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有利于尾矿的优化管理。通过泡沫浮选进行环境脱硫，可以回收尾矿中的大多数硫化物矿物，从而大大降低其反应性，从而使其在化学上适合作为矿山废物回收的覆盖材料。但脱硫对尾矿水文地质性质的影响尚未进行研究。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体系的性能。此外，确定用于盖层系统的材料的化学充足性的通常方法包括静态和动力学试验，这些方法往往不适用于反应性低的材料，并且提供的关于盖层材料长期性能的信息非常有限。利用水文地球化学数值模拟对低活性废石的长期行为进行了预测；然而，需要更多的工作来整合与低反应性材料相关的具体方面。另一个值得研究的方面是利用环境脱硫技术对旧尾矿库进行再处理的可能性，通过生产净化后的尾矿来减少场地的环境责任，从而促进场地的复垦，同时回收过去未回收的有价金属。***拟议的研究计划力求将矿物加工和环境管理结合起来，优化尾矿管理，通过环境脱硫作为一种手段，生产出具有足够水文地质性质的材料，用于矿区复垦。本项目主要目的为：1)研究浮选环境脱硫对尾矿水文地质性质的影响；2)利用数值模型模拟了脱硫尾矿的水文地球化学行为；3)评价环境脱硫作为一种老化尾矿回收方法的应用。为达到这些目标所采用的方法将包括详细的材料表征（水文地质、地球化学、矿物学）、浮选试验、动力学试验和数值模拟。将根据实验室和现场数据开发数值模型，如Vadose/W和MIN3P，以确定脱硫目标，以确保所产生的脱硫尾矿具有足够的性质（地球化学和水文地质），可以长期用作成功的覆盖物（单层或多层系统的一部分）。该项目将培养本科生和研究生，从而为加拿大矿业和研究界提供采矿环境方面急需的专家

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.***The proposed research program strives to integrate mineral processing and environmental management to optimize tailings management, though environmental desulfurization as a mean to produce material with the adequate hydrogeological properties to be used in mine site reclamation. The program aims three objectives: 1) to study the effect of environmental desulfurization by flotation on the tailings hydrogeological properties; 2) to simulate using numerical models the hydrogeochemical behaviour of desulfurized tailings; 3) to evaluate the use of environmental desulfurization as a reclamation method for aged tailings. The methodology used to reach these objectives will comprise detailed material characterization (hydrogeological, geochemical, mineralogical), flotation tests, kinetic tests, and numerical modelling. Numerical models, such as Vadose/W and MIN3P will be developed based on laboratory and field data to determine the desulfurization targets to ensure that the desulfurized tailings produced have adequate properties (geochemical and hydrogeological) to be used as a successful cover (monolayer or part of a multilayer system) over the long term. The program will train undergraduate and graduate students, thus providing the Canadian mining industry and research community with much needed experts in mining environment.***