Tantalum-niobium alloy, and smelting method therefor and use thereof

Abstract

Provided in the present application are a tantalum-niobium alloy, and a smelting method therefor and the use thereof. The method comprises the following steps: subjecting tantalum-niobium waste to sodium-salt-assisted roasting, and washing same to prepare leaching residue; and mixing the leaching residue, a reducing agent and an auxiliary agent, subjecting the resulting mixture to pyrometallurgical smelting, and casting same after the smelting is completed, so as to obtain a tantalum-niobium alloy, wherein the reducing agent comprises at least one of active metals and elemental carbon, the auxiliary agent comprises at least one of a sodium source and a calcium source, and the temperature of the pyrometallurgical smelting is 2800-3500ºC.

Description

Tantalum-niobium alloy and its smelting method and application

[0001] This application claims priority to Chinese patent application No. 202311682868.X filed on December 8, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of metal smelting technology, and in particular to a tantalum-niobium alloy and a smelting method and application thereof. Background Art

[0003] Tantalum-niobium alloy, usually composed of two metal elements, tantalum and niobium, has excellent performance and a wide range of applications. Tantalum-niobium alloy has the following characteristics:

[0004] 1. High melting point and high melting point: The melting point of tantalum is about 2996℃, while the melting point of niobium is about 2468℃. Therefore, tantalum-niobium alloy has a higher melting point, which makes it perform well in high temperature environment.

[0005] 2. Excellent corrosion resistance: Tantalum-niobium alloy has good corrosion resistance and can resist the erosion of corrosive media such as acids and alkalis. Therefore, it is widely used in corrosive environments such as the chemical industry;

[0006] 3. Excellent mechanical properties: The alloy has excellent mechanical properties, including high strength, high hardness and good ductility, and is suitable for a variety of engineering applications.

[0007] The preparation method of tantalum-niobium alloy in the related art is as follows:

[0008] 1. Metallurgical preparation: Tantalum and niobium are mixed in proportion through smelting, casting, heat treatment and other processes

[0009] And a chemical reaction is carried out at a specific temperature to finally obtain a tantalum-niobium alloy;

[0010] 2. Preparation by powder metallurgy: Tantalum and niobium powders are mixed in a certain proportion, and tantalum-niobium alloy is obtained through processes such as pressing and sintering.

[0011] The above method requires first preparing high-purity metallic tantalum and metallic niobium from alloy waste, tantalum ore or niobium ore; then mixing metallic tantalum and niobium in a certain way to prepare tantalum-niobium alloy. It is not possible to directly prepare tantalum-niobium alloy from alloy waste by one-step reduction. Technical issues

[0012] If the pyrometallurgical smelting time is too short, the reaction is insufficient, thus affecting the purity of the tantalum-niobium alloy; if the smelting time is too long, the energy consumption is too high. If the amount of auxiliary agent added is too little and the local concentration of the reducing agent is too high, the auxiliary agent's ability to inhibit the reduction reaction is poor, resulting in an overly violent local reduction reaction; if too much auxiliary agent is added and the local concentration of the reducing agent is too low, the reduction reaction will be too slow, thus affecting the purity of the tantalum-niobium alloy. If the amount of reducing agent added is too little, the reduction will be insufficient, thus affecting the purity of the tantalum-niobium alloy; if the amount of reducing agent added is too much, the residual amount of reducing agent will increase, thus affecting the purity of the tantalum-niobium alloy. If the roasting temperature is too low, the reaction will be too slow; if the temperature is too high, the tungsten element will be converted into tungsten element, which has high melting and boiling points, resulting in an increase in the residual amount of tungsten, thus affecting the purity of the tantalum-niobium alloy. The present application is made in view of the above-mentioned problems, and its purpose is to provide a smelting method for tantalum-niobium alloy, which can produce a high-purity tantalum-niobium alloy by one-step reduction. Technical Solutions

[0013] Specifically, the first aspect of the present application provides a smelting method of tantalum-niobium alloy, comprising the following steps:

[0014] The tantalum-niobium waste is sodium-treated, roasted, and then washed with water to obtain leaching residue;

[0015] The leaching residue, reducing agent and auxiliary agent are mixed and then pyrometallurgically smelted, and after smelting, the mixture is cast to obtain a tantalum-niobium alloy;

[0016] The reducing agent includes at least one of an active metal and a carbon element;

[0017] The auxiliary agent includes at least one of a sodium source and a calcium source;

[0018] The temperature of the pyrometallurgical smelting is 2800°C to 3500°C.

