Qualitative Characteristics of Bauxite „oštrelj“ Near Bosanska Krupa

Abstract

SUMMARYQualitative characteristics of bauxite deposit "Oštrelj" are defined through extensive laboratory testing of chemical and mineralogical-petrographic composition, and geomechanical characteristics. Chemical composition has shown that it is a relative poor bauxite with low Al/Si module (2,28). Low values of Al/Si module are result of lower Al 2 O 3 concentration (48 %), and higher SiO 2 concentration (21 %), what these bauxites define as high silicic or »acidic«. Identified are increased concentrations of larger number of analyzed trace elements (B, Co, Cr, Li, Mn, Ni, Sn, V, Zn) comparing to the medium content in the Earth's crust. Mineralogical composition, structure and texture are uniform.Holders of Al mineralization are bemite and diaspor (to a lesser extent) as crypto-crystalline phases of rock matrix. Lower Cretaceous age (K 1 ) of roof layers over bauxite deposit is paleontologicaly documented, while in the bauxite any fossils are not registrated. Values of geomechanical paramers of layers under and over bauxite is uniform. In bauxite value of compressive strength is increased, which is equivalent to chemical and mineralogical composition, and structural and textural characteristics of tested bauxite samples.