, which began processing metal in June after multiple delays, has brought in less than a 10th of the raw material required, according to customs data. In the 10 months to October, it imported about 147,000 tons of copper concentrate. Competitor The smelter requires about 1.6 million tons of concentrate to function at full strength, Bloomberg reported earlier.Questions sent to the BloombergLive EventsAs a result, treatment and refining charges — the fees miners pay for processing — have hit a record low thi ...