Horizontal continuous casting process for preparing oxygen-free copper

Abstract

The invention discloses a horizontal continuous casting process for preparing oxygen-free copper, which is characterized in that a two-stage gas protection process is adopted, ammonia gas is used as a reducing atmosphere at high temperature to prevent oxidation, hydrogen atoms are extremely high in reducibility when the ammonia gas is decomposed, so that oxygen elements in copper can be effectively combined, and meanwhile, inert gas is used for replacement in the later period, so that the low oxygen content of the oxygen-free copper can be effectively ensured; and the oxygen element in the protective gas is prevented from returning to the oxygen-free copper.

Description

Technical Field

[0001] The invention belongs to the technical field of copper alloys, and in particular relates to a horizontal continuous casting process for preparing oxygen-free copper. Background Art

[0002] Oxygen-free copper has excellent electrical and thermal conductivity, and is free of "hydrogen disease". It is widely used in 5G, new energy vehicles, new infrastructure and other fields. At present, the preparation of TU00 with an oxygen content below 5ppm is mainly carried out by high-purity electrolytic plate + protective gas smelting, and the copper liquid is also specially treated for deoxygenation. However, this method has high requirements on the purity of raw materials, and the process equipment is complex and has strict requirements.

[0003] However, in the above process, oxygen element is always present in the protective gas, reacting with impurities in copper to increase the oxygen content in oxygen-free copper. Summary of the invention

[0004] In view of this, the present invention develops a horizontal continuous casting process for preparing oxygen-free copper, which can effectively prepare oxygen-free copper by controlling a two-stage gas protection process.

[0005] A horizontal continuous casting process for preparing oxygen-free copper comprises the following preparation steps:

[0006] (1) melting raw materials into copper liquid and adding into a crystallizer;

[0007] (2) Two-stage gas protection process:

[0008] A. Pass a mixture of inert gas and ammonia into the mixture;

[0009] B. Then, an inert gas is introduced to replace the above-mentioned mixed gas;

[0010] (3) Casting from a crystallizer.

[0011] Furthermore, the mixed gas is an inert gas: ammonia gas with a volume ratio of 8-9:1.

[0012] Furthermore, the inert gas is N2 or Ar.

[0013] Compared with the prior art, the advantages of the present invention are:

[0014] The present invention adopts a two-stage gas protection process, using ammonia as a reducing atmosphere at high temperature to prevent oxidation. Since the reducing property of hydrogen atoms is extremely strong when ammonia is decomposed, the oxygen element in copper can be effectively combined. At the same time, it is replaced with an inert gas in the later stage, which can effectively ensure the low oxygen content of oxygen-free copper and prevent the oxygen element in the protective gas from returning to the oxygen-free copper. DETAILED DESCRIPTION

[0015] Example 1

[0016] A horizontal continuous casting process for preparing oxygen-free copper comprises the following preparation steps:

[0017] (1) melting raw materials into copper liquid and adding into a crystallizer;

[0018] (2) Two-stage gas protection process:

[0019] A. Pass N2: ammonia gas mixture with a volume ratio of 9:1;

[0020] B. Then introduce N2 to replace the above mixed gas;

[0021] (3) Casting from a crystallizer.

[0022] Comparative Example 1

[0023] The ammonia in the mixed gas was replaced by an equal amount of hydrogen, and the rest was the same as in Example 1.

[0024] Comparative Example 2

[0025] There is no replacement step B of protective gas, and the rest is the same as Example 1.

[0026] Oxygen-free copper was prepared according to the above examples and comparative examples using the same batch of raw materials, and the oxygen content was tested using GB / T5121.8-2008 "Chemical analysis methods for copper and copper alloys Part 8: Determination of oxygen content".

[0027] test Example 1 Comparative Example 1 Comparative Example 2 Oxygen content (ppm) 1.1 2.3 4.8

[0028] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A horizontal continuous casting process for preparing oxygen-free copper, characterized in that: The horizontal continuous casting process comprises the following preparation steps: (1) melting raw materials into copper liquid and adding into a crystallizer; (2) Two-stage gas protection process: A. Pass a mixture of inert gas and ammonia into the mixture; B. Then, an inert gas is introduced to replace the above-mentioned mixed gas; (3) Casting from a crystallizer.

2. The horizontal continuous casting process for preparing oxygen-free copper according to claim 1, characterized in that: The mixed gas is an inert gas: ammonia gas with a volume ratio of 8-9:

1.

3. The horizontal continuous casting process for preparing oxygen-free copper according to claim 1 or 2, characterized in that: The inert gas is N2 or Ar.