Characterization and Beneficiation of Clays from Ewekoro for use as Drilling Mud

The proven bentonite reserve in Nigeria has been modestly estimated at more than 700 million tonnes, however her bentonite does not meet the API regulation standard. Hence this work was done with the aim of characterizing and beneficiating Nigeria bentonite clay to meet the required standard. Bentonite clay was gotten from Ewekoro in Ogun state of Nigeria, it was characterized using X-Ray Diffraction (XRD) to identify the structural layers which indicates the arrangement of the atoms in clay samples and X-Ray Fluorescence Spectrophotometer (XRF) which was used in the quantitative analysis of the elements in the sample. The XRD confirmed the presence of montmorillonite meaning the sample contained bentonite, while the XRF confirmed that the sample is Ca-based rather than the standard Na-based, hence the need for beneficiation. Beneficiation of the bentonite was done by ion exchange with Na2CO3 followed by addition with different compositions of viscosifiers namely: carboxymethyl cellulose (CMC), drispac and guar gum. The rheological properties together with the swelling ratio and filter loss of the clay were determined. Although some of the bentonite compositions met the required standard, but the bentonite formulation with the combination of 20.125 g bentonite + 2.875 g guar gum + 0.6 g drispac gave the best result.