Geochemical behavior and environmental risks related to the use of abandoned base-metal tailings as construction material in the upper-Moulouya district, Morocco.
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.
Laboratoire de Génie Civil et d'Ingénierie Environnementale, Université de Lyon, INSA-Lyon, 20 av. A. Einstein, 69621, Villeurbanne cedex, France. rabei.argane@gmail.com.|Laboratoire de Chimie des Matériaux et de l'Environnement, Faculté des Sciences et Techniques, Université Cadi Ayyad, 40000, Marrakech, Morocco. rabei.argane@gmail.com.
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Argane
Ecole Nationale Supérieure des Mines de Rabat Avenue, Hadj Ahmed Cherkaoui BP 753, Agdal, Rabat, Morocco.
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El Adnani
Laboratoire de Génie Civil et d'Ingénierie Environnementale, Université de Lyon, INSA-Lyon, 20 av. A. Einstein, 69621, Villeurbanne cedex, France.|UQAT, 445 Boulevards de l'université, Rouyn-Noranda, Québec, Canada.
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Benzaazoua
UQAT, 445 Boulevards de l'université, Rouyn-Noranda, Québec, Canada.
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Bouzahzah
Ecole Nationale Supérieure des Mines de Rabat Avenue, Hadj Ahmed Cherkaoui BP 753, Agdal, Rabat, Morocco.
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Khalil
Laboratoire de Chimie des Matériaux et de l'Environnement, Faculté des Sciences et Techniques, Université Cadi Ayyad, 40000, Marrakech, Morocco.
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Hakkou
UQAT, 445 Boulevards de l'université, Rouyn-Noranda, Québec, Canada.
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Taha
D003252:Construction Materials / Q000032:analysis*; D004784:Environmental Monitoring; D004787:Environmental Pollution / Q000032:analysis; D007854:Lead / Q000032:analysis; D058955:Metalloids / Q000032:analysis*; D008670:Metals / Q000032:analysis*; D008903:Minerals / Q000032:analysis; D008906:Mining; D009018:Morocco; D013440:Sulfides / Q000032:analysis
D058955:Metalloids; D008670:Metals; D008903:Minerals; D013440:Sulfides; D007854:Lead
Abandoned mine tailings; Leaching tests; Metal mobility; Mine drainage; Mineralogical characterization; Tailings management