Copper treatment charges for 2026 will fall below the Japanese benchmark of $25 per metric ton, Sumitomo Metal Mining confirmed on 11 May, as China’s smelting overcapacity continues to compress margins across the global concentrate processing industry. Yasuhiro Miyake, executive officer and general manager of finance and accounting at Sumitomo Metal Mining, said negotiations are in their final stages and the company expects to secure double-digit copper treatment charges — without specifying a precise figure.
Copper Treatment Charges Under Pressure from China Overcapacity
Treatment and refining charges (TC/RCs) are the fees miners pay smelters to convert copper concentrate into refined cathode metal. They represent the primary revenue stream for copper smelters and are typically negotiated annually, with a flagship deal between a major miner and Chinese smelters setting the global reference point.
For 2025, that reference was set at $21.25 per metric ton and 2.125 cents per pound, struck between a Chilean miner and Chinese smelters. Japanese smelters — including Sumitomo Metal Mining — negotiated separately and secured higher terms of $25 per metric ton and 2.5 cents per pound. The 2026 outcome, still unresolved, points to further compression from even the Japanese benchmark level.
The structural driver is well established: global copper smelting capacity, led by Chinese investment, is expanding faster than mined concentrate supply. With more smelters competing for a finite pool of ore, miners hold disproportionate negotiating leverage. Spot TC/RCs have fallen further still — in some cases turning negative, meaning smelters are paying miners for access to concentrate rather than being compensated for processing it.
Sumitomo: Higher Premiums to Partially Offset Weaker TC/RCs
Sumitomo Metal Mining has confirmed it has no plans to cut primary copper production despite the weaker processing fee environment. Miyake noted that elevated physical copper premiums — the charges applied above the LME reference price for delivery of refined copper in specific regional markets — are expected to partially offset the TC/RC shortfall.
Sumitomo also expects the supply-demand balance in the copper concentrate market to normalise as miners’ output recovers, though Miyake did not specify a timeframe for that correction.
The company’s position reflects a broader strategic choice facing non-Chinese smelters: maintain throughput and absorb compressed margins, or reduce output and risk losing long-term offtake relationships. Mitsubishi Materials, another major Japanese smelter, has taken the latter path — announcing plans to cut primary copper smelting capacity by 30–40% by its 2035 financial year as it pivots toward secondary smelting.
The Benchmark System Under Strain
The 2026 negotiations are playing out against a fragmented benchmark system. In 2025, the divergence between the Chinese reference ($21.25/t) and the Japanese benchmark ($25/t) signalled that the traditional model — in which a single annual deal sets a global reference — is under structural pressure.
In the spot market, the decline has been even sharper. Spot TC/RCs have turned negative in some cases, echoing the trajectory of the iron ore market, where annual benchmarks were replaced by spot-linked pricing more than a decade ago. Some miners have pushed for a similar overhaul in copper, but non-Chinese smelters have resisted, given the additional margin risk of exposure to a market where spot rates are already deeply compressed.
Japan, Spain, and South Korea issued a joint statement in October 2025 expressing concern about falling TC/RCs, warning the current environment is unsustainable for both smelters and miners over the long term.
For procurement professionals tracking refined copper availability, the pressure on smelter economics is a supply chain signal worth monitoring. Reduced smelting throughput — particularly outside China — narrows the pool of non-Chinese refined copper supply. See the copper price tracker for current LME and COMEX benchmarks, and the top 10 copper mining companies for context on the concentrate supply side.
Sumitomo Metal Mining (TYO: 5713) is Japan’s largest copper smelter and a significant participant in global concentrate markets, with minority stakes in major mining operations including the Quebrada Blanca project in Chile, operated by Teck Resources.
What are copper treatment charges (TC/RCs)?
Treatment charges (TC) are fees paid by copper miners to smelters to convert copper concentrate into refined cathode metal, expressed in US dollars per metric ton of concentrate. Refining charges (RC) are an additional fee expressed in cents per pound of copper recovered. Together they are the primary revenue stream for copper smelters and are negotiated annually.
What copper treatment charges did Sumitomo Metal Mining secure for 2026?
Sumitomo Metal Mining confirmed in May 2026 that it expects to secure double-digit treatment charges per metric ton for 2026 — below the 2025 Japanese benchmark of $25 per metric ton. Negotiations were still in final stages as of 11 May 2026 and no specific figure beyond the double-digit characterisation was disclosed.
Why are copper treatment charges falling in 2026?
Global copper smelting capacity, led by Chinese investment, is expanding faster than mined concentrate supply. With more smelters competing for a finite pool of ore, miners hold greater negotiating leverage, compressing the fees they pay to smelters. Spot TC/RCs have fallen further still, in some cases turning negative.
What is the difference between the Chinese and Japanese copper TC/RC benchmarks?
For 2025, Chinese smelters agreed terms of $21.25 per metric ton and 2.125 cents per pound with a Chilean miner. Japanese smelters — including Sumitomo Metal Mining — negotiated separately and secured $25 per metric ton and 2.5 cents per pound. For 2026, both benchmarks are expected to decline further.
How are non-Chinese copper smelters responding to compressed TC/RCs?
Responses vary. Sumitomo Metal Mining has stated it will maintain primary production and offset weaker TC/RCs through higher physical copper premiums. Mitsubishi Materials has announced plans to cut primary smelting capacity by 30–40% by its 2035 financial year, shifting toward secondary smelting. Japan, Spain, and South Korea issued a joint statement in October 2025 warning the situation is unsustainable.
