Three major Zambian copper smelters undergo concentrated maintenance; copper and sulfuric acid supply expected to tighten from June to September.

News on June 3: Vedanta's subsidiary Konkola Copper Mines (KCM) Nchanga Smelter in Zambia officially commenced a planned 60-day major overhaul. Combined with the scheduled maintenance of Mopani and Chambishi smelters in August and September, Zambia's three core copper smelting enterprises will face intensive shutdowns from June to mid-September, leading to a phased tightening in the global supply of electrolytic copper and by-product sulfuric acid.

KCM's Nchanga Smelter started a 60-day shutdown for maintenance in early June. This maintenance is intended to align with its capacity expansion plan of 300,000 tons/year by 2030; the plant's cathode copper output was 80,200 tons in 2025. Mopani Smelter is scheduled for a 40-45 day major overhaul from August to mid-September, and Chambishi Smelter will suspend operations for the entire month of August, with a maintenance cycle of nearly 2 months.

The maintenance windows of the three smelters are back-to-back with some overlapping periods, directly suppressing Zambia's overall copper smelting operating rate from June to September. The by-product sulfuric acid from smelting is shrinking simultaneously. Although KCM relies on supporting acid production facilities and external procurement to fill the gap for self-use, Zambia has implemented sulfuric acid export control policies to ensure local industrial use, further shrinking the supply available for external sales.

Currently, Nchanga has entered maintenance, while the other two smelters have not yet ceased operations; however, expectations of shrinking raw material supply in the third quarter have already influenced market prices. While these are all planned routine maintenances, the duration is generally higher than the conventional 30-day standard of previous years. The intensive shutdowns may cause phased disruptions to the global supply and demand pattern for refined copper and sulfuric acid.