阅读说明：本技术 一种铜熔体的脱氧方法、纯铜材料、纯铜材料的制备方法 (Deoxidation method of copper melt, pure copper material and preparation method of pure copper material ) 是由 宋克兴 刘海涛 周延军 程楚 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：本发明涉及一种铜熔体的脱氧方法、纯铜材料、纯铜材料的制备方法,属于有色金属加工技术领域。本发明的一种铜熔体的脱氧方法,包括如下步骤：在铜熔体中加入碱金属；所述碱金属选自钠、钾中的一种或两种。本发明的铜熔体的脱氧方法,利用碱金属钠和钾还原性极强、极易与氧结合的特性,能够将铜熔体中的氧含量降至极低水平。此外,钠和钾与氧结合后生成的氧化物,密度低、熔点低,易于从铜熔体中上浮排除,并且金属钠和钾的沸点远低于铜熔炼温度,多余的金属钠和钾易于从铜熔体排除,从而在降低铜熔体中氧含量的同时,不在熔体中增加新的杂质。(The invention relates to a deoxidation method of a copper melt, a pure copper material and a preparation method of the pure copper material, belonging to the technical field of nonferrous metal processing. The invention relates to a deoxidation method of a copper melt, which comprises the following steps: adding alkali metal into the copper melt; the alkali metal is selected from one or two of sodium and potassium. The deoxidation method of the copper melt can reduce the oxygen content in the copper melt to an extremely low level by utilizing the characteristics that alkali metal sodium and potassium have extremely strong reducibility and are very easy to combine with oxygen. In addition, oxides generated after the sodium and the potassium are combined with oxygen have low density and low melting point, and are easy to float upwards and remove from the copper melt, the boiling points of the metal sodium and the metal potassium are far lower than the melting temperature of the copper, and redundant metal sodium and metal potassium are easy to remove from the copper melt, so that the oxygen content in the copper melt is reduced, and new impurities are not added into the melt.)

1. A method for deoxidizing a copper melt, which is characterized by comprising the following steps: the method comprises the following steps: adding alkali metal into the copper melt; the alkali metal is selected from one or two of sodium and potassium.

2. The method of deoxidizing a copper melt as set forth in claim 1, wherein: the alkali metal is fed into the copper melt in the form of an alkali metal cored wire and/or is fed into the copper melt in the form of an alkali metal block; the alkali metal cored wire is formed by wrapping alkali metal particles with a copper strip.

3. The method of deoxidizing a copper melt as set forth in claim 1, wherein: also comprises the following steps: before adding alkali metal, non-metal deoxidant is used to deoxidize the copper melt.

4. A method of deoxidizing a copper melt as set forth in claim 3, wherein: the alkali metal is carried from the bottom of the copper melt into the copper melt in the form of alkali metal particles and/or alkali metal vapors by an inert gas and/or carbon monoxide gas.

5. The method for deoxidizing a copper melt as set forth in claim 3 or 4, wherein: the nonmetal deoxidizer is selected from one or two of carbon and carbon monoxide.

6. A pure copper material characterized by: the pure copper material contains more than or equal to 99.95 percent of copper by mass, less than or equal to 0.0005 percent of oxygen by mass, less than or equal to 0.0015 percent of phosphorus by mass and less than or equal to 0.0030 percent of sulfur by mass; the pure copper material is prepared by adopting a method comprising the following steps: melting the copper material to prepare a copper melt, deoxidizing the copper melt by using the method for deoxidizing the copper melt according to any one of claims 1 to 5, and casting the deoxidized copper melt.

7. The pure copper material of claim 6, wherein: the mass percentage of phosphorus in the pure copper material is less than or equal to 0.0005 percent, and the mass percentage of sulfur in the pure copper material is less than or equal to 0.0018 percent.

8. A preparation method of a pure copper material is characterized by comprising the following steps: the method comprises the following steps: melting the copper material to prepare a copper melt, deoxidizing the copper melt by adopting the deoxidizing method of the copper melt as claimed in any one of claims 1 to 5, and casting the deoxidized copper melt to obtain the alloy.

9. The method for producing a pure copper material according to claim 8, wherein: the mass percentage content of copper in the copper melt is more than or equal to 99.95 percent, the mass percentage content of oxygen is less than or equal to 0.0005 percent, the mass percentage content of phosphorus is less than or equal to 0.0015 percent, and the mass percentage content of sulfur is less than or equal to 0.0030 percent.

10. The method for producing a pure copper material according to claim 8, wherein: the mass percentage of phosphorus in the copper melt is less than or equal to 0.0005 percent, and the mass percentage of sulfur in the copper melt is less than or equal to 0.0018 percent.

Technical Field

The invention relates to a deoxidation method of a copper melt, a pure copper material and a preparation method of the pure copper material, belonging to the technical field of nonferrous metal processing.

