阅读说明：本技术 铜或铜合金的脱氧方法、高纯铜或铜合金的制备方法及由该方法得到的高纯铜或铜合金 (Method for deoxidizing copper or copper alloy, method for producing high-purity copper or copper alloy, and high-purity copper or copper alloy obtained by the method ) 是由 宋克兴 程楚 周延军 刘海涛 安世忠 张彦敏 皇涛 国秀花 李韶林 朱一明 宋金 于 2019-10-28 设计创作，主要内容包括：本发明涉及一种铜或铜合金的脱氧方法、高纯铜或铜合金的制备方法及由该方法得到的高纯铜或铜合金,属于铜及铜合金制备技术领域。本发明提供了一种铜或铜合金的脱氧方法,包括以下步骤：向铜或铜合金的熔体底部通入携带还原性金属蒸汽或粉末的保护气体。还原性金属作为脱氧剂,能够有效脱除熔体中的氧,形成易上浮的低密度金属氧化物,从熔体底部通入携带还原性金属的保护气体的方式有助于还原性金属蒸汽或粉末的上浮,提高了还原性金属蒸汽或粉末的利用率,强化了脱氧效果,有利于脱氧过程实现自动化控制,保护气体不仅起到携带还原性金属的作用,还作为防护气体避免铜或铜合金熔体被氧化,且具有搅拌和携带脱氧产物上浮的作用,脱氧彻底。(The invention relates to a deoxidation method of copper or copper alloy, a preparation method of high-purity copper or copper alloy and the high-purity copper or copper alloy obtained by the method, belonging to the technical field of copper and copper alloy preparation. The invention provides a deoxidation method of copper or copper alloy, which comprises the following steps: and introducing protective gas carrying reducing metal vapor or powder into the bottom of the copper or copper alloy melt. The reducing metal is used as a deoxidizer, oxygen in the melt can be effectively removed, a low-density metal oxide which is easy to float is formed, the mode of introducing protective gas carrying the reducing metal from the bottom of the melt is favorable for floating of reducing metal steam or powder, the utilization rate of the reducing metal steam or powder is improved, the deoxidation effect is strengthened, the automatic control of the deoxidation process is realized, the protective gas not only plays a role in carrying the reducing metal, but also serves as protective gas to avoid copper or copper alloy melt from being oxidized, the deoxidizer has the functions of stirring and carrying the deoxidizer to float, and the deoxidation is thorough.)

1. A method of deoxidizing copper or a copper alloy, comprising the steps of:

and introducing protective gas carrying reducing metal vapor or powder into the bottom of the copper or copper alloy melt.

2. The method for deoxidizing of copper or a copper alloy as set forth in claim 1, wherein an upper surface of said melt is covered with a covering agent.

3. The method for deoxidizing of copper or a copper alloy as set forth in claim 2, wherein said covering agent is mainly composed of the following raw materials in percentage by mass:

60-75% of sodium tetraborate, 10-20% of silicon dioxide, 5-15% of sodium fluoroaluminate and 5-15% of sodium fluoride.

4. The method for deoxidizing copper or a copper alloy as set forth in claim 2, wherein said melt whose upper surface is covered with a covering agent is prepared by a method comprising the steps of:

and in the atmosphere of protective gas, adding a covering agent into the metal material of copper or copper alloy, and heating to melt the metal material and the covering agent to obtain the copper-copper alloy.

5. The method for deoxidizing of copper or a copper alloy as set forth in claim 4, wherein a weight of said covering agent is 0.6 to 1.5% of a weight of said metal material.

6. The method for deoxidizing of copper or a copper alloy as set forth in any one of claims 1 to 5, wherein said reducing metal is one or two or more of Ca, Mg, Na, K, or Li.

7. The method for deoxidizing of copper or a copper alloy as set forth in any one of claims 1 to 5, wherein the weight of said reducing metal is 0.2% to 1.0% of the weight of the melt.

8. The method for deoxidizing of copper or a copper alloy as set forth in any one of claims 1 to 5, wherein said deoxidizing is performed in an induction furnace, and a frequency of said induction furnace is 1000 to 2500 Hz.

