China’s Refined Copper Output Falls 0.67% in September to 1.139 Million Tonnes
Key Facts
Shanghai Metals Market estimated China’s copper cathode output at 1.139 million metric tonnes in September 2026, down 0.67% from August, indicating that tight raw material supplies and maintenance are limiting production growth. The company said concentrated maintenance at large smelters is expected to reduce output for the month by more than 30,000 tonnes. The estimate follows output of 1.147 million tonnes in August, up 1.79% month on month but still 2.09% below its level a year earlier. The figures reflect simultaneous pressure on supplies of concentrates and scrap, both key inputs for Chinese smelters. In this context, available smelting capacity alone is not enough to ensure higher cathode output if the necessary raw materials cannot be secured.
Customs data compiled by the company show part of this pressure: China imported 2.508 million wet tonnes of copper concentrates in August, up 5.4% from July, but the volume was 9.8% below its year-earlier level. The company’s spot treatment charge index for imported concentrates also fell to a record low of -$241.43 per dry tonne, signalling intense competition among smelters for available feedstock. A shortage of concentrates alongside tight scrap supplies is affecting smelters’ ability to switch between feed sources, according to an Argus analyst quoted by Reuters. The analyst said, "The concern now is that scrap is becoming scarce at the same time as concentrates, reducing smelters’ ability to substitute between raw materials." This means the monthly rise in concentrate imports has not erased the supply gap compared with the previous year.
Pressure on smelter economics has intensified as returns from byproducts, which had offset some of the impact of low treatment charges, have fallen. The company said persistently lower sulphuric acid prices had weakened those returns, while OilChem Information said acid prices dropped 11% in September. Reuters reported that the lower price of this byproduct reduced a source of income for smelters at a time when they face negative charges for processing concentrates. Taken together, these factors point to tight operating margins, but do not mean that every smelter will cut output or extend maintenance. The company framed the impact as a possibility that could lead some companies to prolong maintenance or delay the resumption of production.
The supply slowdown also shapes annual production forecasts, with analysts expecting China’s refined copper output to grow by 3% to 3.4% in 2026, compared with a 10.4% increase in 2025. A Reuters review of official records found that this would be the slowest growth rate since at least 2000. Analysts attributed the slowdown to tighter taxation that is reducing copper scrap supplies, worsening the prolonged shortage of concentrates, the main raw material for smelting. The comparison marks a shift from last year’s growth, but concerns annual output and does not change the company’s monthly estimate for September. This trajectory places raw material and maintenance pressures within the broader picture for China’s refined copper supply.
Attention is turning to planned maintenance in the coming months, with 7 Chinese smelters planning equipment maintenance lasting 30 to 60 days during October and November. Reuters estimated that the work would reduce refined copper supplies by about 80,000 tonnes over the period. The company had said that tight raw material supplies, negative treatment charges and lower byproduct returns could lead some smelters to extend maintenance or delay the resumption of production, potentially making the supply impact more pronounced in the fourth quarter. An extension of maintenance remains a possibility raised by the company, while the 80,000-tonne figure is a separate estimate for planned maintenance at the seven smelters. This follows concentrated maintenance at large smelters that is expected to cut September output by more than 30,000 tonnes.