ABSTRACT
The effect of temperature on acid activated clay was investigated. Natural clay samples from Ohono, Kogi State were obtained and the clay samples were crushed with the aid of a ceramic mortar and pestle, and afterwards ground mechanically in a ceramic plate to ensure that the clay was properly crushed, then sieved to obtain fine clay particles. The clay samples were put in a crucible and dried in an oven at 105°C-110°C to remove moisture. The clay samples were mixed with 30% (v/v) HCl solution, then agitated mechanically for twenty-four hours, filtered and thoroughly washed with distilled deionized water until no chloride ion was detected. The acidified clay samples were oven dried at 105°C-110°C, and then calcined at temperatures of 200°C and 400°C respectively.in a furnace. The calcined samples were subjected to the following analysis: Brunauer-Emmet-Teller (BET), Scanning Electron Microscopy-Energy Dispersing X-ray (SEM-EDX), X-ray diffraction (XRD), and Fourier-transform infrared Spectroscopy (FT-IR) and the analysis showed the surface area, pore volume, surface topology, elemental analysis, mineralogical components and adsorption frequencies of the clay. The BET results showed that at high temperature (400°C), there was an increase in the surface area and pore volume of the samples. (At 200°C the surface area was 233.0 and at 400°C the surface area increased to 475.0, the pore volume at 200°C was 0.127 and at 400°C the pore volume increased to 0.232). The SEM-EDX results showed that the clay samples heated to 200°C had a porous structure, while the clay samples heated at 400°C had a polished appearance and also a non-porous region and different element with different weight percent were present for the samples heated at 200ºc and 400ºc. The XRD results showed that distinct minerals were deposited on the acid activated clay samples. At 200°C Chrysolite,Quartz (low) and Evenkite were deposited while at 400°C Orthoclase, Quartz (low), Chrysolite, Afghanite, Kyanite and Halloysite were deposited with a slight change in d-value of chrysolite and quartz when exposed to higher temperature (200°C and 400°C). The FT-IR results showed different peaks on the spectra, the clay sample heated to 200°C had more peaks than the clay sample heated to 400°C and the functional group that were present on the clay samples are almost the same for the samples heated at 200 and 400ºC, though some bands were broken at elevated temperature.