9. The preparation method of the high-purity copper or the copper alloy is characterized by comprising the following steps of:

deoxidizing the melt of copper or copper alloy by using the deoxidizing method of copper or copper alloy as claimed in any one of claims 1 to 8, then cooling to 1100-1200 ℃, casting, and removing slag to obtain the product.

10. A high purity copper or copper alloy obtained by the method for producing high purity copper or copper alloy according to claim 9.

Technical Field

The invention relates to a deoxidation method of copper or copper alloy, a preparation method of high-purity copper or copper alloy and the high-purity copper or copper alloy obtained by the method, belonging to the technical field of copper and copper alloy preparation.

Background

Oxygen is hardly dissolved in copper, and when oxygen-containing copper is solidified, oxygen is precipitated in the form of eutectic and distributed on the grain boundary of copper. When the oxygen content in the cast oxygen-containing copper is extremely low, the Cu content appears along with the increase of the oxygen content₂Hypo-, co-and hypereutectic of O. In copper alloys, the influence of oxygen in the presence of other elements is extremely complex, and the mechanical properties, electrical conductivity and other properties of the alloy are affected to different degrees. At present, common oxygen-free copper and copper alloy are generally smelted in an induction furnace, and high-purity oxygen-free copper is smelted in a vacuum induction furnace. In the process of smelting copper and copper alloy in an induction furnace, in order to prevent the melt from being polluted,smelting and refining are generally carried out without any additive, but protection is carried out by covering the surface of a molten pool with charcoal and in a reducing atmosphere; however, charcoal is apt to absorb moist air and even directly absorb moisture, and thus it becomes a channel that makes it possible for the copper bath to absorb a large amount of hydrogen, and therefore it is difficult to smelt high-quality copper and copper alloys using an induction furnace.

At present, a pure copper smelting method has been disclosed. Preheating a graphite crucible to dark red, adding a layer of dry charcoal or covering agent (60% of borax and 37% of cullet) with the thickness of 30-50 mm at the bottom of the crucible, sequentially adding leftover materials, waste blocks and bar materials, and finally adding pure copper; adding the preheated supplemented alloy elements into a crucible, heating to completely melt the alloy elements, adding phosphorus copper accounting for 0.3-0.4% of the mass of the alloy liquid for deoxidation when the temperature is raised to 1200-1220 ℃, removing slag after full reaction, and casting to obtain pure copper. In addition, a method of smelting pure copper or high copper containing alloy feedstock is disclosed. The method uses N in the alloy smelting process₂And H₂、CO、C₂H₂The mixed gas (containing nitrogen gas of 95% or more) is used as a protective gas to inhibit the oxidation of the copper alloy melt. In the prior art, the oxygen content in copper and copper alloy obtained by adopting a smelting process under a non-vacuum condition is higher, and the requirement of modern industrial development on the oxygen content in pure copper and copper alloy cannot be met.

Disclosure of Invention

The invention provides a deoxidation method for copper or copper alloy, which has high efficiency and simple operation and can obviously reduce the oxygen content in the copper or copper alloy.

The invention provides a preparation method of high-purity copper or copper alloy.

The invention provides high-purity copper or copper alloy.

The technical scheme of the invention is as follows:

a method of deoxidizing copper or a copper alloy, comprising the steps of:

and introducing protective gas carrying reducing metal vapor or powder into the bottom of the copper or copper alloy melt.

The specific kind of the copper alloy is not limited, and the copper alloy may be a copper alloy conventional in the art, for example, the copper alloy may be a Cu-Ni-Al alloy, wherein the mass fraction of Ni is 12.0% to 15.0%, the mass fraction of Al is 2.3% to 3.0%, and the balance is copper; or Cu-Zn-Al alloy, wherein the mass fraction of Cu is 66.0-68.0%, the mass fraction of Al is 2.0-3.0%, and the balance is zinc; the alloy can also be Cu-Al alloy, wherein the mass fraction of Al is 4.0-6.0%, and the balance is copper.

