This input is key for the production of leached copper, which accounts for 20% of all the copper Chile exports. Due to this restriction, companies may be forced to seek acid on the spot market, where prices are already 100% higher than what the industry currently pays.
By G.O.
Sulfuric acid has become a new headache for the mining industry after China announced a halt to exports of this strategic input used in copper production in order to prioritize its domestic market, directly affecting Chile. Sulfuric acid is a critical input for the production of leached copper (hydrometallurgy), which represents around 20% of the total copper Chile exports worldwide.
The situation has become increasingly tight in recent years following the reduction in smelting capacity, mainly due to the closure of Codelco’s smelting operations in central Chile. Sulfuric acid is produced in smelters (pyrometallurgical process) by capturing sulfur gases emitted during the production of anodes or blister copper.
This forced the country to source the input abroad, with China — the global leader in mining smelting — taking a leading role. The issue is that mining competes with other uses for sulfuric acid, such as phosphate fertilizer production, as well as various applications in the chemical and metallurgical industries.
Andrés González, Head of Mining Industry Analysis at Plusmining, explains that in 2025 Chile imported nearly 4 million tonnes of sulfuric acid, of which 1.5 million tonnes came from China. Therefore, he warns that any potential disruption would force companies to seek alternative suppliers.
Market alternatives for sulfuric acid
The problem is precisely that there are not many alternatives. “Peru, Chile’s second-largest supplier, with close to 1 million tonnes annually, already allocates virtually all of its surplus to Chile, leaving very limited room for expansion. Other suppliers with smaller volumes to Chile include Japan, South Korea, Mexico, and Europe,” González adds.
The expert notes that, in a scenario where supply remains available, the main impact would be on prices. “Most of the supply for 2026 was negotiated at the end of 2025 through annual contracts at around US$160–175 per tonne. However, volumes exposed to the spot market are already facing prices of around US$330 per tonne. Under this scenario, we estimate that sulfuric acid could rise from representing between 22% and 33% of average operating costs (C1) in Chilean leaching operations,” he explains.
Furthermore, if this situation persists, operations located at the upper end of the cost curve may evaluate production cuts or temporary suspensions, which would directly impact Chile’s copper production.
What is striking is that Chile was practically self-sufficient in sulfuric acid during the 1990s, partly because leaching production capacity had not yet been developed, resulting in low consumption. Since then, however, the country has shifted into a deficit position.
“It is noteworthy that although leachable copper production has fallen from 2.1 Mt in 2009 to 1.1 Mt in 2025 (-46%), acid consumption has increased from 6.9 Mt to nearly 8 Mt (+15%), reflecting greater usage intensity due to declining ore grades,” says the Plusmining expert.
Finally, González argues that long-term solutions must be structural. The main one is increasing smelting capacity, which would allow for greater sulfuric acid generation as a byproduct and reduce external dependence.
“However, this requires significant investment and faces an unfavorable environment, given that spot treatment charges are currently at low or even negative levels, discouraging new developments. Other alternatives include building dedicated sulfur recovery plants, improving logistical integration between supply and demand regions, and, to a lesser extent, technological advances that reduce acid consumption,” González concludes.
Source: La Tercera