Important investments permit Mineração Usiminas to make great strides of capacity from 8 million tons/year to 12 million tons/year of iron ore. Gaining this new level is due to the implantation of the Friables Project, which seek to obtain high quality ore, with less impurities and higher levels of iron.
The Friables Project is formed by two ore processing plants: the Ore Treatment Facility (OTF) Samambaia, in the Eastern Mine, and the Flotation Ore Treatment Facility, in the Central Mine.
Samambaia OTF is divided into two circuits: dry, which involves crushing, screening and piling of the ore; and humid, which will concentrate the material and generate sinter feed, ore formed by particulates between 6.35mm and 0.15mm. This product will go to the sinterization plants in the steel mill, where it is transformed into sinter and used to make up the metallic load of the blast furnaces.
Flotation OTF will receive part of the material from the Samambaia OTF, as well as gross tailings from settling ponds to produce pellet feed, which has finer particulates, below 0.15mm, which will be obtained by a flotation concentration process, followed by vacuum filtering, generating the final concentrate with Iron > 65% and humidity of around 10%.