United States Antimony Corp (USAC) has restarted its Madero antimony smelter in Mexico with plans to ramp up production to 200tpm of antimony metal by the end of 2025.

The Madero plant was shut down in March 2024 after a financial review and USAC had planned to sell off its Mexican assets, including a suite of mines. Back in 2014/15, the Madero smelter operated using concentrates from Australia’s Hillgrove Mine.  When the Australian operation shut down, feedstock was replaced by USAC ramping up domestic mining in Mexico, which came to an end in March 2024.

Since antimony prices soared to record levels in mid-2024, USAC has been looking to restart Madero, but with international feedstock from third-party sources. Trade data shows that shipments from Australia totalled over 100t in Q1 2025, sourced from Mandalay Resources’ Costerfield operation. The Hillgrove mine is targeting a restart and could once again supply Madero in future.

Hillgrove’s restart is being carried out by Larvotto Resources, which successfully raised capital in 2024 and is progressing a new DFS. The company stated a “conservative price assumption of US$2,400/oz for gold and US$25,000/t for antimony”, well below current market price levels.  While US$25,000/t is less than 50% of the current antimony spot price outside of China, it is more than double the price of antimony 18 months ago, when prices were already elevated on the back of supply shortages.

Australia’s Costerfield operation, owned by Mandalay Resources, together with every other non-Chinese operation, will be looking to capitalise on high spot prices outside China, which continue to be elevated because of the escalating trade war tit-for-tat between the USA and China which has seen Chinese exports to the USA banned.

However, smelting capacity outside of China is limited with China consuming around two-thirds of global antimony concentrates. While antimony payabilities have improved for concentrates amid a structural shortage in China, smelters are struggling to compete with high by-product gold payabilities offered from Chinese antimony ingot smelters with advanced gold recovery circuits.

Project Blue expects the global antimony concentrate market to remain tight in the near term, supporting elevated spot prices.  We note that the longer this continues, the more likely it is that demand destruction (in flame retardants) takes hold and that additional supply from Russia and Tajikistan on top of record production out of Myanmar will move the market back into balance.