Rio Tinto's profits for the January to June period have reached a record first-half high for the firm, fuelled by Chinese demand for its iron ore.

The Anglo-Australian group saw its half-year net profits more than triple to $5.8bn. This compares with $1.6bn for the same six months last year.

Earnings from Rio's iron ore operation, the biggest part of its business, more than doubled to $4.1bn, up from $1.9bn a year ago.

Meanwhile, its aluminium arm returned to profit, with earnings of $313m, as overall metal demand and prices continued to rise as the global economy improved.

The aluminium business had struggled since Rio purchased Canada's Alcan for $38.1bn in October 2007, only to see metal prices then fall sharply in the second half of 2008 as the global recession took hold.