sequences, and modeling a long-distance time sequence dependency relationship of flame dynamic change according to the spatial-temporal features to obtain spatial-temporal feature vectors; fusing the time feature vector and the space-time feature vector to generate a flame state characterization vector; and predicting the reaction state of the electrolysis process according to the generated flame state characterization vector. According to the invention, the problems of low efficiency, high subjectivity, difficulty in guaranteeing precision and high risk in a severe environment existing in manual observation in the prior art can be solved.

The invention provides a photocatalyst as well as a preparation method and application thereof. The photocatalyst comprises CdS quantum dots and metal single atoms doped in the CdS quantum dots, the metal single atoms comprise any one of transition metal, rare earth metal or Bi, and the rare earth metal comprises Sm or Ce. The CdS quantum dots are doped with the metal monatomic to serve as the photocatalyst, on one hand, the CdS quantum dots can provide a large specific surface area and many reaction active sites, on the other hand, doping of the metal monatomic promotes electron transfer in the catalyst, and through the synergistic effect of the CdS quantum dots and the metal monatomic, the specific surface area of the CdS quantum dots is increased. The catalyst shows excellent hydrogen evolution and photocatalytic plastic conversion performance; in addition, the preparation method provided by the invention is simple and suitable for large-scale application.

The invention provides a rare earth metal electrolytic furnace discharging robot and a tail end compliance control method and system thereof, and the method comprises the steps: building a rare earth discharging simulation environment for simulating a discharging scene, and building a rare earth discharging control model for simulating the motion trail of a discharging tool through reinforcement learning training based on the simulation environment; contact force sense information between a discharging tool and the electrolytic furnace in the discharging process of the rare earth metal electrolytic furnace is obtained in real time and input into the rare earth discharging control model, and a real-time discharging tool movement track is obtained; and the real-time discharging tool motion trail is input into a discharging robot controller so as to achieve flexible control over the tail end of the discharging robot. According to the robot discharging operation method suitable for the rare earth metal electrolytic furnace, the robot discharging operation method suitable for the rare earth metal electrolytic furnace is achieved on the basis of reinforcement learning and force sensing, the force sensor senses the acting force of a tool and the electrolytic furnace, the working tail end of the rare earth metal electrolytic furnace is controlled through the reinforcement learning method, and then anthropomorphic discharging operation is achieved.

The invention relates to the technical field of catalysts, and discloses a catalyst, a preparation method thereof and a method for preparing hydrogen peroxide through anthraquinone hydrogenation. The catalyst comprises a modified carrier and an active component loaded on the modified carrier; the modified carrier comprises an inorganic heat-resistant oxide and a modified component, and is characterized in that the modified component comprises rare earth metal, and the atom dispersity of the rare earth metal in the catalyst is not less than 92%. The rare earth metal in the catalyst provided by the invention is highly dispersed, so that the catalyst has excellent catalytic performance; according to the method for preparing the catalyst provided by the invention, the rare earth metal can be highly dispersed on the carrier in a short time, and the agglomeration phenomenon in the roasting process is avoided, so that the catalyst has excellent catalytic performance, hydrogenation efficiency, hydrogen peroxide selectivity and relatively high production capacity.

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 invention discloses a preparation method and application of a rare earth element doped ruthenium oxide catalyst, and the preparation method comprises the following steps: (1) dissolving a rare earth metal salt, a ruthenium metal salt, dopamine hydrochloride and a Tris-HCl buffer agent in water to obtain a mixed solution, and carrying out in-situ polymerization reaction, solid-liquid separation and drying to obtain a powder precursor; and (2) carrying out high-temperature calcination on the powder precursor obtained in the step (1) to obtain the rare earth doped ruthenium oxide catalyst. Rare earth metal salt and ruthenium salt precursors are dispersed on an in-situ constructed porous carbon substrate, and the rare earth element doped ruthenium oxide nanosheet is generated by oxidation under a high-temperature condition through a self-sacrifice template method. The method has the characteristics of high efficiency and no pollution. The rare earth element doped ruthenium oxide disclosed by the invention is used as a catalyst for the anodic reaction of the acidic electrolyzed water, and shows excellent catalytic activity and wide application prospect.

