83results about How to "Low melting point" patented technology

The invention discloses a high-strength silver-free copper-based brazing filler metal which is composed of P, Sn, Ni and Cu. The high-strength silver-free copper-based brazing filler metal is low in cost, safe, environmentally friendly and good in welding effect; through the adding of Sn and Ni, the melting point of brazing filler metal alloy is reduced, and the tensile strength and wettability of the brazing filler metal alloy are enhanced.

The present application relates to a kind of compositions and applications comprising polyamide.The composition includes polyamide and sheet structure mineral powder, wherein, with 100 mass parts of polyamide, sheet structure mineral powder in the composition is 0.1-10 mass parts.The polyamide material in the present application has lightweight, easy processing, has cost advantage, compared with steel material has obvious advantage.Sheet structure mineral powder is added in polyamide material by intercalation modification, further improve the barrier property of product, effectively avoid "hydrogen embrittlement" risk, with "hydrogen embrittlement" resistance, low hydrogen permeability, and suitable for the temperature range of application, it has high toughness in low temperature environment condition, the performance of polyamide material reaches a good balance, and the comprehensive performance is better.Suitable for hydrogen pipeline, hydrogen storage bottle etc., has advantage in hydrogen energy automobile and other application scenarios.

The application belongs to the technical field of comprehensive utilization of waste lithium-ion power battery, and discloses a deep eutectic lithium supplement and a method for repairing and regenerating positive electrode material of waste lithium-ion battery, wherein the deep eutectic lithium supplement is prepared by taking a solid-state reducing organic acid as a hydrogen bond donor and a solid-state lithium source as a hydrogen bond acceptor, mixing the hydrogen bond donor and the hydrogen bond acceptor, and reacting to obtain a deep eutectic melting state system; and the deep eutectic lithium supplement can be used for repairing and regenerating the positive electrode material of the waste lithium-ion battery. The application can prepare a liquid-state deep eutectic lithium supplement by using a solid-state reducing acid and a solid-state lithium source, is green and friendly, can realize self-limiting lithium supplement without strict control of the lithium supplement amount, has low energy consumption in the lithium supplement process, can greatly reduce the cost, and can be used for repairing and regenerating the positive electrode material of the waste lithium-ion battery.

The utility model relates to a solar cell. The solar cell includes: a substrate; the grid lines are fixedly arranged on the substrate; and a plurality of attachment blocks, the plurality of attachment blocks are fixedly arranged on two sides of the grid line in a staggered manner along the length direction of the grid line, and the plurality of attachment blocks are fixedly arranged on the substrate. The adhesion blocks arranged on the two sides of the grid line of the solar cell in a staggered manner can enhance the fixing strength of the grid line on the substrate, so that the grid line is not easy to fall off from the substrate, the conductivity of the grid line is improved, and the photoelectric conversion efficiency of the solar cell is improved.

This invention discloses a refractory high-entropy alloy resistant to high-temperature molten aluminum corrosion and erosion-wear, its preparation method, and its applications. The refractory high-entropy alloy of this invention comprises, by atomic percentage: 40-50 at.% Nb, 35-40 at.% Ti, 4-10 at.% Mo, 4.5-5 at.% Cr, and no more than 10 at.% Al. This invention obtains the refractory high-entropy alloy by mixing and melting the raw materials under a protective atmosphere. The refractory high-entropy alloy ingot of this invention has a single-phase BCC microstructure, exhibiting stable structure, good mechanical properties, and excellent resistance to molten aluminum corrosion and erosion-wear. The Nb-Ti-Mo-Cr based refractory high-entropy alloy resistant to molten aluminum corrosion and erosion-wear prepared using this invention can significantly improve the service life of components, reduce replacement frequency, and has high economic benefits.

This invention relates to transition layer materials and welding processes for welding dissimilar steel and aluminum materials, belonging to the field of welding technology. The transition layer material for welding dissimilar steel and aluminum materials of this invention comprises a copper layer, a copper alloy layer, and a zinc alloy layer arranged sequentially; the copper layer is adjacent to the steel base material, and the zinc alloy layer is adjacent to the aluminum base material; the copper content in the copper alloy layer is 62.0%-64.0%; the zinc content in the zinc alloy layer is 89.0%-91.0%; the mass ratio of the copper layer, copper alloy layer, and zinc alloy layer is (0.9-1.1):(2.3-2.7):(1.8-2.2). By sequentially setting the copper layer, copper alloy layer, and zinc alloy layer between the steel base material and the aluminum base material, a gradual transition from the steel base material to the aluminum base material is achieved, effectively avoiding the formation of brittle Fe-Al intermetallic compounds during direct welding, and enhancing the mechanical properties and durability of the welded joint.

