Utilizing nano-computed tomography to characterize the structural nature of industrial minerals

Abstract X-ray computed tomography (XRT) is a nondestructive and thus reproducible examination method allowing the three-dimensional (3D) investigation of the internal and external structures of objects regardless of their material and geometry. In the present study, XRT was used to investigate the influence of hydrochloric acid leaching on the composition and constitution of iron-rich bauxite grains. Reducing the iron content in raw bauxites by acid leaching is a promising method for the beneficiation of iron-rich bauxites for subsequent use in the refractory industry. Not only the effect of the leaching process on the chemical composition of the bauxites, but also aspects such as the acid’s influence on the mineralogical composition and the resulting porosity of the individual grains have hardly been taken into account so far. To address these issues, various bauxites were examined before and after acid leaching using XRT analysis and specifically characterized with regard to their constitution.