Aluminium is Rio Tinto’s albatross. As self-inflicted curses go, the miner’s $38.1bn Alcan acquisition two years ago is hard to beat. It saddled Rio with huge debts, and dragged it into a $15.2bn rescue rights issue. Although Alcan accounts for 60 per cent of Rio’s assets, it is the biggest drag on its first-half earnings, which more than halved to $2.6bn. The distraction may continue for a while: the near-term demand outlook for aluminium is still subdued.

To be fair, the miner’s aluminium losses of $689m were not as dire as analysts feared thanks to drastic cost reduction initiatives by Tom Albanese, chief executive, including smelter closures. He has also had to fast-track disposals of non-core Alcan packaging assets and tame Rio’s debt beast. Net borrowings rose slightly to $39bn but would more than halve by year end thanks to Rio’s cash call and $5.7bn of asset sales.