The invention discloses an electrochemical test performed by preparing a novel electrochemical luminescence material and application of the electrochemical luminescence material to an electrochemical luminescence sensor. The invention designs an electrochemical luminescence sensor for detecting carbaryl based on a rare earth metal Eu co-reaction-free promoter complex illuminant. Specifically, the electrochemical luminescence sensor is prepared by taking a complex of rare earth metal europium as a luminescent material and potassium persulfate as a co-reactant. The sensor shows an excellent development prospect in the aspect of carbaryl detection.

The invention discloses a rare earth metal electrolysis system and an electrolysis furnace thereof, and relates to the technical field of metallurgy, the rare earth metal electrolysis system is characterized by comprising a potential data acquisition and preprocessing module, a dendritic crystal feature extraction and quantification module, a dendritic crystal identification and intelligent determination module and an inverse pulse control and dynamic regulation module, in the electrolysis process, potential distribution original data of the surface of a rare earth metal cathode are detected and collected in real time, the obtained original data are preprocessed, and a preprocessed potential data set is established based on a time sequence. According to the method, intelligent, real-time and accurate inhibition of dendritic crystals in the rare earth metal electrolysis process is achieved, short circuit, splashing and electrode ablation are effectively prevented, the compactness and purity of metal deposition are improved, the current efficiency is remarkably improved, and compared with a traditional scheme, the method has the advantages of being high in real-time performance, good in inhibition effect, small in interference and high in adaptability, and the method is suitable for popularization and application. And efficient and safe preparation of the rare earth metal is ensured.

The invention provides a conductive paste and a preparation method and application thereof, and the conductive paste comprises 84-91 wt% of a conductive phase, 0.8-5.2 wt% of a glass phase, 4-11 wt% of an organic carrier, 0.1-3 wt% of a dispersant, and the balance of a solvent. The conductive phase comprises 5-60 wt% of nickel alloy powder and 40-95 wt% of silver powder, the nickel alloy powder comprises at least one nickel alloy compound, the nickel alloy compound has a general formula of Ni-alpha-beta-gamma, alpha, beta and gamma are three non-nickel elements which are different from one another, and the sum of the alpha, the beta and the gamma is 100%. The elements alpha, beta and gamma are respectively selected from any one of transition metal, rare earth metal, alkaline earth metal and other non-nickel elements, the mass content of the nickel element is 10-99 wt%, and the sum of the mass content of the elements alpha, beta and gamma is 1-90 wt%. Nickel elements and non-nickel elements alpha, beta and gamma in a proper mass ratio are screened to form nickel alloy powder, so that the physical and chemical properties of the nickel alloy powder are improved, the ratio of the nickel alloy powder for replacing silver powder is increased, the electrical properties in the conductive slurry can be guaranteed, and the cost of the slurry is remarkably reduced.

The invention belongs to the technical field of air purification, and discloses a nitrogen-doped MOF derived hollow porous carbon-rare earth metal doped MnO2-graphene aerogel composite material as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: taking a nitrogen-containing organic heterocyclic ligand, a nitrogen doping agent, a non-noble metal salt compound and chitosan, carrying out a first hydrothermal reaction, carrying out tannic acid etching and first calcination treatment, carrying out MnO2 in-situ growth on the obtained nitrogen-doped MOF derived hollow porous carbon material, and introducing a rare earth metal salt compound to obtain the nitrogen-doped MOF derived hollow porous carbon material. And finally, taking the obtained nitrogen-doped MOF derived hollow porous carbon-rare earth metal doped MnO2 composite material, graphene oxide and a reducing agent to carry out second hydrothermal reaction, ethanol soaking, freezing and freeze-drying treatment to obtain the nitrogen-doped MOF derived hollow porous carbon-rare earth metal doped MnO2 composite material. The nitrogen-doped MOF-derived hollow porous carbon-rare earth metal doped MnO2-graphene aerogel composite material has excellent adsorption and catalytic degradation activity on TVOC (Total Volatile Organic Compounds) such as formaldehyde and the like, and the composite material has a good application prospect in air purification.

