Title: Effect of Heavy Metals Immobilization on the Properties of Alkali Activated Slag Mortars

Author(s): J. Malolepszy and JK. Deja

Publication: Symposium Paper

Volume: 153

Issue:

Appears on pages(s): 1087-1102

Keywords: alkali-aggregate reactions; carbonates; compressive strength; leaching; mortars (material); porosity; slags; sodium; Materials Research

DOI: 10.14359/1108

Date: 6/1/1995

Abstract:
The granulated blast furnace slags or nonferrous slags are the main component of the alkali activated slag cementitious materials. The calcium silica hydrates (C-S-H type) of low basicity, hydrogarnets, and sodium zeolites form as the alkali activated slag hydration products. Their structure and properties indicate that they can play an essential role in the immobilization of some elements. The microstructure of alkali activated slag pastes shows a higher gel pores content as compared with normal portland cement pastes and, simultaneously, significantly lower capillary pores fraction. The properties of alkali activated slag pastes in the presence of Zn, Cd, Cr, and Pb ions were studied. The results of the strength tests, as well as the data relating to the phase composition and microstructure of pastes, are presented in this paper. The mortars containing alkali activated slag show very high heavy metals immobilization ratio. Probably it is an effect of phase composition of the mortars and absence of capillary pores in their structure.