This invention belongs to the field of aluminum alloy materials technology, and relates to a high-strength and ductile aluminum alloy and its preparation method. The alloy comprises, by mass fraction: 2-6% Mg, 0.4-0.9% Mn, 0.2-0.6% Si, 0.05-0.15% Sn, Fe≤0.15%, Ti≤0.1%, with the balance being Al. By introducing Sn, a low-melting-point MgSiSn primary phase is formed in the as-cast stage, and transforms from a continuous network to a discontinuous granular structure during homogenization heat treatment, weakening the adverse effects of brittle intermetallic compounds at grain boundaries. Simultaneously, Sn dissolved in the aluminum matrix forms a nanoscale MgSiSn precipitate during homogenization, serving as a heterogeneous nucleation core for the Mn-containing second phase, lowering its nucleation energy barrier, and promoting high-density, fine, and uniform precipitation, thereby achieving a synergistic improvement in the alloy's strength and ductility.

The invention relates to the technical field of silicon carbide ceramics, in particular to an in-situ induced low-temperature eutectic silicon carbide porous ceramic and a preparation method thereof. The material is prepared by mixing and sintering the following materials: silicon carbide, a synergistic sintering system, a dispersing agent, a plasticizer and water, wherein the synergistic sintering system comprises the following components: pregelatinized starch, a silicate mineral material, aluminum oxide, calcium carbonate, glass powder and rare earth oxide; the pregelatinized starch is adopted as an adhesive, the thermal decomposition behavior of the pregelatinized starch and the chemical reaction activity of the glass powder and the calcium carbonate form synergy in the process, seamless connection of the whole process from the room temperature to the sintering temperature is achieved, the sintering temperature is greatly reduced, meanwhile, the glue discharging step is omitted, and the silicon carbide porous ceramic product with good performance and few defects is obtained.

This invention provides a collector for recovering platinum group metals (PGMs) from spent catalysts, its preparation method, and its application, belonging to the technical field of precious metal recovery. The collector comprises a copper matrix, a flux, a framework support, and a lattice activator: the copper matrix, flux, and lattice activator are loaded on the surface of the framework support; the copper matrix is ​​elemental copper or a copper-based compound; the flux is boric acid or a borate; the framework support is a porous inorganic material; and the lattice activator is tin, a tin alloy, or a metal sulfide. The collector serves as a collector for the pyrometallurgical recovery of PGMs from spent catalysts. This invention constructs a multi-component synergistic collector composed of a copper matrix, flux, framework support, and lattice activator, which significantly improves the recovery rate of PGMs, especially rhodium, from spent automotive exhaust purification catalysts in pyrometallurgical treatment, and reduces the smelting temperature required for pyrometallurgical treatment, thus significantly reducing energy consumption.

The application discloses isosorbide bio-based polyurethane acrylate, which is prepared from bio-based isosorbide, bio-based 1,2-pentanediol, bio-based 1,5-pentanediol and bio-based succinic acid as raw materials through esterification reaction, vacuum polycondensation reaction, bio-based hydroxyl-terminated polyester, reaction of bio-based hydroxyl-terminated polyester and bio-based 1,5-pentamethylene diisocyanate, bio-based polyurethane, reaction of bio-based polyurethane and hydroxyethyl acrylate, and UV-curable isosorbide bio-based polyurethane acrylate. The application discloses application of the isosorbide bio-based polyurethane acrylate in preparation of UV coating, ink and adhesive. The isosorbide bio-based polyurethane acrylate is compounded with a UV monomer into a UV resin, the UV resin is compounded into a UV coating, and after curing, the UV coating has excellent properties such as high hardness, wear resistance, scratch resistance, heat resistance and weather resistance, and can be used as raw material of the UV coating, ink and adhesive.

