China has resumed exporting sulphuric acid to Chile, the world’s largest copper producer, after a three month halt, customs data reported on Tuesday showed, with shipments to Chile accounting for nearly all of the month’s exports. Shanghai Metals Market put China’s total September sulphuric acid exports at 33,873 tonnes, up 1,269 percent from August but down 92 percent from a year earlier, with Chile, Angola and Cambodia the main destinations. Cumulative exports for January to September were 821,684 tonnes, down 76 percent year on year.
The context is an export restriction, not a normal trade dip. China, which produces more than 40 percent of the world’s sulphuric acid, restricted most exports from May 1, 2026 to protect domestic supply amid the sulphur disruption that followed the Middle East conflict, and a first permitted shipment of about 32,000 tonnes left Nanjing for Chile while wider restrictions remained in place. Chile imports roughly four million tonnes of acid a year, so one month of resumed flow at this scale is a signal, not a restoration of supply.
Acid is not a minor input. Copper miners use it to leach metal from oxide ores, and it is also essential in lithium, nickel, cobalt and uranium processing. Morgan Stanley estimated in April that about 1.1 million tonnes of Chile’s annual leached copper output could be exposed to a Chinese export ban. Chilean spot acid prices at Mejillones doubled in under seven weeks earlier this year, from 190 dollars a tonne on February 25 to 380 dollars by April 15, and acid’s share of processing costs has risen sharply in lithium and nickel operations.
For copper supply, the resumption removes the worst case for the fourth quarter without removing the risk. Chilean national copper output is already falling, down 8 percent in the first eight months of the year on operational setbacks, grade declines and disruptions, and acid availability is one of the few constraints that sits outside miners’ control. Whether Beijing licenses regular shipments or treats September as a single permitted cargo is the question the next customs release answers.