Benefication of metallurgical bauxite ores with low module

Almost all of the commer cial alumina (and aluminum) production is obtained by Bayer process which uses bauxite as raw material. However, the form and content of impurities such as silicate minerals in bauxite ores are critical for Bayer process. Because the high silica content based on siliceous impurities causes some technical problems and serious economic losses on Bayer process. Therefore, the ratio of available alumina to reactive silica (A/S), which is formulated as Al2O3 / SiO2 and is defined as the module, plays a significative role on the economic viability of Bayer process. In this thesis, bauxite ore obtained from Doğankuzu-Mortaş (Seydişehir / Konya) open-pit bauxite mine was used as experimental material. chemical analysis showed that the raw ore contains 57.33% Al2O3, 9.01% SiO2 and other constituents; module values were found to be 6.36. Froth flotation experiments were performed to reduce the silica content of bauxite ore that could not be fed directly to the Bayer process due to it is relatively high silica content. As a result of the flotation experiments carried out on the ore samples milled to various particle size, a bauxite concentrate with a grade of Al2O3 60.02% could be obtained with recovery of Al2O3 42.87%. The module value of the same concentrate was determined as 8.54.