Comparative Study of Chemical And Biological Methods of Beneficiation of Kankara Kaolin

Abstract- Kaolin is a clay mineral that has a wide application in the industry depending on its purity. The quality of kaolin mined around the world is depleting especially with depth and rate of mining. Consequently the usability of this mineral is threatened by the presence of some inherent impurities. Beneficiation enhances kaolin applications hence it becomes imperative to understudy comparative means of upgrading kaolin for the process integration and optimization. In this work chemical and biological leaching of iron rich kaolin sample was carried out using sulphuric acid oxalic acid cultured and un-cultured Aspergillus niger A. niger. The kinetics of leaching determined from XRF analysis was observed to be higher for acid compared to biological method and at shorter contact time. The conversion of alumina for oxalic sulphuric un-cultured and cultured A. niger were determined to be 77.81 87.73 26.38 and 28.37 respectively while that of iron were 66.07 98.32 25.71 and 28.51. The kaolin leached with un-cultured A.niger was observed to digest both alumina and iron at an enhanced rate in the first 6 days while the cultured remained inactive due to adaptation for the same number of days. The cultured A.niger was later observed to leach more than the un-cultured one despite the adaptation period it went through.