[0019] In one embodiment, the active metal includes at least one of sodium, sodium alloy, calcium, and calcium alloy.

[0020] In one embodiment, the sodium source includes at least one of sodium hydroxide and sodium carbonate.

[0021] In one embodiment, the calcium source includes at least one of calcium hydroxide, calcium oxide and calcium carbonate.

[0022] In one embodiment, the pyrometallurgical smelting time is 1 hour to 3 hours.

[0023] In one embodiment, the mass ratio of the leaching residue to the auxiliary agent is 100:(15~25).

[0024] In one embodiment, the mass ratio of the leaching residue to the reducing agent is 100:(15-30).

[0025] In one embodiment, the temperature of the sodium calcination is 800°C to 1000°C.

[0026] In one embodiment, a sodium-containing reducing agent is added during the sodium roasting process.

[0027] In one embodiment, the mass ratio of the sodium-containing reducing agent to the tantalum-niobium waste is (20-40):100.

[0028] The second aspect of the present application further provides a tantalum-niobium alloy, which is smelted by the above-mentioned smelting method.

[0029] The third aspect of the present application further provides the use of the above-mentioned tantalum-niobium alloy in the aerospace industry, the preparation of tantalum capacitors and / or the preparation of communication equipment. Beneficial effects

[0030] In this application, the tantalum-niobium scrap contains not only tantalum and niobium, but also tungsten and silicon. To produce a high-purity tantalum-niobium alloy, this application first sodium-treats the tantalum-niobium scrap and roasts it, converting silicon into sodium silicate and tungsten into sodium tungstate. The tungsten and silicon in the tantalum-niobium scrap are then removed by water washing, utilizing the water solubility of sodium silicate and sodium tungstate. The tantalum and niobium are then initially reduced, thereby removing tungsten, silicon, and other soluble impurities through sodium-treats roasting and then water washing.

[0031] The present application then produces a high-purity tantalum-niobium alloy by mixing the leached slag, a reducing agent, and an auxiliary agent and then subjecting the mixture to pyrometallurgy. Under the action of the reducing agent, tantalum oxide is converted into metallic tantalum, and niobium oxide is converted into metallic niobium. At the pyrometallurgy temperature of the present application, metallic niobium is converted into a liquid and forms a tantalum-niobium alloy with metallic tantalum. The active metal is gaseous at the temperature of the present application, and the residual amount in the formed tantalum-niobium alloy is low. At the same time, due to the high reactivity of the active metal, an auxiliary agent is required to reduce the concentration of the active metal to prevent excessive reaction. After the carbon element reduces the metal oxides (tantalum oxide and niobium oxide) to metal, part of it is converted into gaseous carbon oxides (such as CO or CO2), which also do not remain in the tantalum-niobium alloy in large quantities. In other words, the present application produces a high-purity tantalum-niobium alloy by synergistically combining the pyrometallurgy temperature, the reducing agent, and the auxiliary agent.

[0032] Sodium alone, sodium alloys, calcium alone, and calcium alloys have low boiling points and high activity, and can sufficiently reduce tantalum oxide and niobium oxide.

[0033] By adding sodium hydroxide or sodium carbonate as an auxiliary agent, the contact area between the materials can be reduced to prevent the local reaction from being too intense.

[0034] By adding calcium hydroxide, calcium oxide and calcium carbonate as auxiliary agents, the contact area between materials can be reduced and excessive local reactions can be prevented.

[0035] During the sodium roasting process, a sodium-containing reducing agent is added, which will initially reduce the tantalum and niobium elements; the sodium-containing reducing agent will be converted into a strong alkaline substance, which will convert the tungsten and silicon elements into soluble salts, thereby removing them.

