Faculty of Engineering, Tarbiat Modares University, Tehran, Iran.
W.H. Bryan Geology and Mining Research Centre, Sustainable Minerals Institute, University of Queensland, 4068, Australia.
J Environ Manage. 2022 May 1;309:114712. doi: 10.1016/j.jenvman.2022.114712. Epub 2022 Feb 16.
Although the environmental significance of acid rock drainage (ARD) generated from mining wastes is well known, selecting the appropriate ARD management strategy can prove a complicated task. Chemical methods are favored for initial mine waste characterization but using these exclusively can overlook key factors, e.g., mineralogy, which controls the formation and elution of ARD. This paper first presents an ARD waste rock classification developed on Triple Characterization Criteria (TCC) which considers three input parameters: neutralizing potential ratio (NPR), net acid generation (NAG pH), and modal mineralogy weathering index (MMWI) values. Second, a new mixed-integer programming (MIP) model to guide waste dump construction with the dual aim of preventing ARD across the life-of-mine (LOM) and reducing waste rock re-handling, is introduced. Last, the spatial distribution of TCC in a planned waste dump is simulated via geo-statistical techniques to evaluate the MIP model. The proposed waste rock classification and dump planning model has been tested at an iron mine. The results of the MIP modeling and simulation of TCC showed the successful prevention of ARD by achieving large values of TCC (NPR ≥2, NAG pH ≥ 4.5, and MMWI ≥4.7) for dump cells, with the planned mine production maintained. The integrated TCC approach introduced in this study is intended to enable mine operators, at the start of the LOM, to effectively forecast ARD from future waste rock. Further, the MIP model will facilitate development of a mine schedule that optimizes the use of the waste materials based on TCC values. If used correctly, the TCC and MIP model have the potential to enable mine operators to reduce their environmental footprint across the entire LOM.
虽然采矿废物产生的酸性岩石排水（ARD）的环境意义众所周知，但选择合适的 ARD 管理策略可能证明是一项复杂的任务。化学方法常用于初始矿山废物特征描述，但单独使用这些方法可能会忽略关键因素，例如控制 ARD 形成和洗脱的矿物学。本文首先提出了一种基于三重特征标准（TCC）的 ARD 废石分类方法，该方法考虑了三个输入参数：中和潜力比（NPR）、净酸生成（NAG pH）和模态矿物风化指数（MMWI）值。其次，引入了一种新的混合整数规划（MIP）模型，以指导废物堆的构建，其双重目的是防止矿山寿命（LOM）内的 ARD 和减少废石再处理。最后，通过地质统计技术模拟 TCC 在计划废物堆中的空间分布，以评估 MIP 模型。提出的废石分类和堆规划模型已在铁矿进行了测试。MIP 建模和 TCC 模拟的结果表明，通过为堆单元实现大的 TCC 值（NPR≥2、NAG pH≥4.5 和 MMWI≥4.7），成功地防止了 ARD，同时保持了计划的矿山生产。本研究中引入的综合 TCC 方法旨在使矿山运营商能够在 LOM 开始时有效地预测未来废石中的 ARD。此外，MIP 模型将有助于根据 TCC 值制定优化废物利用的矿山计划。如果使用正确，TCC 和 MIP 模型有可能使矿山运营商在整个 LOM 内减少其环境足迹。
