The 22 smelters in its copper production survey churned out 792,800 tonnes of cathodes last month, up from a low base in coronavirus-affected March 2020 and a 28-day February in 2021.
A slight increase in maintenance this month will see April cathode output fall to around 780,000 tonnes, Antaike said.
"There's no point having money in copper at this point because we're not going anywhere," said commodities broker Anna Stablum of Marex Spectron.
"The shorter-term money...has already disappeared and moved on to where you can make more short-term gains, but...there's substantial sticky, longer-term money basically (still) sat in that long," she said.
Three-month copper on the London Metal Exchange climbed as much as 3.6% to $9,104 a tonne, its highest since March 23.
The most-traded May copper contract on the Shanghai Futures Exchange also hit its highest in two weeks, advancing as much as 2.3% to 67,670 yuan ($10,308.32) a tonne.
Rio operates the mine via its Canadian subsidiary Turquoise Hill, which owns 66% of Oyu Tolgoi. The rest of the mine has been owned by the Mongolian government since the project was launched in 2009.
Activist investor Pentwater Capital Management LP is Turquoise Hill's largest shareholder after Rio with a 9% stake.
The smelter will have an input capacity of 2.4 million tonnes of copper concentrate and an output capacity of 600,000 tonnes, a slide presented by Luhut at a live broadcast on CNBC Indonesia showed.
Luhut said last month that the smelter will produce copper pipes and wires of which output can be worth $10 billion or more.
Escalating tensions between China and the West, as well as potential US tax hikes also hit sentiment and led to investors buying into safe-haven dollar.
"The yields rising indeed brought more demand for the US dollar...(but) the Fed meeting was actually very bullish for value or cyclical assets," said a Singapore-based metal trader.
The state-run Chilean Copper Commission (Cochilco) reported that production by Codelco, the world's largest miner of the red metal, rose 19.4% year-on-year to 142,000 tonnes in the month.
Collahuasi - a partnership between Glencore and Anglo American along with Japanese companies - posted a 6.5% year-on-year rise in production to 57,000 tonnes.
ShFE aluminium declined 2% to 17,045 yuan a tonne, nickel slipped 2.4% to 138,680 yuan a tonne, zinc shed 1.4% to 21,360 yuan a tonne, tin dropped 3.2% to 182,340 yuan a tonne while lead lost 2.5% to 15,325 yuan a tonne.
Other industrial metals also jumped, with aluminium at its highest since 2018, nickel its strongest since 2014, tin its strongest since 2012 and lead its highest since 2019.
Benchmark copper on the London Metal Exchange (LME) was up 2.9% at $8,631 a tonne in official trading after touching $8,633. Prices are up around 10% this month.
Benchmark copper slipped 0.4% to $8,251 a tonne in official trading after touching an eight-year peak on Thursday, having surged nearly 90% since March last year.
There was some last-minute restocking by the Chinese ahead of their holiday, so when they come back they'll be able to gear up pretty quickly.
Benchmark copper was down 0.4% at $8,248.50 a tonne by 1140 GMT after touching an eight-year peak on Thursday, having surged nearly 90% since March last year.
There was some last-minute restocking by the Chinese ahead of their holiday, so when they come back they'll be able to gear up pretty quickly.