Three developments this week force a reckoning with a single uncomfortable truth: Western critical mineral strategy has been built on an assumption of future diversification that the data no longer supports. China's sulfuric acid export ban, now in effect, is crippling copper output in Chile and the DRC. The U.S. government's flagship $12 billion stockpile must buy from Chinese processors because no alternative exists at scale. And new IEA data confirms that refining concentration is getting worse, not better, despite years of policy effort and billions in public investment.
Introduction
Three developments landed in the same week, and they tell the same story from three different angles. On May 1, China's ban on sulfuric acid exports took effect, immediately tightening the supply of a critical processing chemical for copper and cobalt miners from Chile to the Democratic Republic of the Congo. Two days earlier, the U.S. Export-Import Bank confirmed publicly what many had suspected about Project Vault, the administration's $12 billion strategic minerals reserve: in its opening phase, it will buy from Chinese processors, because no viable alternative exists at commercial scale. And new data from the International Energy Agency shows that the average market share of the top three refining nations for key energy minerals rose to 86 percent in 2024, up from 82 percent in 2020, with nearly all growth concentrated in a single dominant supplier.
These are not three separate stories. They are three readings of the same structural failure. For years, Western governments have spoken about supply chain diversification as a goal being actively pursued. The implicit promise was that the dependence on Chinese refining and processing capacity was a temporary condition, one that capital, policy, and political will could fix within a reasonable timeframe. What this week's evidence suggests, collectively, is that the timeframe is far longer than policymakers have publicly acknowledged, and that the vulnerabilities are deeper than most commodity strategies have been designed to address.
This matters to a wide audience: to the automakers and defense contractors whose supply commitments depend on allied sourcing assurances, to the copper miners watching their input costs spike with no quick fix available, to the policymakers defending diversification timelines that the IEA data is quietly dismantling, and to the investors trying to price risk into offtake agreements written against a supply landscape that may look very different in five years.
When a Processing Chemical Becomes a Strategic Weapon
Sulfuric acid is not glamorous. It rarely appears in headlines about the energy transition, and it does not feature on most lists of critical minerals. But it is indispensable. Roughly 20 percent of global copper production relies on a hydrometallurgical process called solvent extraction and electrowinning, in which acid is applied to oxidized ores to dissolve and then recover copper. Without acid, those operations stop. It is that simple.
China produced approximately 110 million tonnes of sulfuric acid in 2025, accounting for more than 40 percent of global output. That year, it exported a record 4.65 million tonnes, having transitioned from a net importer to a net exporter almost overnight. Then, effective May 1, 2026, it halted those exports entirely. The policy logic in Beijing is coherent from a domestic standpoint: China runs a structural sulfur import deficit, its fertilizer production needs acid during peak planting seasons, and the National Development and Reform Commission has been systematically restricting agricultural chemical exports since December 2025. Sulfuric acid is simply the latest product in a broader food-security-first resource strategy.
The timing could not be worse for producers elsewhere. Independently of China's decision, the conflict in the Middle East and effective closure of the Strait of Hormuz to commercial shipping since late February 2026 had already disrupted roughly one-third of global sulfur output. Sulfur is the primary feedstock for sulfuric acid production, and seaborne sulfur prices had nearly tripled in the twelve months before the conflict began. The two disruptions did not compound gradually. They converged suddenly, removing what CRU principal analyst Peter Harrisson described bluntly: "The loss of Chinese trade cannot be replaced with other origins."
The price signals confirm the severity. The S&P Global Platts benchmark for Chilean copper miners doubled in less than seven weeks, with a 26.7 percent single-week spike following China's announcement. Spot prices in the DRC's Kolwezi mining region reached approximately $700 per tonne against a long-term forecast price of $150 per tonne. In Chile, operators are already reporting less than 30 days of acid inventory. Goldman Sachs now estimates that a year-long Chinese ban could put roughly 200,000 tonnes of Chilean cathode production at risk, and that extended Strait of Hormuz disruption past June could curtail another 125,000 tonnes of DRC copper output this year. Building on my analysis of these converging supply disruptions in April, the sulfuric acid story is the clearest illustration yet that the binding constraint in critical mineral supply chains was never the ore in the ground: it is always the chemistry required to unlock it.
