The Transformation of Green Rusts on the Surface of Portland Cement Hydration Materials

Abstract

Ordinary Portland cement (OPC) is widely used building material, and its hydration products can be recycling as low-cost absorbents. The loading of iron oxide is helpful to further improve their adsorption performance. In view of the fact that green rusts are frequently occurrence intermediate products in the co-precipitation of iron salt and prone to be oxidized into stable iron minerals. This study simulated co-precipitation to carry out iron-modification on hydration OPC. The results demonstrate that as the carrier materials, hydration OPC behaves excellent affinity with green rusts. Under the conditions of high temperature (70 oC) and high alklinity (pH=11), green rusts mainly transformed into feroxydrate, and a minor part are into magnetite. The enrichment and transformation of green rust can be regarded as an efficient approach for immobilization of iron oxide (oxyhydroxide).