The present application relates to the field of composite ceramics, and aims to provide a new B4C-cBN composite ceramic with good mechanical properties and thermal conductivity, and a preparation method thereof, which comprises the following steps: S100, mixing boron carbide 5-9 parts, cubic boron nitride 1-5 parts and sintering additives to obtain a mixture; S200, obtaining the B4C-cBN composite ceramic through a sintering process; the sintering temperature is 1400-1550 DEG C; the sintering pressure is 4.9-5.5 GPa; and the sintering time is 1-3 h. The reason why aluminum and cobalt are selected as sintering additives is that the melting point of aluminum is low, and a liquid phase formed in the sintering process can effectively fill the pores through capillary action, thereby promoting the sintering process. Aluminum reacts with cubic boron nitride to form aluminum nitride, which can inhibit the conversion of cubic boron nitride into hexagonal boron nitride. Cobalt has oxygen affinity and can play a purifying role of "deoxidation and degassing", thereby reducing pores, improving density and improving the sintering performance of the composite ceramic. The optimal raw material ratio and sintering parameters are determined, so that the mechanical properties and thermal conductivity of the composite ceramic are both excellent.

A battery module and a manufacturing method thereof are disclosed. The battery module according to one embodiment of the present application includes: a battery cell stack in which a plurality of battery cells are stacked; a busbar frame connected to the battery cell stack; an electrode lead connected to the battery cell stack and including a first metal; and a busbar overlapping the electrode lead and including a second metal, wherein the electrode lead and the busbar form a weld by welding, the weld includes a first region in which a center part is located in the electrode lead and a second region in which a center part is located in the busbar with respect to a boundary between the electrode lead and the busbar, and precipitates of the first metal and the second metal are distributed in both the first region and the second region.

The application discloses a kind of PEI or PEEK-based 3D printing wave-absorbing materials and preparation method thereof.The 3D printing wave-absorbing material includes the following components by mass fraction: polyetherimide resin or polyether ether ketone resin: 45~65 parts;Electromagnetic wave absorber: 10~50 parts;Impact modifier: 4~12 parts;Flow aid: 2~8 parts;Antioxidant: 0.5~3 parts;Wherein, the electromagnetic wave absorber includes magnetic absorber and carbon-based absorber, the impact modifier and the carbon-based absorber are pre-coated to form the carbon-based absorber coated with the impact modifier on the surface, and the magnetic absorber is surface modified by silane coupling agent.The application significantly improves the mechanical properties and thermal stability of the material by using specific raw material composition and combining specific multi-layer co-extrusion and online heat treatment process.The preparation process is simple and easy to operate, and is suitable for industrial continuous production.

The present application relates to a kind of synergistic flame-retardant low melting point polyester chip for polyester sheath-core and its preparation method, the melting point of product is reduced by introducing part of asymmetric isomer of terephthalic acid in esterification process, while introducing part of symmetric structure alcohol with small difference with ethylene glycol, the chain regularity is less damaged, a small amount of introduction will not significantly damage the crystallization ability of product while reducing the melting point. After esterification, by means of blending and co-melting and alcoholysis repolymerization, flexible chain segment (‑O‑(CH2)4‑O‑) with fast crystallization speed is introduced to improve the crystallization performance of product, and finally the modified synergistic flame retardant is added. Nitrogen, phosphorus and silicon elements are introduced into the product chain segment during polycondensation reaction, and a triple protection system covering condensed phase, gas phase and interface is formed through the multidimensional complementary action of the three elements during combustion. Through the above steps, polyester chip for polyester sheath-core with high flame retardancy, low melting point and high crystallinity is finally synthesized.

The application relates to the technical field of organic synthesis, in particular to a polymeric Schiff base metal compound, a preparation method and application thereof, the polymeric Schiff base metal compound has structures shown in formula I to formula IV. The polycentered polymeric Schiff base metal compound provided by the application has the advantages of simple synthesis method, easy purification and high product purity. Since long-chain polyether glycol is introduced, the melting point of the Schiff base catalyst is low, and the Schiff base catalyst is better dispersed in glycolide. The polymeric Schiff base catalyst has a polycentered structure, and the catalytic activity of the original single-center catalyst can be improved through the synergistic coordination effect between the poly-metal centers. The polymeric Schiff base catalyst provided by the application has high catalytic activity, and when the polymeric Schiff base catalyst is used to catalyze the ring-opening polymerization of glycolide to generate polyglycolic acid, the polymerization reaction speed is high. Experimental results show that when the polyglycolic acid is prepared by using the catalyst provided by the application, the reaction yield can reach 97.2%.

