Abstract：
The environmentally sustainable treatment of steel slag (SS) and oil shale waste (OSW) is a significant concern in the field of industrial development. The mining industry also faces challenges related to the high costs and carbon emissions associated with ordinary Portland cement (OPC), leading to environmental pollution. To address these challenges, this study aimed to develop a cost-effective and environmentally friendly binder for cemented paste backfill (CPB) by utilizing SS and calcined oil shale waste (COSW) as primary precursors. Extensive investigations were conducted to evaluate the properties of the CPB sample with varying COSW content, including rheological properties, mechanical strength, and microstructure. The binder sample was comprehensively characterized using isothermal calorimetric analysis, X-ray diffraction (XRD), thermogravimetry (TG), and scanning electron microscopy (SEM). Based on systematic experimentation, an optimal blend ratio for the binder was determined, consisting of 60 wt% SS, 15 wt% COSW, 15 wt% phosphogypsum (PG), and 10 wt% OPC. The exceptional performance of the binder was attributed to the substantial formation of precipitated ettringite (AFt), resulting in a more compact structure and improved mechanical strength. Additionally, a sequential extraction test revealed that the heavy metals in the CPB sample were mainly present in the residual fraction, demonstrating the effective immobilization of heavy metals by the binder.
摘要：
钢渣（SS）和油页岩废物（OSW）的环境可持续处理是工业发展领域的重要问题。采矿业还面临着与普通波特兰水泥（OPC）相关的高成本和碳排放相关的挑战，导致环境污染。为了应对这些挑战，本研究旨在通过利用SS和煅烧油页岩废料（COSW）作为主要前体，开发用于胶结膏体回填（CPB）的具有成本效益和环境友好的粘合剂。进行了广泛的调查，以评估具有不同COSW含量的CPB样品的特性，包括流变特性，机械强度,和微观结构。使用等温量热分析对粘合剂样品进行了全面表征，X射线衍射(XRD)热重分析(TG),和扫描电子显微镜（SEM）。基于系统的实验，确定了粘合剂的最佳混合比，由60重量%的SS组成，15wt%COSW,15重量%磷石膏（PG），和10wt%OPC。粘结剂的特殊性能归因于沉淀钙矾石(AFt)的大量形成，导致更紧凑的结构和提高的机械强度。此外,连续提取试验表明，CPB样品中的重金属主要存在于残留部分中，证明了粘合剂对重金属的有效固定。
