Copper smelting activity fell sharply in March, satellite data shows

Global copper smelting activity fell sharply in March to the weakest reading so far in 2025 as some smelters in the world’s top copper refiner China entered the usual maintenance season early, data from satellite surveillance showed on Thursday.

Earth-i, which specializes in observational data, tracks smelters representing up to 95% of global production for its SAVANT service and sells data to fund managers, traders and miners.

Last month, an average of 12.6% of global copper smelter capacity monitored was inactive, up from 8.8% in February, the company said in a statement.

Smelter inactivity in China, home to over 40% of capacity covered by its services, rose by 4.5 percentage points to 9.6%, according to Earth-i.

Chinese copper smelters, which typically shut down for maintenance in April-May, have been hit by tight copper concentrate supply due to rising smelting capacity. The scramble for the raw material can be seen in the negative level of spot treatment and refining charges (TC/RCs).

Negative TC/RCs mean that smelters that are not integrated into a nearby large mining complex and instead source their concentrates from third parties are effectively paying for the right to process concentrates rather than being paid for their service.

Copper smelting activity outside China also fell in March, with the inactivity capacity index rising by 3.4 percentage points to 14.9%. This represented the largest single month increase since May 2023.

(By Polina Devitt; Editing by Joe Bavier)