Exploration of iron ore tailings with high volume in sustainable cement and ecofriendly cementitious material

Abstract

In this work, sustainable cement clinkers and ecofriendly cementitious materials (ECMs) were prepared with iron ore tailings (IOTs). Alternative raw meals with IOTs were sintered to cement clinkers by conventional sintering processes. The results of X-ray diffraction (XRD), scanning electron microscopy (SEM) and mechanical tests suggested that the cement clinker within 10 wt% IOTs had better quality than those without IOTs. In addition, the hydration and hydration products of the IOT-based cement were analyzed via XRD and SEM. Before preparing ECMs, IOTs were pretreated with a 100 mesh Tyler screen to remove silt and clay. Then, the pretreated IOTs and whole IOTs partly instead of fine aggregates, together with IOT-based cement were used to produce ECMs. The ratio of water-binder and compressive strength properties of the ECMs were investigated. It is suggested that the pretreated IOTs sand can be used as much as 60 wt%, while the amount of whole IOTs sand must be limited to 20 wt% before the performance dramatically decrease. These findings suggest that disposal of a high volume of Yeshan IOTs in sustainable construction building materials has feasibility and operational significance.

Keywords

• Iron ore tailings
• Clinker
• Cementitious composite
• Mechanical properties
• Physical properties