When the Strait of Hormuz closed to commercial shipping in February 2026, markets focused on oil. The less visible casualty was sulphuric acid, an industrial chemical so fundamental to mining that over half of global lithium, cobalt, and rare earth production is now exposed to its shortage. Benchmark Mineral Intelligence data shows acid costs have more than doubled in key markets, and for high-purity manganese sulphate used in EV batteries, 100% of supply is at risk.
Introduction
This story is about a chemical most people have never thought about. It is also about why that chemical now sits at the centre of the global energy transition, food security, and a supply crisis that analysts are calling the worst since 2008.
Sulphuric acid is the world's most produced industrial chemical, with annual output exceeding 260 million metric tonnes. It dissolves copper from oxide ores, converts hard rock into lithium chemicals, strips nickel from laterite deposits, and produces the phosphate fertilisers that feed roughly half the planet. When supply tightens, the consequences cascade across industries that rarely appear in the same sentence.
Supply has tightened dramatically. On February 28, 2026, the Strait of Hormuz closed to commercial dry bulk traffic. The world's attention went to oil. But approximately half of global seaborne sulphur trade also transits that strait, and sulphur is the raw material from which sulphuric acid is made. Sulphur accounts for roughly 80% of acid's production cost. When the sulphur stopped moving, acid prices moved fast.
Two months later, China amplified the shock. On April 10, 2026, Beijing announced a full export ban on sulphuric acid through August 2026, replacing an already-reduced quota with a complete cessation. China produces more than 40% of global sulphuric acid. It exported 4.65 million tonnes in 2025. In June 2026, that figure collapsed by 99.2% month on month. The combination of a geographic chokepoint and a policy decision by the world's largest producer has produced a supply shock with no quick exit.
What Happened: Three Shocks, One Chemical
Think of sulphur as a by-product that the world depends on but cannot directly control. It is recovered during the refining of oil and natural gas, not produced in response to sulphur demand. When a refinery runs, sulphur comes out. When a refinery slows or a trade route closes, the sulphur stops. No producer increases output because the price has risen, because output is a function of refinery throughput, not market signals. That structural rigidity is what makes geographic concentration so dangerous.
The Middle East produces approximately one-third of global sulphur supply. Qatar's Ras Laffan Industrial City alone processes over 70 million cubic metres of natural gas per day, generating substantial sulphur by-products exported through purpose-built bulk terminals. When the Strait of Hormuz closed, Kpler tracked the cargo build-up in near-real time as loaded vessels queued with no exit. The disruption affected roughly 4 million metric tonnes per year of seaborne sulphur trade.
Russia added to the pressure. A ban on Russian sulphur exports, first imposed in November 2025 following drone strikes on the Astrakhan facility that produces nearly 60% of Russia's sulphur, was extended through June 2026. Turkey introduced its own export ban in April 2026. Then China moved. The stated rationale in Beijing was domestic agricultural priority: sulphuric acid is essential for phosphate fertiliser production, and China was protecting its own supplies during the spring planting season. The effect on international markets was immediate and severe.
Syed Salman Shaffi, President of the Gold Miners Club, summarised the dynamic clearly: "China's export ban is a crisis multiplier. The Iran conflict created a shortage of raw materials. China's export halt triggers a commercial drought. These events shift the burden from Chinese smelters to copper mines in Chile, mining operations in Congo, and fertilizer blenders in India."
The price data confirms the shift. S&P Global Platts assessed the FOB Middle East sulphur price at $695 to $700 per metric tonne in March 2026, up $200 per tonne from pre-conflict levels. Seaborne spot prices for sulphur rose from approximately $155 per tonne to around $400 per tonne CFR Mediterranean. Benchmark Mineral Intelligence reports sulphur prices have climbed more than 50% since the start of the conflict and sulphuric acid prices have more than doubled in key regions. In the Democratic Republic of Congo, delivered acid prices reached $1,000 to $1,400 per metric tonne.
What It Means for Critical Minerals: From Lithium to Manganese
Sulphuric acid is not a peripheral input to critical mineral processing. It is, in many cases, the process. To understand why the current shortage matters so much, it helps to trace acid through the supply chain.
In hard-rock lithium processing, spodumene concentrate is roasted and then leached with sulphuric acid to produce lithium sulphate, which is converted into lithium carbonate or lithium hydroxide. Before the current crisis, acid accounted for roughly 3% of the operating cost of producing lithium chemicals from hard-rock sources. Benchmark Mineral Intelligence now estimates that figure at 11%, and one analysis places acid's contribution at 22% of total hard-rock lithium conversion costs, making it the single most volatile and material input in the process. Battery-grade lithium carbonate prices in China have risen approximately 65% this year in US dollar terms as a direct downstream consequence.