Background

The high-purity high-conductivity copper has excellent electric and heat conducting performance, cold and hot processing performance, hydrogen embrittlement sensitivity resistance, high-temperature oxidation resistance, vacuum volatilization resistance and the like, is a key material for manufacturing devices in the electronic and electric fields with high performance and reliability which are vital, and particularly has urgent requirements on the manufacture of vacuum electronic devices, high-power IGBTs, electric vacuum devices, integrated circuits, automobile electronics, aerospace and military electronic components and the like.

The presence of oxygen is clearly extremely detrimental to high purity high conductivity copper, particularly for vacuum electronics. Oxygen is hardly dissolved in copper, and when the oxygen-containing copper melt is solidified, Cu-containing copper appears along with the increase of oxygen content₂The hypoeutectic, eutectic and hypereutectic of O jeopardizes the electric and thermal conductivity, ductility, high-temperature oxidation resistance, hydrogen embrittlement resistance and the like of copper, thereby influencing the high performance and reliability of the copper in the service processAnd (5) sex requirements.

The traditional method for reducing the oxygen content in the high-purity high-conductivity copper generally adopts carbon reduction deoxidation, CO reducing gas deoxidation or addition of a deoxidizer for deoxidation. After the copper liquid is deoxidized by the traditional method, although the oxygen content can be greatly reduced, the problem that the oxygen content level can not meet the requirement still exists, and the cost of part of the deoxidation method is higher. In particular, the addition of a deoxidizer is still the current main deoxidation method for producing copper, such as the deoxidation method of copper solution disclosed in the chinese patent application with application publication No. CN102140584A, in which a deoxidizer mixture comprising Mn, Mg, Cu — P alloys is wrapped with a copper strip into a deoxidizer pack and placed in the copper solution, and these deoxidizer packs are pressed into the bottom of the copper solution and then stirred. Besides the deoxidizers disclosed in the prior art, the deoxidizers commonly used in the prior art include phosphorus copper, lithium calcium alloy, lithium copper alloy, magnesium boride, boron slag, magnesium and the like, and the deoxidizers have limited deoxidizing capacity on copper melts, easily stain the copper melts, and cause the chemical components of copper to be qualified and fail to meet the requirement of effectively reducing the oxygen content in high-purity high-conductivity copper by slight carelessness.

Disclosure of Invention

The invention aims to provide a deoxidation method of a copper melt, which can greatly reduce the oxygen content in the copper melt.

The invention also provides a pure copper material, the conductivity of the pure copper material is more than or equal to 100% IACS, the oxide layer is not peeled at the high temperature of 850 +/-20 ℃, and the hydrogen embrittlement resistance is excellent.

The invention also provides a preparation method of the pure copper material, which can greatly reduce the oxygen content in the pure copper material.

In order to achieve the above purpose, the deoxidation method of the copper melt adopts the technical scheme that:

a method for deoxidizing a copper melt comprises the following steps: adding alkali metal into the copper melt; the alkali metal is selected from one or two of sodium and potassium.

The deoxidation method of the copper melt can reduce the oxygen content in the copper melt to an extremely low level by utilizing the characteristics that alkali metal sodium and potassium have extremely strong reducibility and are very easy to combine with oxygen. In addition, because oxides generated after the sodium and the potassium are combined with oxygen have low density and low melting point and are easy to float upwards and remove from the copper melt, the boiling points of the metal sodium and the metal potassium are far lower than the melting temperature of the copper, and redundant metal sodium and metal potassium are easy to remove from the copper melt, the deoxidation method of the invention reduces the oxygen content in the copper melt and simultaneously does not add new impurities into the melt.

Preferably, the alkali metal is fed into the copper melt in the form of an alkali metal cored wire and/or is fed into the copper melt in the form of an alkali metal slug; the alkali metal cored wire is formed by wrapping alkali metal particles with a copper strip. In order to reduce the introduction of impurities, the copper strip adopted by the alkali metal cored wire is oxygen-free copper or copper material with the same or similar composition with copper melt.

In order to further optimize the deoxidation effect, the copper melt is protected from oxygen in the whole deoxidation process. The protection is one of vacuum protection, sealing protection, inert gas protection and covering protection, and can also be a combination of several protection modes, such as inert gas protection and covering protection.

Preferably, the method for deoxidizing a copper melt further comprises the following steps: before adding alkali metal, non-metal deoxidant is used to deoxidize the copper melt. Because the alkali metal is relatively active, the reducibility is strong, the melting point is low, and the reaction is violent and difficult to control under the high-temperature condition when the oxygen content in the melt is higher. The conventional non-metal deoxidizer has limited deoxidizing capacity on the copper melt, and is used for deoxidizing the copper melt before adding the alkali metal to reduce the oxygen content in the copper melt, and then the alkali metal is used for deoxidizing, so that the deoxidizing process is stable and easy to control, and compared with the method of directly removing a large amount of oxygen by using the alkali metal, the deoxidizing cost is reduced.

