A method for preparing CuAs alloy based on aluminum-thermal self-propagating using multi-field coupling

Abstract

The present application relates to a kind of based on aluminium heat self-propagating using multi-field coupling preparation CuAs alloy method, belong to metallurgical technical field.The method described in the present application includes: (1) using induction furnace electric heating rapid melting metal pure copper to obtain copper melt;(2) Ca3 (AsO4) 2, Al powder mixture material is introduced into copper melt using mechanical stirring and eddy current generated by electromagnetic stirring;(3) mixture material occurs in situ reduction reaction to generate elemental As and Al2O3-CaO reduction slag;(4) using additional induction coil to carry out heat preservation smelting;(5) Al2O3-CaO reduction slag is discharged after using overflow slagging method, and calcium aluminate cement clinker is directly prepared after water quenching, the homogeneous CuAs alloy melt in lower layer is poured into water-cooled crystallizer and is rapidly cooled, the process uses reduction and mechanical stirring synergistic effect to make As element uniformly dispersed in Cu matrix, effectively solve the segregation problem, no waste is discharged in whole process, realize clean preparation CuAs alloy.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical technology, and specifically relates to a method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling. Background Technology

[0002] CuAs master alloy is an alloy composed of pure copper as the base and added aspartic acid (As). It is an important additive for producing copper alloys and other special alloy materials. In existing technologies, alloy preparation mostly employs pyrometallurgical processes. Patent CN101423907a discloses a method for preparing a tin-germanium-arsenic alloy, which first involves reacting arsenic, germanium, and tin raw materials in a high-pressure reactor to form a master alloy; then, it is melted and refined together with the remaining tin and germanium, and cast to obtain the tin-germanium-arsenic alloy material. This method is energy-intensive and highly polluting. Patent CN101748307a discloses a gold-arsenic alloy and its preparation method. First, the raw materials are weighed according to the required proportions and placed in a high-pressure reactor for reaction. The pressure and temperature inside the reactor are controlled to obtain a master alloy ingot; then, the master alloy ingot is melted and refined together with the remaining gold, and cast to obtain the gold-arsenic alloy material. Currently, another method for preparing CuAs master alloys is the vacuum induction melting method, which uses high-purity electrolytic copper plates and non-metallic As as raw materials, and melts them in a vacuum induction furnace at high temperatures, followed by rapid solidification. This method increases the cost of raw materials. Such methods are complex, require high vacuum levels, are cumbersome, and are difficult to control in terms of temperature.

[0003] To address the technical problems existing in current copper-arsenic alloy synthesis processes, application number 201910807554.5 provides a simple and low-cost method for in-situ synthesis of copper-arsenic alloys from copper electrolytes. However, this method cannot be used for large-scale production of CuAs alloys. Therefore, how to reduce the production cost of existing technologies while producing CuAs alloys with quality comparable to or even better than commercially available alloys to achieve significant economic benefits is the research direction for CuAs alloys. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention uses the combined action of mechanical stirring and electromagnetic stirring to introduce eddy currents in the copper melt, adds a mixture of Ca3(AsO4)2 powder and Al powder into the melt, and tempers the high-temperature melt under the protection of slag to ensure effective separation of slag and gold, finally obtaining CuAs alloy and Al2O3-CaO smelting slag.

[0005] A method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling is performed according to the following steps:

[0006] (1) Use an induction furnace to heat pure copper to a temperature of 1100-1300℃ to obtain copper melt;

[0007] (2) A vortex is formed in the copper molten body;

[0008] (3) After uniformly mixing Al powder and Ca3(AsO4)2, it is carried into the copper melt by eddy current at a temperature of 1200℃-1400℃. The mixture undergoes an in-situ aluminothermic reduction reaction, and under the action of multi-field coupling, As is dispersedly added to the copper melt.

[0009] (4) Using an external induction coil for heat preservation and melting, Al2O3-CaO reduction slag and CuAs alloy melt are obtained;

[0010] (5) The CuAs alloy melt is cast into a water-cooled crystallizer for rapid cooling to obtain CuAs alloy.

