Rio Tinto has begun restarting underground mining at Oyu Tolgoi in Mongolia after a seismic event caused a rockfall on October 29. Separately, Chinese border checks have cut the mine's copper concentrate exports by about 70% over two weeks.
At a glance
- Three workers were injured in the rockfall, with no fatalities and no structural damage underground.
- Daily truck convoys to China have fallen to about four from 12 to 13.
- Oyu Tolgoi supplied about 56% of Rio Tinto's consolidated copper output in the third quarter.
Background
Oyu Tolgoi in Mongolia is one of the world's largest known copper and gold deposits and is central to Rio Tinto's copper growth. Rio owns 66% and runs the mine, while Mongolia's government holds 34%. Its copper concentrate is trucked across the border to China.
What happened
Rio Tinto said on Friday it had begun progressively restarting underground operations at Oyu Tolgoi after safety reviews, Reuters reported. A seismic event on October 29 triggered a localised rockfall in a temporary storage area next to the production zone.
Three employees were injured, two of whom are still being treated for non-life-threatening injuries. Rio said there was no structural damage to the underground cave or operating infrastructure.
The border bottleneck
Copper concentrate exports have dropped about 70% over the past two weeks because of Chinese border restrictions, the Associated Press reported. Daily truck convoys fell to about four from 12 to 13 at the crossing between Mongolia's Gashuunsukhait and China's Ganqimaodu ports.
Mongolian officials blamed infrastructure and technology upgrades in China, including a facial-recognition system for truck drivers. The work began in August and could last until the end of December. Rio also flagged delays affecting all vehicles at the crossing.
What it means
Oyu Tolgoi produced 113,500 tonnes of copper in concentrate in the third quarter, up 27%, and accounted for about 56% of Rio's consolidated copper output. Rio targets about 500,000 tonnes a year from the mine from 2028 to 2036.
Rio records sales when customers collect concentrate at the border, so a lasting slowdown could delay sales. Its group copper forecast of 800,000 to 870,000 tonnes for this year was set before the slowdown.
Our read
Outlook: bullish. Border delays and a brief underground halt at a major mine could tighten copper concentrate supply to China.
What to watch
- How quickly underground output returns to normal rates.
- Whether border truck traffic recovers before the end of December.
- Any change to Rio Tinto's 2026 copper guidance.
For information only, not investment advice.
Copper price in India
metalscost.com India reference price as of 2026-11-01.
Detailed analysis
Timeline
- 2026-10-29: A seismic event triggers a rockfall at Oyu Tolgoi's underground mine.
- 2026-10-30: Rio Tinto begins restarting underground operations.
Supply Drivers
Border delays have cut Oyu Tolgoi's copper concentrate exports by about 70% in two weeks.
Government Policies
Chinese border upgrades, including driver facial recognition, are slowing truck crossings.
Mining Production
A rockfall briefly halted underground mining at a mine producing 113,500 tonnes of copper a quarter.
What could lift prices
- Less copper concentrate is reaching China from one of the world's largest mines.
- Border work could continue until the end of December.
What could weigh on prices
- Underground mining is already restarting with no structural damage.
- Concentrate held back at the border could reach buyers once traffic recovers.
Country impact
| Country | Impact | Reason |
|---|---|---|
| Mongolia | High | Its biggest mine faces export delays and a brief underground halt. |
| China | Medium | Border upgrades are slowing copper concentrate imports. |
Industry impact
| Industry | Effect | Reason |
|---|---|---|
| Copper Mining | Negative | A major producer faces a safety incident and export delays. |
Who gains, who loses
- Other copper concentrate suppliers to China: Delayed Oyu Tolgoi shipments could raise demand for their material.
- Rio Tinto: Its main copper growth asset faces delayed sales and a brief halt.
Other ways this could play out
- If border traffic recovers soon, the effect on Rio's annual output could be small.
- If delays last until December, Rio's fourth-quarter copper sales could fall.
Price risks
- Further seismic events could interrupt underground mining again.
- Delayed sales could pressure Rio Tinto's copper guidance.
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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