Effect of Beneficiation on the Characteristics of Gambe and Pindiga Bentonitic Clays

Abstract

Comparative study of the effect of beneficiation on the chemical, physical and mineralogical properties of Pindiga and Gambe bentonitic clays was carried out. The raw clays were mined and beneficiated using the wet beneficiation method. The raw and beneficiated clay samples were characterized using XRD and XRF techniques, the specific density and pH values of the clays were also determined. The characterization results showed that the clays developed higher purity after beneficiation, as reflected by the decrease in organic impurities in the form of carbon and graphite and reduction in quartz and soluble salts. The raw Pindiga clay sample had high iron oxide content up to 26.54 wt% which reduced to 24.15 wt% after beneficiation, while the raw Gambe clay contained 11.87 wt% iron oxide which reduced to 4.96 wt% after beneficiation. Also, the raw Gambe clay sample had high calcium oxide content up to 20.0 wt% which reduced to 18.5 wt% after beneficiation, while the raw Pindiga clay contained 2.46 wt% calcium oxide which reduced to 2.0 wt% after beneficiation. Both clays showed calcium montmorillonite peaks in the XRD patterns. The specific density and pH values for the raw and beneficiated Pindiga clay were 2.58, 7.90 and 2.45, 6.50 respectively. While those for the raw and beneficiated Gambe clay were 2.47, 7.30, and 2.36, 7.00 respectively.