Composition of ilmenite and provenance of zircon in northern Brazil

The mineral ilmenite (FeTiO₃) is an important component of heavy-mineral placer deposits and constitutes the largest volume of valuable mineral in such deposits. The minerals zircon (ZrSiO₄) and rutile (TiO₂), which occur in lower concentrations than ilmenite in the deposits, have a greater value per ton – c. 1100 and 900 $/ton respectively – compared to ilmenite that ranges from 100 to 200 $/ton depending on its composition. Other minerals such as staurolite, sillimanite, amphibole and garnet are generally also present in placer deposits, but are of minor or no commercial value and, e.g. amphibole needs to be separated from the valuable heavy minerals which adds to the production cost.