[0036] The tantalum-niobium alloy prepared by the present application scheme can be further applied to the preparation of tantalum metal. Tantalum metal has excellent physical and chemical properties (excellent corrosion resistance, excellent high temperature resistance and high strength), and its application fields are very wide; application fields include aerospace industry, capacitors, and communication equipment (5G and above). That is, the tantalum-niobium alloy prepared by the present application scheme has broad application prospects. Modes for Carrying Out the Invention

[0037] The following detailed description specifically discloses the tantalum-niobium alloy, its smelting method, and embodiments of its applications. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially identical structures may be omitted. This is to avoid unnecessary length and facilitate understanding by those skilled in the art. Furthermore, the following description is provided to enable those skilled in the art to fully understand the present application and is not intended to limit the subject matter recited in the claims.

[0038] " range " disclosed in the present application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be to include end value or not include end value, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the scope of 60-120 and 80-110 is listed for specific parameters, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range value 1 and 2 are listed, and if the maximum range value 3,4 and 5 are listed, then the following range can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise specified, the numerical range " ab " represents the abbreviation of any real number combination between a and b, wherein a and b are all real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is simply an abbreviation for these numerical combinations. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0039] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0040] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0041] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0042] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0043] Unless otherwise specified, the term "or" is used in this application to be inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, the condition "A or B" is satisfied if any of the following conditions are met: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0044] Specifically, a first aspect of the present invention provides a smelting method of a tantalum-niobium alloy, comprising the following steps:

[0045] The tantalum-niobium waste is sodium-treated, roasted, and then washed with water to obtain leaching residue;

[0046] The leaching residue, reducing agent and auxiliary agent are mixed and then pyrometallurgically smelted, and after smelting, the mixture is cast to obtain a tantalum-niobium alloy;

[0047] The reducing agent includes at least one of an active metal and a carbon element;

[0048] The auxiliary agent includes at least one of a sodium source and a calcium source;

[0049] The temperature of the pyrometallurgical smelting is 2800°C to 3500°C.

[0050] In this application, the tantalum-niobium scrap contains not only tantalum and niobium, but also tungsten and silicon. To produce a high-purity tantalum-niobium alloy, this application first sodium-treats the tantalum-niobium scrap and roasts it, converting silicon into sodium silicate and tungsten into sodium tungstate. The tungsten and silicon in the tantalum-niobium scrap are then removed by water washing, utilizing the water solubility of sodium silicate and sodium tungstate. The tantalum and niobium are then initially reduced, thereby removing tungsten, silicon, and other water-soluble impurities through sodium-treats roasting and then water washing.

[0051] The present application then produces a high-purity tantalum-niobium alloy by mixing the leached slag, a reducing agent, and an auxiliary agent and then subjecting the mixture to pyrometallurgy. Under the action of the reducing agent, tantalum oxide is converted into metallic tantalum, and niobium oxide is converted into metallic niobium. At the pyrometallurgy temperature of the present application, metallic niobium is converted into a liquid and forms a tantalum-niobium alloy with metallic tantalum. The active metal is gaseous at the temperature of the present application, and the residual amount in the formed tantalum-niobium alloy is low. At the same time, due to the high reactivity of the active metal, an auxiliary agent is required to reduce the concentration of the active metal to prevent excessive reaction. After the carbon element reduces the metal oxides (tantalum oxide and niobium oxide) to metal, part of it is converted into gaseous carbon oxides (such as CO or CO2), which also do not remain in the tantalum-niobium alloy in large quantities. In other words, the present application produces a high-purity tantalum-niobium alloy by synergistically combining the pyrometallurgy temperature, the reducing agent, and the auxiliary agent.

[0052] The tantalum-niobium alloy prepared by the present application scheme can be further applied to the preparation of tantalum metal. Tantalum metal has excellent physical and chemical properties (excellent corrosion resistance, excellent high temperature resistance and high strength), and its application fields are very wide; application fields include aerospace industry, capacitors, and communication equipment (5G and above). That is, the tantalum-niobium alloy prepared by the present application scheme has broad application prospects.

[0053] In some embodiments, the active metal includes at least one of sodium, sodium alloy, calcium, and calcium alloy.

