Comparative analysis on chemical composition of bentonite clays obtained from Ashaka and tango deposits in Gombe State, Nigeria

Abstract

A combination of some analytical techniques such as X-ray Flourescence (XRF), X-ray diffraction (XRD), infrared spectral (IR) analysis and Scanning electron microscopy (SEM) were employed to characterize bentonite samples from Ashaka and Tango (Gombe State, Nigeria). The results obtained for the two samples were compared. From the XRF analysis, the most abundant oxides in both the samples are SiO₂ and Al₂O₃. The silica (SiO₂), alumina, (Al₂O₃), iron (Fe₂O₃), calcium (CaO) and potassium (K₂O) contents of bentonite from Tango (GT) (49.87 wt%, 14.98 wt%, 5.12 wt%, 1.18 wt% and 1.76 wt% ) are higher than those from Ashaka (GA) (48.16 wt%, 14.86 wt%, 4.80 wt%, 1.16 wt% and1.60 wt% respectively). From the FTIR spectra, both of the samples show OH stretching vibrations in the Si-OH and Al-OH groups of the tetrahedral and octahedral sheets at 3693cm^-1 and 3622cm^-1. Bands at 1115cm^-1 and 1113 cm^-1; 998 cm^-1 and 1004 cm^-1 were produced by the stretching mode of Si–O (out-of-plane) and (in-plane) for the GA and GT respectively. The basal spacing of samples GA and GT as determined from the XRD analysis is 15.23Å and 12.99Å respectively. Sample GT shows a SEM image with more phase separation between the particles. All the results of the analysis for the two samples were similar or close to reported literature values.

Keywords: Bentonite, XRF; XRD; FTIR; SEM; Basal spacing