Preparation of y-alumina from Kankara Kaolin in Nigeria by acid leaching using Hydrochloric Acid

Abstract

The paper reports the preparation of y-alumina from kankara kaolin using acid leaching method. Kaolin was initially fired at 600°C for 4 hours to increase its reactivity. For better yield Hydrochloric Acid (HCl) was used for the digestion instead of the conventional Sulphuric acid (H2SO4). The gelatinous precipitate of the hydrated alumina was further filtered under vacuum at 400°C for 2h until the formation of y-alumina. The crystallographic structure of y-alumina was confirmed by XRD analysisand its corresponding diffractogram parameters.The mean particles size of y-alumina was determined by SEM micrographs to be 3 - 9 μm. Foamy agglomerates at low magnification and the presence of larger voids in theirs structures at high magnification were visible from the SEM images. The study revealed that Kankara kaolin could be promising material for preparation of y-alumina.