17 results about "Nuclear graphite" patented technology

The invention relates to the technical field of micro-nano particle preparation, and discloses particle size controllable micro-nano silver powder and a preparation method thereof.The preparation method comprises the steps that S1, micron-sized silver cores and nano-sized silver particles are prepared; s2, performing surface activation on the micron-sized silver core; s3, filling pore gaps of a porous template with the micron-sized silver cores; s4, spraying graphene dispersion liquid on the porous template, and forming graphene network coverage on the surface of each silver core; and S5, after the porous template is removed, nanoscale silver particles are deposited on the surface of the exposed silver core, and a silver shell structure wrapping the silver core and the graphene network is formed. Through gradient compounding of a micron silver core-graphene network-nano silver shell structure, the width difference between two sintering necks formed between the circuit board and connecting plate interfaces on the two sides during sintering is reduced by effectively utilizing the wettability of a nano silver shell and the stress dispersity of graphene, and meanwhile the excellent electrical conductivity and thermal conductivity of the material are utilized; and the sintering performance of the circuit board is optimized.

The invention relates to the technical field of graphite production, in particular to a pressing device for high-temperature gas cooled reactor nuclear graphite material processing, which comprises a pressing machine base, a pressing assembly for pressing a graphite material is arranged on the pressing machine base, an L-shaped plate is fixedly connected to the side wall of the pressing machine base, a collecting box is arranged on the L-shaped plate, and a fixing plate is fixedly connected to the top end of the pressing machine base. Through the arrangement of the straight block, the inclined block, the main pushing frame, the side pushing plate and other structures, three cylindrical graphite workpieces which are pressed can be automatically pushed out, the three pieces of graphite are pushed together, and the pressing efficiency is greatly improved. And then the main pushing frame is driven to push the three pieces of graphite into the collecting box together to be collected and treated, so that automatic arrangement and discharging of the pressed and formed graphite are achieved, workers do not need to place the formed graphite workpieces into the collecting box one by one, and the convenience performance of the device is greatly improved.

The invention discloses a treatment method for blocking open pores of nuclear graphite by adopting a silicon carbide nanostructure so as to prevent molten salt and molten metal from infiltrating graphite. Comprising the following steps: 1) mixing polycarbosilane and an organic solvent according to a mass concentration ratio of 50%-70% to form a solution, adding a catalyst to serve as a precursor solution, and completely immersing the precursor solution into graphite pores through vacuum infiltration or pressure infiltration; 2) placing the infiltrated graphite in a closed environment of 70-200 DEG C, hydrolyzing and curing the precursor solution to form a gel network, then drying in a vacuum environment of 0-300 DEG C, and forming an aerogel precursor in graphite holes; and 3) in an inert gas atmosphere or a vacuum environment, heating to 1300-1800 DEG C, and pyrolyzing the aerogel precursor to form the silicon carbide nanostructure. Compared with a traditional method, the method has the advantages of simple process, difficulty in failure, no change of the original performance of graphite and the like, and has relatively high economic value and application prospect.

The present invention relates to the technical field of micro-nano particle preparation, and discloses a micro-nano silver powder with controllable particle size and a preparation method thereof, comprising: S1, preparing micron-sized silver cores and nano-sized silver particles; S2, surface activating the micron-sized silver cores; S3, filling the micron-sized silver cores into the pore gaps of a porous template; S4, spraying a graphene dispersion onto the porous template to form a graphene network covering the surface of each silver core; S5, after removing the porous template, depositing nano-sized silver particles on the exposed silver core surfaces to form a silver shell structure that encapsulates the silver cores and the graphene network. The present invention utilizes a gradient composite of a micron-sized silver core-graphene network-nano silver shell structure, effectively utilizing the wettability of the nano-silver shell and the stress dispersibility of graphene to reduce the width difference between two sintering necks formed at the interface with the connecting plates on both sides during sintering of the circuit board, while utilizing the excellent electrical and thermal conductivity of the material itself to optimize the sintering performance of the circuit board.