[0054] Sodium alone, sodium alloys, calcium alone, and calcium alloys have low boiling points and high activity, and can sufficiently reduce tantalum oxide and niobium oxide.

[0055] In some embodiments, the sodium source comprises at least one of sodium hydroxide and sodium carbonate.

[0056] By adding sodium hydroxide or sodium carbonate as an auxiliary agent, the contact area between the materials can be reduced to prevent the local reaction from being too intense.

[0057] In some embodiments, the calcium source includes at least one of calcium hydroxide, calcium oxide, and calcium carbonate.

[0058] By adding calcium hydroxide, calcium oxide or calcium carbonate as an auxiliary agent, the contact area between the materials can be reduced to prevent the local reaction from being too intense.

[0059] In some embodiments, the pyrometallurgical smelting time is 1 hour to 3 hours.

[0060] If the pyrometallurgical smelting time is too short, the reaction will be insufficient, thus affecting the purity of the tantalum-niobium alloy; while if the smelting time is too long, the energy consumption will be too high.

[0061] In some embodiments, the mass ratio of the leaching residue to the auxiliary agent is 100:(15~25).

[0062] If the amount of auxiliary agent added is too little and the local concentration of the reducing agent is too high, the auxiliary agent will have poor ability to inhibit the reduction reaction, resulting in an overly intense local reduction reaction; if the amount of auxiliary agent added is too much and the local concentration of the reducing agent is too low, the reduction reaction will be too slow, thereby affecting the purity of the tantalum-niobium alloy.

[0063] In some embodiments, the mass ratio of the leaching residue to the reducing agent is 100:(15~30).

[0064] If the amount of reducing agent added is too little, the reduction will be insufficient, thus affecting the purity of the tantalum-niobium alloy; if the amount of reducing agent added is too much, the residual amount of reducing agent will increase, thus affecting the purity of the tantalum-niobium alloy.

[0065] In some embodiments, the carbon element is graphite.

[0066] In some embodiments, the reducing agent consists of an active metal and carbon.

[0067] In some embodiments, the mass ratio of the active metal to the carbon element is 1:(2-3).

[0068] If the amount of active metal used is too much, the production cost will be high; if the amount of active metal used is too little, the reducibility of the pyrometallurgical system will be reduced, thereby affecting the purity of the tantalum-niobium alloy.

[0069] In some embodiments, the reducing agent consists of elemental sodium, elemental calcium, and elemental carbon.

[0070] The boiling point of sodium element is 883°C, and the boiling point of calcium element is 1484°C. During the pyrometallurgical process, both sodium element and calcium element will vaporize to form a reducing atmosphere; and during the heating process of pyrometallurgy, sodium element will vaporize first to form a reducing atmosphere; and during the vaporization process of sodium element, it will be initially reduced with solid niobium oxide and tantalum pentoxide; and calcium element will then vaporize and contact with molten niobium pentoxide (melting point is 1460°C), thereby achieving efficient reduction; finally, tantalum pentoxide (melting point is 1800°C) melts and fully contacts with carbon element in the system for further reduction; that is, in this application, the reduction efficiency is further improved by further selecting the reducing agent, thereby further improving the purity of the tantalum-niobium alloy.

[0071] In some embodiments, the mass ratio of sodium, calcium, and carbon in the reducing agent is 1:(2-3):(6-12).

[0072] In some embodiments, the mass ratio of sodium, calcium, and carbon in the reducing agent is 1:(2-3):(6-10).

[0073] In some embodiments, the mass ratio of sodium, calcium, and carbon in the reducing agent is 1:(2-3):(6-9).

[0074] In some embodiments, the heating process of the pyrometallurgical process consists of the following heating stages:

[0075] The first stage of heating: 20℃~30℃ to 1000℃~1200℃; heating time is 0.5h~1h;

[0076] The first stage of heat preservation: heat preservation at 1000℃~1200℃ for 0.5h~1h;

[0077] The second stage of heating: 1000℃~1200℃ to 1800℃~1900℃; the heating time is 0.5h~1h;

[0078] The second stage of heat preservation: heat preservation at 1800℃~1900℃ for 0.4h~0.6h;

[0079] The third stage of heating: from 1800℃~1900℃ to 2800℃~3500℃; the heating time is 1h~1.5h.

