Alloy powder and method for preparing alloy powder by short process of metal oxide

Abstract

The application provides an alloy powder and a method for preparing the alloy powder through a short process of metal oxides; the method for preparing the alloy powder through the short process of metal oxides comprises the following steps: S1, providing step-by-step reduced metal oxides and directly reduced metal oxides; performing a reduction pretreatment on the step-by-step reduced metal oxides to obtain pretreated materials; S2, allowing a mixture comprising the pretreated materials and the directly reduced metal oxides to react with a reducing agent in a plasma reaction device to obtain the alloy powder. The application solves the technical problems of different reduction steps of metal oxides, oxygen precipitation interference of step-by-step reduction, difficulty in directly obtaining the alloy powder and a long process flow.

Description

Technical Field

[0001] This invention belongs to the field of alloy smelting, and particularly relates to a short-process method for preparing alloy powders from alloy powders and metal oxides. Background Technology

[0002] Traditional alloy powder preparation often uses high-purity elemental metals as raw materials, or involves the stepwise reduction and casting of metal oxides into ingots, followed by multiple post-processing steps such as cutting and crushing to produce powder. This process is lengthy, energy-intensive, and has low energy utilization. Although existing research has explored methods for obtaining alloy melts through the reduction and smelting of oxide ores, obtaining alloy powder still requires additional post-processing such as ball milling, which also suffers from lengthy and cumbersome processes, high energy consumption, and low energy utilization.

[0003] While plasma technology has been applied to metal reduction and alloying, its limitations in alloy preparation stem from its non-equilibrium, ultra-high temperature, instantaneous energy input and ultrafast reaction kinetics. Firstly, when both stepwise and direct reduction of valence metal oxides are present, the reduction of the stepwise oxides requires a stepwise reduction, which is mismatched with the one-step reduction of the direct oxides. This can lead to difficulties in synchronous reaction and obtaining alloy powders, as well as elemental segregation. Secondly, the stepwise oxygen evolution during the reduction of stepwise oxides can interfere with the plasma working environment and affect reaction efficiency. Thirdly, current technologies generally employ a stepwise processing approach for alloy powder preparation, and have not yet achieved the simultaneous integration of reduction, powder preparation, and alloying using the ultra-high energy of plasma.

[0004] Therefore, it is necessary to provide a method for preparing alloy powder from alloy powder and metal oxide in a short process to solve the technical problems of asynchronous reduction of metal oxide, interference from oxygen evolution during stepwise oxidation, difficulty in directly obtaining alloy powder, and lengthy process flow. Summary of the Invention

[0005] The main objective of this invention is to provide a method for preparing alloy powder from alloy powder and metal oxides using a short process, aiming to solve the technical problems of asynchronous reduction of metal oxides, interference from oxygen evolution during stepwise oxidation, difficulty in directly obtaining alloy powder, and lengthy process flow.

[0006] To achieve the above objectives, the present invention provides a method for preparing alloy powders using a short-process method with metal oxides, comprising the following steps: S1 provides step-down price reduction metal oxides and direct price reduction metal oxides; The stepwise decreasing valence metal oxide includes a first variable valence metal oxide, wherein the metal element in the first variable valence metal oxide is not in the lowest valence state bound to oxygen; the direct decreasing valence metal oxide includes at least one of a second variable valence metal oxide and a non-variable valence metal oxide, wherein the metal element in the second variable valence metal oxide is in the lowest valence state bound to oxygen. The stepwise de-valence metal oxide is subjected to a de-valence pretreatment to reduce the valence state of the metal element in the stepwise de-valence metal oxide and cause deoxidation, thereby obtaining a pretreated material; S2, the mixture including the pretreated material and the directly reduced metal oxide is subjected to a reduction reaction with a reducing agent in a plasma reactor, the volatilized metal vapor is collected and condensed to obtain alloy powder.

[0007] Furthermore, the mass ratio of the stepwise valence-reducing metal oxide to the direct valence-reducing metal oxide is 1:0.01-100.

[0008] Furthermore, the first variable valence metal oxide includes at least one of copper oxide, manganese dioxide, and tin dioxide.

[0009] Furthermore, the directly depreciating metal oxide includes the non-variable valence metal oxide, which includes at least one of magnesium oxide, zinc oxide, and cadmium oxide.