[0011] Furthermore, the eddy current in step (2) is generated by a straight-blade open turbine propeller under the combined action of mechanical stirring and electromagnetic stirring, and the stirring speed of the turbine propeller is 200-300 rpm.

[0012] Further, the Al powder and Ca3(AsO4)2 described in step (3) are uniformly mixed in a molar ratio of 10:(3-5).

[0013] Further, the amount of Ca3(AsO4)2 added in step (3) is 1.1 to 1.3 times the chemical reaction stoichiometry, and the amount of As added is controlled within the range of 20% to 30%. The chemical reaction stoichiometry (1) is as follows, where x is 0.21 to 0.37 mol.

[0014] Cu+0.5xCa3(AsO4)2+5 / 3xAl=[Cu-xAs]+5 / 6x(Al2O3·1.8CaO) (1).

[0015] Further, the uniform mixing in step (3) involves mixing Al powder and Ca3(AsO4)2 in a ball mill for 30-60 minutes, and then pressing it into a blank at 10-20 MPa.

[0016] Further, the melting temperature in step (4) is 1400-1600℃, the holding time is 5-10 min, and the frequency of the external induction coil is 3000-4500Hz.

[0017] Furthermore, the melting point of the Al2O3-CaO reducing slag described in step (4) is 1350℃~1550℃.

[0018] Furthermore, the Al2O3-CaO reducing slag described in step (4) is directly quenched by overflow slag discharge to prepare calcium aluminate cement clinker.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] (1) Compared with vacuum melting, this method uses Ca3(AsO4)2, which is cheaper, as raw material, resulting in lower production costs. It can be prepared in a non-vacuum environment without requiring a high degree of vacuum.

[0021] (2) This paper uses Ca3(AsO4)2 as raw material and does not require the addition of CaO or other slag-forming agents. CaO and Al2O3 are generated directly in situ for internal slag formation, which reduces energy loss.

[0022] (3) The generated CaO and Al2O3 reduction slag is water-quenched using the overflow slag discharge method to prepare CA-50 grade, with no waste discharge throughout the process, achieving clean preparation of CuAs alloy.

[0023] (4) Compared with traditional metallurgical methods, this process uses the synergistic effect of reduction and mechanical stirring to make As uniformly dispersed in the Cu matrix, effectively solving the segregation problem. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Example 1

[0026] Prepare Cu blocks, Ca3(AsO4)2 powder and Al powder according to the composition of the CuAs20 gold ingot to be prepared. Place the Ca3(AsO4)2 required for the reaction in an oven and bake at 150°C for 24 hours.

[0027] 5 kg of Cu blocks were placed in an induction furnace and heated to 1300℃ until the Cu blocks were completely melted and in a molten state. A mechanical stirring system was then added, with the stirring speed set to 200 rpm. During the mixing process, 3317 g of Ca3(AsO4)2 powder and 750 g of Al powder were placed in a mixing tank and mixed in a ball mill for 30 minutes. The mixture was then pressed into a billet under 10 MPa. The billet is added to the melt in batches by a vortex generated by mechanical stirring. As elemental is generated in the melt through an aluminothermic reduction reaction and is evenly dispersed inside the melt by mechanical and electromagnetic stirring. Finally, a high-temperature melt composed of CuAs alloy melt and Al2O3-CaO reducing slag is obtained. The high-temperature melt is then smelted into alloy slag under the action of an electromagnetic field. The electromagnetic induction parameters are: 3000Hz, smelting temperature 1400℃, and smelting time 5min. A reducing slag is formed on the upper layer and an alloy melt is formed on the lower layer. The overflow slag removal method is used to directly prepare CA-50 grade calcium aluminate cement clinker by water quenching. After refining and slag removal, the CuAs alloy melt is cast into a water-cooled crystallizer for rapid solidification to obtain CuAs20 alloy ingots. The As content in the alloy is 19-21%.

[0028] Example 2

[0029] Prepare Cu blocks, Ca3(AsO4)2 powder and Al powder according to the composition of the CuAs23 gold ingot to be prepared. Place the Ca3(AsO4)2 required for the reaction in an oven and dry it at 150°C for 24 hours.

