ABSTRACT
Excavated hydrothermally altered rocks naturally contain hazardous elements. When these rocks are exposed to the environment, they generate leachates containing toxic elements like lead and arsenic exceeding the environmental regulations. In this study, column percolation tests were performed for crushed hydrothermally altered acid rock sample at various particle sizes and column dimensions to assess the leaching of lead. Both the larger particle size and larger thickness lowered the pH values of the effluents and promoted the leaching of Pb, almost proportional to the specific surface area of the samples and the retention time in the column. pH values influenced by the particle size and layer thickness were found to have a significant correlation with Pb concentrations. This finding supports that the scaling effects arising from particle size and column dimensions on Pb leachability can be accounted for by the pH alternation.
