Iron mineral admixtures improve the sulfuric acid resistance of low-calcium alkali-activated cements

We investigated the sulfuric acid resistance of low-calcium alkali-activated materials (i.e., geopolymers) supplemented with an iron mineral admixture hematite). Geopolymers without and 5% hematite were produced at two alkali contents (Na:Al = 0.86 1.39). Acid degradation reactions comprehensibly studied through three replenishes acid. Results demonstrate that is chemically active upon exposure yielding a short-term increase in neutralization capacity. Prolonged was enhanced high content formulations hematite. revealed minimal changes to mineralogy, molecular structure, micro-scale porosity these samples, resulting less dealumination silicon leaching. Thus, results indicate buffering capacity geopolymers, specifically higher formulations, increases due addition The increased leads lower degrees N-A-S-H cementitious binder. These are important as they may help explain durability synthesized from industrial aluminosilicate precursors (e.g., slag, fly ash, lateritic clays) contain minerals.