The gain came as the FTSE 100 rose 1.62% to 10,378.82 in a broadly positive London trading session on Thursday.
Despite the advance, the miner's stock closed 20.68% below its 52-week high of £44.75 reached on 25 February.
Trading volume was 1.3 million shares, below the 50-day average of 1.5 million, indicating lighter-than-usual activity during the rise.
Antofagasta's stock is rallying, but can its ambitious projects overcome rising geopolitical and operational risks in Chile to deliver promised growth?
Can Antofagasta's 'green' copper for the energy transition justify the environmental footprint of its massive operations in water-scarce Chile?