[0010] Furthermore, the price reduction pretreatment includes: heat treatment of the stepwise price reduction metal oxide under the protection of a protective gas; the temperature of the heat treatment is not less than the deoxidation temperature of the stepwise price reduction metal oxide; and the heat treatment time is not less than 10 minutes.

[0011] Furthermore, the reducing agent includes a solid reducing substance, which includes elemental carbon; The solid reducing agent, the pretreated material, and the directly reduced metal oxide coexist in the mixture; the mass percentage of the solid reducing agent in the mixture is 10-30%.

[0012] Furthermore, the reducing agent includes a gaseous reducing substance; the gaseous reducing substance includes at least one of a carbon-containing reducing gas and hydrogen; the carbon-containing reducing gas includes at least one of C1 gaseous hydrocarbons, C2 gaseous hydrocarbons, C3 gaseous hydrocarbons, and C4 gaseous hydrocarbons. During the reduction reaction, the gaseous reducing substance is introduced into the reaction zone of the plasma reaction device; the gaseous reducing substance accounts for 5-80% of the total volume in the atmosphere.

[0013] Furthermore, prior to the reduction reaction, the mixture is subjected to a molding process; the molding process includes pressing the mixture at a pressure of 30-60 MPa.

[0014] Furthermore, the operating current of the plasma reaction device is set to 0.01-6 g / A; the reaction rate of the reduction reaction is not less than 0.2 g / min; The plasma reaction device includes a thermal plasma generator; the thermal plasma generator includes one of a transferred arc plasma device and a non-transferred arc plasma device.

[0015] The present invention also provides an alloy powder, which is prepared by the short-process method for preparing alloy powder from metal oxides as described above.

[0016] Compared with the prior art, the present invention has at least the following advantages: This invention solves the technical problems of asynchronous reduction of metal oxides, interference from oxygen evolution during stepwise oxidation reduction, difficulty in directly obtaining alloy powders, and lengthy process flows. Furthermore, this invention can rationally utilize the ultra-high energy of plasma, resulting in high energy utilization. When using both stepwise and direct oxidation-reducing metal oxides as alloying raw materials, this invention first pre-treats the metal elements in the stepwise oxidation-reducing metal oxides to lower their oxidation states and remove some oxygen atoms, thereby converting high-valence oxides into low-valence oxides and narrowing the reduction thermodynamic difference between different metal oxides. Then, this invention utilizes the high temperature and large enthalpy of thermal plasma to simultaneously provide energy for both the reduction and volatilization powdering processes, achieving a one-step direct preparation of alloy powders.

[0017] Compared to other alloy smelting methods, this invention can simultaneously reduce different metal oxides based on the rapid and high-intensity reduction characteristics of plasma reaction devices. It can also reduce the differences between step-decreasing metal oxides and directly decreasing metal oxides during the reduction process, as well as reduce the oxygen evolution interference caused by step-decreasing metal oxides during the reduction process. Finally, it can achieve the one-step completion of "reduction-powdering-alloying" by utilizing the ultra-high energy of plasma, solving the problems of lengthy process flow, high energy consumption, and low energy utilization, and obtaining alloy powder. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 The images show the bright-field morphology and mapping of a single magnesium-copper alloy powder particle in Example 1 of this invention; wherein, (a) is a bright-field morphology image of a single magnesium-copper alloy powder particle obtained by scanning transmission electron microscopy, (b) is a surface distribution energy spectrum mapping image of copper, and (c) is a surface distribution energy spectrum mapping image of magnesium. Figure 2 The image shows the XRD pattern of the magnesium-copper alloy powder in Example 1 of this invention. Figure 3 The images show the bright-field morphology and mapping of a single magnesium-tin alloy powder particle in Example 2 of this invention; wherein, (a) is a bright-field morphology image of a single magnesium-tin alloy powder particle obtained by scanning transmission electron microscopy, (b) is a surface distribution energy spectrum mapping image of magnesium, and (c) is a surface distribution energy spectrum mapping image of tin. Figure 4 The images show the bright-field morphology and mapping of a single magnesium-manganese alloy powder particle in Example 3 of the present invention; wherein, (a) is a bright-field morphology image of a single magnesium-manganese alloy powder particle obtained by scanning transmission electron microscopy, (b) is a surface distribution energy spectrum mapping image of magnesium, and (c) is a surface distribution energy spectrum mapping image of manganese. Figure 5 The images show the bright-field morphology and mapping of a single magnesium-copper powder particle in Comparative Example 1 of this invention; wherein, (a) is a bright-field morphology image of a single magnesium-copper powder particle obtained by scanning transmission electron microscopy, (b) is a surface distribution energy spectrum mapping image of magnesium, and (c) is a surface distribution energy spectrum mapping image of copper.

