China suspended sulfuric acid exports, threatening a major disruption to global copper supplies. Wet-process copper smelting accounts for nearly 20% of the world's mined copper supply. Geopolitical tensions between the U.S. and Iran have tightened the global market for sulfur derivatives.
Chile is the world's top copper producer and relies on China as its largest acid supplier. China’s sulfuric acid exports to Chile reportedly fell to zero in March 2026. The suspension creates a potential monthly shortage of 125,000 tons.
Large mining operations currently maintain inventories to buffer the supply shock. Prolonged shortages could squeeze small and medium-sized producers. These constraints threaten to reduce copper output and tighten the global market.