Biočki stan

Biočki stan deposit is located in northern region od Nikšićka Župa, at plateau of Štitovo. Immediate surroundings is marked by Siljevac hill (1716 m), and the deposit was discovered at north-west slopes of this hill. The altitude of the deposit terrain surface ranges between 1550 and 1630m.

It connects to Nikšić by 28 km long tarmac road to the offset of the deposit, i.e. by 24 km long tarmac road and 3 km long Seoca mine to deeper parts of deposit.

Geological structure

Wider area of Biočki stan consists of sediment rocks of upper Triassic, Jurassic and Cretaceous. Upper Triassic rocks build immediate western part of deposit area, as well as paleorelief, i.e. bauxite shelf. They are represented by massive and banked megalodon limestone, which have been intensely karstified. On its surface, the deposit is represented by two offsets in its western margin, which have been dug up by open – pit mining. It spreads 1600m towards west – east, whereas the width is from 100 m to 600 m. Bauxite is red and reddish-brown, of tinsel fracture and relatively small hardness (around 3). The structure is aphanitic, with rear occasions of pisolit. At some points, the bauxite has plastic clay of different colors, having the thickness from 20 to 50 cm. The bauxite is transgressive, represented by layered, marly limestones of Teton, with the width of 5 do 20 meters. Above these sediments there are Lower Cretaceous banked and layered dolomite and dolomite limestones, with occurrences of limestone.

In outline borders, with bauxite thickness of more than 1,8 meters, the surface of Biočki stan deposit is 600 000m2. Bauxite in this deposit has irregular layered shape, with adjustable thickness due to expressive morphology of paleorelief. Great part of bauxite is located at a depth of 100 to 300 meters below terrain surface, therefore the pit mining of bauxite has been planned. Tectonic structure of Biočki stan deposit is compound, and is reflected in secondary refraction, which caused the formation of complex structures of rupture shape.

During previous period, west part of Biočki stan deposit has been dug up above 1406m of altitude, as well as the slopes 1.393, 1.381, 1.373, 1.364, 1.355,5 and 1.347, and during 2007 mining, it was a part of 1 338 slope in the midst part of deposit. Mining in Biočki stan pit was ceased in 2008.

Quality of bauxite

Based on composition tests in 1978, mineral composition for Biočki stan deposit is defined in the following way: boehmite 65,50%, kaolinite 9,31%, hematite 19,98%, calcite 2,20% and anatase 2,92%. The same tests showed the following composition of microelements (in ppm): Pb-22, Ga-40, V-140, Cu-35, Y-30, Zr-200, Ni-80, Co-15, Sc-14, Cr-300, La-80, Sr-15, Li-55, U-6 and Th-44.

Mineral and qualitative characteristics of Biočki stan bauxite deposit enable the processing through Bayer’s process for obtaining aluminium.

Bauxite reserves

Last calculation of red bauxite reserves in Biočki stan deposit has been carried out within the Study on classification, categorization and calculation of red bauxite reserves in Nikšićka Župa deposits: Zagrad, Biočki stan, Đurakov do, Štitovo II and Borovnik, status on 31 December 2006, using a method of parallel vertical profiles. The study has not been certified by competent Ministry. Research proved that red bauxite deposit Biočki stan belongs to a first group and has a high degree of exploration A:B:C=78%: 11%:11%.

Category Balance geological reserves Al2O3 SiO2 Fe2O3 TiO2 CaO Other
A 6 518 035 58,66 3,91 20,87 2,93 0,61 12,69
B 934 846 58,55 4,79 20,18 2,90 0,62 12,66
C1 903 391 59,12 3,29 20,89 2,97 0,68 12,75
A+B+C1 8 356 272 58,70 3,95 20,80 2,93 0,62 12,69