[0020] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0023] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention, as well as the prior art known to those skilled in the art and the description of this invention, may be implemented using any prior art methods, devices, and materials similar to or equivalent to those described, used, or made of materials in the embodiments of this invention.

[0024] This invention provides a method for preparing alloy powder from metal oxides using a short process, comprising the following steps: S1 provides step-down price reduction metal oxides and direct price reduction metal oxides.

[0025] In this invention, the stepwise decreasing valence metal oxide refers to a metal oxide with multiple valence states and variable valence characteristics that cannot be thermodynamically reduced to a metallic element in one step; typically, it needs to undergo a phase transition to generate a low-valence oxide intermediate before further reduction to a metallic element. The direct decreasing valence metal oxide refers to a metal oxide that can be directly reduced to a metallic element in one step without stepwise phase inversion.

[0026] In this invention, the stepwise decreasing valence metal oxide includes a first variable valence metal oxide, wherein the metal element in the first variable valence metal oxide is not in the lowest valence state bound to oxygen; that is, the valence state of the metal element in the first variable valence metal oxide is greater than the lowest valence state bound to oxygen; in some embodiments, the first metal oxide is a compound of a metal element and an oxygen element, and the first metal oxide may include at least one type of single metal oxide.

[0027] As an explanation of the first variable valence metal oxide, since the metal element in the first variable valence metal oxide is not in the lowest valence state that combines with oxygen, its valence state will decrease after subsequent valence reduction pretreatment, and some oxygen atoms will be removed; for example, it will be transformed from a high-valence oxide into a low-valence suboxide.

[0028] For example, the metal element in the first variable valence metal oxide includes at least one of copper, manganese, and tin; specifically, the first variable valence metal oxide includes at least one of copper oxide, manganese dioxide, and tin dioxide.

[0029] In this invention, the directly decreasing valence metal oxide includes at least one of a second variable valence metal oxide and a non-variable valence metal oxide.

[0030] As an explanation of the second variable-valence metal oxide, the metal element in the second variable-valence metal oxide is in its lowest valence state, where it is bonded to oxygen; that is, although the metal element in the second variable-valence metal oxide is a variable-valence metal, the second metal oxide is a low-valence oxide or a low-valence suboxide. In some embodiments, the second metal oxide is a compound of a metal element and oxygen, and the second metal oxide may include at least one type of single-metal oxide. In some embodiments, the second variable-valence metal oxide includes at least one of cuprous oxide, manganese monoxide, and tin monoxide.

[0031] In a preferred embodiment of the present invention, the directly decreasing valence metal oxide includes the non-variable valence metal oxide; or, the directly decreasing valence metal oxide includes both the non-variable valence metal oxide and the second variable valence metal oxide. In some specific implementations, the stepwise decreasing valence metal oxide is the first variable valence metal oxide, and the directly decreasing valence metal oxide is the non-variable valence metal oxide.

[0032] As an explanation of the non-variable valence metal oxide, the metal element in the non-variable valence metal oxide is a non-variable valence metal. In some embodiments, the non-variable valence metal oxide is a compound of a metal element and oxygen, and the non-variable valence metal oxide may include at least one type of single metal oxide. In some embodiments, the non-variable valence metal oxide includes at least one of magnesium oxide, zinc oxide, and cadmium oxide.

[0033] In this invention, the stepwise de-valence metal oxide is subjected to a de-valence pretreatment to reduce the valence state of the metal element in the stepwise de-valence metal oxide and cause deoxidation, thereby obtaining a pretreated material; specifically, during the de-valence pretreatment, the valence state of the metal element in the stepwise de-valence metal oxide decreases to the lowest valence state that combines with oxygen, and partial deoxidation occurs.

[0034] It should be noted that the present invention requires the stepwise reduction of valence metal oxides to undergo the aforementioned valence reduction pretreatment. Without this pretreatment, the stepwise reduction of valence metal oxides cannot be transformed into lower valence oxides with even lower reduction free energy, making it difficult to reduce the reduction thermodynamic differences between the various metal oxides, resulting in significant challenges in simultaneous reduction, and making alloying difficult or producing poor alloying effects.