The deoxidation method of the copper or the copper alloy has the advantages that the protective gas carrying the reductive metal steam or powder is introduced to the bottom of the melt of the copper or the copper alloy for deoxidation, the efficiency is high, and the operation is simple. The method adopts reductive metal steam or powder as a deoxidizer, can effectively remove oxygen in the melt to form low-density metal oxide which is easy to float upwards, is favorable for floating of the reductive metal steam or powder in a mode of introducing protective gas carrying the reductive metal steam or powder from the bottom of the melt, improves the utilization rate of the reductive metal steam or powder, strengthens the deoxidation effect, is favorable for realizing automatic control of the deoxidation process, and has the functions of stirring and carrying the deoxidation product to float upwards as the protective gas to prevent the copper or copper alloy melt from being oxidized.

Preferably, the upper surface of the melt is covered with a covering agent. The covering agent has the function of isolating oxygen and can prevent the melt of copper or copper alloy from being oxidized.

Preferably, the covering agent mainly comprises the following raw materials in percentage by mass: 60-75% of sodium tetraborate, 10-20% of silicon dioxide, 5-15% of sodium fluoroaluminate and 5-15% of sodium fluoride. The covering agent can absorb metal oxide formed by reducing metal and oxygen, improve the deoxidation efficiency and effectively prevent the melt from being oxidized.

Preferably, the covering agent mainly comprises the following raw materials in percentage by mass: 60-75% of sodium tetraborate, 15-20% of silicon dioxide, 5-10% of sodium fluoroaluminate and 5-10% of sodium fluoride. The covering agent can absorb metal oxide formed by reducing metal and oxygen, further improve the deoxidation efficiency and effectively prevent the melt from being oxidized.

Preferably, the melt with the upper surface covered with the covering agent is prepared by a method comprising the following steps:

and in the atmosphere of protective gas, adding a covering agent into the metal material of copper or copper alloy, and heating to melt the metal material and the covering agent to obtain the copper-copper alloy. The atmosphere of the protective gas can prevent the copper or the copper alloy from being oxidized in the melting process, and after the metal material of the copper or the copper alloy and the covering agent are melted, the covering agent is positioned on the surface of the copper or the copper alloy melt, so that the copper or the copper alloy melt can be further prevented from being oxidized.

It should be noted that the metal material of copper or copper alloy is dried by pretreatment, and the pretreatment drying process is to preheat and dry the copper or copper alloy at 300-450 ℃. The covering agent is mixed and dried, and the mixture can be mixed by ball milling for 0.5 to 3 hours on a ball mill, and then dried for 6 to 12 hours at 150 to 250 ℃ to remove water.

It can be understood that the atmosphere of the protective gas can be realized by introducing the protective gas into the reaction device, and the flow rate of the protective gas is 0.5-3 m³The preferred time is 5-10 min.

Preferably, the weight of the covering agent is 0.6-1.5% of the weight of the metal material. The covering agent accounts for 0.6-1.5% of the weight of the metal material, can effectively give consideration to the cost and the oxygen isolation effect, and can effectively adsorb a deoxidation product.

Preferably, the weight of the covering agent is 0.8-1.2% of the weight of the metal material. Better considers the cost and the oxygen isolation effect and effectively adsorbs the deoxidation product.

Preferably, the reducing metal is one or more of Ca, Mg, Na, K, or Li. Ca. Mg, Na, K or Li is strong reducing metal steam or powder, can effectively remove oxygen in the copper liquid, forms low-density metal oxide inclusions, and is beneficial to floating and removing deoxidation products.

Preferably, the weight of the reducing metal is 0.2% to 1.0% of the weight of the melt. When the weight of the reducing metal steam or powder is 0.2-1.0% of the weight of the melt, the cost and the deoxidation effect can be effectively considered.

Preferably, the weight of the reducing metal is 0.5% to 1.0% of the weight of the melt. When the weight of the reducing metal steam or powder is 0.2 to 1.0 percent of the weight of the melt, the cost and the deoxidation effect can be more effectively considered.

