Iron removal from PLK rock: An optimisation study using response surface methodology

Abstract

Partially laterised Khondalite (PLK) rock is a solid overburden material produced when bauxite is mined. PLK rock is gaining importance as a critical resource after the maximum removal of iron values by different physical and chemical beneficiation techniques for industrial applications. The present paper focuses on iron removal from PLK rock by leaching with HCl using the Response Surface Methodology (RSM) technique. PLK rock is influenced by different variables such as acid content, pulp density, temperature and time. In RSM, Central Composite Design is used as a process optimisation for maximum removal of iron. 3D graphs are utilised to illustrate the influence of the process variables for iron removal. The study indicates that the optimum conditions for leaching to reduce the iron concentration (to less than 2 %) are 70 degrees C temperature, 4 hr. time, 4.5 mol. concentration, and 12.5% pulp density. Thus, the value added product obtained can be utilised as a critical resource for refractory and ceramic applications. (c) 2026 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.