Diversified mining company Rio Tinto and its Pilbara joint venture (JV) partners Japanese group Mitsui and steel producer Nippon Steel & Sumitomo Metal have approved a $1.55-billion investment to sustain production capacity at two iron-ore projects that form part of the Robe River JV, in Western Australia. Rio Tinto’s 53% share of expenditure will amount to $820-million. The company’s Pilbara operations include an integrated network of 16 iron-ore mines, four independent port terminals, a 1 700 km rail network and related infrastructure.