[0030] 5 kg of Cu blocks were placed in an induction furnace and heated to 1300℃ until the Cu blocks were completely melted and in a molten state. A mechanical stirring system was then added, with the stirring speed set to 200 rpm. During the mixing process, 3963 g of Ca3(AsO4)2 powder and 896 g of Al powder were placed in a mixing tank and mixed in a ball mill for 30 minutes. The mixture was then pressed into a billet under 13 MPa. The billet is added to the melt in batches by a vortex generated by mechanical stirring. As elemental is generated in the melt through an aluminothermic reduction reaction and is evenly dispersed inside the melt by mechanical and electromagnetic stirring. Finally, a high-temperature melt composed of CuAs alloy melt and Al2O3-CaO reducing slag is obtained. The high-temperature melt is then smelted into alloy slag under the action of an electromagnetic field. The electromagnetic induction parameters are: 3500Hz, smelting temperature 1400℃, and smelting time 8min. A reducing slag is formed on the upper layer and an alloy melt is formed on the lower layer. The overflow slag removal method is used to directly prepare CA-50 grade calcium aluminate cement clinker by water quenching. After refining and slag removal, the CuAs alloy melt is cast into a water-cooled crystallizer for rapid solidification to obtain CuAs23 alloy ingots. The As content in the alloy is 21-24%.

[0031] Example 3

[0032] Prepare Cu blocks, Ca3(AsO4)2 powder and Al powder according to the composition of the CuAs25 gold ingot to be prepared. Place the Ca3(AsO4)2 required for the reaction in an oven and bake at 150°C for 24 hours.

[0033] 5 kg of Cu blocks were placed in an induction furnace and heated to 1300℃ until the Cu blocks were completely melted and in a molten state. A mechanical stirring system was then added, with the stirring speed set to 200 rpm. During the mixing process, 4864 g of Ca3(AsO4)2 powder and 1000 g of Al powder were placed in a mixing tank and mixed in a ball mill for 30 minutes. The mixture was then pressed into a billet under 15 MPa. The billet is added to the melt in batches by a vortex generated by mechanical stirring. As elemental is generated in the melt through an aluminothermic reduction reaction and is evenly dispersed inside the melt by mechanical and electromagnetic stirring. Finally, a high-temperature melt composed of CuAs alloy melt and Al2O3-CaO reducing slag is obtained. The high-temperature melt is then smelted into alloy slag under the action of an electromagnetic field. The electromagnetic induction parameters are 3800 Hz, the smelting temperature is 1450℃, and the smelting time is 10 min. A reducing slag is formed on the upper layer and an alloy melt is formed on the lower layer. The overflow slag removal method is used to directly prepare CA-50 grade calcium aluminate cement clinker by water quenching. After refining and slag removal, the CuAs alloy melt is cast into a water-cooled crystallizer for rapid solidification to obtain CuAs25 alloy ingots. The As content in the alloy is 23-26%.

[0034] Example 4

[0035] Prepare Cu blocks, Ca3(AsO4)2 powder and Al powder according to the composition of the CuAs28 gold ingot to be prepared. Place the Ca3(AsO4)2 required for the reaction in an oven and dry it at 150°C for 24 hours.

[0036] 5 kg of Cu blocks were placed in an induction furnace and heated to 1300℃ until the Cu blocks were completely melted and in a molten state. A mechanical stirring system was then added, with the stirring speed set to 200 rpm. During the mixing process, 5675 g of Ca3(AsO4)2 powder and 1167 g of Al powder were placed in a mixing tank and mixed in a ball mill for 30 minutes. The mixture was then pressed into a billet under 18 MPa. The billet is added to the melt in batches by a vortex generated by mechanical stirring. As elemental is generated in the melt through an aluminothermic reduction reaction and is evenly dispersed inside the melt by mechanical and electromagnetic stirring. Finally, a high-temperature melt composed of CuAs alloy melt and Al2O3-CaO reducing slag is obtained. The high-temperature melt is then smelted into alloy slag under the action of an electromagnetic field. The electromagnetic induction parameters are: 4000Hz, smelting temperature 1450℃, and smelting time 10min. A reducing slag is formed on the upper layer and an alloy melt is formed in the lower layer. The overflow slag removal method is used to directly prepare CA-50 grade calcium aluminate cement clinker by water quenching. After refining and slag removal, the CuAs alloy melt is cast into a water-cooled crystallizer for rapid solidification to obtain CuAs28 alloy ingots. The As content in the alloy is 27-29%.

