In April and may, domestic smelters entered the centralized

     As of last Friday (April 30), the import copper concentrate index of smm4 in April was at US $30.54/t, down by US $2.22/t compared with the previous period. However, the weekly import copper concentrate index of SMM was at US $32.48/t, up by US $2.28/t compared with the previous period. The trading center of copper concentrate market was significantly elevated, and the overall increase was significantly expanded. On the other hand, crude copper processing fee