[0080] In some embodiments, the temperature of the pyrometallurgical smelting is 2800°C to 3000°C.

[0081] In some embodiments, the final temperature of the third stage of heating is 2800°C to 3000°C.

[0082] In some embodiments, the temperature of the sodium calcination is 800°C to 1000°C.

[0083] If the roasting temperature is too low, the reaction will be too slow; if the temperature is too high, the tungsten element will be converted into tungsten element, which has high melting and boiling points, resulting in an increase in the residual amount of tungsten, thereby affecting the purity of the tantalum-niobium alloy.

[0084] In some embodiments, a sodium-containing reducing agent is added during the sodium roasting process.

[0085] During the sodium roasting process, a sodium-containing reducing agent is added, which will initially reduce the tantalum and niobium elements; the sodium-containing reducing agent will be converted into a strong alkaline substance, which will convert the tungsten and silicon elements into soluble salts, thereby removing them.

[0086] In some embodiments, the mass ratio of the sodium-containing reducing agent to the tantalum-niobium waste is (20-40):100.

[0087] In some embodiments, the sodium-containing reducing agent comprises at least one of elemental sodium and a sodium alloy.

[0088] In some embodiments, the sodium calcination time is 1 hour to 2 hours.

[0089] In some embodiments, the water temperature used for washing is 20°C to 30°C.

[0090] In some embodiments, the water washing time is 0.5h~1h.

[0091] In some embodiments, the mass fraction of tantalum pentoxide in the tantalum-niobium waste is greater than 1.5%.

[0092] In some embodiments, the mass fraction of niobium pentoxide in the tantalum-niobium waste is greater than 1.5%.

[0093] In some embodiments, the mass fraction of tungsten oxide in the tantalum-niobium waste is greater than 1.5%.

[0094] In some embodiments, the mass fraction of silicon oxide in the tantalum-niobium waste is greater than 20%.

[0095] By controlling the smelting conditions, the embodiments of the present application achieve the recovery of tantalum-niobium metal from tantalum-niobium waste with high silicon, low tantalum and low niobium content, greatly reducing production costs.

[0096] A second aspect of the embodiments of the present application further provides a tantalum-niobium alloy, which is smelted by the above-mentioned smelting method.

[0097] The third aspect of the embodiments of the present application further provides the application of the above-mentioned tantalum-niobium alloy in the aerospace industry, the preparation of tantalum capacitors and / or the preparation of communication equipment.

[0098] The mass contents of the elements (calculated as oxides) in the tantalum-niobium waste materials used in this embodiment and the comparative example are as follows:

[0099] Tantalum pentoxide 2.67%, niobium pentoxide 1.89%, tungsten trioxide 1.53%, silicon dioxide 36.3% and the balance are other impurities.

[0100] Example 1

[0101] This embodiment is a smelting method of tantalum-niobium alloy, which comprises the following steps:

[0102] S1. Mixing tantalum and niobium waste and sodium element, then performing sodiumization roasting (roasting temperature is 900°C, time is 1.5 hours), and washing (washing water temperature is 25°C, time is 1 hour) to obtain leaching residue;

[0103] The mass ratio of sodium element and tantalum-niobium waste is 1:4;

[0104] S2, mixing the leaching residue, the reducing agent and the auxiliary agent, heating and pyrometallurgically smelting the mixture (the pyrometallurgical temperature is 3000° C. and the pyrometallurgical time is 2 hours); after the smelting is completed, casting is performed to obtain a tantalum-niobium alloy;

[0105] The mass ratio of leaching residue to auxiliary agent in this step is 100:18;

[0106] The mass ratio of leaching residue to reducing agent is 100:22;

[0107] The reducing agent is composed of the following raw materials in parts by mass:

[0108] 1 part of sodium, 2.4 parts of calcium and 10 parts of graphite;

[0109] The auxiliary agent is composed of a sodium source (sodium hydroxide) and a calcium source (calcium oxide and calcium carbonate, with the mass ratio of calcium oxide to calcium carbonate being 1:3); the mass ratio of the sodium source to the calcium source is 1:2;

[0110] The heating process before pyrometallurgy consists of the following heating stages:

[0111] The first stage of heating: 25℃ to 1200℃; heating time is 0.8h;

[0112] The first stage of heat preservation: heat preservation at 1200℃ for 0.6h;

[0113] The second stage of heating: 1200℃ to 1850℃; heating time is 0.6h;

[0114] The second stage of heat preservation: heat preservation at 1850℃ for 0.5h;

[0115] The third stage of heating: 1850℃ to 3000℃; the heating time is 1.2h.

