Diversified miner Rio Tinto said Tuesday it expects its copper output to start rising again in 2013 following three straight years of decline, thanks to improving ore grades and the start of its Mongolian mine.

“Rio Tinto”s copper production is expected to increase from 2013 as a result of improving grades and investments at Kennecott [Utah] and Escondida [Chile] and by the start of production from the Oyu Tolgoi mine in Mongolia,” it said ahead of an investor seminar.

In July, Rio acquired 133,571,192 common shares under Turquoise Hill”s, previously called Ivanhoe, rights offering at a total cost of $934,998,344 or $7/share.

The purpose of Rio acquiring additional shares under Turquoise Hill”s rights offering was to honor its contractual obligations and to provide additional funding to ensure the timely development the Oyu Tolgoi copper-gold mine in Mongolia.