Preparation of Beneficiated Bauxte for an Evaluation of Quality

摘要

As a sequel to the work on the beneficiation of crude bauxite from the Natal deposits, assays and preliminary beneficiation tests were conducted on the six samples provided by the Geological Survey. The composition and response to beneficiation of five of the samples (Mintek samples nos. J269 to J273) were similar, the alumina contents of these samples being in the range 39,3 to 40,4 per cent. The slime fractions resulting from attrition scrubbing were enriched in iron but not in silica. The sixth sample (Mintek sample no. J268) was of low grade because of its high silica content, but much of the silica was removed in the slime fraction, leaving a deslimed product similar to the deslimed material obtained from the other five samples. The samples of beneficiated bauxite required for an evaluation of quality were obtained from Mintek sample no. J272 by a procedure that comprised attrition scrubbing for the removal of slime, magnetic separation for the removal of fractions high in iron oxides, and flotation for the removal of silica.