Environmental desulfurization as a tool to improve mine waste management and mine site reclamation

矿山废物管理，包括矿山尾矿，是采矿作业最重要的挑战。以上游为导向的方法将有利于优化尾矿管理。采用泡沫浮选法进行环境脱硫，可以回收尾矿中的大部分硫化物矿物，大大降低其反应活性，使其在化学上适合作为矿山废渣回收的覆盖材料。然而，目前还没有关于脱硫对尾矿水文地质性质影响的研究。这些特性，特别是粒度分布，可能会因脱硫过程而改变，并最终影响由脱硫尾矿制成的覆盖系统的性能。此外，确定覆盖系统材料的化学充分性的通常方法包括静态和动态测试，这往往不适用于反应性低的材料，并且提供的关于作为覆盖层的材料的长期性能的信息非常有限。水文地球化学数值模拟被用来预测低活性废石的长期行为；然而，需要做更多的工作来综合与低活性材料有关的具体方面。另一个值得研究的方面是，利用环境脱硫对旧尾矿库进行再处理的可能性，通过生产经过净化的尾矿来减少对场地的环境责任，同时回收过去没有回收的有价值的金属，从而促进场地的复垦。

Mine waste management, including mine tailings, is the most important challenge of mining operations. An upstream-oriented approach would be beneficial for optimal tailings management. Environmental desulfurization, performed by froth flotation, allows recovering most sulfide minerals in the tailings to reduce significantly its reactivity, thus making it chemically suitable as cover material for mine waste reclamation. However, no studies were performed on the effect of desulfurization on tailings hydrogeological properties. Those properties, specifically particle size distribution, may be altered by the desulfurization process and ultimately affect the performance of cover systems made of desulfurized tailings. Furthermore, the usual methods to determine the chemical adequacy of materials for cover systems involve static and kinetic tests, which tend to be inadequate for materials that have low reactivity, and provide very limited information on long term performance of materials as covers. Hydrogeochemical numerical modelling was used to predict the long term behaviour of low reactive waste rock; however more work is required to integrate specific aspects related to low reactive material. Another aspect that deserves investigation is the possibility of using environmental desulfurization to reprocess old tailing ponds to facilitate site reclamation by producing decontaminated tailings that reduce the environmental liability of the site, while at the same time to recover valuable metals that were not recovered in the past.