REUTERS/David GrayLONDON, Aug 3 (Reuters) - Rio Tinto (RIO.L) is finding out just how hard it is to produce low-carbon aluminium. The company's biggest carbon headache is its aluminium business, which last year accounted for 21.1 million metric tons of carbon emissions out of a group total of 30.3 million metric tons. The pilot plant will produce around 6,000 metric tons of alumina per year while cutting carbon dioxide emissions by about 3,000 metric tons per year. Capacity at the low-carbon AP60 smelter, also in Quebec, will be expanded by 160,000 metric tons per year, with commissioning expected in 2026. Rio is investing heavily in recycled aluminium, which can be remelted using just 5% of the power needed to produce virgin metal.

---

Persons: David Gray, Rio, we're, Jakob Stausholm, Peter Cunningham, Jan Harvey Organizations: Rio Tinto, REUTERS, David Gray LONDON, Queensland Aluminium, Japan's Sumitomo Corp, International Aluminium Institute, Alcoa, Giampaolo, Reuters, Thomson Locations: Rio, Gove, Darwin, Australia's Northern, Pacific, Queensland, Australia, Portland, U.S, Canada, Quebec, North