Oyu Tolgoi, Rio Tinto's part-owned giant copper-gold mine in Mongolia, has started shipping copper concentrate to customers."The shipping of concentrate is the culmination of a three-year, US$6.2bn project to build the first phase of one of the world's top five copper mines," the company said on Tuesday morning.The mine is 66% owned by Turquoise Hill Resources, in which Rio Tinto has a 51% stake, while a 34% interest goes to the state-owned Erdenes Oyu Tolgoi.Average annual production over 20 years from open pit and underground mine is forecast to be 430,000 tonnes of copper and 425,000 ounces of gold.Rio Tinto said that by the time Oyu Tolgoi reaches full production in 2020, it is expected to be responsible for over 30% of Mongolia's gross domestic product. The project has paid $1.1bn in taxes and payments to the government of Mongolia so far (through June 2013).As of April 30th, nearly 11,000 Mongolians were employed at Oyu Tolgoi and the project has so far made a $126m investment in education and training in the country."It has taken the vision and hard work of thousands of people to get to this point, where we are starting to convert the rich resources beneath the desert into real wealth and opportunity for all stakeholders, including the Mongolian people," said Jean-Sebastien Jacques, the Chief Executive of Rio Tinto's copper division. "Oyu Tolgoi starts production at a time when undeveloped quality copper assets are scarce and the outlook for copper continues to be strong. With continued development, Oyu Tolgoi will generate wealth for many decades to come."The stock was up 2.55% at 2,737.5p by 08:23 on Tuesday.