[0116] Example 2

[0117] This embodiment is a smelting method of tantalum-niobium alloy, which comprises the following steps:

[0118] S1. Mixing tantalum and niobium waste and sodium element, then performing sodiumization roasting (roasting temperature is 1000°C, time is 1.5 hours), and washing (washing water temperature is 25°C, time is 1 hour) to obtain leaching residue;

[0119] The mass ratio of sodium element and tantalum-niobium waste is 1:5;

[0120] S2, mixing the leaching residue, the reducing agent and the auxiliary agent, heating and pyrometallurgically smelting the mixture (the pyrometallurgical temperature is 2900° C. and the pyrometallurgical time is 2 hours); after the smelting is completed, casting is performed to obtain a tantalum-niobium alloy;

[0121] The mass ratio of leaching residue to auxiliary agent in this step is 100:20;

[0122] The mass ratio of leaching residue to reducing agent is 100:20;

[0123] The reducing agent is composed of the following raw materials in parts by mass:

[0124] 1 part of sodium, 2 parts of calcium and 8 parts of graphite;

[0125] The auxiliary agent is composed of a sodium source (sodium carbonate) and a calcium source (calcium oxide and calcium carbonate, the mass ratio of calcium oxide to calcium carbonate is 1:3); the mass ratio of the sodium source to the calcium source is 1:2;

[0126] The heating process before pyrometallurgy consists of the following heating stages:

[0127] The first stage of heating: 25℃ to 1100℃; heating time is 0.5h;

[0128] The first stage of heat preservation: heat preservation at 1100℃ for 1h;

[0129] The second stage of heating: 1100℃ to 1800℃; heating time is 1h;

[0130] The second stage of heat preservation: heat preservation at 1800℃ for 0.6h;

[0131] The third stage of heating: 1800℃ to 2900℃; the heating time is 1h.

[0132] Example 3

[0133] This embodiment is a smelting method of tantalum-niobium alloy, which comprises the following steps:

[0134] S1. Mixing tantalum and niobium waste and sodium element, then performing sodiumization roasting (roasting temperature is 920°C, time is 1.5h), and washing (washing temperature is 25°C, time is 0.5h) to obtain leaching residue;

[0135] The mass ratio of sodium element and tantalum-niobium waste is 1:4;

[0136] S2, mixing the leaching residue, the reducing agent and the auxiliary agent, heating and pyrometallurgically smelting the mixture (the pyrometallurgical temperature is 2800° C. and the pyrometallurgical time is 2 hours); after the smelting is completed, casting is performed to obtain a tantalum-niobium alloy;

[0137] The mass ratio of leaching residue to auxiliary agent in this step is 100:20;

[0138] The mass ratio of leaching residue to reducing agent is 100:30;

[0139] The reducing agent is composed of the following raw materials in parts by mass:

[0140] 1 part of sodium, 3 parts of calcium and 10 parts of graphite;

[0141] The auxiliary agent is composed of a sodium source (sodium carbonate) and a calcium source (calcium oxide and calcium carbonate, the mass ratio of calcium oxide to calcium carbonate is 1:3); the mass ratio of the sodium source to the calcium source is 1:2;

[0142] The heating process before pyrometallurgy consists of the following heating stages:

[0143] The first stage of heating: 25℃ to 1120℃; heating time is 0.6h;

[0144] The first stage of heat preservation: heat preservation at 1120℃ for 1h;

[0145] The second stage of heating: 1120℃ to 1880℃; heating time is 1h;

[0146] The second stage of heat preservation: heat preservation at 1880℃ for 0.5h;

[0147] The third stage of heating: 1880℃ to 2800℃; the heating time is 1h.