Project Vault's Uncomfortable Confession
On April 30, Export-Import Bank Chief Banking Officer Brian Greeley confirmed publicly what the architecture of Project Vault had implied from its February launch: the $12 billion U.S. strategic minerals reserve will, in its initial phase, source materials from anywhere in the world, including China. The program will eventually operate on what Greeley called a "waterfall" model, prioritizing domestic suppliers first, then allied nations, then other sources. But the starting point is the global spot market, because for a meaningful number of the roughly 60 minerals on the USGS Critical Minerals List, commercial-scale alternative supply simply does not exist.
This is not a scandal. It is an honest acknowledgment of the gap between where policy wants to be and where supply chains actually are. The procurement agents designated to execute Vault's initial purchasing, Glencore, Hartree Partners, Traxys, and Mercuria, will begin acquiring material in the second quarter of 2026, using existing warehouse networks before Vault builds its own dedicated storage infrastructure. Participating manufacturers including Boeing, GE Vernova, and Clarios have made financial commitments in exchange for guaranteed access during disruptions. The model is demand-led in a genuinely innovative way: original equipment manufacturers define what they need, at what grade and volume, before purchases are made.
The contradiction, however, is real and worth naming clearly. A program designed explicitly to reduce dependence on Chinese supply chains must, at the outset, reinforce those same supply chains in order to function. Analysts at the Center for Strategic and International Studies and the Council on Foreign Relations have flagged concerns about market distortion: a large, non-commercial buyer entering the global market in Q2 2026 will exert upward price pressure on several critical commodities, potentially making it harder for allied producers to compete. There are also questions about whether a stockpile that temporarily stores Chinese-processed material solves the underlying problem, or merely defers it.
As one analyst involved in the program noted, "the bottleneck is not just the mining and sourcing; it's also the processing. Even if the U.S. can stockpile many of these materials, how and who is going to do the processing depending on the end-use applications?" That question does not have a near-term answer. Refining capacity takes years to build. The stockpile creates breathing room, which is valuable, but breathing room is not a substitute for the capacity itself.
The IEA Data That Reframes Everything
Against this backdrop, the IEA's latest data on global critical mineral refining concentration arrives with particular force. The headline finding: concentration is worsening, not improving. The average market share of the top three refining nations for copper, lithium, nickel, cobalt, graphite, and rare earth elements rose to 86 percent in 2024, up from 82 percent in 2020. Almost all of that growth came from a single supplier: Indonesia for nickel, and China for every other mineral on the list.
The forward projection is more sobering still. Based on current policy settings and investment trends, the IEA projects the average share of the top three suppliers will decline only marginally over the next decade, effectively returning to 2020 concentration levels by 2035. China is projected to supply over 60 percent of refined lithium and cobalt in 2035, and around 80 percent of battery-grade graphite and rare earth elements. For procurement officers writing offtake agreements today against allied-supply assurances, these numbers deserve careful attention. The assurance is accurate in the narrow sense: allied supply exists, or will exist, for certain minerals in certain volumes. But at aggregate scale, Chinese refining dominance will remain the structural reality for the foreseeable future.
The IEA's N-1 vulnerability analysis adds a further layer of risk. For graphite and rare earth elements, non-Chinese supply would cover only 35 to 40 percent of demand in a disruption scenario. For nickel, the ratio falls below 55 percent, and would drop further if battery-grade nickel sulphate from Chinese processors were also disrupted. For lithium and cobalt, the gaps are less acute but still significant. The implication is that even where global supply appears adequate in aggregate, the concentration of processing capacity creates severe fragility in any disruption scenario: exactly the scenario that the sulfuric acid ban and the Strait of Hormuz closure are now demonstrating in real time.
Investment momentum is also weakening at a moment when it needs to accelerate. Spending on critical mineral development grew by just 5 percent in 2024, down from 14 percent in 2023. Exploration activity plateaued. Start-up funding showed signs of slowdown. The IEA estimates that meeting rising mineral demand through 2040 will require approximately $500 billion in new mining capital under even a conservative scenario. The current trajectory falls well short of that figure.
