Eterigho E J, Farrow T S, Habibu Uthman and Faruq Aisha (2016), Effects of Dealumination on the Physio-chemical Properties of Clay for Industrial Applications, Proceedings of the 46th Annual General Meeting, International Conference of Nigerian Society of Chemical Engineers on Development and Optimisation of Nigeria’s Solid Mineral Sector for National Growth: The Role of Chemical Engineering (Nigerian Society of Chemical Engineers A division of Nigerian Society of Engineers), Abuja, Nigeria, November 17–19

Abstract

The physiochemical properties of natural clay and its modified form after acidic treatment were investigated for use as catalyst. The clay samples were collected from Ukpor, Enugu state, south eastern state Nigeria. The samples were ground and sieved (2mm). To improve the activity of the clay, a known weight of the natural clay was mixed with a standard analytical-grade 36 N Sulphuric acid (H2SO4) solution at a molar ratio of 1: 5. The aliquot was placed in open quartz crucible, which was heated in a furnace at 500oC, ramped at 5oC/min for one hour. The resulted clay was calcined in a furnace at a temperature of 600oC for a period of 6 hours. The natural clay and its treated samples were analysed using X-ray fluorescence equipment (XRF), X-ray diffraction (XRDP) powder patterns, Scanning Electron microscopy (SEM) X-ray photoelectron spectroscopy (XPS), Energy Dispersive X-ray (EDX). The XRD results showed that the morphology of the clay was crystalline (42.06 nm) while the treated clay samples were amorphous. Based on the intensities of their photoelectrons, the XPS results of the treated sample revealed 67% increase of silicon and same percentage reduction of aluminum. The EDX of the treated clay samples revealed 36.5% Si, 2.4% Al, and that of the natural clay samples were 21.5% and 18.0% for Si and Al respectively. Increasingly, no significant change in the oxygen of both samples. Surface area was increased from 500 to 900 m2/g for the treated sample. In addition, the Si/Al ratio was raised to 15.0 for the treated clay sample by the chemical reaction. The treatment method employed showed greater influence on the morphology, surface area and percentages of the elemental composition of the treated clay samples compared to using aqueous HCl, NaHSO4 and H2SO4. This opens up higher possibilities of controlling the degree of alumina, silica and aluminum sulphate by choice, for different industrial applications.