[0035] Meanwhile, if the stepwise reducing oxidation state metal oxide is not subjected to the aforementioned pretreatment, but is directly subjected to a reduction reaction, oxygen will be released slowly in batches during the stepwise reduction and oxygen evolution of the metal elements in the stepwise reducing oxidation state metal oxide. This results in free oxygen being present throughout the reaction, interfering with the plasma reaction process and reducing reaction efficiency. In contrast to the stepwise reducing oxidation state metal oxide, the metal elements in the directly reducing oxidation state metal oxide do not undergo stepwise reduction in oxidation state and there is no stepwise oxygen evolution. Oxygen is only released once during reduction, resulting in concentrated oxygen release and a short residence time.

[0036] The present invention pre-treats the stepwise reducing metal oxides, mixes the different metal oxides, and then carries out the subsequent reduction reaction together. This can replace high-purity metal elements with low-cost metal oxides, significantly reducing raw material costs.

[0037] In some embodiments of the present invention, the price reduction pretreatment includes: heat treatment of the stepwise price reduction metal oxide under the protection of a protective gas; the protective gas does not contain oxygen, and the protective gas further includes an inert gas, which may include at least one of argon, helium, and nitrogen.

[0038] It should be noted that when performing the pretreatment for price reduction using the heat treatment method described above, it must be carried out under the protection of a protective gas to avoid interference from the air atmosphere. If the heat treatment is carried out directly in the air atmosphere, the transformation of the stepwise price reduction metal oxide to a low reduction free energy and low valence state cannot be achieved in the air atmosphere, and the difference in reduction thermodynamics between the stepwise price reduction metal oxide and the directly price reduction metal oxide cannot be reduced, making it difficult to achieve synchronous reduction in the subsequent process and affecting alloying.

[0039] In this invention, the temperature of the heat treatment is not less than the deoxidation temperature of the stepwise deoxidation metal oxide; in some embodiments, the temperature of the heat treatment is not less than the deoxidation temperature of the stepwise deoxidation metal oxide, and the difference between the heat treatment temperature and the deoxidation temperature is not greater than 200°C.

[0040] In this invention, the deoxidation temperature of copper oxide is 1120℃, the deoxidation temperature of manganese dioxide is 1000℃, and the deoxidation temperature of tin dioxide is 2440℃. In some specific embodiments, the heat treatment temperature is not less than 1000℃, and the stepwise deoxidation metal oxide includes manganese dioxide; or, the heat treatment temperature is not less than 1120℃, and the stepwise deoxidation metal oxide includes at least one of manganese dioxide and copper oxide; or, the heat treatment temperature is not less than 2440℃, and the stepwise deoxidation metal oxide includes at least one of manganese dioxide, copper oxide, and tin dioxide.

[0041] In some other specific implementations, the heat treatment temperature is 1000-2800℃, and the step-decreasing metal oxide includes at least one of manganese dioxide, copper oxide, and tin dioxide; or, the heat treatment temperature is 1000-2500℃, and the step-decreasing metal oxide includes at least one of manganese dioxide, copper oxide, and tin dioxide; or, the heat treatment temperature is 1000-1150℃, and the step-decreasing metal oxide includes manganese dioxide; or, the heat treatment temperature is 1120-1300℃, and the step-decreasing metal oxide includes at least one of manganese dioxide and copper oxide; or, the heat treatment temperature is 2440-2600℃, and the step-decreasing metal oxide includes at least one of manganese dioxide, copper oxide, and tin dioxide.

[0042] The present invention employs the aforementioned heat treatment method for the pretreatment of oxidation state reduction, which can control the oxidation state of the stepwise oxidation state metal oxide, transforming it from a high oxidation state bound to oxygen to a low oxidation state bound to oxygen. Both the low oxidation state oxide and the directly oxidation state metal oxide can be reduced to elemental metal in one step, thereby reducing the reduction difference between the stepwise oxidation state metal oxide and the directly oxidation state metal oxide components, achieving simultaneous reaction of multiple components, and avoiding the adverse effects of oxygen evolution during stepwise oxidation state reduction on subsequent reduction reactions.

[0043] In some embodiments of the present invention, the heat treatment time is not less than 10 min, and more preferably not less than 20 min; or, the heat treatment time is 10-60 min, more preferably 10-30 min or 20-50 min.

