By Penny Langford
The global copper market is currently grappling with a "chemical ceiling" that threatens to derail production forecasts just as demand for the energy transition reaches a fever pitch. While the industry has long focused on declining ore grades and labor disputes, a more fundamental bottleneck has emerged in 2026: a critical shortage of sulphuric acid.
Sulphuric acid is the invisible lifeblood of modern copper mining, particularly for operations utilizing solvent extraction-electrowinning (SX-EW). This "wet" processing route accounts for approximately 17% of global copper output, making it indispensable for low-grade oxide and secondary sulphide ores. As of mid-2026, a combination of geopolitical chokepoints and structural trade shifts has pushed acid prices in key regions like Chile and the Democratic Republic of Congo (DRC) to historic highs, forcing operators to reconsider the economics of their leaching pads.
The Mechanics: Why Acid is Non-Negotiable
For many of the world's largest copper mines, production is not just about moving earth; it is a chemical process. In the SX-EW method, crushed ore is piled onto massive "leach pads" and irrigated with a diluted sulphuric acid solution. This acid dissolves the copper from the rock, creating a copper-rich solution that is later processed into high-purity cathodes.
When acid supply tightens, the impact on production is almost immediate. Mines are forced to reduce the concentration of acid in their leaching solutions, which lowers the "grade" of the resulting solution and directly reduces the volume of finished copper cathode produced. If the shortage persists, operators must delay the commissioning of new leach pads or shut down high-cost marginal projects entirely.
In Chile, the world's top copper producer, the reliance on imported acid is a strategic vulnerability. Roughly 37% of Chile’s sulphuric acid imports have historically originated from China. When that supply is interrupted, the cost of production for leached copper: which sits higher on the cost curve than traditional concentrate smelting: spikes dramatically.
The 2026 Perfect Storm: Hormuz and the China Ban
The current crisis is driven by three overlapping disruptions that have constricted global sulphur and acid flows:
- The Strait of Hormuz Blockade: The ongoing conflict in the Middle East has led to a partial blockade of the Strait of Hormuz. This is a critical chokepoint for seaborne sulphur, a byproduct of oil and gas refining and the primary feedstock for sulphuric acid. Analysts estimate that nearly 50% of global seaborne sulphur supply has been impacted, cutting off essential volumes to African and South American miners.
- China’s Sulphuric Acid Export Ban: In May 2026, Beijing implemented a strict ban on the export of sulphuric acid. While this move was intended to support domestic Chinese smelters by lowering internal chemical costs, it removed a massive volume of liquidity from the international market.
- Smelter Decarbonization: A longer-term structural trend is also at play. As global smelters move toward "cleaner" operations to meet 2026 ESG and audit-ready compliance standards, the production of sulphuric acid: traditionally a byproduct of capturing sulphur dioxide emissions: has become more volatile.
Market Data: 2026 Acid Price and Production Risk
The following table outlines the current price environment and the estimated copper production at risk due to the chemical shortage.
| Region | Acid Contract Price ($/t) | 2026 Spot Price ($/t) | Estimated Copper at Risk (2026) |
|---|---|---|---|
| Chile | $160 – $175 | $380 – $420 | 200,000 – 300,000 tonnes |
| DRC / Zambia | $180 – $210 | $450 – $500 | 125,000 – 150,000 tonnes |
| China | $90 – $110 | $75 – $85 (Internal) | Negligible (Surplus) |
| Global Total | — | — | 325,000 – 450,000 tonnes |
Source: Skillings Mining Intelligence / S&P Global / Morgan Stanley
Regional Deep Dive: Chile and the DRC
The impact of the sulphuric acid crisis is not felt equally. In Chile, the surge in acid prices has contributed to a 6% drop in copper production during the first half of 2026. Companies operating aged ore piles or low-grade projects are seeing acid costs jump to nearly 33% of their total C1 operating costs. The situation has been further complicated by extreme weather events in the Chilean copper belt, which have disrupted the logistics of transporting chemicals from ports to inland mine sites.
In the Democratic Republic of Congo (DRC), the distance from major ports makes the region even more sensitive to sulphur logistics. Many DRC mines rely on Middle Eastern sulphur shipped through Durban or Dar es Salaam. With the Hormuz disruption, these mines are facing lead times that have doubled and transport costs that have tripled. Some operators in the Copper Belt have already signaled that their 2026 production targets are no longer achievable if acid availability does not normalize by Q4.
Financial Implications: The $11,000/t Price Floor
For investors, the sulphuric acid crisis has fundamentally altered the copper cost curve. The "marginal cost of production": the cost of the last tonne of copper needed to meet demand: has been pushed higher by these reagent costs.
As a result, many analysts believe a structural floor has been set for copper prices. Even as new mining technologies such as autonomous drilling and AI-ready processing improve efficiency, the soaring cost of chemicals remains a stubborn inflationary pressure. Spot copper has recently breached $14,000 per tonne, and even in a bearish economic scenario, the "chemical ceiling" suggests that prices are unlikely to drop below $11,500 per tonne in the near term.
2026 Outlook: Base, Bull, and Bear Case
The trajectory of the copper market for the remainder of 2026 depends heavily on geopolitical resolutions.
- Base Case: Sulphuric acid prices remain in the $250–$400/t range. Global copper supply growth remains constrained at approximately 1.6%, with total refined copper losses reaching 300,000 tonnes. Copper prices stabilize between $12,000 and $13,000/t.
- Bull Case: Prolonged Hormuz closure and the continuation of China’s export ban lead to a total acid cutoff for marginal projects. Copper supply losses exceed 500,000 tonnes, potentially pushing copper prices toward $15,000/t as demand from AI infrastructure and power grids converges.
- Bear Case: A diplomatic resolution in the Middle East allows sulphur flows to resume, and China eases its export ban to capitalize on high international prices. Acid prices retreat below $200/t, and copper prices revert to the $10,000–$11,000/t range.
The 2026 sulphuric acid crisis is a stark reminder that the energy transition relies as much on chemical supply chains as it does on the ore in the ground. For copper miners, the priority is no longer just finding the metal: it is securing the reagents required to extract it.
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The "chemical ceiling" has arrived. A global sulphuric acid shortage: driven by the Hormuz blockade and China’s export ban; is threatening up to 450,000 tonnes of copper output in 2026. In Chile, acid costs now represent 33% of operating costs for some leaching projects. Is the $11,000/t copper floor permanent? Penny Langford breaks down the supply chain mechanics of the 2026 acid crisis. #CopperMining #SulphuricAcid #EnergyTransition #Commodities2026 #MiningNews