The invention discloses a preparation method of modified high-carbon ferrochrome, and belongs to the technical field of nano modification. The method comprises the following steps: ultrasonically dispersing Fe-Cr alloy powder, a nano carbon material, a nitrogen source precursor and nano ceramic particles in an alcohol solvent, heating and stirring, sintering, and etching with hydrofluoric acid to obtain core-shell particles; adding the core-shell particles into the high-carbon ferrochrome matrix for mechanical stirring, and then adding graphene powder for smelting to obtain a modified melt; the modified melt is poured and subjected to directional solidification, and a modified casting is obtained; the casting is immersed in a hexamethylenetetramine ethanol solution, and a surface wear-resistant layer is formed through pyrolysis treatment and laser remelting; and the casting is quenched and tempered, and the modified casting with the surface nanocrystalline structure is obtained. The comprehensive performance of the high-carbon ferro-chrome is remarkably improved through synergistic modification of nanometer heterogeneous nucleation, graphene enhancement and surface nanometer crystallization.

The invention relates to a laser, chemical and mechanical composite cutting device and method, and belongs to the technical field of nuclear graphite decommissioning. The composite cutting device comprises a conversion part, a mechanical cutting part, a laser cutting part and an air injection part; the conversion part comprises a turntable and a turntable motor; the mechanical cutting part and the laser cutting part are symmetrically mounted at the bottom of the turntable; the air injection part on one side of the laser cutting part is mounted on the turntable; the laser cutting component comprises a laser cutting head, and the laser cutting component emits laser through the laser cutting head to cut a target object; the air injection component comprises an air injection head, the air injection head faces the cutting direction of the laser cutting head, and the air injection component injects air to a target object through the air injection head; the turntable motor drives the turntable to rotate and drives the mechanical cutting component and the laser cutting component to alternately cut a target object. According to the method, efficient, accurate and economical cutting machining of the radioactive super-thick nuclear graphite is achieved through multiple times of alternate shallow cutting of chemical auxiliary laser cutting and mechanical cutting.

A preparation method of isotropic coke for nuclear graphite, distillation of high-temperature coal tar to obtain fractional oil; the fractional oil is mixed with a solvent, and then flocculation separation is performed to obtain light phase oil and heavy phase oil; the light phase oil is subjected to distillation to recover the solvent, and then light purified tar is obtained; the heavy phase oil is subjected to distillation to recover the solvent, and then heavy tar is obtained; the heavy tar and the solvent are subjected to extraction separation to obtain a soluble phase and an insoluble phase; the soluble phase is subjected to distillation to recover the solvent, and then heavy purified tar is obtained; the light purified tar is subjected to multi-stage series hydrogenation to obtain fractional oil A; the heavy purified tar is subjected to hydrocracking to obtain fractional oil B; the fractional oil B is subjected to vacuum distillation to obtain fractional oil C; the fractional oil A is subjected to asphaltization reaction to obtain pre-polymerized asphalt; the fractional oil C and the pre-polymerized asphalt are mixed and subjected to liquid-phase carbonization to obtain mosaic structure green coke; the mosaic structure green coke is crushed and subjected to calcination to obtain isotropic coke for nuclear graphite. The coke has excellent physical and chemical properties, low manufacturing cost and short manufacturing period.

The present invention relates to the field of graphite production technology, and in particular to a pressing device for processing high-temperature gas-cooled reactor nuclear graphite materials, comprising a pressing machine base, a pressing assembly for pressing graphite materials being provided on the pressing machine base, an L-shaped plate being fixedly connected to the side wall of the pressing machine base, a collecting box being provided on the L-shaped plate, a fixed plate being fixedly connected to the top of the pressing machine base, a main push electric telescopic cylinder being fixedly connected to the side wall of the fixed plate, and an upper U-shaped plate being provided on the pressing machine base. The present invention can automatically push out three cylindrical graphite workpieces that have been pressed, and push the three graphite pieces together, and then drive the main push frame to push the three graphite pieces into the collecting box for collection and processing, thereby realizing automatic sorting and unloading of pressed graphite, without the need for workers to place the formed graphite workpieces one by one into the collecting box, thereby greatly improving the convenience of the device.