This invention relates to a GaAs-based flip-chip Mini LED and its fabrication method. The chip comprises, from bottom to top, a transparent substrate, a bonding layer, a P-current spreading layer, and a P-ohm layer. A mesa is disposed on the P-ohm layer. The mesa, from bottom to top, comprises a P-waveguide layer, a light-emitting layer, an N-waveguide layer, an N-current spreading layer, an N-buffer layer, and an N-ohm layer. A P-electrode is disposed on the P-ohm layer below the mesa; an N-electrode is disposed on the N-ohm layer above the mesa. Electrode pads are disposed directly above both the P-electrode and the N-electrode. By setting electrode pads, the soldering required in packaging production is combined with the electrode structure, eliminating the need for solder paste application on the substrate, thus achieving chip-substrate interconnection and facilitating modular production of the packaged chip. This effectively improves the problems of weak chip-substrate bonding strength, high coefficient of thermal expansion, cumbersome manufacturing, and high production costs in chip packaging.

This invention discloses a high-nickel ternary cathode material, its preparation method, and a lithium battery, relating to the field of lithium battery technology. A coating layer is formed on a high-nickel ternary cathode material substrate using fluorinated liquid crystal molecules. These fluorinated liquid crystal molecules have a lower melting point, making it easier to form an ideal coating layer compared to traditional coating agents. Furthermore, the liquid crystal molecules exhibit better solvent and electrolyte corrosion resistance, significantly improving the high-temperature cycling performance of the cathode material.

The invention discloses a method for controlling Ds inclusions in bearing steel produced by a small-section casting blank, and relates to the technical field of steel smelting. Comprising the steps that the element mass fraction, the temperature and the oxygen activity of molten steel are collected, a Ds type inclusion oxide system is determined and matched with a phase diagram, and the generation state of Ds type inclusions is accurately judged through phase diagram positioning and reaction quotient-equilibrium constant comparison; and adding ferrosilicon alloy to directionally convert the ferrosilicon alloy into harmless silicate, and supplementing oxygen activity double-threshold control and refining slag regulation and control. Compared with a traditional method for producing bearing steel through a small-section casting blank, when calcium and aluminum inclusion products are monitored, fine adjustment of silicon iron is automatically triggered, inclusion components are locked in a silicate inclusion interval, the pain point of hysteresis of manual regulation in the traditional smelting process is solved, active regulation of the inclusion components is achieved, and the production efficiency of the bearing steel is improved. And finally, the purpose of effectively controlling the Ds type inclusions of the bearing steel casting blank is achieved.

The invention relates to the technical field of batteries, in particular to a wide-temperature-range high-rate lithium battery ester-based electrolyte and application. The electrolyte comprises soluble lithium salt and a liquid component, the liquid component is a solvent; the solvent comprises at least three of propylene carbonate, fluoroethylene carbonate, isopropyl trifluoroacetate, ethyl trifluoroacetate, ethyl acetate, methyl acetate and methyl trifluoroacetate; the lithium salt lithium battery comprises at least two of common lithium salts. The electrolyte developed by the invention is used in the lithium battery and can stably work at 40-60 DEG C, the specific discharge capacity of the battery is still 62.83% of the specific discharge capacity of the battery at room temperature even at 30 DEG C and 4C multiplying power, and the electrolyte has excellent wide-temperature fast charge performance. In addition, the electrolyte effectively inhibits the growth of lithium dendrites and the side reaction of an electrode-electrolyte interface at low temperature, and promotes the formation of a solid interface film which is rich in inorganic matters and low in interface impedance. The invention has the advantages of reasonable component design and excellent product performance, and is convenient for industrial application.

The application discloses a preparation method of a titanium carbide doped polymer solid electrolyte, which can effectively reduce the crystallinity of PEO, enhance the ionic conductivity of the polymer solid electrolyte and widen the electrochemical window by grafting PCL (polycaprolactone) on the surface of a two-dimensional material titanium carbide (MXene) and blending the PCL with a PEO (polyethylene oxide) blend.The steps adopted by the application are as follows: firstly, PCL is grafted on the surface of MXene through a one-pot method; then, the grafted material is mixed with PEO and LiTFSI (lithium bis(trifluoromethanesulfonyl)imide) in a certain proportion, is subjected to ultrasonic oscillation and is uniformly mixed by heating; finally, the solution is poured on a glass culture medium, the solvent is volatilized at room temperature, the solvent is removed by heating, and a solid polymer electrolyte film is obtained.The polymer solid electrolyte film prepared by the method of the application has good mechanical properties, high ionic conductivity, a wide electrochemical stability window, stable charge and discharge processes of an assembled battery and excellent cycle performance.

