Characterization and Beneficiation of the Glass Making Potentials of Silica Sand Deposit from River Benue North Central Nigeria

Abstract

Analytical techniques such as X – Ray Fluorescence Spectroscopy (XRF) and Atomic Absorption Spectroscopy (AAS) were employed to characterize the glass making potentials of silica sand obtained from River Benue, North Central Region of Nigeria. The results of analyses reveal that silicon dioxide (SiO₂) forms the predominant metal oxide in the entire samples with a percentage mean concentration of 93.946 ± 0.4775%, followed by (Fe₂O₃; 0.7116 ± 0.0829%) (P₂O₅; 0.1160± 0.1746%), (MnO; 0.0692 ± 0.0851%), (Na₂O; 0.0460 ± 0.0047%), (BaO; 0.0494 ± 0.0183%), (PbO;0.0342± 0.0319%) (NiO; 0.0280± 0.0178%), (TiO₂; 0.0240± 0.0021%),  (Al₂O₃;0.0142 ± 0.0035%),and trace amounts of CaO, MgO,K₂O ZnO and CuO. Further beneficiation( using acid leaching method) of the silica sand samples reveal an increased silica (SiO₂) content from 93.946 ± 0.4775% to 96.1590 ± 0.0683%, with a corresponding decrease in Fe₂O₃ content (0.7116 ± 0.0829% to 0.4150 ± 0.0014% across samples. Physico-chemical analysis shows a moderate pH value of 7.03 signifying high basic oxides content in the silica sand samples. Acid Demand Value (ADV) test reveals a moderately low ADV in samples of 20.09, signifying the presence of low soluble carbonates in the silica sand samples. Grain size distribution analysis reveals that a high percentage of the samples grains size distribution fraction are within the recommended screen sizes (40-100 mesh). Heavy liquid separation test reveals a significant trace amount of principal minerals such as ilminite, magnetite, mica, calcite and kaolinite. A correlation between the mean values of SiO₂ and Fe₂O₃ in all the samples reveals an inverse relationship between SiO₂ and Fe₂O₃ which implies that as the values of SiO₂ increases that of Fe₂O₃. Furthermore, comparison of observed mean of SiO₂, Fe₂O₃, CaO, Al₂O₃ and TiO₂ with their observed minimum standard (95.00%; 0.005%; 0.1000% and 0.0120%) shows that the silica sand samples from River Benue can be used as a source of SiO₂ for glass making.

Key Words: Silica sand, Grain size, Chemical composition, Metal Oxides, Beneficiation, Acid demand values, Characterization.