Integration method of copper cutting waste

Abstract

To provide an integration method of copper cutting waste which can reduce operation energy and avoid deterioration of electric resistance value due to lowering of purity of copper.SOLUTION: An integration method of copper cutting waste comprises: a mounting step (S11) which scatters and mounts copper cutting waste 101 on a die with a recess part; and an integration step (S12) in which a rotatable and columnar rotary tool 103 is pressed against the copper cutting waste laid on the recess part of the die 102, the columnar rotary tool 103 is rotated so that the copper cutting waste is heated to be more than softening temperature of copper, and the copper cutting waste is agitated in the recess part of the die 102 by the columnar rotary tool 103 to integrate the copper cutting waste.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for consolidating copper cuttings. [Background technology]

[0002] In current motor manufacturing lines, a considerable amount of copper cutting chips is generated when stripping off the coil coating. This copper cutting chips are melted and refined to return to copper products. Patent Document 1 describes a method in which a briquette made by incorporating an alloy component with a melting point lower than that of copper into copper alloy cutting chips and compressing and solidifying it is immersed in molten metal to melt it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-173142 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the melting and refining method described in Patent Document 1 has problems in that it requires a large amount of operating energy and emits a large amount of carbon dioxide, and oxygen is mixed in during melting, reducing the copper purity and worsening the electrical resistance value.

[0005] In particular, the melting point of copper is 1100°C, and in order to bring copper to molten temperature during melting and refining, a large amount of operating energy is required, making the copper more susceptible to oxidation. [Means for solving the problem]

[0006] One embodiment of a method for consolidating copper cutting chips includes a placing step of placing copper cutting chips on a die having a recess while scattering the copper cutting chips, and a consolidation step of pressing a rotatable cylindrical rotating tool against the copper cutting chips placed in the recess of the die and rotating the cylindrical rotating tool to heat the copper cutting chips to a temperature equal to or higher than the softening temperature of copper and stir the copper cutting chips within the recess of the die with the cylindrical rotating tool, thereby integrating the copper cutting chips.

[0007] In one embodiment, the method for consolidating copper cutting chips includes a particle size adjustment step of collecting copper cutting chips in a shredder and adjusting the particle size of the collected copper cutting chips by shredding them through the shredder, a pre-compression step of transferring the particle size-adjusted copper cutting chips to a recess in a die after the particle size adjustment step and pre-compressing the copper cutting chips with a punch, performing the consolidation step after the pre-compression step, and a removal step of removing the integrated copper cutting chips from the die after the consolidation step. Effect of the Invention

[0008] According to the method for consolidating copper cutting chips of the present disclosure, it is possible to reduce operating energy and to avoid deterioration of electrical resistance value due to a decrease in copper purity. [Brief description of the drawings]

[0009] [Figure 1] 1 is a flowchart and a schematic diagram showing an example of a method for consolidating copper cutting chips according to a first embodiment. [Diagram 2] 1 is a schematic diagram for explaining a method for consolidating copper cutting chips according to a first embodiment. [Diagram 3] 1 is a bar graph showing a comparison of refining process energies. [Figure 4] 11 is a flow chart and a schematic diagram showing an example of a method for consolidating copper cutting chips according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First embodiment Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, in which: Fig. 1 is a flow chart and a schematic diagram showing an example of a method for consolidating copper cutting chips according to a first embodiment.

[0011] First, in step S11, copper cutting chips 101 are placed on a die having a recess while being scattered thereon, and then the process proceeds to step S12.

[0012] Next, in step S12, a rotatable cylindrical rotary tool 103 is pressed against the copper cutting chips placed in the recess of the die 102, and the cylindrical rotary tool 103 is rotated. This rotation heats the copper cutting chips 101 to a temperature equal to or higher than the softening point of copper. Then, together with this heating, the copper cutting chips 101 are stirred by the cylindrical rotary tool 103 in the recess of the die 102, and the copper cutting chips 101 are integrated. The integrated copper shavings 104 are then removed from the die 102 .

[0013] Next, friction stir welding will be described. Fig. 2 is a schematic diagram for explaining a method for integrating copper cutting chips according to the first embodiment. As shown in Fig. 2, friction stir welding (FSW) is a technique for integrating the workpiece 202 by pressing a rotating tool 201 against the workpiece 202, heating it to 200 to 300°C, which is the softening temperature of copper, with the generated frictional heat, and stirring it with the tool 201.

