Leaching processes of the dicalcium silicate and copper oxide solidification/stabilization system
Journal
Toxicological & Environmental Chemistry
Journal Volume
44
Journal Issue
1-2
Pages
89-100
Date Issued
1994
Author(s)
Abstract
Cement based solidification/stabilization technology has been widely practiced for the treatment of inorganic hazardous wastes, especially metal-bearing wastes. The advantage of using the solidification/stabilization process is that the mobility of the hazardous materials is greatly retarded in the final disposal sites. The purpose of this study is to assess the stability of a synthetic solid waste through the renewable leaching test. A major cement constituent, dicalcium silicate (C2S), was used as a model binder to react with copper oxide to form a solid waste matrix. The semi-dynamic leaching test using 1 N acetic acid was employed to investigate the leaching characteristics of the C2S/CuO system. The results show that the dissolution of Ca(OH)2 is the primary mechanism for the destruction of the matrix, and the subsequent leaching of copper ion. The surface-controlled dissolution reaction increases the pore size and porosity of the matrix, thus increasing the diffusion rate of copper ion transport. The C2S hydration product, silicate hydrate, might play a role in adsorbing the copper ion in the leaching system. © 1994, Taylor & Francis Group, LLC. All rights reserved.
Subjects
copper oxide; dicalcium silicate; leaching processes; Waste leaching
Other Subjects
Acetic acid; Calcium compounds; Copper; Copper oxides; Diffusion; Dissolution; Hazardous materials; Hydrates; Industrial wastes; Porosity; Solidification; Stabilization; Dicalcium silicate; Metal bearing waste; Pore size; Silicate hydrate; Solid waste; Leaching
Type
journal article