•An Ohno continuous casting was applied to purify the copper of scrap copper.•Numerical simulation of solidification model can clarify the OCC process.•Morphology and EBSD analysis showed the structure of single crystal copper.•Resistance of single crystal copper is smaller than ordinary copper wire. 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 onthe 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 × 10-6 to 3 × 10-5 Ω m. Obviously, the resistance of the single crystal copper was significantly smaller than that of ordinary copper wire (9.0 × 10-3 Ω m). This study provided a key theoretical and practical basis for the high value-added reuse of copper in e-waste.