[0044] In some embodiments of the present invention, the mass ratio of the stepwise decreasing valence metal oxide to the direct decreasing valence metal oxide is 1:0.01-100, further 1:0.03-63, 1:0.01-0.1, 1:0.01-0.05, 1:5-15, or 1:50-70. In some specific embodiments, the stepwise decreasing valence metal oxide is copper oxide, and the direct decreasing valence metal oxide is magnesium oxide, with a mass ratio of 1:0.01-0.1 or 1:0.01-0.05; or, the stepwise decreasing valence metal oxide is tin dioxide, and the direct decreasing valence metal oxide is magnesium oxide, with a mass ratio of 1:5-15; or, the stepwise decreasing valence metal oxide is manganese dioxide, and the direct decreasing valence metal oxide is magnesium oxide, with a mass ratio of 1:50-70.

[0045] S2, the mixture including the pretreated material and the directly reduced metal oxide is subjected to a reduction reaction with a reducing agent in a plasma reactor, the volatilized metal vapor is collected and condensed to obtain alloy powder.

[0046] In this invention, during the reduction reaction, an inert gas is introduced into the reaction region of the plasma reactor; further, when an inert gas is introduced, no oxidizing gas is introduced into the reaction region of the plasma reactor. Specifically, only an inert gas is introduced into the reaction region of the plasma reactor; or, only an inert gas and a gaseous reducing substance are introduced into the reaction region of the plasma reactor. In the reduction reaction process of this invention, the inert gas introduced can be used for arc ignition in the plasma reactor, and the inert gas may include at least one of argon and helium.

[0047] In some embodiments of the present invention, the working pressure of the reaction zone is controlled by an inlet / outlet gas balance system to be 5-130 kPa, further to 10-130 kPa, further to 15-125 kPa, or 10-30 kPa or 100-130 kPa.

[0048] Prior to the reduction reaction, the present invention performs a molding process on the mixture; the molding process includes pressing the mixture at a pressure of 30-60 MPa. Specifically, after performing the molding process, the mixture is placed in the reaction zone of the plasma reactor. By performing this molding process, the present invention can improve the material density, prevent the plasma gas flow and electric arc from dispersing the material, and ensure a stable reaction.

[0049] In this invention, the plasma reaction device includes a thermal plasma generator. The thermal plasma generator includes one of a transferred arc plasma device and a non-transferred arc plasma device; the type of thermal plasma generator may also include one of a DC arc plasma device, a radio frequency induction plasma device, and a high frequency induction plasma device. This invention utilizes the ultra-high energy of plasma to achieve a one-step "reduction-powdering-alloying" process, solving the problems of lengthy process flows, high energy consumption, and low energy utilization.

[0050] Preferably, the plasma reaction device is a transferred arc plasma device; the transferred arc plasma device has an anode and a cathode, and the arc is ignited by an inert gas; during the reduction reaction, the mixture is placed in a container corresponding to the anode; specifically, the anode is an anode crucible, and the cathode is a cathode tungsten needle.

[0051] In this invention, to further ensure the acquisition of the alloy powder, the operating current of the plasma reaction device during the reduction reaction can be set to 0.01-6 g / A, further to 0.08-5.5 g / A, 0.05-0.15 g / A, 0.2-0.8 g / A, or 3-6 g / A, where g / A refers to the ratio of the mass of the oxide reaction to the current. All material combinations of this invention can use any of the operating currents described herein to prepare the alloy powder. In other embodiments, the operating current of the plasma reaction device during the reduction reaction can be 20-1000 A, further to 20-800 A, 30-750 A, 25-50 A, 25-100 A, 700-850 A, or 750-800 A; all material combinations of this invention can use any of the operating currents described herein to prepare the alloy powder.

[0052] In this invention, the reaction rate of the reduction reaction may be not less than 0.2 g / min, more preferably 1-10 g / min, more preferably 1.5-8 g / min, 1-2 g / min, 5-7 g / min, or 7-9 g / min, where g / min refers to the ratio of the mass of the oxide reaction to the reaction time. In some other embodiments, the reaction time of the reduction reaction is not less than 5 min, more preferably 5-120 min, 5-60 min, or 5-30 min.

