Characterizing the Leaching Behavior of Red Mud at Different pH Levels

Abstract Red mud is classified as hazardous waste due to its high alkalinity and the presence of radioactive materials. This study aims to investigate the leaching properties of major metals and rare earth elements in red mud at pH levels of 2, 7, and 13. We performed XRD, XRF, and ICP analyses to determine the effect of pH on metal leaching in red mud. The findings revealed that the pH of the solution substantially affected the concentration of dissolved metals. Metal dissolution increases dramatically at an acidic pH (pH 2), but metal concentration drops quickly at a neutral pH (pH 7). At alkaline pH (pH 13), Al dissolves significantly, whereas Fe remains reasonably stable. These findings indicate that the red mud processing industry can utilize pH modulation to enhance the leaching effectiveness of specific metals, a crucial step towards developing more efficient and environmentally friendly purification procedures.