The abandoned Touissit-Bou Beker mining district has accumulated tens of millions of tons of tailings, stored without environmental safeguards. Due to the limited ore processing method, the tailings exhibit a significant zinc (2 wt%) and lead (0.3 wt%) content, mainly buried in carbonate minerals. These tailings pose environmental concerns but also offer economic opportunities. This study investigated the feasibility of decontaminating these tailings using froth flotation to produce a clean mineral byproduct. Composite samples were collected via reverse circulation (RC) drilling, and flotation conditions were optimized. Quantitative mineralogy and environmental behavior were assessed using quantitative evaluation of materials by scanning electron microscope (QEMSCAN®) and toxicity characteristic leaching procedure (TCLP), respectively. Under optimal conditions — potassium amyl xanthate (KAX) 350 g/t, CuSO4 1,250 g/t, Na2S 1,250 g/t, sodium hexametaphosphate (SH) 1,750 g/t, and pH 11—Zn and Pb recoveries reached up to 94 % and 71 %, respectively. Residual Pb–Zn remained partially locked within the non-sulfide gangue minerals or present as slime particles. TCLP results indicate minimal risk, suggesting reprocessing mine tailings in abandoned mine sites in Morocco could offer economic and environmental benefits. The current study is expected to serve as a reference for decision-makers when evaluating sustainable management options for mine tailings.

中文翻译：

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通过泡沫浮选对 Pb-Zn 矿山尾矿进行可持续后处理，用于废弃矿区的资源回收和环境修复


废弃的 Touissit-Bou Beker 矿区已经积累了数千万吨尾矿，在没有环境保护措施的情况下储存。由于矿石加工方法有限，尾矿表现出显着的锌 （2 wt%） 和铅 （0.3 wt%） 含量，主要隐藏在碳酸盐矿物中。这些尾矿带来了环境问题，但也提供了经济机会。本研究调查了使用泡沫浮选对这些尾矿进行净化以产生清洁矿物副产品的可行性。通过反循环 （RC） 钻孔收集复合样品，并优化浮选条件。分别使用扫描电子显微镜 （QEMSCAN）® 和毒性特征浸出程序 （TCLP） 对材料进行定量评估来评估定量矿物学和环境行为。在最佳条件下 — 戊基黄原酸钾 （KAX） 350 克/吨、CuSO4 1,250 克/吨、Na2S 1,250 克/吨、六偏磷酸钠 （SH） 1,750 克/吨和 pH 11—Zn 和 Pb 回收率分别高达 94% 和 71%。残留的 Pb-Zn 仍部分锁定在非硫化物脉石矿物中或以粘液颗粒形式存在。TCLP 结果表明风险最小，表明在摩洛哥废弃矿区对尾矿进行再处理可以带来经济和环境效益。目前的研究有望为决策者在评估尾矿的可持续管理方案时提供参考。