Mechanisms of metal stabilization in cementitious matrix: Interaction of C₃S paste and copper oxide

Cement constituent‐tricalcium silicate (C₃S)‐was synthesized as a model binder for mechanistic investigation on solidification/stabilization process. X‐ray diffraction, scanning electron microscopy, and energy dispersive analysis of X‐ray using micro‐probe and line scanning techniques were used in this study. A sandwich sample consists of C₃S paste, CuO, and copper foil layers was developed for investigating the possible interactions between hydrated C₃S and CuO which served as model metal‐bearing sludge. We verify that the interactions between C₃S paste and CuO can be reasoned in two models. The chemical interactions do occur at the interfacial zone between the hydration product containing Ca of C₃S paste and CuO, and a new phase was developed which consists of Ca and Cu. The new phase identified here probably has Ca to Cu ratio about 0.59. The other phenomena observed was that the hydration product containing Ca and Si of C₃S paste and CuO system do not reveal any evidences for the possible chemical interactions but only physical diffusion at the interfacial zone. The interactions of C₃S and CuO were defined as two models: chemical reaction with new phase generated and physical diffusion.

Key Words:

• Cement
• tricalcium silicate
• metal stabilization

Notes

Author to whom correspondence should be addressed.