The utility model relates to the field of snow and ice removal of railway tracks, and discloses a snow and ice removal mechanism for railway tracks, which comprises a snow sweeper body, anti-skid tires are fixedly connected outside the snow sweeper body, an ice breaking component is mounted outside the snow sweeper body, and a snow removal component is mounted outside the snow sweeper body. The ice breaking assembly comprises an electric push rod, the exterior of the electric push rod is installed at the bottom of the snow sweeper body, a supporting frame is fixedly connected to the end of the electric push rod, an ice breaking knife is rotatably connected to the interior of the supporting frame, and a second driving motor is fixedly connected to the exterior of the supporting frame. The ice breaking knife is rotationally connected to the output end of the second driving motor. According to the snow and ice removing mechanism for the railway track, accumulated snow in the track is pushed to the two sides through the baffles to be preliminarily dispersed, the second driving motor is started to drive the ice breaking knife, and the blade of the snow and ice removing mechanism for the railway track cuts and crushes an ice layer.

This invention relates to the field of knife manufacturing technology and discloses a method for preparing a knife with antibacterial effects, comprising the following steps: smelting a nitrogen-containing antibacterial martensitic stainless steel blade blank; heating, cooling, and tempering the nitrogen-containing antibacterial martensitic stainless steel blade blank to obtain the blade; hot isostatic pressing of a pure titanium ingot to obtain a densified titanium metal handle; and connecting the blade to the densified titanium metal handle using a tin-silver-based brazing filler metal at 680°C to 750°C via induction heating. This invention solves the problems of decreased hardness and corrosion resistance caused by silver precipitation through the synergistic effect of nitrogen and silver, utilizing nitrogen solid solution strengthening and potential compensation mechanisms; and employs a low-temperature tin-containing brazing process to construct a physical barrier layer, blocking carbon diffusion to the titanium side and the formation of brittle phases, thus avoiding over-tempering softening of the blade substrate, resulting in a knife with high hardness, corrosion resistance, long-lasting antibacterial properties, and high connection strength.

This invention discloses a high-elongation cast Al-Cu-Zn-Mg alloy with good resistance to hot cracking. The alloy composition, by mass percentage, includes: Cu 3.5–4.5%, Mg 0.4–1.5%, Mn 0.2–0.5%, Ti 0.10–0.2%, Zn 2.5–3.5%, with the balance being Al and unavoidable impurity elements. Addressing the limitations of existing Al-Cu casting alloys, such as wide solidification temperature range, poor fluidity, and hot cracking, this invention provides a high-Zn-content Al-Cu-Zn-Mg alloy with good resistance to hot cracking. This alloy has a low melting point, a narrowed solidification temperature range, and excellent resistance to hot cracking and mechanical properties. It can be used for various high-strength cast aluminum alloy structural parts, effectively avoiding casting defects such as hot cracking, shrinkage cavities, and porosity, and significantly improving the overall mechanical properties of the alloy.

This invention provides molybdenum disulfide tungsten nanosheets and their preparation method, belonging to the field of nanomaterials. The method includes: spin-coating a molybdenum source solution onto a first substrate, and spin-coating a mixed solution of a tungsten source and a catalyst onto a second substrate; placing a sulfur source in a first temperature zone of a partitioned heating device, placing the first and second substrates in a second temperature zone of the same device, and controlling the spacing between the first and second substrates; placing the partitioned heating device in a carrier gas atmosphere, with the first temperature zone located upstream of the second temperature zone relative to the carrier gas flow direction; and heating the partitioned heating device using a set heating mode to obtain molybdenum disulfide tungsten nanosheets. By adjusting the spacing between the first and second substrates, the composition of the grown monolayer two-dimensional molybdenum disulfide tungsten alloy can be controlled, with the tungsten composition adjustable over a wide range from 0 to 0.8.

The application discloses a white light emitting phosphate glass material based on divalent tin ions and a preparation method thereof, and belongs to the technical field of luminescent glass. The white light emitting phosphate glass material based on divalent tin ions is prepared from raw materials including 2.5-25% of SnO, 15-37.5% of ZnO, 20% of ZnCl2 and 40% of P2O5 in terms of mole percentage; and a reducing agent Si3N4 can be further added when the white light emitting phosphate glass material is prepared. The phosphate glass prepared in air can promote the luminescence of Sn 2+ ; meanwhile, the introduction of the reducing agent can effectively control the valence state of Sn ions, and the phosphate glass has excellent comprehensive performance, a low glass transition temperature, good mechanical performance and thermal stability, and is suitable for white light LED lighting and display devices.

