矿渣-钢渣-脱硫石膏胶结剂水化固砷机理研究

Environmental contamination caused by Arsenic(As)in non-ferrous metal ore tailings is one of the most critical issues for ecological civilization construction of China. Currently, pyrogenic process and wet process (chemical precipitation) are the major two ways to solidify As-bearing solid hazardous wastes, which are quite expensive and have small processing capacity. Therefore, these methods are not suitable for non-ferrous metal ore tailings that are in huge stockpile.Based on the background of widespread of whole tailings backfilling technology, this project proposes the use of newly developed backfilling agent made of blast furnace slag-steel slag-flue gas desulfurization gypsum to bond these tailings. Such mixture can be used as backfill material to be transported to the underground mine for cavity support. Preliminary study found that blast furnace slag-steel slag-flue gas desulfurization gypsum agent (BSFA) shows 5-10 times higher of Assolidification capacity than ordinary Portland cement.In order to investigate the solidification mechanisms and to further improve the solidification capacity of BSFA, this project proposes to carry out three main aspects of study, including research on the environmental stability, hydration products characterization, and hydration process of backfilling material made of BSFA and As-bearing non-ferrous metal tailing.The successful performing of this project is expected to provide an economic solution for disposing of As-bearing non-ferrous metal tailings as well as other As-bearing hazardous wastes, to contribute to the data accumulation used for predicating the long term stability of hardened backfill material containing As and to promote the development of backfill mining technology.

有色金属尾矿砷污染问题是我国生态文明建设亟待解决的重要问题。目前，含砷固体废弃物的固化方法主要有火法和湿法两类，这两类方法成本高、处理能力有限，不适用于治理数量巨大的有色金属尾矿。本项目结合当前矿业充填采矿技术的必然发展趋势，提出采用矿渣-钢渣-脱硫石膏全固废胶结剂对含砷有色金属尾矿进行胶结并回填井下采空区。前期探索研究发现该矿渣-钢渣-脱硫石膏胶结剂的固砷能力为普通硅酸盐水泥的5-10倍。以此为基础，本项目拟开展矿渣-钢渣-脱硫石膏胶结剂固砷硬化体中砷的环境稳定性、矿渣-钢渣-脱硫石膏胶结剂固砷硬化体水化产物鉴别、矿渣-钢渣-脱硫石膏胶结剂水化固砷的过程研究等方面的研究，揭示该胶结剂的固砷机理。该项目的成功实施对解决含砷有色金属尾矿以及其他含砷危废的低成本地下安全处置、为预测充填体长期稳定性提供理论基础、推动充填采矿技术的发展等方面具有重要意义。

有色金属尾砂砷污染问题是我国生态文明建设亟待解决的重要问题。目前，含砷固体废弃物的固化方法主要有火法和湿法两类。这两类方法成本高、处理能力有限，不适用于治理数量巨大的有色金属尾砂。本项目结合当前矿业充填采矿技术的必然发展趋势，提出采用矿渣-钢渣-脱硫石膏全固废胶结剂对含砷有色金属尾砂进行胶结并回填井下采空区。前期探索研究发现该矿渣-钢渣-脱硫石膏胶结剂固砷能力为普通硅酸盐水泥的5-10倍。以此为基础，本项目拟开展矿渣-钢渣-脱硫石膏胶结剂固砷硬化体中砷的环境稳定性、矿渣-钢渣-脱硫石膏胶结剂固砷硬化体水化产物鉴别、矿渣-钢渣-脱硫石膏胶结剂水化固砷的过程研究等方面的研究，揭示该胶结剂的固砷机理，提出进一步提高其固化能力的调控技术。该项目的成功实施对解决含砷有色金属尾砂以及其他含砷危废的低成本地下安全处置、为预测充填体长期稳定性提供理论基础、推动充填采矿技术的发展等方面具有重要意义。