[0037] Example 5

[0038] Prepare Cu blocks, Ca3(AsO4)2 powder and Al powder according to the composition of the CuAs30 gold ingot to be prepared. Place the Ca3(AsO4)2 required for the reaction in an oven and bake at 150°C for 24 hours.

[0039] 5 kg of Cu blocks were placed in an induction furnace and heated to 1300℃ until the Cu blocks were completely melted and in a molten state. A mechanical stirring system was then added, with the stirring speed set to 200 rpm. During the mixing process, 6823 g of Ca3(AsO4)2 powder and 1286 g of Al powder were placed in a mixing tank and mixed in a ball mill for 30 minutes. The mixture was then pressed into a billet under 20 MPa. The billet is added to the melt in batches by a vortex generated by mechanical stirring. As elemental is generated in the melt through an aluminothermic reduction reaction and is evenly dispersed inside the melt by mechanical and electromagnetic stirring. Finally, a high-temperature melt composed of CuAs alloy melt and Al2O3-CaO reducing slag is obtained. The high-temperature melt is then smelted under the action of an electromagnetic field with the following parameters: electromagnetic induction parameters: 4500 Hz, smelting temperature: 1500℃, and smelting time: 10 min. A reducing slag is formed on the upper layer, and an alloy melt is formed on the lower layer. The overflow slag removal method is used to directly prepare CA-50 grade calcium aluminate cement clinker by water quenching. After refining and slag removal, the CuAs alloy melt is cast into a water-cooled crystallizer for rapid solidification to obtain CuAs30 alloy ingots with an As content of 29-32%.

Claims

1. A method for preparing CuAs alloys based on aluminothermic self-propagation using multi-field coupling, characterized in that: Follow these steps: (1) Use an induction furnace to heat pure copper to a temperature of 1100-1300℃ to obtain copper melt; (2) A vortex is formed in the copper molten body; (3) After uniformly mixing Al powder and Ca3(AsO4)2, it is carried into the copper melt by eddy current at a temperature of 1200℃-1400℃. The mixture undergoes an in-situ aluminothermic reduction reaction, and under the action of multi-field coupling, As is dispersedly added to the copper melt. (4) Using an external induction coil for heat preservation and melting, Al2O3-CaO reduction slag and CuAs alloy melt are obtained; (5) The CuAs alloy melt is cast into a water-cooled crystallizer for rapid cooling to obtain CuAs alloy.

2. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: The eddy current in step (2) is generated by using a straight-blade open turbine propeller under the combined action of mechanical stirring and electromagnetic stirring, and the stirring speed of the turbine propeller is 200-300 rpm.

3. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: The Al powder and Ca3(AsO4)2 mentioned in step (3) are mixed evenly in a molar ratio of 10:(3-5).

4. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: The amount of Ca3(AsO4)2 added in step (3) is 1.1 to 1.3 times the chemical reaction stoichiometry, and the amount of As added is controlled within the range of 20% to 30%. The chemical reaction stoichiometry (1) is as follows, where x is 0.21 to 0.37 mol. Cu+0.5xCa3(AsO4)2+5 / 3xAl=[Cu-xAs]+5 / 6x(Al2O3·1.8CaO) (1).

5. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: The uniform mixing in step (3) involves mixing Al powder and Ca3(AsO4)2 in a ball mill for 30-60 minutes, and then pressing it into a blank under 10-20 MPa.

6. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: Step (4) The melting temperature is 1400~1600℃, the holding time is 5~10min, and the frequency of the external induction coil is 3000~4500Hz.

7. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: The melting point of the Al2O3-CaO reducing slag in step (4) is 1350℃~1550℃.

8. The method for preparing CuAs alloys based on aluminothermic self-propagation and multi-field coupling according to claim 1, characterized in that: In step (4), the Al2O3-CaO reducing slag is directly quenched by overflow slag discharge to prepare calcium aluminate cement clinker.