SAO PAULO--Brazilian mining company Vale SA (VALE, VALE5.BR) said Wednesday its new Serra Sul iron-ore project in the Brazilian Amazon will have the lowest production costs among the company's mines. Serra Sul, the world's biggest iron-ore project to date with a projected annual output of 90 million metric tons of high-quality iron ore, will have "extremely low costs," Vale's ferrous and strategies director, Jose Carlos Martins, said at the Brazil Steel Institute annual congress in Sao Paulo. Serra Sul, due to start producing in 2016, will export iron ore to Asia, where Vale currently sells as much as 70% of its iron ore, as crisis-ridden Europe is only showing "marginal demand," Mr. Martins said. China, Vale's single biggest customer for iron ore, currently consumes 50% of the world's seaborne iron ore and 80% of the world's total iron-ore output, including the country's own production, Mr. Martins said. Due to continued steel demand for urbanization projects, China may eventually consume as much as 90% of the world's total iron-ore output in coming years, Mr. Martins said. Write to Diana Kinch at email@example.com.