MINERALOGICAL AND CHEMICAL STUDY OF THE HYDRARGYLLITIC BAUXITE AND OF THE RED MUD RESULTED AS BY-PRODUCT FOR ITS REVALUATION

11th International Multidisciplinary Scientific GeoConference SGEM2011, www.sgem.org, SGEM2011 Conference Proceedings/ ISSN 1314-2704, June 20-25, 2011, Vol. 1, 1163-1170 pp

ABSTRACT

The bauxite is not processed through the usual processes of ore enrichment because of
the mineralogical composition and structure, the intergrowths of minerals being very
fine. Mineralogical characterization is very important to choose the method of
extracting alumina from bauxite.

This paper presents the mineralogical study of a hydrargyllitic bauxite from Sierra
Leone and of the red mud resulted after extraction of alumina by Bayer method. The
mineralogical characterization of red mud is needed to choose the method of
neutralization of red mud dumps and recovery of by-products.

The present study was made by chemical and physical methods - X-ray diffraction,
differential scanning calorimetry and optical microscopy in polarized light. The
physico-chemical characterization was performed in the National Institute of Research
and Development for Non-ferrous and Rare Metals.

Keywords: red mud, bauxite, Bayer process