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

包括尾矿在内的矿山废物管理是采矿作业的最重要挑战。面向上游的办法将有利于尾矿的最佳管理。通过泡沫浮选进行的环境脱硫允许回收尾矿中的大多数硫化物矿物，以显著降低其反应性，从而使其在化学上适合作为矿山废物回收的覆盖材料。然而，没有研究脱硫对尾矿水文地质性质的影响。这些特性，特别是颗粒尺寸分布，可能会被脱硫过程改变，并最终影响由脱硫尾矿制成的覆盖系统的性能。此外，通常的方法来确定覆盖系统的材料的化学充分性涉及静态和动态测试，这往往是不充分的材料具有低反应性，并提供非常有限的信息，长期性能的材料作为覆盖。水文地球化学数值模拟用于预测低活性废石的长期行为;然而，需要更多的工作来整合与低活性材料相关的具体方面。另一个值得研究的方面是，是否可能利用环境脱硫技术对旧尾矿池进行再处理，以通过生产净化尾矿来促进场地复垦，减少场地的环境责任，同时回收过去没有回收的有价值金属。

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.