[0053] As a further explanation of the reducing agent described in this invention: The reducing agent includes a solid reducing substance, which includes elemental carbon; the solid reducing substance, the pretreated material, and the directly reduced-valence metal oxide coexist in the mixture; the mass percentage of the solid reducing substance in the mixture is 10-30%, more specifically 20-30%.

[0054] Alternatively, the reducing agent comprises a gaseous reducing substance; the gaseous reducing substance comprises at least one of a carbon-containing reducing gas and hydrogen; the carbon-containing reducing gas comprises at least one of C1 gaseous hydrocarbons, C2 gaseous hydrocarbons, C3 gaseous hydrocarbons, and C4 gaseous hydrocarbons. The C1 gaseous hydrocarbons include methane; the C2 gaseous hydrocarbons include at least one of ethane, ethylene, and acetylene; the C3 gaseous hydrocarbons include at least one of propane, propylene, and propyne; and the C4 gaseous hydrocarbons include at least one of butane, isobutane, butene, and butyne. During the reduction reaction, the gaseous reducing substance is introduced into the reaction zone of the plasma reactor; the volume percentage of the gaseous reducing substance in the total atmosphere is 5-80%, further 60-80%; the remainder, besides the gaseous reducing substance, can be inert gases. In this invention, the gaseous reducing substance ionizes into highly reactive reducing free radicals in the plasma reactor, reducing metal oxides.

[0055] In some embodiments of the present invention, the mixture includes a solid reducing agent, and the gaseous reducing agent is not introduced into the reaction region of the plasma reactor; or, the mixture does not include a solid reducing agent, and the gaseous reducing agent is introduced into the reaction region of the plasma reactor; or, the mixture includes a solid reducing agent, and the gaseous reducing agent is introduced into the reaction region of the plasma reactor.

[0056] In some embodiments of the present invention, after the mixture is fed into the reaction zone of the plasma reactor, a vacuum is first drawn, and then a working gas is introduced. The working gas includes an inert gas, or the working gas includes an inert gas and the gaseous reducing substance.

[0057] The present invention also provides an alloy powder, which is prepared by the short-process method for preparing alloy powder from metal oxides as described above.

[0058] In some embodiments, the average particle size of the alloy powder is 200-650 nm, more specifically 225-550 nm. Optionally, when the alloy powder is a magnesium-copper alloy powder, the average particle size is 200-250 nm; optionally, when the alloy powder is a magnesium-tin alloy powder, the average particle size is 200-300 nm; optionally, when the alloy powder is a magnesium-manganese alloy powder, the average particle size is 450-650 nm.

[0059] The following are specific examples of the present invention: Example 1 The steps in this embodiment are as follows: S1. First, take copper oxide and heat it at 1200℃ for 20 minutes under a nitrogen atmosphere to obtain the pretreated material.

[0060] The pretreated material was uniformly mixed with magnesium oxide, and then pressed into a molded mixture at a pressure of 40 MPa. In this embodiment, the mass of copper oxide and magnesium oxide were 14.5 g and 0.5 g, respectively.

[0061] S2, the above mixture is placed into the anode crucible of the DC arc plasma reactor, which is a transferred arc plasma device with a cathode tungsten needle opposite to the anode crucible; the reaction area of ​​the DC arc plasma reactor is sequentially evacuated and replaced with argon gas.

[0062] Ethane (75% by volume, the remainder being argon) is introduced into the above-treated reaction zone, and the DC arc plasma reactor is started to carry out the reduction reaction. The working current is adjusted to 30 A, and the working pressure of the reaction zone is controlled to 15 kPa through the inlet and outlet gas balance system.

[0063] In this embodiment, the reduction reaction time is 10 minutes, and the magnesium-copper alloy powder is obtained by collecting the volatilized and condensing it.

[0064] See Figure 1 As shown, it can be seen that the magnesium-copper alloy powder has uniform alloying and no component segregation in a single particle.

[0065] See Figure 2 As shown in the figure, the characteristic diffraction peaks of magnesium-copper alloy appear in the spectrum, which further indicates that magnesium-copper alloy powder was prepared in this embodiment.

[0066] In this embodiment, the magnesium-copper alloy powder contains 95.13% magnesium-copper alloy by mass.

[0067] In this embodiment, the mass percentage of oxygen in the magnesium-copper alloy powder is 3.48%.

[0068] In this embodiment, the yield of magnesium-copper alloy powder is 94.58%; the yield is calculated as: (mass of magnesium and copper elements in magnesium-copper alloy powder ÷ mass of magnesium and copper elements in the mixture) × 100%.

