Brazil's mining company, Vale, is preparing to start operations in Mozambique as South America's largest economy steps up its involvement in the scramble for Africa's resources. The remote town of Tete in central Mozambique sits on top of some of the world's largest reserves of coal. With migrant workers and contractors flooding in to take advantage of the opportunities created by this multi-billion dollar Brazilian investment, Tete has become a boomtown, its infrastructure creaking under the constant flow of business visitors.