Deoxidation process for improving copper deoxidation effect

Abstract

The invention provides a deoxidation process for improving the copper deoxidation effect, and belongs to the technical field of non-ferrous metal smelting. The method comprises the following steps: putting a copper material into a smelting furnace, covering the copper material with an anaerobic layer, and then smelting the copper material into molten copper; adding a deoxidizing agent into the copper liquid, pressing the deoxidizing agent below the anaerobic layer to enable the deoxidizing agent to react with the copper liquid, removing the anaerobic layer after the reaction is finished, and fishing scum on the surface of the copper liquid; wherein the deoxidizing agent comprises phosphorus-copper alloy powder and a copper sheet coated outside the phosphorus-copper alloy powder. According to the method, the phosphorus-copper alloy powder is coated in the copper sheet, and meanwhile, the design of the anaerobic layer is combined, so that the oxidation consumption of the phosphorus-copper alloy powder in the copper deoxidation process is remarkably reduced, and the utilization rate of the phosphorus element is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-ferrous metal smelting, in particular to a deoxidation process for improving the deoxidation effect of copper. BACKGROUND

[0002] Copper has the property of absorbing oxygen in the molten state, and the ability to absorb oxygen increases with temperature. Oxygen exists in the form of cuprous oxide (Cu2O) in copper, and the solubility of Cu2O in copper melt increases with temperature. After solidification, Cu2O exists in the form of Cu-Cu2O eutectic, and the eutectic temperature is very high. Cu2O is a brittle phase, which can cause copper material to crack during cold working, resulting in cold brittleness and rough surface of copper products. Therefore, deoxidation treatment is needed during copper product smelting. Currently, using phosphor copper alloy to deoxidize copper melt is a relatively effective deoxidation method.

[0003] The current phosphor copper alloy deoxidation process usually involves putting block-shaped phosphor copper intermediate alloy into molten copper liquid. The phosphor copper intermediate alloy can react with oxygen in the copper liquid to generate gaseous P2O5, which can automatically escape from the copper liquid. However, the main problem of this process is that the phosphor copper intermediate alloy is easily affected by oxygen after being put into the copper liquid, leading to rapid consumption of phosphorus element and reducing the effective utilization rate of phosphorus element, thereby affecting the quality of the final copper product. SUMMARY

[0004] In order to improve the problem of low effective utilization rate of phosphorus element in the current phosphor copper alloy deoxidation process, the present application provides a deoxidation process for improving the deoxidation effect of copper.

[0005] The present application provides a deoxidation process for improving the deoxidation effect of copper, which adopts the following technical solution: A deoxidation process for improving the deoxidation effect of copper, comprising the following steps: Put copper material into a furnace and cover it with an oxygen barrier layer above, then melt the copper material into copper liquid; Add deoxidizing agent to the copper liquid and press it below the oxygen barrier layer to react with the copper liquid. After the reaction is complete, remove the oxygen barrier layer and collect the dross on the surface of the copper liquid; The deoxidizing agent includes phosphor copper alloy powder and copper skin coated outside the phosphor copper alloy powder.

[0006] The present application uses copper skin to wrap the powder form of phosphor copper alloy to form a deoxidizing agent, reducing the direct contact between phosphor copper alloy and oxygen. At the same time, an oxygen barrier layer is covered on the surface of the copper liquid before the deoxidizing agent is added, further reducing the oxygen content on the surface of the copper liquid, thereby improving the utilization rate of phosphorus element in the copper liquid and solving the problem of easy consumption of phosphor copper alloy.

[0007] When the deoxidizer is put into the copper liquid, the copper skin is rapidly melted under the high temperature of the copper liquid and is integrated with the copper liquid, so that the phosphor copper alloy powder is directly exposed to the inside of the copper liquid, avoiding oxidation by contacting air, and ensuring that the phosphorus element in the phosphor copper alloy powder can be used for reaction with oxygen in the copper liquid, and the deoxidation product P2O5 produced by the reaction is vaporized and floated to the surface of the copper liquid to form a slag under high temperature, so that the oxygen in the copper liquid can be removed by this way.

[0008] Optionally, the particle size of the phosphor copper alloy powder is 50-100 μm.

[0009] The present application further limits the particle size of the phosphor copper alloy powder, which can ensure that the phosphor copper alloy powder can be fully contacted with the copper liquid without being consumed too fast.

[0010] Optionally, the thickness of the copper skin is 0.3-0.6 mm.

[0011] The present application further limits the thickness of the copper skin, which can provide good oxygen isolation effect and can be completely melted into the copper liquid in a short time without affecting the full reaction of the phosphor copper alloy powder.

[0012] Optionally, the deoxidizer is put in when the temperature of the copper liquid reaches 1100-1200℃.

[0013] The present application further limits the adding time of the deoxidizer, which can be beneficial to the rapid and uniform dispersion and reaction of the phosphor copper alloy powder when the copper liquid is stable at 1100-1200℃, and further improves the reaction efficiency of the phosphorus element.