The Allied Supply Gap: Between Promise and Pipeline
There is a coherent version of the optimistic story. Project Vault does create a meaningful buffer against short-term disruptions. The bilateral frameworks signed at the February 2026 Critical Minerals Ministerial with eleven countries, including Argentina, Morocco, Peru, and the Philippines, do expand the diplomatic architecture for future allied supply. Some diversification is genuinely occurring at the mining level: lithium is a meaningful exception to the concentration trend, with growth coming from emerging producers in Argentina and Zimbabwe. And operations like Ivanhoe Mines' Kamoa-Kakula copper complex in the DRC, which produces its own sulfuric acid as a smelting byproduct and sells it to neighboring oxide miners, demonstrate that integration and vertical positioning can create real resilience at the project level.
But the gap between the diplomatic architecture and commercial reality remains large. Even if new mines open in Australia, Vietnam, or Brazil, most ore still requires Chinese refining to become usable material. China accounts for approximately 91 percent of global rare earth refining and processing capacity as of 2024. It is the leading refiner for 19 of the 20 minerals analyzed by the IEA, with an average market share of around 70 percent across those minerals. Diversifying mining jurisdictions does not eliminate exposure to Chinese export controls. Processing capacity outside China is the binding constraint.
The sulfuric acid episode illustrates this precisely. The acid is not a finished mineral. It is a byproduct of copper and zinc smelting: a secondary chemical that most supply chain risk assessments did not model as a critical single point of failure. Yet its sudden disappearance from global trade flows is threatening to curtail hundreds of thousands of tonnes of copper cathode output, raise costs sharply for fertilizer producers, reduce byproduct silver output, and compress margins across nickel hydrometallurgy in Indonesia. The lesson is that Chinese processing leverage does not only operate through direct export controls on finished minerals. It operates through every chemical, every intermediate product, and every processing step where Chinese capacity has become structurally dominant.
The export control trajectory reinforces this concern. Since 2023, China has restricted gallium, germanium, antimony, tungsten, tellurium, bismuth, indium, molybdenum, seven heavy rare earth elements, and now sulfuric acid. Each new control adds a node to the network of leverage. The pattern is consistent: China is systematically mapping the full processing and chemical supply chain and asserting control at each layer where it holds dominant position.
What Happens Next
For copper markets, the immediate question is whether the sulfuric acid squeeze eases before inventories in Chile and the DRC run out. Chilean miners currently hold less than 30 days of acid inventory, and procurement specialist Fiona Boyd at Acuity Commodities has flagged uncovered demand for the second half of the year. Goldman Sachs has trimmed its 2026 copper price forecast to $12,650 per tonne, citing softer demand expectations, while simultaneously warning that acid disruptions could curtail up to 325,000 combined tonnes of Chilean and DRC production. That combination, a surplus market with a concentrated supply shock, creates unusual pricing dynamics that traders and miners are still working to price.
For Project Vault, the coming months will test whether the waterfall sourcing model can begin transitioning toward allied supply faster than the IEA's projections suggest is feasible. The Q2 2026 procurement phase will provide the first real data on how the program functions under live market conditions, including whether the entry of large non-commercial buyers distorts prices in ways that disadvantage smaller allied producers.
For policymakers, the IEA data presents a challenge that is difficult to address through press releases alone. The concentration trend is moving in the wrong direction despite billions in government investment and dozens of bilateral frameworks. Closing the gap requires refinery construction, not just mining agreements, and refineries take years to permit, finance, and build. The IEA's ministerial declaration in February called for accelerating strategic projects and enhancing preparedness for supply disruptions caused by export restrictions. Those are the right objectives. The question is whether the investment pipeline and policy toolkit are equal to a timeline measured in decades rather than years.
The honest conclusion is that the diversification story Western governments have been telling, to their publics, to their manufacturers, and perhaps to themselves, is running ahead of the underlying reality. That does not mean the effort is misguided. Project Vault, allied frameworks, and investment in non-Chinese processing capacity are all necessary. But they are early-stage responses to a structural problem that has been compounding for years. The sulfuric acid ban, the China sourcing paradox at the heart of Project Vault, and the IEA's concentration data together suggest that the gap between where policy aspires to be and where supply chains actually are is wider, and will remain wider for longer, than the official timelines acknowledge.