Provided is a compound represented by the following general formula (1) or (2): where R1 to R4 each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the like, R5 and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, M1 represents a gallium atom or an indium atom; where R7 to R10 each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the like, R11 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and M2 represents a gallium atom or an indium atom.

This invention belongs to the field of brazing materials technology, and relates to a composite structure welding strip, its preparation method, and its application. A composite structure welding strip is prepared by ultrasonic welding or ultrasonic hot rolling of a first surface layer, a core layer, and a second surface layer. The first and second surface layers are metal alloy foil strips prepared by a strip spinning method. The first and second surface layers, by mass percentage, consist of the following components: Si 11-13%, Eu 0.05-2%, with the balance being Al. The core layer is porous foamed copper, accounting for 4-20% of the total mass of the composite structure welding strip. The thickness of the porous foamed copper is 30-60 μm. The thickness of the composite structure welding strip is 80-120 μm. This composite structure welding strip, as a thin-strip welding material, has a low melting point, good flexibility, can be prepared into rolls, exhibits strong interfacial bonding, a short welding stroke, good fluidity, and high spread rate, thus improving the performance of brazed joints.

The invention discloses a phase change storage material and device based on two-dimensional elementary bismuthene. The chemical component of the phase change storage material is bismuth elementary substance, and the melting point is lt; 300 DEG C; an amorphous phase of the material is of a long-range disordered atom arrangement structure, a local structure is mainly a defective octahedron and has a four-membered ring and five-membered ring structure, the coordination number of most atoms is 3, and an energy band structure has no band gap; a crystal phase of the two-dimensional bismuthene material has a buckling hexagonal honeycomb layered structure, adjacent layers are connected with each other through Van der Waals force, and an energy band structure has a band gap. According to the invention, the two-dimensional elemental bismuthene is used as a phase change functional layer material, so that the component segregation phenomenon in the use process of the device can be physically and essentially eliminated, and meanwhile, the ultrathin size and the low melting point characteristic of the material have the advantages in the aspects of high-density integration and low-power-consumption operation of the phase change memory device.

The present application relates to continuous casting protective slag technical field. The protective slag includes silica 29-33%, calcium oxide 35-39%, aluminum oxide 4-6%, magnesium oxide 1-3%, sodium oxide 6-8%, lithium oxide 0.5-1.5%, calcium fluoride 6-10%, diboron trioxide 1-3%, diiron trioxide 1-3%, manganese oxide 1-3% and carbonaceous material 2-4% by mass percentage. The mass ratio of calcium oxide and silica is maintained at a high level to promote the precipitation of jacobsite, control the heat transfer in the crystallizer, and introduce lithium oxide with strong fluxing ability, significantly reduce the melting point and viscosity without reducing the alkalinity to ensure high pulling speed lubrication, and then a small amount of diboron trioxide is used to regulate the crystallization speed and avoid excessive crystallization of the slag film. The present application takes into account the heat transfer control and lubrication performance, and can simultaneously reduce the occurrence rate of surface longitudinal crack of weathering steel billet and the sticking leakage rate.

The invention provides a method for recycling laterite-nickel ore high-pressure acid leaching residues. The method comprises the following steps that S1, the high-pressure acid leaching residues, pulverized coal and fluorite are mixed in proportion, and then water is added to prepare ore balls; s2, adding coal particles into the ore balls, and carrying out reduction roasting to prepare a roasted sample; s3, the roasted sample is subjected to ore grinding, and crude ore is prepared; and S4, the crude ore is subjected to magnetic separation, and reduced iron powder is prepared. Through the synergistic effect of the fluorite and the pulverized coal, the pulverized coal provides a basic reducing environment, and iron in the high-pressure acid leaching residues is reduced into reduced iron; wherein the fluorite destroys a calcium silicate (CaO-SiO2) network structure, so that the melting point of a slag phase is reduced, the flowability is enhanced, and the reduction reaction efficiency is improved; meanwhile, the pulverized coal provides reduction conditions, and the desulfurization reaction of fluorite is accelerated.