Copper Sulphuric Acid Shortage Threatens Supply

• Copper sulphuric acid shortage risk grows after Hormuz closure
• IEA 2026 outlook narrows global copper supply gap to 25%
• Strait of Hormuz closure cut roughly half of seaborne sulphur trade
• China’s export ban removes a major slice of ex-China acid supply
• CFR Mejillones acid benchmark doubled in under seven weeks
• Chile sources over a third of its acid imports from China
• Russia extended its own sulphur export ban through end of 2026

A copper sulphuric acid shortage triggered by the closure of the Strait of Hormuz and a Chinese export ban is now constraining leach-based copper output in the Democratic Republic of Congo and Chile, according to the International Energy Agency’s Global Critical Minerals Outlook 2026, published 16 July 2026.

Copper Sulphuric Acid Shortage Squeezes SxEW Output

Leaching, solvent extraction and electrowinning (SxEW) accounts for more than 15% of global primary copper output, turning acid-leached ore into finished cathode at the mine site. The IEA describes constrained acid availability as a significant risk to this production route, layered on top of slower than expected recoveries at major mines.

The root cause is the effective closure of the Strait of Hormuz to commercial shipping since late February 2026 amid the regional conflict. The Middle East accounts for roughly a third of global sulphur production and around half of seaborne sulphur trade, and the disruption has already driven up Middle East sulphur benchmarks sharply from pre-conflict levels. China compounded the shock with a sulphuric acid export halt from May 2026, covering acid produced as a byproduct of copper and zinc smelting, with analysts flagging the restriction could run through the rest of the year.

Sulphuric Acid Prices Double as Hormuz and China Squeeze Supply

The impact showed up fastest in benchmark pricing. The CFR Mejillones assessment, the standard reference for Chilean copper miners, rose from around $190 a tonne in late February to $300 by early April, then to $380 a tonne in mid-April, doubling in under seven weeks with a single-week jump of nearly 27% following China’s announcement, according to S&P Global Platts data.

Chile is the world’s largest sulphuric acid importer, buying around 4 million tonnes a year, with roughly 37% historically sourced from China, 24% from Peru and 11% from Japan. Around a fifth of Chile’s refined copper output, more than a million tonnes annually, depends on acid-intensive SxEW heap leaching, leaving the country directly exposed as Chinese volumes dry up. Around 60% of global sulphuric acid demand goes to fertiliser production, with the remainder covering copper and nickel extraction, uranium leaching and other industrial uses, meaning the disruption reaches well beyond mining.

DRC and Chile Face Acid Supply Chain Risk

Almost 45% of copper production in the DRC depends on sulphuric acid leaching, exposing roughly 1.5 million tonnes of output to the current squeeze.

Chile, already managing its own acid supply crunch, adds further strain to a country that anchors global refined copper supply. Russia has separately extended its own ban on industrial sulphur exports through the end of 2026, removing another potential swing source just as buyers look for alternatives to Chinese and Middle Eastern volumes.

Copper Price and Long-Term Supply Gap

Despite record copper prices on the LME, the annual treatment and refining charge benchmark settled at $0 per tonne for 2026, the lowest ever agreed, as a surge in Chinese smelter capacity leaves processors competing for shrinking margins.

The IEA has narrowed its projected 2035 primary copper supply gap to around 25%, down from roughly 30% a year earlier, helped by new DRC and Zambia project additions. For current benchmark levels, see CMN’s copper price tracker.

What to watch: whether China’s acid export ban, running through the end of 2026, gets extended, whether Hormuz shipping routes normalise, and Q3 production updates from DRC and Chilean SxEW operators facing a tightening acid market on two fronts at once.