[0014] Optionally, the oxygen isolation layer is pure carbon or machine-made charcoal.

[0015] By using pure carbon or machine-made charcoal as the oxygen isolation layer, the carbon content is high, the service life is long, and the heat preservation effect is good, which can form a more dense oxygen isolation layer on the surface of the copper liquid, the oxygen isolation effect is better, the air is prevented from directly contacting the surface of the copper liquid, and new impurities are not introduced into the copper liquid; at the same time, the pure carbon or machine-made charcoal can also be incompletely combusted with the residual oxygen in the furnace under the high temperature of the copper liquid, producing carbon monoxide gas to form a local reducing atmosphere, the carbon monoxide gas can reduce the cuprous oxide generated into copper to prevent further oxidation and consume the oxygen trying to approach the copper liquid.

[0016] Optionally, the thickness of the oxygen isolation layer is 1-2 cm.

[0017] The thickness of the oxygen isolation layer is further limited, which can achieve the purpose of isolating air, and does not hinder the pressing of the deoxidizer.

[0018] Optionally, the weight ratio of the phosphor copper alloy powder to the copper liquid is 0.02% to 0.05%.

[0019] By further limiting the amount of phosphor copper alloy powder, it can be ensured that the oxygen in the copper liquid can be fully reacted, and the oxygen content in the copper liquid can be controlled below the target value.

[0020] Optionally, the method further comprises a step of rapidly cooling the copper liquid after the reaction is completed, and the cooling rate is 10-20℃ / s.

[0021] After the deoxidation reaction, a small amount of deoxidation product P2O5 that fails to escape from the copper liquid tends to aggregate into large-sized inclusions in the high-temperature copper liquid. Rapid cooling can rapidly reduce the temperature of the copper liquid and shorten the residence time of the deoxidation product in the liquid copper, so that the deoxidation product cannot fully aggregate and grow before solidification, thereby being kept in a fine and dispersed distribution. Moreover, if a common slow cooling method is used, the removed oxygen is likely to be re-dissolved into the copper matrix. By using the rapid cooling method, the oxygen can be “frozen” in the deoxidation product.

[0022] In addition, the rapid cooling method can also increase the undercooling degree to improve the nucleation rate, thereby indirectly refining the copper grains and improving the mechanical properties, and avoiding the performance degradation caused by the conventional slow cooling.

[0023] In summary, the present application includes at least one of the following beneficial effects: 1. The present application significantly reduces the oxidation consumption of the phosphor copper alloy powder in the copper deoxidation process by coating the phosphor copper alloy powder in the copper skin, and improves the utilization rate of phosphorus by combining with the design of the oxygen-free layer.

[0024] 2. The present application optimizes the particle size of the phosphor copper alloy powder, the thickness of the copper skin, and the deoxidizer addition time, effectively improves the reaction efficiency of phosphorus in the copper liquid, significantly enhances the deoxidation effect of copper, and can control the oxygen content in the copper liquid to be below 65ppm, and the performance of the finished copper is obviously improved. DETAILED DESCRIPTION

[0025] The present application will be further described below in conjunction with specific examples and comparative examples. The following examples are illustrative and not limiting, and the protection scope of the present application cannot be limited by the following examples.

[0026] The phosphor copper alloy powder used in the following examples and comparative examples has a mass fraction of 1% of phosphorus.

[0027] Example 1: Example 1 provides a deoxidation process for improving the deoxidation effect of copper, and the specific operation steps are as follows: 6 tons of copper material is put into the furnace, and a layer of pure carbon layer with a thickness of 1 cm is covered on the top, and then the copper material is melted into copper liquid; when the temperature of the copper liquid reaches 1100℃, the deoxidizer is added to the copper liquid, and the deoxidizer is pressed into the pure carbon layer below by using the un-melted electrolytic copper plate, so that it reacts with the copper liquid, the reaction time is 30 minutes, after the reaction is completed, the pure carbon layer is removed, and the dross on the surface of the copper liquid is taken out; finally, the copper liquid is rapidly cooled, and the cooling rate is 20℃ / s.

[0028] In the example 1, the deoxidizer used is phosphor copper alloy powder with an average particle size of 50μm and copper skin coated outside the phosphor copper alloy powder, the thickness of the copper skin is 0.6mm, and the total amount of phosphor copper alloy powder in the deoxidizer is 3kg.

[0029] Example 2: Example 2 is basically the same as example 1, the only difference is that the deoxidizer used in example 2 is phosphor copper alloy powder with an average particle size of 75μm and copper skin coated outside the phosphor copper alloy powder, the thickness of the copper skin is 0.6mm; the adding time of the deoxidizer is when the temperature of the copper liquid reaches 1180℃, the deoxidizer is added to the copper liquid.

[0030] Example 3: Example 3 is basically the same as example 1, the only difference is that the deoxidizer used in example 3 is phosphor copper alloy powder with an average particle size of 100μm and copper skin coated outside the phosphor copper alloy powder, the thickness of the copper skin is 0.6mm. The adding time of the deoxidizer is when the temperature of the copper liquid reaches 1200℃, the deoxidizer is added to the copper liquid.