Preferably, the protective gas is one or more of argon, helium, neon, krypton and xenon. One or more of argon, helium, neon, krypton and xenon are used as carrier gas to carry the reducing metal vapor or powder, and do not react with the reducing metal vapor or powder, nor react with the metal oxide formed by the reducing metal vapor or powder and oxygen.

Preferably, the pressure of the protective gas is 0.5-2 MPa; the flow of the protective gas is 0.5-3 m³H is used as the reference value. The protective gas with the pressure of 0.5-2 MPa has a good stirring effect and a floating effect of carrying reductive metal steam or powder and deoxidation products. The flow rate is 0.5-3 m³The protective gas has good stirring effect and floating effect of carrying reductive metal vapor or powder and deoxidation products.

Preferably, the temperature of the melt is 1200-1280 ℃, and the time for introducing the protective gas carrying the reductive metal vapor or powder is 5-15 min. The temperature of the melt and the time of gas introduction can effectively remove oxygen.

Preferably, the temperature of the melt is 1250-1280 ℃, and the time for introducing the protective gas carrying the reducing metal steam or powder is 10-15 min. The deoxidation efficiency is further improved and the oxygen content is reduced by reasonably adjusting and optimizing the temperature of the melt and the time for introducing gas.

Preferably, after the deoxidation is completed, the method further comprises the following steps: and after the introduction of the protective gas carrying the reducing metal steam or powder is finished, continuously introducing the protective gas to the bottom of the copper or copper alloy melt for 10-25 min. And after the protective gas carrying the reducing metal steam or powder is introduced, the protective gas is continuously introduced into the melt of the copper or the copper alloy, so that the upward floating of the carried deoxidation product is facilitated.

Preferably, after the introduction of the protective gas carrying the reducing metal vapor or powder is finished, the flow of the protective gas continuously introduced to the bottom of the copper or copper alloy melt is 0.5-2 m³/h。

Preferably, after the introduction of the protective gas carrying the reducing metal vapor or powder is finished, the flow of the protective gas continuously introduced to the bottom of the copper or copper alloy melt is 0.5-0.9 m³/h。

Preferably, the deoxidation is carried out in an induction furnace, and the frequency of the induction furnace is 1000-2500 Hz. The magnetic field generated in the induction furnace with the frequency of 1000-2500 Hz has a stirring effect, and is beneficial to aggregation, growth and floating of deoxidation products.

A preparation method of high-purity copper or copper alloy comprises the following steps:

deoxidizing the melt of the copper or the copper alloy by adopting a deoxidation method of the copper or the copper alloy, then cooling to 1100-1200 ℃, casting, and removing slag to obtain the alloy.

The melt of the copper or the copper alloy obtained by deoxidizing the melt of the copper or the copper alloy by adopting the deoxidation method of the copper or the copper alloy has low oxygen content and high purity.

A high-purity copper or copper alloy is prepared by a preparation method of the high-purity copper or copper alloy.

The copper or copper alloy prepared by the preparation method of the high-purity copper or copper alloy has low oxygen content, high purity, better mechanical property, conductivity and other properties.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Na used in the examples of the present invention₂B₄O₇The purity is more than or equal to 99.98 percent, and the granularity is 100-300 meshes.

The NaF adopted in the embodiment of the invention has the purity of more than or equal to 99.98% and the granularity of 100-300 meshes.

SiO used in the examples of the present invention₂The purity is more than or equal to 99.98 percent, and the granularity is 100-300 meshes.

Na used in the examples of the present invention₃AlF₆The purity is more than or equal to 99.98 percent, and the granularity is 100-300 meshes.

The deoxidation device of the embodiment of the invention is a medium-frequency induction furnace which is provided with a high-purity graphite lining crucible with a bottom blowing air brick. The slit of the air brick is less than or equal to 0.1mm, and the purity of the graphite is more than 99.99 percent.

The mould for casting in the embodiment of the invention is a high-purity graphite casting mould, and the purity of graphite used by the high-purity graphite casting mould is more than 99.99%.

The purity of the protective gas used in the embodiment of the invention is more than 99.99%.

First, a specific example of the deoxidation method of copper or a copper alloy of the present invention is as follows: