2.1 Material preparation and leaching experiments
The local clay was obtained from Ozoro (6.24oN, 5.55oE) in Delta State Nigeria. The characterization of this clay by Orugba et al., (2014) revealed Ozoro clay has 33.90% of alumina making it a very viable source of the ore. The clay was soaked in water for two days in order to ease the removal of debris and stony materials. The dissolved clay was properly sieved and sun-dried for 24 hours then oven dried at 60oC for 18 hours to aggregate the particles. The clay samples were subjected to heat activation in a muffle furnace at different temperatures ranging from 400oC to 900oC for a period of 1hour. The activated clay samples were ground to the same particle size of 0.045mm and properly labeled and were subjected to leaching.
In the leaching experiments, 20g of the activated clay was weighed into an already determined volume of the acid and heated in a round bottom flask based on the liquid-solid ratio of each run for a period of 30minutes. At the end of the period, 2ml of each sample was collected and analyzed for alumina iron using the Atomic Adsorption Spectra (AAS).