[0031] Example 4: Example 4 is basically the same as example 1, the only difference is that the deoxidizer used in example 4 is phosphor copper alloy powder with an average particle size of 50μm and copper skin coated outside the phosphor copper alloy powder, the thickness of the copper skin is 0.3mm; the adding time of the deoxidizer is when the temperature of the copper liquid reaches 1100℃, the deoxidizer is added to the copper liquid.

[0032] Example 5: Example 5 is basically the same as example 1, the only difference is that in example 5, a pure carbon layer is covered on the surface of the copper material, and the thickness of the layer is 2cm.

[0033] Example 6: Example 6 is basically the same as example 1, the only difference is that in example 6, a machine-made charcoal is covered on the surface of the copper material, and the thickness of the layer is 1cm.

[0034] Example 7: Example 7 is basically the same as example 1, the only difference is that in example 7, the total amount of phosphor copper alloy powder in the deoxidizer is 1.2kg.

[0035] Example 8: Example 8 is basically the same as example 1, the only difference is that in example 8, the cooling rate of the copper liquid is 10℃ / s.

[0036] Comparative Example 1 is basically the same as Example 1, except that in Comparative Example 1, a pure carbon layer is not coated on the surface of the copper material.

[0037] Comparative Example 2 is basically the same as Example 1, except that in Comparative Example 2, a phosphor copper alloy block is used instead of the deoxidizer, and the amount of the phosphor copper alloy block used in Comparative Example 2 is the same as the amount of the phosphor copper alloy powder used in the deoxidizer of Example 1.

[0038] Comparative Example 3 is basically the same as Example 1, except that in Comparative Example 3, a phosphor copper alloy powder without copper skin coating is used as the deoxidizer, and the amount of the phosphor copper alloy powder used in Comparative Example 3 is the same as the amount of the phosphor copper alloy powder used in the deoxidizer of Example 1.

[0039] Comparative Example 4 is basically the same as Example 1, except that in Comparative Example 4, the copper liquid is cooled by natural air cooling.

[0040] For the deoxidation processes of the above examples and comparative examples, the oxygen content in the copper material and the cooled copper product is measured, and the reference standard is GB / T 5121.8-2008 Chemical Analysis Methods for Copper and Copper Alloys Part 8: Determination of Oxygen Content. The test results are shown in Table 1, where the deoxidation rate (%) = (initial oxygen content - deoxidized oxygen content) / initial oxygen content x 100%.

[0041] Table 1 Test Results As can be seen from the results in Table 1, Examples 1-7 significantly reduce the oxidation consumption of the phosphor copper alloy powder during copper deoxidation by coating the phosphor copper alloy powder in the copper skin, and improve the utilization rate of phosphorus by combining with the design of the deoxidation layer.

[0042] Comparative Example 1 does not use a deoxidation layer, and the oxygen content after deoxidation is significantly higher than that of Example 1, indicating that the deoxidation layer effectively blocks air contact and avoids premature oxidation of phosphorus. Comparative Example 2 uses a phosphor copper alloy block as a deoxidizer, with an oxygen content of up to 180 ppm, indicating that the block alloy has a small surface area, slow reaction, and direct exposure to air, resulting in low phosphorus utilization. Comparative Example 3 uses a phosphor copper alloy powder without copper skin coating as a deoxidizer, with an oxygen content of up to 210 ppm, indicating that the copper skin coating structure isolates oxygen before melting at high temperatures, ensuring that phosphorus is fully utilized in the copper liquid. The oxygen content of Comparative Example 4, which uses normal air cooling to cool the copper liquid, is 171% higher than that of Example 1, indicating that rapid cooling can inhibit oxygen back-dissolution and refine the structure.

[0043] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A deoxidation process for improving copper deoxidation efficiency, characterized in that, Includes the following steps: The copper material is put into the furnace and covered with an oxygen-free layer before being melted into molten copper. Add a deoxidizer to the copper liquid and press it under the oxygen-free layer to react with the copper liquid. After the reaction is complete, remove the oxygen-free layer and remove the scum from the surface of the copper liquid. The deoxidizer includes phosphor bronze alloy powder and a copper foil covering the phosphor bronze alloy powder.

2. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, The particle size range of the phosphor bronze alloy powder is 50-100 μm.

3. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, The thickness of the copper foil is 0.3-0.6 mm.

4. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, When the temperature of the copper liquid reaches 1100-1200℃, the deoxidizer is added.

5. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, The oxygen-free layer is made of pure carbon or machine-made charcoal.

6. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, The thickness of the oxygen-free layer is 1~2cm.

7. The deoxidation process for improving copper deoxidation effect according to claim 1, characterized in that, The weight ratio of the phosphor bronze alloy powder to the molten copper is 0.02% to 0.05%.

8. The deoxidation process for improving copper deoxidation effect according to any one of claims 1-7, characterized in that, It also includes a step of rapidly cooling the molten copper after the reaction is complete, with a cooling rate of 10-20℃ / s.

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