Process simulation of Ohno continuous casting for single crystal copper prepared from scrap copper in waste printed circuit boards

How to realize the high value-added utilization of scrap copper from e-waste is a meaningful topic. In the study, an Ohno Continuous Casting (OCC) process is an existing method you applied to purify the copper. Based on the model of diffusion-controlled grain growth kinetics, the redistribution of impurity of tin in the scrap copper were studied under the different continuous casting speed and mold temperature. On the centerline, macrosegregation in the axial direction of the tin was more obvious with the decrease of continuous casting speed. The small continuous casting rate was beneficial to the segregation and enrichment of tin. The axial segregation gradually decreased with the increase of the mold temperature. The flattening of the liquid-solid interface resulted in a weakening of the solute enrichment at the root of the interface with the increase of temperature. Morphology, electron backscattered diffraction (EBSD) analysis showed the structure of single crystal copper. The range of resistance of single crystal copper was from 5 x 10(-6) to 3 x 10(-5) Omega m. Obviously, the resistance of the single crystal copper was significantly smaller than that of ordinary copper wire (9.0 x 10(-3) Omega m). This study provided a key theoretical and practical basis for the high value-added reuse of copper in e-waste. (C) 2021 Elsevier Ltd. All rights reserved.