Rio Tinto's push to reduce the carbon intensity of the aluminium sector has taken a step forward with the creation of a new venture with rival producer Alcoa and tech giant Apple that will seek to produce the metal with zero emissions.

Rio's flagship aluminium smelters in Canada are powered by emissions-free hydro-electricity, and the company has in recent years sought to spruik the smelters' relatively low carbon footprint through the "RenewAL" brand of aluminium, which is claimed to generate about 66 per cent fewer emissions than the average aluminium smelter.