1. Geology

The base unit of the sequence of metamorphic rocks that compose the Buritirama mountain range is made of micaceous quartzite, superposed by mica schists, incasing of the manganese ore lenses, banded iron-quartzite and by a thick unit of mica schists and quartz schists. The occurrence of manganese ore bodies with economic interest is restricted to the altered mica schists, intercalated between the basal quartzite and the banded quartzite, in the form of lenses or layers composed of pulverulent ore to be granulated. Manganese ore has a complex mineralogy, including oxides, hydroxides, carbonates and silicates, with a predominance of cryptomelane, lithiophorite and amorphous manganese bioxides (MnO2).

Geologic Map B5 Body

Geologic sections B5 Body

Mineral Reserves

The Buritirama manganese ore may be ranked as metallurgic, with 45% Mn grade, low phosphorous (P) grades and Mn/Fe ratio equal to 15.