Preparation of Industrial α-Alumina Powder from Ijero Ekiti (Nigeria) Kaolin ore by Acid Leaching Process

The global demand for pure industrial kaolin ores for paper, cosmetics, porcelain and metallurgical industries cannot be over emphasized. Thus, the need to continuously develop feasible and low-cost routes of ore processing to meet industrial demands becomes paramount. In this study, alumina powder of defined industrial utilities was prepared from a Nigerian kaolin ore containing admixtures of kaolinite (Al2.00Si2.00O5.00(OH)4.00: 96-900-9235), albite (NaAlSi3.00O8.00: 96-900-9664) and muscovite (KAl2.00(FOH)2.00: 96-900-1057), with traces of some other valuable mineral phases by acid leaching method using hydrochloric acid (HCl) as the lixiviant was examined. At optimal leaching conditions (6 M HCl, 70 °C, 6 h), the crystalline powder formed after precipitating to remove iron and other associated impurities was followed by washing, drying and quantitatively characterized. The pure α-alumina powder produced (Al2O3: 14-366-9038, melting point = 2064 °C, density = 3.99 g/cm3) as characterized could serve as a valuable product in the metallurgical and cosmetics industries.