Argane R, El Adnani M, Benzaazoua M, Bouzahzah H, Khalil A, Hakkou R, Taha Y
Laboratoire de Génie Civil et d'Ingénierie Environnementale, Université de Lyon, INSA-Lyon, 20 av. A. Einstein, 69621, Villeurbanne cedex, France.
Laboratoire de Chimie des Matériaux et de l'Environnement, Faculté des Sciences et Techniques, Université Cadi Ayyad, 40000, Marrakech, Morocco.
Environ Sci Pollut Res Int. 2016 Jan;23(1):598-611. doi: 10.1007/s11356-015-5292-y. Epub 2015 Sep 2.
In some developing countries, base-metal residues that were abandoned in tailing ponds or impoundments are increasingly used as construction material without any control, engineering basis, or environmental concern. This uncontrolled reuse of mine tailings may constitute a new form of pollution risks for humans and ecosystems through metal leaching. Therefore, the aim of the current study is to assess mine drainage, metal mobility, and geochemical behavior of two abandoned mine tailings commonly used in the upper-Moulouya region (eastern Morocco) as fine aggregates for mortar preparation. Their detailed physical, chemical, and mineralogical properties were subsequently evaluated in the context of developing appropriate alternative reuses to replace their conventional disposal and limit their weathering exposure. The obtained results showed that both tailings contain relatively high quantities of residual metals and metalloids with lead (ranging between 3610 and 5940 mg/kg) being the major pollutant. However, the mineralogical investigations revealed the presence of abundant neutralizing minerals and low sulfide content which influence mine drainage geochemistry and subsequently lower metals mobility. In fact, leachate analyses from weathering cell kinetic tests showed neutral conditions and low sulfide oxidation rates. According to these results, the tailings used as construction material in the upper-Moulouya region have very low generating potential of contaminated effluents and their reuse as aggregates may constitute a sustainable alternative method for efficient tailing management.
在一些发展中国家，弃置于尾矿池或蓄水池中的贱金属残渣越来越多地被用作建筑材料，且没有任何管控、工程依据或环境考量。这种对尾矿的无节制再利用可能会通过金属浸出对人类和生态系统构成一种新的污染风险。因此，本研究的目的是评估摩洛哥东部穆卢亚河上游地区常用作制备砂浆细集料的两种废弃尾矿的矿坑排水、金属迁移性和地球化学行为。随后，在开发合适的替代再利用方式以取代其传统处置方法并限制其风化暴露的背景下，对它们详细的物理、化学和矿物学性质进行了评估。所得结果表明，两种尾矿都含有相对大量的残留金属和类金属，其中铅（含量在3610至5940毫克/千克之间）是主要污染物。然而，矿物学研究表明存在大量中和矿物且硫化物含量低，这影响了矿坑排水地球化学，进而降低了金属迁移性。事实上，风化槽动力学试验的渗滤液分析显示为中性条件且硫化物氧化率低。根据这些结果，穆卢亚河上游地区用作建筑材料的尾矿产生受污染废水的可能性非常低，将其作为集料再利用可能构成一种可持续的尾矿有效管理替代方法。