The application belongs to the technical field of photocatalytic functional materials, and specifically provides a core-shell-shell three-level structure composite material and a preparation method and application thereof, and belongs to the technical field of photocatalytic functional materials. The core-shell-shell three-level structure composite material takes an up-conversion micron particle as a core, graphite phase carbon nitride as an intermediate shell layer, and magnetic sepiolite as an outer shell layer. The core-shell combination of the UCMPs and g-C3N4 is realized through a one-step calcination method, the sepiolite is magnetically modified through a coprecipitation method, and finally, the core-shell-shell structure is formed through interface self-assembly. The obtained material has both photocatalytic activity and magnetic separation performance, the degradation efficiency of organic pollutants under simulated sunlight is increased by more than 257% compared with a single component, and the material can be quickly recycled and reused through an external magnetic field. The application has simple process and low cost, and is suitable for large-scale production.

A dual-optical-path nuclear graphite damage evolution and crack propagation whole-process deformation field measurement method comprises the following steps: constructing a fracture triggering mechanism, setting a low-speed high-resolution camera to continuously collect in a whole period, and capturing a crack image through a high-speed low-resolution camera when a triggering condition is met; a global high-precision deformation field of the surface of the test piece in a full loading period is solved through a digital image correlation method (PINN-DIC) based on a physical information neural network, a displacement field of the surface of the test piece in a high-speed fracture process is solved through the PINN-DIC while a damage feature region is identified, and crack core parameters are extracted; and in combination with strain distribution evolution characteristics and crack initiation positions, high-speed fracture information is mapped to a main coordinate system, and a cross-scale correlation mechanism is established. According to the method, accurate measurement and cross-scale data communication of the nuclear graphite damage evolution-fracture failure complete-period deformation field are realized, the deformation field measurement accuracy of a boundary region and a crack neighborhood is remarkably improved, and a key technical support is provided for analysis of a nuclear graphite fracture mechanism.

The invention belongs to the technical field of nuclear graphite decommissioning treatment, and particularly relates to a decommissioning nuclear graphite potential prediction method and system based on multi-modal vision, and the method comprises the steps: collecting the multi-modal image data of the surface morphology, temperature distribution, radiation intensity and internal structure of decommissioning nuclear graphite, carrying out the preprocessing, and carrying out the prediction of the potential of the decommissioning nuclear graphite. A deep learning model is utilized to extract key features, a feature fusion technology is adopted to generate a multi-dimensional feature map, a key region is focused in combination with an attention mechanism, the attention of the model on the features is enhanced, then a feature extraction network is constructed through a U-Net image segmentation algorithm for training, and the optimized model can display the state and prediction result of nuclear graphite in real time. And an appropriate waste treatment scheme is selected in an assisted manner. According to the method, the limitation of a traditional single detection mode is overcome, the potential of the decommissioning nuclear graphite is accurately predicted through multi-dimensional data fusion and intelligent analysis, and the safety of the nuclear reactor decommissioning process is improved.

The present application relates to a dismantling device and dismantling equipment. The dismantling device includes a main body, a driving member, a first drill bit, an alignment member, and a second drill bit. The driving member is fixed to the main body, and the first drill bit is connected to the driving member. The driving member is configured to drive the first drill bit to move relative to the main body along a first direction. The alignment member is used to align the first drill bit with the fixed structure on the graphite block. The second drill bit is connected to the main body. When the dismantling device is in a demolition mode, the first drill bit is aligned with the fixed structure on the graphite block, and the driving member drives the first drill bit to feed along the first direction so that the first drill bit can destroy the fixed structure. When the dismantling device is in a tensioning mode, the main body drives the first drill bit and the second drill bit to feed along the first direction so that the first drill bit and the second drill bit can drill into the graphite block and be tensioned and fixed to the graphite block. The above-mentioned dismantling device can achieve stable grasping of graphite blocks with high density and large weight, solving the problem of difficult nuclear graphite dismantling.

The invention belongs to the technical field of photocatalytic functional materials, and particularly provides a core-shell-shell three-stage structure composite material and a preparation method and application thereof, and belongs to the technical field of photocatalytic functional materials. The core-shell-shell three-stage structure composite material takes up-conversion micron particles as a core and graphite phase carbon nitride as a middle shell layer; the magnetic sepiolite is a shell layer; core-shell combination of UCMPs and g-C3N4 is achieved through a one-step calcination method, sepiolite is subjected to magnetic modification through a coprecipitation method, finally, a core-shell-shell structure is formed through interface self-assembly, the obtained material has photocatalytic activity and magnetic separation performance, the degradation efficiency on organic pollutants under simulated sunlight is improved by 257% or above compared with a single component, and the material has a good application prospect. The method can be quickly recycled through an external magnetic field, and is simple in process, low in cost and suitable for large-scale production.

