Effects of Leaching on Pore Size Distribution of Solidified/Stabilized Wastes

摘要

Chemical solidification/stabilization processes are commonly used to immobilizemetals in fly ash and flue gas desulfurization (FGD) sludges and to convert these wastes into monolithic or granular materials with better handling properties and reduced permeabilities. The study evaluated the role of pore structure of solidified materials during leaching. The solidified material's initial pore structure, changes in the pore structure which result during leaching, and the effects of pore structure on leaching are discussed. It was found that pore structures varied depending upon the wastes used and the solidification mix formulations tested. After acetic acid leaching, the pore structures of samples changed remarkably. Total pore volumes and pore sizes increased. The higher the alkalinity in a sample, the greater the change of pore structure due to leaching. Changes in pore structure were primarily due to leaching of calcium hydroxide. (Copyright (c) 1992 Elsevier Science Publishers B.V.)