[0148] Example 4

[0149] This embodiment is a smelting method of tantalum-niobium alloy, which comprises the following steps:

[0150] S1. Mixing tantalum and niobium waste and sodium element, then performing sodiumization roasting (roasting temperature is 950°C, time is 1.5 hours), and washing (washing water temperature is 25°C, time is 1 hour) to obtain leaching residue;

[0151] The mass ratio of sodium element and tantalum-niobium waste is 1:5;

[0152] S2, mixing the leaching residue, the reducing agent and the auxiliary agent, heating and pyrometallurgically smelting the mixture (the pyrometallurgical temperature is 3100° C. and the pyrometallurgical time is 2 hours); after the smelting is completed, casting is performed to obtain a tantalum-niobium alloy;

[0153] The mass ratio of leaching residue to auxiliary agent in this step is 100:18;

[0154] The mass ratio of leaching residue to reducing agent is 100:25;

[0155] The reducing agent is composed of the following raw materials in parts by mass:

[0156] 1 part of sodium, 2.8 parts of calcium and 11 parts of graphite;

[0157] The auxiliary agent is composed of a sodium source (sodium hydroxide) and a calcium source (calcium oxide and calcium carbonate, with the mass ratio of calcium oxide to calcium carbonate being 1:3); the mass ratio of the sodium source to the calcium source is 1:2;

[0158] The heating process before pyrometallurgy consists of the following heating stages:

[0159] The first stage of heating: 25℃ to 1150℃; heating time is 1h;

[0160] The first stage of heat preservation: heat preservation at 1150℃ for 0.8h;

[0161] The second stage of heating: 1150℃ to 1810℃; heating time is 0.6h;

[0162] The second stage of heat preservation: heat preservation at 1810℃ for 0.6h;

[0163] The third stage of heating: 1810℃ to 3100℃; heating time is 1.5h.

[0164] Example 5

[0165] This embodiment is a smelting method of tantalum-niobium alloy, which comprises the following steps:

[0166] S1. Mixing tantalum and niobium waste and sodium element, roasting them (the roasting temperature is 860°C, the time is 1.5 hours), and washing them (the water temperature of the washing is 25°C, the time is 1 hour) to obtain leaching residue;

[0167] The mass ratio of sodium element and tantalum-niobium waste is 1:4;

[0168] S2, mixing the leaching residue, the reducing agent and the auxiliary agent, heating and pyrometallurgizing (pyrometallurgical temperature is 3200° C., time is 2 hours); after smelting, casting is performed to obtain tantalum-niobium alloy;

[0169] The mass ratio of leaching residue to auxiliary agent in this step is 100:17;

[0170] The mass ratio of leaching residue to reducing agent is 100:26;

[0171] The reducing agent is composed of the following raw materials in parts by mass:

[0172] 1 part of sodium, 2.2 parts of calcium and 9 parts of graphite;

[0173] The auxiliary agent is composed of a sodium source (sodium carbonate) and a calcium source (calcium oxide and calcium carbonate, the mass ratio of calcium oxide to calcium carbonate is 1:3); the mass ratio of the sodium source to the calcium source is 1:2;

[0174] The heating process before pyrometallurgy consists of the following heating stages:

[0175] The first stage of heating: 25℃ to 1160℃; heating time is 0.5h;

[0176] The first stage of heat preservation: heat preservation at 1160℃ for 0.5h;

[0177] The second stage of heating: 1160℃ to 1900℃; heating time is 1h;

[0178] The second stage of heat preservation: heat preservation at 1900℃ for 0.5h;

[0179] The third stage of heating: 1900℃ to 3200℃; the heating time is 1.5h.

[0180] Example 6

[0181] This embodiment is a smelting method of tantalum-niobium alloy, which differs from embodiment 5 only in that:

[0182] Replace the reducing agent with graphite.

[0183] Example 7

[0184] This embodiment is a smelting method of tantalum-niobium alloy, which differs from embodiment 5 only in that:

[0185] Replace the reducing agent with elemental sodium.

[0186] Example 8

[0187] This embodiment is a smelting method of tantalum-niobium alloy, which differs from embodiment 5 only in that:

[0188] Replace the reducing agent with elemental calcium.