For nickel produced through high-pressure acid leaching, known as HPAL, the numbers are starker. Sulphur now represents 42% of HPAL nickel costs, up from 26% before the conflict. Sulphuric acid represents 59% of purified phosphoric acid production costs, a material used in lithium iron phosphate batteries. Across key supply chains, Benchmark estimates sulphur and acid now account for an average of 33% of first-cost production expenses.
The most acute exposure sits with high-purity manganese sulphate monohydrate, known as HPMSM, which is used in manganese-containing EV battery cathodes. Benchmark's analysis finds that 100% of HPMSM supply is exposed to the sulphuric acid shortage. There is no workaround in the chemistry. The acid is not a component that can be substituted or reduced without changing the process entirely.
Will Talbot, raw materials research manager at Benchmark Mineral Intelligence, put the risk plainly: "Not only do high acid prices increase the cost base of lithium, nickel, copper, manganese, phosphoric acid and rare earth refiners, a lack of physical sulphur also threatens production." He added that the outstanding risk is that more critical minerals players cut production or shut down operations entirely. That is not a remote scenario. It is already beginning to happen.
The Copper Sector: Oxide Mines Under Threat
Copper is where the acid shortage becomes most immediately visible as a production threat rather than a cost management problem.
About 20% of global copper supply comes from a process called heap leaching, in which sulphuric acid is applied to oxidised ores to dissolve and extract the copper. There is no acid, there is no copper, at least from this category of deposit. The process requires three to three and a half tonnes of acid per tonne of copper cathode produced. Chile, the world's largest copper producer, imports more than one million tonnes of Chinese sulphuric acid annually to support the leaching operations that generate roughly a fifth of global copper output. Chile's CFR Mejillones spot acid prices rose from $190 per tonne on February 25 to $380 per tonne by mid-April, a doubling in under seven weeks, with a single-week spike of 26.7% following the China announcement.
The DRC's oxide copper mines face the same problem in a more acute form. Copper mines in the DRC, the world's second-largest copper producer, have already cut acid usage or are considering output reductions. Delivered prices in the DRC have reached $1,000 to $1,400 per metric tonne, levels at which some oxide operations cannot remain economically viable.
Zambia, Africa's second-largest copper producer, generates approximately two million metric tonnes of sulphuric acid annually as a smelter by-product, with excess historically exported to the DRC. That buffer has evaporated. First Quantum Minerals' Zambia leadership has confirmed that domestic stocks are so depleted there is effectively no capacity to export. On March 27, 2026, Zambia introduced a permit-based export control system, citing a critical market imbalance.
There is one notable counterexample. Ivanhoe Mines' Kamoa-Kakula Copper Complex in the DRC operates its own copper smelter, which produces high-strength sulphuric acid as a by-product of smelting sulphide concentrates. The facility produced 117,871 metric tonnes of acid in Q1 2026 and 112,307 tonnes in Q2 2026. At commission in December 2025, Ivanhoe expected to sell that acid for $200 to $250 per tonne. By March 2026, realised prices had passed $500 per tonne. Q3 contract prices reached approximately $840 per tonne. Ivanhoe co-chairman Robert Friedland described the smelter as providing "a natural hedge" and said acid revenues covered the smelter's operating costs during Q2 2026, growing into what he called "a one-million-dollar-a-day operating credit." Glencore and Kazakhstan's Eurasian Resources Group are among the customers. Even so, at maximum capacity of 600,000 to 700,000 tonnes annually, Kamoa-Kakula's output covers only roughly one-third of DRC leaching requirements.
Competing With Food: The Fertiliser Industry's Claim on Acid Supply
One reason the acid shortage is so difficult to resolve is that mining is not first in line for available supply. Fertiliser production consumes roughly 60% of global sulphuric acid output, and fertiliser is not optional.
Phosphate fertilisers are produced by reacting phosphate rock with sulphuric acid. When acid supply tightens, phosphate output falls, and food prices follow. Fertiliser costs are projected to rise 15 to 20% in the first two quarters of 2026 directly because of the acid shortage. In the US, Mosaic has cut domestic phosphate output by approximately two million tonnes. Morocco's state phosphate company OCP received its last cargo of Middle East sulphur on April 10, 2026, and is now reliant on Russian supply. India, whose sulphuric acid demand exceeds 20 million tonnes annually, has seen its sulphur stockpiles fall below two weeks of cover.
This is the structural competition that makes the mining sector's position so uncomfortable. When a critical mineral processor and a fertiliser plant are bidding for the same acid tonne, governments do not stay neutral for long. China's export restrictions reflect exactly this logic: Beijing is choosing domestic agricultural stability over global market integration, and the legal architecture supports that choice. China's new Hazardous Chemicals Safety Law, which took effect May 1, adds a regulatory dimension that makes a rapid reversal of policy unlikely.
