SMM, April 28: the current contract of electrolytic copper in North China today rose 220 yuan / ton to 300 yuan / ton, with a transaction price of 42470 yuan / ton to 42730 yuan / ton. Shanghai copper vomiting part of the increase to 42400 yuan / ton front line, the first two weeks due to the price difference between Tianjin and Shanghai opened 150 yuan / ton, Shanghai shipped to Tianjin wet method and fire method supply has increased significantly, the local supply has been supplemented, high water quotation is difficult to maintain, smelters and traders take the initiative to try to close, the average price of rising water 260 yuan / ton, 35 yuan / ton lower than yesterday, the transaction is still weak after rising water.