China resumed sulphuric acid exports to Chile in September after a three-month halt. Consultancy CRU expects acid delivered to Chile to fall to $215 a tonne by late 2027, less than half this year's record, easing costs for copper miners.
At a glance
- China shipped 31,666 tonnes of acid to Chile in September, 93.5% of its total exports that month.
- Total Chinese acid exports are still far below May's 116,703 tonnes.
- CRU expects spot copper treatment charges to recover to minus $75 a tonne by late 2027, from nearly minus $300.
Background
Chilean copper mines use sulphuric acid to leach copper out of oxide ore. Copper smelters produce acid as a by-product and sell it, which has helped them cope with treatment charges, the fees miners pay smelters to process concentrate, falling below zero. China halted most acid exports from May to protect fertiliser supply after the Iran war disrupted sulphur shipments.
What happened
China shipped 31,666 tonnes of sulphuric acid to Chile in September, Chinese customs data showed on Tuesday, Reuters reported. That was 93.5% of China's total acid exports of 33,873 tonnes for the month, and the first shipments to Chile since May.
Exports are still well below May's level of 116,703 tonnes. China moved to halt acid exports that month to protect domestic fertiliser supply. Shipments fell below 1,000 tonnes in both June and July. Indonesia, which uses acid to process nickel and was China's biggest buyer earlier this year, received none for a fourth month.
CRU expects prices to keep falling
Acid delivered to Chile is forecast to fall to $215 a tonne in the fourth quarter of 2027, consultancy CRU said at an LME Week seminar in London. That compares with a record $451 earlier this year. "There's a bit of relief for those that are more exposed to the spot and contract sulphuric acid markets," CRU analyst Chris Lawson said. Prices will still stay above their historical averages, he added.
Cheaper acid should also help copper treatment charges recover. CRU expects spot charges of minus $75 a tonne in late 2027, compared with nearly minus $300 now.
A shift in how concentrate is sold
CRU analyst Tom Rutland said copper concentrate buying has moved from fixed contracts to index pricing. In 2024, 52% of buying used 12-month fixed contracts; this year that share has dropped to 14%, while index-linked deals rose from 12% to 51%.
What it means
For Chile's leaching mines, the return of Chinese acid and a lower price outlook ease one of this year's biggest cost pressures. For smelters, falling acid prices cut a revenue stream that has helped offset negative treatment charges, though CRU expects those charges to improve too.
Our read
Outlook: neutral. Cheaper acid lowers mining costs but does not change copper supply much in the near term.
What to watch
- Whether China's acid exports keep rising in October and November.
- Copper treatment charges in year-end smelter contract talks.
For information only, not investment advice.
Copper price in India
metalscost.com India reference price as of 2026-11-01.
Detailed analysis
Timeline
- 2026-10-20: Customs data show China shipped 31,666 tonnes of acid to Chile in September, its first since May.
- 2026-10-20: CRU forecasts acid in Chile at $215 a tonne by late 2027.
Government Policies
China's acid export restrictions are easing for Chile but remain tight overall.
Refinery Output
Smelters lose some acid revenue but should see treatment charges recover.
What could lift prices
- Chinese acid exports remain far below May levels.
- Acid prices are expected to stay above historical averages.
What could weigh on prices
- Cheaper acid lowers costs and supports leaching output in Chile.
- Recovering treatment charges ease pressure on smelters.
Country impact
| Country | Impact | Reason |
|---|---|---|
| Chile | Medium | Leaching mines regain Chinese acid supply and expect lower prices. |
| China | Low | Smelters regain an export outlet for by-product acid. |
| Indonesia | Low | Nickel processors received no Chinese acid for a fourth month. |
Industry impact
| Industry | Effect | Reason |
|---|---|---|
| Mining | Positive | Leaching mines face lower acid costs. |
| Smelting | Neutral | Lower acid revenue is offset by recovering treatment charges. |
Who gains, who loses
- Chilean copper miners: They regain Chinese acid and expect prices to fall by more than half.
- Copper smelters: Falling acid prices reduce a by-product revenue stream.
Other ways this could play out
- If Chinese exports keep recovering, acid prices could fall faster.
- If sulphur supply from the Gulf stays disrupted, prices could stay high for longer.
Price risks
- A new Chinese export halt would tighten acid supply again.
- Further disruption to Gulf sulphur supply would lift acid prices.
Technical view
Price is trading below both its 20-period and 50-period moving averages, a bearish alignment.
Computed from metalscost.com's own stored price history.
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