[0014] Since heat is generated in a spot manner near the tool 201, the energy required to heat a 20 mm x 20 mm x 20 mm area around the workpiece 202 to 300°C was calculated from the specific heat of the material. Table 1 shows the weight, specific heat, and required energy for each part. [Table 1] This energy is equivalent to 0.12 kWh / kg of copper.

[0015] Next, the energy required for FSW was estimated as follows. Figure 3 is a bar graph showing a comparison of energy required for the refining process. In Figure 3, the vertical axis shows the energy required for the refining process, and the horizontal axis shows the type of material. As shown in Figure 3, the energy required for FSW is much smaller than the energy required for melting and refining.

[0016] Thus, according to the copper cutting chip integration method of the first embodiment, the copper cutting chips are collected, and the FSW energy is applied to solidify them into a single chip, thereby reducing the operating energy. Also, according to the copper cutting chip integration method of the first embodiment, the copper cutting chips can be integrated without melting and refining, and the deterioration of the electrical resistance value due to the decrease in copper purity can be avoided.

[0017] Embodiment 2 Even if copper cutting chips are collected and a rotating tool is applied to them, the copper chips may scatter. In the second embodiment, a method for consolidating copper cutting chips that can deal with the case where copper chips scatter will be described. FIG. 4 is a flow chart and a schematic diagram showing an example of the method for consolidating copper cutting chips according to the second embodiment.

[0018] First, in step S41, copper cutting chips 401 are prepared. Then, the process proceeds to step S42.

[0019] Next, in step S42, the copper cutting chips 401 are collected in the shredder 402. The collected copper cutting chips 401 are then subjected to the shredder 402, whereby the grain size of the copper cutting chips is adjusted. Then, the process proceeds to step S43.

[0020] In step S43, the copper cutting chips 401 whose grain size has been adjusted are transferred to the recess of the die 403. Then, the copper cutting chips 401 are compressed by the punch 404. The compression is preferably performed with a pressure that does not put a strain on the die (generally 700 MPa as a guideline). Then, the process proceeds to step S44.

[0021] In step S44, a rotatable cylindrical rotary tool 405 is pressed against the copper cutting chips 401 placed in the recess of the die 403, and the cylindrical rotary tool 405 is rotated. This rotation heats the copper cutting chips 401 to a temperature equal to or higher than the softening point of copper. Then, together with this heating, the copper cutting chips 401 are stirred by the cylindrical rotary tool 405 in the recess of the die 403, and the copper cutting chips 401 are integrated. Then, the process proceeds to step S45.

[0022] In step S45, the integrated copper shavings 406 are removed from the die.

[0023] Thus, according to the method for consolidating copper cutting chips of embodiment 2, the grain size of the copper cutting chips is adjusted, the copper cutting chips are compressed, and then FSW energy is applied to solidify them into a single chip, thereby obtaining stable, integrated copper without the copper chips scattering.

[0024] The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, instead of using a shredder (crusher), the grain size may be adjusted by crushing with a rolling roll. [Explanation of symbols]

[0025] 101, 104, 401, 406 Copper cutting waste 102, 403 Die 103, 405 Cylindrical Rotation Tool 201 Tools 202 Work 402 Shredder 404 Punch

Claims

1. A step of placing the substrate on a die having a recess while scattering copper cutting chips; and a consolidation step of pressing a rotatable cylindrical rotating tool against the copper cutting chips placed in the recess of the die and rotating the cylindrical rotating tool to heat the copper cutting chips to a temperature equal to or higher than the softening temperature of copper and stir the copper cutting chips in the recess of the die with the cylindrical rotating tool to consolidate the copper cutting chips.

2. A particle size adjusting step of collecting copper cutting chips in a shredder and adjusting the particle size of the collected copper cutting chips by shredding the shredder is provided, a pre-compression step of transferring the copper cutting chips having the adjusted grain size into a recess of a die and pre-compressing the copper cutting chips with a punch after the grain size adjustment step; After the pre-compression step, the integration step is carried out; The method for consolidating copper cutting chips according to claim 1 , further comprising a removing step of removing the consolidated copper cutting chips from the die after the consolidation step.

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