Richards Bay Minerals (RBM) is a South African mining company. RBM's principal product is titanium dioxide in the form of an 85% pure titanium dioxide slag; the company also produces the higher-purity 95% titanium dioxide product rutile as well as pig iron and zircon. RBM is controlled by Rio Tinto which owns 74% of it. Blue Horizon Investments (24%) and RBM permanent employees (2%) also have an interest in the mine.Prior to 2012 BHP Billiton owned 37% but that interest was later purchased by Rio Tinto in February 2012.