[0069] Using a laser particle size analyzer, the average particle size D of the magnesium-copper alloy powder in this embodiment is 225 nm.

[0070] Example 2 The steps in this embodiment are as follows: S1. First, take tin dioxide and heat it at 2450℃ for 30 minutes under a nitrogen atmosphere to obtain the pretreated material.

[0071] The pretreated material was uniformly mixed with magnesium oxide and coke, and then pressed into shape at a pressure of 35 MPa to obtain the shaped mixture. In this embodiment, the masses of tin dioxide, magnesium oxide, and coke were 6.5 g, 58.5 g, and 19.5 g, respectively.

[0072] S2, the above mixture is placed into the anode crucible of the DC arc plasma reactor, which is a transferred arc plasma device with a cathode tungsten needle opposite to the anode crucible; the reaction area of ​​the DC arc plasma reactor is sequentially evacuated and replaced with argon gas.

[0073] Argon gas is continuously introduced into the reaction area after the above treatment, and the DC arc plasma reactor is started to carry out the reduction reaction. The working current is adjusted to 750A, and the working pressure of the reaction area is controlled to 20 kPa through the gas inlet and outlet balance system.

[0074] In this embodiment, the reduction reaction time is 10 minutes, and the magnesium-tin alloy powder is obtained by collecting the volatilized and condensing it.

[0075] See Figure 3 As shown, it can be seen that the magnesium-tin alloy powder has uniform alloying and no component segregation in a single particle.

[0076] In this embodiment, the magnesium-tin alloy powder contains 95.65% magnesium-tin alloy by mass.

[0077] In this embodiment, the mass percentage of oxygen in the magnesium-tin alloy powder is 3.66%.

[0078] In this embodiment, the yield of magnesium-tin alloy powder is 90.53%; the yield is calculated as: (mass of magnesium and tin elements in magnesium-tin alloy powder ÷ mass of magnesium and tin elements in the mixture) × 100%.

[0079] Using a laser particle size analyzer, the average particle size D of the magnesium-tin alloy powder in this embodiment is 250 nm.

[0080] Example 3 The steps in this embodiment are as follows: S1. First, take manganese dioxide and heat it at 1050℃ for 30 minutes under a nitrogen atmosphere to obtain the pretreated material.

[0081] The pretreated material was uniformly mixed with magnesium oxide, and then pressed into a molded mixture at a pressure of 50 MPa. In this embodiment, the mass of manganese dioxide and magnesium oxide were 2.5 g and 157.5 g, respectively.

[0082] S2, the above mixture is placed into the anode crucible of the DC arc plasma reactor, which is a transferred arc plasma device with a cathode tungsten needle opposite to the anode crucible; the reaction area of ​​the DC arc plasma reactor is sequentially evacuated and replaced with argon gas.

[0083] Ethane (65% by volume, the remainder being argon) is introduced into the above-treated reaction zone, and the DC arc plasma reactor is started to carry out the reduction reaction. The working current is adjusted to 30 A, and the working pressure of the reaction zone is controlled to 125 kPa through the inlet and outlet gas balance system.

[0084] In this embodiment, the reduction reaction time is 20 minutes, and the magnesium-manganese alloy powder is obtained by collecting the volatilized and condensing it.

[0085] See Figure 4 As shown, it can be seen that the alloying of individual particles of magnesium-manganese alloy powder is uniform and there is no component segregation.

[0086] In this embodiment, the magnesium-manganese alloy powder contains 92.48% magnesium-manganese alloy by mass.

[0087] In this embodiment, the mass percentage of oxygen in the magnesium-manganese alloy powder is 3.37%.

[0088] In this embodiment, the yield of magnesium-manganese alloy powder is 96.60%; the yield is calculated as: (mass of magnesium and manganese elements in magnesium-manganese alloy powder ÷ mass of magnesium and manganese elements in the mixture) × 100%.

[0089] Using a laser particle size analyzer, the average particle size D of the magnesium-manganese alloy powder in this embodiment is 550 nm.

[0090] Comparative Example 1 Compared to Example 1, this comparative example did not involve heat treatment of copper oxide; instead, copper oxide was directly and uniformly mixed with magnesium oxide, while other experimental conditions remained unchanged.

[0091] See Figure 5 As shown, the product obtained in this comparative example is magnesium-copper powder, rather than powder that has reached the degree of alloying.