[0189] Example 9

[0190] This embodiment is a smelting method of tantalum-niobium alloy, which differs from embodiment 5 only in that:

[0191] The heating process in Example 5 is replaced by the following heating process:

[0192] The heating process consists of the following heating stages:

[0193] The first stage of heating: 25℃ to 1160℃; heating time is 0.5h;

[0194] The first stage of heat preservation: heat preservation at 1160℃ for 0.5h;

[0195] The second stage of heating: 1160℃ to 3200℃; the heating time is 2.5h.

[0196] Example 10

[0197] This embodiment is a smelting method of tantalum-niobium alloy, which differs from embodiment 5 only in that:

[0198] The heating process in Example 5 is replaced by the following heating process:

[0199] The heating process consists of the following heating stages:

[0200] Heat from 25℃ to 3200℃; heating time is 3h.

[0201] The purity and yield test methods of the tantalum-niobium alloys prepared in Examples 1 to 10 are as follows:

[0202] The contents of tantalum and niobium in the tantalum-niobium alloy were determined in accordance with GB / T-15076.2. The purity and yield of the tantalum-niobium alloy were calculated by testing the contents of tantalum and niobium in the tantalum-niobium alloy. The test results are shown in Table 1.

[0203] Table 1 Purity and yield test results of tantalum-niobium alloys prepared in Examples 1 to 10

[0204] -Purity (%) Yield (%) Example 1 56.695.3 Example 2 55.995.1 Example 3 55.494.6 Example 4 54.794.2 Example 5 54.993.4 Example 6 50.190.5 Example 7 48.386.6 Example 8 48.987.4 Example 9 52.391.8 Example 10 51.790.3

[0205] From the comparison between Example 5 and Examples 6 to 8, it can be seen that the reduction effect of the composite reducing agent is better than that of a single reducing agent. The reason is that the composite reducing agent can perform multi-stage reduction of the oxide, thereby improving the reduction effect and further improving the purity and yield of the tantalum-niobium alloy.

[0206] From the comparison between Example 5 and Examples 9-10, it can be seen that the three-stage heating process is beneficial to further improving the reduction effect of tantalum-niobium waste. The reason is that different reducing agents exert the main reduction effect in different insulation sections of the three-stage heating process, thereby further improving the reduction effect of the reducing agent, thereby producing a higher purity tantalum-niobium alloy.

[0207] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A method for smelting tantalum-niobium alloy, wherein: The smelting method of the tantalum-niobium alloy comprises the following steps: The tantalum-niobium waste is sodium-treated, roasted and then washed with water to obtain leaching residue; The leached slag, the reducing agent and the auxiliary agent are mixed and then subjected to pyrometallurgical smelting, and after the smelting is completed, casting is performed to obtain a tantalum-niobium alloy; The reducing agent includes at least one of an active metal and a carbon element; The auxiliary agent includes at least one of a sodium source and a calcium source; The temperature of the pyrometallurgical smelting is 2800°C to 3500°C.

2. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The active metal includes at least one of sodium element, sodium alloy, calcium element and calcium alloy.

3. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The sodium source includes at least one of sodium hydroxide and sodium carbonate.

4. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The calcium source includes at least one of calcium oxide and calcium carbonate.

5. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The pyrometallurgical smelting time is 1h~3h.

6. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The mass ratio of the leaching residue to the auxiliary agent is 100:(15-25).

7. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The mass ratio of the leaching residue to the reducing agent is 100:(15-30).

8. The smelting method of tantalum-niobium alloy according to claim 1, wherein: The temperature of the sodium calcination is 800°C to 1000°C; and / or, a sodium-containing reducing agent is added during the sodium roasting process; And / or, the mass ratio of the sodium-containing reducing agent to the tantalum-niobium waste is (20-40):

100.

9. A tantalum-niobium alloy, wherein: The tantalum-niobium alloy is smelted by the smelting method according to any one of claims 1 to 8.

10. Use of the tantalum-niobium alloy according to claim 9 in the aerospace industry, in the preparation of tantalum capacitors and / or in the preparation of communication equipment.