Preferably, the alkali metal is carried into the copper melt from the bottom thereof in the form of alkali metal particles and/or alkali metal vapors by an inert gas and/or carbon monoxide gas. The alkali metal particles and/or the alkali metal steam are carried in from the bottom of the copper melt by the gas, so that the alkali metal can be fully utilized, the gas can promote the oxide generated by the reaction to float to the surface of the copper melt, and the deoxidation efficiency is improved. The method of the present invention can be used in combination of two or more of the above-mentioned methods of feeding the alkali metal cored wire, feeding the alkali metal block, introducing the gas carrying the alkali metal vapor, and introducing the gas carrying the alkali metal particles when the alkali metal is added to the copper melt.

In order to accelerate the deoxidation efficiency, the copper melt is stirred during the addition of the alkali metal. For example, the stirring can be achieved by introducing inert gas into the copper melt, or the stirring rod made of high-purity graphite is directly used for mechanically stirring the copper melt, and of course, the stirring rod can be used for stirring while introducing inert gas into the copper melt.

Preferably, the deoxidizer is one or two selected from carbon and carbon monoxide. Carbon and carbon monoxide tend to reduce the oxygen content of the copper melt and the oxygen-depleted product is CO₂The gas is discharged in a form, and secondary pollution to the copper liquid is avoided.

In order to further reduce the deoxidation cost, it is preferable that the copper melt is deoxidized by using a deoxidizer until the oxygen content in the copper melt is not higher than 0.0020%. The oxygen content in the copper melt can be determined by sampling and detecting.

Preferably, the alkali metal is added to the copper melt to an oxygen content in the copper melt of not more than 0.0005%.

The pure copper material adopts the technical scheme that:

a pure copper material, wherein the mass percent of copper in the pure copper material is more than or equal to 99.95 percent, the mass percent of oxygen is less than or equal to 0.0005 percent, the mass percent of phosphorus is less than or equal to 0.0015 percent, and the mass percent of sulfur is less than or equal to 0.0030 percent; the pure copper material is prepared by adopting a method comprising the following steps: melting the copper material to prepare a copper melt, deoxidizing the copper melt by adopting any one of the deoxidizing methods of the copper melt, and casting the deoxidized copper melt.

The pure copper material has the advantages of electrical conductivity of more than or equal to 100% IACS, no peeling of a high-temperature oxidation layer at 850 +/-20 ℃, excellent hydrogen embrittlement resistance, and capability of meeting the requirements of devices in the fields of electronics and electric power on high-performance and high-reliability high-purity high-conductivity copper.

Preferably, the mass percent of phosphorus in the pure copper material is less than or equal to 0.0005 percent, and the mass percent of sulfur in the pure copper material is less than or equal to 0.0018 percent.

The preparation method of the pure copper material adopts the technical scheme that:

a preparation method of a pure copper material comprises the following steps: melting the copper material to prepare a copper melt, deoxidizing the copper melt by adopting any one of the above deoxidizing methods of the copper melt, and casting the deoxidized copper melt to obtain the alloy.

The preparation method of the pure copper material can greatly reduce the oxygen content of the prepared pure copper material and improve the conductivity, the high-temperature oxidation layer stripping resistance and the hydrogen embrittlement resistance of the pure copper material.

Preferably, the mass percent of copper in the copper melt is more than or equal to 99.95 percent, the mass percent of phosphorus is less than or equal to 0.0005 percent, and the mass percent of sulfur is less than or equal to 0.0018 percent. By controlling the mass percent of copper in the copper melt before deoxidation not to be lower than 99.95 percent, the mass percent of phosphorus not to be higher than 0.0015 percent and the mass percent of sulfur not to be higher than 0.0030 percent, the preparation method of the pure copper material greatly improves the conductivity and the high-temperature oxidation layer stripping resistance of the pure copper material, particularly when the oxygen content in the copper melt is not higher than 0.0005 percent after deoxidation, the conductivity of the prepared pure copper material is not less than 100 percent IACS, the high-temperature oxidation layer at 850 +/-20 ℃ is not stripped, the hydrogen embrittlement resistance is excellent, and the requirements of devices in the electronic and electric fields on high-performance and high-reliability high-purity high-conductivity copper are met.

Preferably, the mass percent of phosphorus in the copper melt is less than or equal to 0.0005 percent, and the mass percent of sulfur in the copper melt is less than or equal to 0.0018 percent.

Detailed Description

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

The following examples of the method for producing a pure copper material used an electrolytic cathode copper in which the mass percent of copper was 99.95%, the mass percent of oxygen was 0.0050%, the mass percent of phosphorus was 0.0010%, and the mass percent of sulfur was 0.0021%. In other embodiments of the method for preparing the pure copper material, other copper materials with higher impurity element content can be used as raw materials to prepare the pure copper material.

Examples of the preparation of pure copper materials