[0092] In this comparative example, the yield of magnesium-copper powder was 91.05%; the yield was calculated as: (mass of magnesium-copper elements in magnesium-copper powder ÷ mass of magnesium-copper elements in the mixture) × 100%.

[0093] In this comparative example of magnesium-copper powder, the mass percentage of oxygen is 8.47%.

[0094] The average particle size of the magnesium-copper powder in this comparative example was D=200nm, as determined by a laser particle size analyzer.

[0095] Comparative Example 2 Compared to Example 1, this comparative example only changed the nitrogen atmosphere in step S1 to an air atmosphere, while keeping other experimental conditions unchanged.

[0096] The product obtained in this comparative example is magnesium-copper powder, rather than powder that has reached the degree of alloying.

[0097] In this comparative example, the yield of magnesium-copper powder was 90.26%; the yield was calculated as: (mass of magnesium-copper elements in magnesium-copper powder ÷ mass of magnesium-copper elements in the mixture) × 100%.

[0098] In this comparative example of magnesium-copper powder, the mass percentage of oxygen is 9.12%.

[0099] The average particle size of the magnesium-copper powder in this comparative example was D=200nm, as determined by a laser particle size analyzer.

[0100] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made under the technical concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for preparing alloy powder from metal oxides using a short-process method, characterized in that, Including the following steps: S1 provides step-down price reduction metal oxides and direct price reduction metal oxides; The stepwise decreasing valence metal oxide includes a first variable valence metal oxide, wherein the metal element in the first variable valence metal oxide is not in the lowest valence state bound to oxygen; the direct decreasing valence metal oxide includes at least one of a second variable valence metal oxide and a non-variable valence metal oxide, wherein the metal element in the second variable valence metal oxide is in the lowest valence state bound to oxygen. The stepwise de-valence metal oxide is subjected to a de-valence pretreatment to reduce the valence state of the metal element in the stepwise de-valence metal oxide and cause deoxidation, thereby obtaining a pretreated material; The price reduction pretreatment includes: heat treatment of the stepwise price reduction metal oxide under the protection of a protective gas; the temperature of the heat treatment is not lower than the deoxidation temperature of the stepwise price reduction metal oxide; S2, the mixture including the pretreated material and the directly reduced metal oxide is subjected to a reduction reaction with a reducing agent in a plasma reactor, the volatilized metal vapor is collected and condensed to obtain alloy powder.

2. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The mass ratio of the stepwise valence-reducing metal oxide to the direct valence-reducing metal oxide is 1:0.01-100.

3. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The first variable valence metal oxide includes at least one of copper oxide, manganese dioxide, and tin dioxide.

4. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The directly decreasing valence metal oxide includes the non-variable valence metal oxide, which includes at least one of magnesium oxide, zinc oxide, and cadmium oxide.

5. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The heat treatment time shall not be less than 10 minutes.

6. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The reducing agent includes a solid reducing substance, which includes elemental carbon. The solid reducing agent, the pretreated material, and the directly reduced metal oxide coexist in the mixture; the mass percentage of the solid reducing agent in the mixture is 10-30%.

7. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The reducing agent includes a gaseous reducing substance; the gaseous reducing substance includes at least one of a carbon-containing reducing gas and hydrogen; the carbon-containing reducing gas includes at least one of C1 gaseous hydrocarbons, C2 gaseous hydrocarbons, C3 gaseous hydrocarbons, and C4 gaseous hydrocarbons. During the reduction reaction, the gaseous reducing substance is introduced into the reaction zone of the plasma reaction device; The gaseous reducing agent accounts for 5-80% of the total volume in the atmosphere.

8. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, Prior to the reduction reaction, the mixture is subjected to a molding process; the molding process includes pressing the mixture at a pressure of 30-60 MPa.

9. The method for preparing alloy powder from metal oxides using a short-process method according to claim 1, characterized in that, The operating current of the plasma reaction device is set to 0.01-6 g / A; the reaction rate of the reduction reaction is not less than 0.2 g / min; The plasma reaction device includes a thermal plasma generator; the thermal plasma generator includes one of a transferred arc plasma device and a non-transferred arc plasma device.

10. An alloy powder, characterized in that, The alloy powder is prepared using the short-process method for preparing alloy powder from metal oxides as described in any one of claims 1-9.

Images