The invention relates to the technical field of flux-cored wires, and discloses a high-rust-resistance flux-cored wire preparation method which comprises the following steps of S1, raw material pretreatment, S2, powder adding and forming, S3, surface modification and S4, finished product inspection. Before work is started, a worker prepares raw materials including high-carbon ferrochrome, tungsten carbide, boron carbide, rare-earth metal oxide and ferromolybdenum powder, then grinding equipment is used for grinding the raw materials, then the ground powder is dried for 2-3 hours through equipment at the temperature of 100-150 DEG C, the dryness of the raw materials is guaranteed, and the raw materials are evenly mixed. The method comprises the following steps: firstly, preparing a flux-cored wire, then uniformly stirring by utilizing three-dimensional mixing equipment, and then mixing and proportioning according to different proportions according to a corrosion-resistant flux-cored wire, an acid-base-resistant flux-cored wire and a high-hardness high-temperature-resistant flux-cored wire, so that the welding wires with corresponding properties can be conveniently used according to different environments, and the maximization of the functionality of the welding wire is improved.

The invention discloses a nylon composite material as well as a preparation method and application thereof. Belongs to the technical field of high polymer materials. 28-55 parts of an arc extinguishing filler; 0.4 to 2.2 parts of a gas production accelerant; 2.8-11 parts of a rare earth metal oxide; 0-5.2 parts of a flame retardant; 0-16 parts of glass fiber; and 0-5 parts of an auxiliary agent. The nylon composite material disclosed by the invention has excellent flame-retardant, arc-extinguishing and mechanical properties at the same time.

The invention relates to the technical field of catalysts, in particular to a composite catalyst for nitrous oxide decomposition and a preparation method thereof.The composite catalyst is of a three-dimensional flower-shaped structure and comprises a composite carrier and active metal loaded on the composite carrier; the composite carrier is composed of a modification additive and a carrier oxide; the performance additive is composed of alkali metal oxide and rare earth metal oxide; the carrier oxide is selected from one of aluminum oxide, titanium dioxide and silicon dioxide; the active metal comprises cobalt oxide and vanadium oxide. The multi-metal catalyst has the advantages that the multi-metal catalyst with a three-dimensional flower-shaped structure is formed by loading cobalt and vanadium active metals on aluminum oxide and under the synergistic effect of alkali metal and rare earth metal, so that the stability and durability of the catalyst in a high-temperature environment are remarkably improved.

The utility model discloses an electrolytic bath for preparing rare earth metal. The electrolytic cell comprises a cell body, a solid cathode, a crucible and an anode, the tank body is provided with a graphite layer, the graphite layer comprises a graphite layer side part and a graphite layer bottom, and the graphite layer bottom is provided with a notch; the solid-state cathode is arranged in the cell body, and one part of the solid-state cathode is arranged in the notch; the upper end of the solid cathode is higher than the upper end face of the bottom of the graphite layer, an expansion cavity is formed between the side face of the solid cathode and the inner surface of the graphite layer, and an insulating layer is arranged in the expansion cavity; the crucible is arranged above the solid-state cathode and is in contact with the solid-state cathode; the crucible is arranged to receive liquid rare earth metal generated by electrolysis; and at least one part of the anode is arranged in the tank body, and the anode is arranged above the crucible. The solid-liquid mixed cathode at the bottom of the electrolytic cell is used as the cathode, so that the reaction area is increased, and the electrolytic efficiency is improved.