Mining operations, unlike fertiliser plants, can in principle switch chemistries, though not quickly or cheaply. The SART process can recycle acid in certain copper leaching operations, reducing fresh acid demand by 10 to 15%. Glycine leaching offers a commercially available alternative for some copper oxide deposits. For nickel, a shift to pyrometallurgical processing eliminates acid use entirely, but requires substantially higher energy input and different capital infrastructure. None of these alternatives can be deployed at scale within the timeframe of the current shock, and none address the acute physical shortage now confronting operators in the DRC, Chile, and Indonesia.
Why This Is a Multi-Year Problem, Not a Spike
The temptation in coverage of commodity price shocks is to treat them as transient: prices spike, producers respond, markets rebalance. The sulphuric acid situation does not fit that model, for reasons that are structural rather than cyclical.
New sulphuric acid production capacity takes years, not months, to build. New shipping routes and logistics infrastructure take years to develop. The countries best positioned to partially fill the China-shaped gap, specifically Japan, South Korea, and India, could collectively increase exports by only approximately 0.5 million metric tonnes, against China's reduction of more than three million tonnes. Contractual supply from the Middle East is substantially committed under long-term agreements to India and Morocco, meaning that even when the Strait of Hormuz fully reopens, a meaningful share of released supply will not reach the open market.
As I reported in August when covering the simultaneous copper and aluminium supply dislocations, the deeper pattern here is one that extractive industry supply chains keep rediscovering: the assumption that finding and extracting raw materials is the hard part of supply security has repeatedly proven wrong. The hard parts are in the middle, where refining, processing, and logistics concentrate risk in ways that geological and financial analysis tends to underestimate. Sulphuric acid is a vivid illustration. It is not a mineral. It is not traded on any major exchange with the visibility of copper or lithium. It is a foundational industrial chemical that the energy transition has made structurally essential, and whose supply geography was allowed to concentrate without serious strategic attention.
The IEA's 2026 Critical Minerals Outlook has flagged increased production costs and heightened supply risks across metals and battery-material value chains as a direct result of the acid price surge. Benchmark Mineral Intelligence warns that if Middle East sulphur supply chains remain disrupted or Chinese domestic fertiliser security concerns persist, export controls could extend into 2027. That scenario would sustain elevated spot prices for an extended period and apply maximum pressure on the heap-leach copper operations in Chile, the HPAL nickel plants in Indonesia, and the rare earth and battery material refiners that have built their economics on acid being available and affordable.
The legal dimension is also unresolved. Producers and off-takers across Chile, Peru, the DRC, Zambia, and Indonesia are now operating long-term supply contracts in a market where the underlying supply no longer exists at contracted volumes or prices. China's government prohibition will typically qualify as a force majeure event under standard export restriction clauses, but the commercial disputes arising from that determination are only beginning to work through commercial and legal channels.
What to Watch
Three developments will determine how this crisis evolves over the next twelve months.
First, the status of the Strait of Hormuz. The strait remains the fulcrum of the entire crisis. A durable reopening would release a meaningful volume of committed supply, though not all of it will reach spot markets given long-term contract obligations. A continued closure, or a partial reopening followed by another incident, would extend the disruption through 2027 and deepen the structural damage to critical mineral processing economics.
Second, the duration and scope of China's export controls. Beijing's restrictions are currently scheduled through the end of 2026. The stated rationale, protecting domestic fertiliser supply during planting season, becomes harder to sustain as a justification for restrictions running through winter. But China's new regulatory framework gives authorities considerable flexibility to extend controls on hazardous chemicals, and the domestic sulphur price environment in China, which reached approximately $1,330 per metric tonne in June 2026, suggests that domestic supply pressure has not eased.
Third, the pace at which affected producers implement structural mitigations. Building buffer stocks, locking in multi-year contracts with non-Chinese suppliers, co-investing in on-site acid production, and piloting alternative leaching chemistries are all being discussed. Few are moving quickly enough to matter within the current crisis window. The Kamoa-Kakula model, in which an integrated copper smelter generates acid as a by-product that can be sold locally, is instructive. But building a copper smelter is not a response that most miners can execute in months.
Sulphuric acid will not become a headline commodity in the way copper or lithium have. It is too industrial, too unsexy, too far removed from the battery pack in a consumer's electric vehicle. But as the events of 2026 have demonstrated, the energy transition runs on chemistry, and the chemistry runs on inputs that policymakers and investors have consistently underestimated. The acid problem is not going away quietly.