Historically Low TCs Threaten Chinese Copper Smelters’ Survival – Sulfuric Acid & Geopolitics Emerge as Key Variables

Since the beginning of this year, the spot treatment charge market for copper concentrates has shown an unprecedented and severe downward trend. The SMM Copper Concentrate Spot Index has fallen from -45 USD/dmt at the start of the year to near -70 USD/dmt, with the speed and magnitude of the decline being historically rare. A negative treatment charge means that when smelters purchase copper concentrates, they not only fail to receive traditional processing income from miners but instead must pay the sellers. Based on the current TC of -70 USD/dmt, the actual cost smelters pay sellers in the copper smelting process is equivalent to a TC of 70 USD, or further converted to a TC+RC of approximately 112 USD. This extreme price signal has quickly drawn high market attention to smelter profitability and even sparked concerns about the sustainability of domestic copper smelting production.

Despite treatment charges falling to historic lows, copper cathode production by Chinese smelters remains at high levels, currently around 1.2 million tons per month. This phenomenon of "producing more while losing more" appears, on the surface, to contradict market logic, but actually reflects smelters' passive choices and structural supporting factors in the current complex environment. Historically, extreme treatment charge scenarios are not unprecedented. In past industry downturns, smelters often relied on one or several factors—exchange rate fluctuations, rising sulfuric acid prices, or treatment charges themselves—to barely maintain cash flow balance. In the current cycle, the sharp rise in sulfuric acid prices has become a key variable supporting smelter survival.

Currently, the ex-factory prices of smelter acid sold by domestic copper smelters generally range from 800 to 1,600 yuan per ton. The latest SMM Copper Smelting Acid Index stands at 1,235.5 yuan/ton. As a crucial byproduct of copper smelting, sulfuric acid price fluctuations significantly impact smelters' comprehensive earnings. Typically, smelters produce approximately one ton of sulfuric acid for every dry metric ton of copper concentrate processed. Based on the current sulfuric acid price of 1,235.5 yuan/ton, after deducting value-added tax (at a 13% rate) and converting to US dollars (using an exchange rate of 6.9), each ton of sulfuric acid can contribute about 158 USD in revenue for the smelter, equivalent to an additional 158 USD per dry metric ton of copper concentrate. If further converted to the TC+RC metric, this amounts to about 99 USD. Thus, the rise in sulfuric acid prices has significantly offset the loss pressure from negative copper concentrate treatment charges, with some more efficient smelters even achieving marginal profitability. It is precisely this "stabilizer" role of sulfuric acid that allows smelters to maintain high operating rates under extreme treatment charge conditions.

However, the support of sulfuric acid for smelting profits is not unlimited, as its price trend is itself influenced by more complex international geopolitical factors. The recent sharp escalation of the Middle East situation has brought significant uncertainty to the global sulfuric acid and sulfur supply chain. Since the joint US-Israeli military strike against Iran on February 28, 2026, the Strait of Hormuz, the world's most critical energy transport route, has rapidly fallen into a severe transit crisis. After taking office, Iran's new Supreme Leader, Mojtaba Khamenei, immediately declared that the strait would remain closed as a strategic lever against the US-Israeli alliance and suggested that neighboring countries close US military bases. The Islamic Revolutionary Guard Corps subsequently explicitly announced a ban on any vessels associated with the US or Israel from passing through the Strait of Hormuz, warning of severe consequences for unauthorized passage.

The Strait of Hormuz is a critical chokepoint for global sulfur transport. Statistics show that before the conflict, over 100 ships passed through the strait daily. However, after the conflict erupted, transit traffic plummeted by over 90%, with extreme cases of no ships passing for an entire day, leaving over 3,000 vessels stranded in nearby waters. This effective blockade has not only directly impacted the crude oil market—with Brent crude futures rising over 50% within a month to exceed 114 USD per barrel—but has also severely disrupted the global supply chain for sulfur and sulfuric acid. War risks have caused shipping insurance costs to soar to over 20% of the cargo value, further increasing logistics costs and plunging global sulfur supply into a logistical crisis.

Although Iran claims to allow passage for vessels from "non-hostile" countries, requiring them to obtain prior permission, actual transit volumes remain extremely low, far below global trade demand. Simultaneously, the Houthi armed group in Yemen has announced its involvement, posing new security threats to the Red Sea-Suez route. The compounding pressure on the two major shipping chokepoints of the Strait of Hormuz and the Red Sea is posing a systemic challenge to the global supply chains for energy and chemical raw materials. As the primary raw material for sulfuric acid production, the disruption in sulfur supply directly drives international and domestic sulfuric acid prices progressively higher. Given the current situation, geopolitical conflicts show no signs of easing in the short term, implying further room for sulfuric acid price increases.

The continued rise in sulfuric acid prices will have a dual impact on the domestic copper smelting industry. On the one hand, increased sulfuric acid revenue will continue to provide crucial profit supplementation for smelters, enabling them to maintain production even at lower TC levels and potentially further depressing spot copper concentrate treatment charges. On the other hand, this surge in sulfuric acid prices, driven by geopolitical conflict, also makes smelter profitability highly dependent on external unstable factors, rendering the industry's overall risk resilience increasingly fragile.

Notably, the extreme treatment charge environment has begun to have a tangible impact on the global layout of copper smelting capacity. Mitsubishi Materials of Japan recently announced its plan to cease operations at its Onahama copper smelter by the end of March 2027. The smelter has a crude and refined capacity of 230,000 tons, and the main reason for the closure is precisely the intensified competition in the global copper smelting industry, leading to a sharp deterioration in copper concentrate TC/RC and persistent pressure on business prospects. This decision sends a clear signal: against the backdrop of continuously bottoming treatment charges and industry profits highly dependent on byproducts and external environments, some high-cost smelting capacity or those lacking comprehensive recovery capabilities are facing pressure to exit the market.

In summary, China's copper smelting industry is currently at a highly unusual cyclical juncture. On one hand, smelters, benefiting from high sulfuric acid prices, have temporarily weathered the impact of negative treatment charges, maintaining high output. On the other hand, sulfuric acid prices themselves are heavily dependent on geopolitical situations, and external variables like the Strait of Hormuz blockade introduce significant uncertainty into the sustainability of smelting profits. If tensions in the Middle East persist, sulfuric acid prices may continue to rise, leaving room for TC to fall further, potentially enhancing smelters' tolerance for extreme treatment charges in phases. However, if geopolitical tensions ease, sulfur supply chains recover, and sulfuric acid prices retreat from their highs, smelters would face the risk of a "double blow" from both low treatment charges and reduced byproduct revenue, potentially heralding a genuine phase of capacity reduction and deep adjustment for the industry.

Therefore, the current apparent "resilience" of the copper smelting industry is essentially built upon a fragile balance between geopolitical factors and the byproduct market. For market participants, besides monitoring TC trends, it is crucial to closely track changes in sulfuric acid prices and the underlying geopolitical factors to make more accurate judgments regarding the production sustainability and profitability prospects of the smelting industry.