The invention belongs to the technical field of resourceful treatment of retired nuclear graphite, and particularly relates to a resourceful treatment method of retired nuclear graphite. The treatment method comprises the following steps: (1) crushing a decommissioned graphite block into graphite powder; (2) uniformly mixing the graphite powder obtained in the step (1) with a brominating agent to obtain mixed powder; and (3) carrying out roasting treatment on the mixed powder obtained in the step (2) in an inert atmosphere at the roasting temperature of 900-1300 DEG C, so that the radioactive metal elements in the retired nuclear graphite form gaseous metal bromides and are volatilized from the retired nuclear graphite. According to the method disclosed by the invention, radioactive metal elements such as 59, 63Ni, 134, 137Cs, 152, 154 and 155Eu are roasted and recovered by adopting a 100% N2 inert atmosphere, so that the adsorption capacity between the radioactive metal elements and the surface of nuclear graphite is weakened, and meanwhile, a metal bromide which is low in melting point, high in saturated steam pressure, easy to dissolve in water and easy to reduce is formed between a brominating agent and metal ions; the cleaning treatment of the retired nuclear graphite and the resource recovery of radioactive metal elements are realized.

This invention discloses a wear-resistant dry-coupled probe device for nuclear graphite detection, relating to the field of dry-coupled probe technology. It includes a probe housing with a measurement window at one end. An elastomer core and an ultrasonic transducer assembly are housed within the probe housing, with the elastomer core positioned closer to the measurement window than the ultrasonic transducer assembly. A protective film is detachably connected to the measurement window. This invention adds a detachable protective film to the outside of the elastomer core. During actual testing, the elastomer core contacts the material being tested through the protective film, preventing wear on the elastomer core and thus improving the device's lifespan and detection accuracy.

A method for preparing impregnating pitch for nuclear graphite comprises: subjecting raw oil to solid-liquid separation and distillation to obtain a hydrogenated precursor; subjecting the hydrogenated precursor to multi-stage serial hydrogenation and impurity removal to obtain distillate oil A; subjecting distillate oil A to vacuum distillation to obtain distillate oil C; subjecting distillate oil A to hydrocatalytic cracking to obtain distillate oil B; subjecting distillate oil B to vacuum distillation to obtain distillate oil D; subjecting distillate oil A to vacuum distillation to obtain distillate oil E, which is then subjected to an asphalting reaction to obtain refined asphalt; mixing distillates C and D with the refined asphalt and subjecting them to pressurized thermal polymerization to obtain nuclear-grade asphalt; extracting the nuclear-grade asphalt to obtain a low-quinoline-insoluble nuclear-grade high-softening-point asphalt; and using the low-quinoline-insoluble nuclear-grade high-softening-point asphalt directly as the impregnating pitch for nuclear graphite or subjecting it to component cutting and removal of light components to obtain the impregnating pitch for nuclear graphite. The impregnating pitch for nuclear graphite has a wide mesophase melting temperature range, which improves the rheological mechanical properties of the system.

The application discloses a preparation method of modified high-carbon ferrochrome and belongs to the technical field of nano modification. The method comprises the following steps: ultrasonic dispersion and heating stirring of Fe-Cr alloy powder, nano carbon material, nitrogen source precursor and nano ceramic particles in an alcohol solvent, sintering, hydrofluoric acid etching to obtain core-shell particles; mechanical stirring of the core-shell particles into a high-carbon ferrochrome matrix, followed by addition of graphene powder for smelting to obtain a modified melt; pouring of the modified melt and directional solidification to obtain a modified casting; immersion of the casting into a hexamethylenetetramine ethanol solution, pyrolysis treatment and laser remelting to form a surface wear-resistant layer; quenching and tempering treatment of the casting to obtain a modified casting with a surface nanocrystalline structure. The application remarkably improves the comprehensive performance of the high-carbon ferrochrome through nano heterogeneous nucleation, graphene reinforcement and surface nanocrystallization synergistic modification.