Influence of inorganic admixtures on the 11 A-tobermorite formation prepared from steel slags: XRD and FTIR analysis

摘要

Calcium silicate hydrate is synthesized from steel slag by adding lime and quartz by dynamic hydrother-mal method at 185℃. The products mainly consist of disordered calcium silicate hydrate, but more crystallized phase such as 11 A-tobermorite forms for the presence of inorganic admixtures. The formation of tobermorite is affected by the types of ions according to XRD and FTIR results. Adding 2% crystallized tobermorite is beneficial to form the ordered structure; alkali cations and SO_4~(2-) anions are effective accelerators; Al~(3+) plays a role of stabilization during the reaction. The products also vary with the initial alka-linities of steel slag.