– 643 – Journal of Siberian Federal University. Engineering & Technologies, 2016, 9(5), 643-656 ~ ~ ~ УДК 669.713.17 Full Analysis of Sierra Leone Bauxite and Possibilities of Bauxite Residue Filtration Gheorghe Dobra*, Anatoly Kiselev, Laurentiu Filipescu, Vicol Alistarh, Nicolae Anghelovici and Sorin Iliev VIMETCO ALUM SA 82 Isaccei Str., Tulcea, 820228, Romania Received 17.02.2016, received in revised form 20.04.2016, accepted 21.06.2016 Chemical analysis, classical or instrumental using ICP and the XRF spectrometry, offers complete information on elemental composition and major chemical constituents of bauxite and bauxite residues resulted from the Bayer process. The XRD diffractometric analysis provides information on quantitative mineralogical composition of these materials and it enables the real identi icat ion of main chemical combinations, whose reactivity is essential in driving the process of obtaining alumina through the Bayer process. Mineralogical components identi ied in the bauxite samples were Gibbsite (30-40 %), Al – goethite (20-30 %) and hematite (less than 5 %). About 40 % of the Sierra Leone bauxite mineralogical phases were found in amorphous state, but all these amorphous phases are also originating from the above crystalline components, under the excessive wearing during bauxite deposit formation and its metamorphic transformations. The minor crystalline components from bauxite are: kaolin, quartz, zircon, ilmenite and anatase, but their concentration is below 2 % (close to the detection limit of the XRD analysis). The main mineralogical components identi ied in red mud are the Al-goethite (35 %) and the hematite (12 %). The minor crystalline components from red mud are: gibbsite, katoite, sodalite, calcite, rutile and anatase. Experimental data of this type of bauxite have shown that a compact mass of approximately 50-55 % of bauxite passes fully untransformed through all important stages of the Bayer process. This material of uniform size and composition can form a structure with low hydraulic resistance, easy ilterable both on convent ional or hyperbaric steam ilters. Keywords: bauxite, Sierra Leone, mineralogy description, iltration. Citation: Dobra G., Kiselev A., Filipescu L., Alistarh V., Anghelovici N., Iliev S. Full analysis of sierra leone bauxite and possibilities of bauxite residue iltration, J. Sib. Fed. Univ. Eng. technol., 2016, 9(5), 643-656. DOI: 10.17516/1999-494X-2016- 9-5-643-656. © Siberian Federal University. All rights reserved * Corresponding author E-mail address: dobra@alro.ro