Background

Fly ashes from municipal solid waste incineration contain significant amounts of (technology critical) elements. Processes to recover Cu or Zn are already in practice, but it still remains difficult to evaluate the full secondary resource potential of the ashes. One reason is the absence of a worldwide comparable analytical basis for detailed market analyses. To encounter this, (i) an advice on how to analyse 65 elements after microwave-assisted digestion by ICP-OES and ICP-MS is delivered, (ii) the heterogeneity (hours to annual cycle) is evaluated for a incineration plant, (iii) leaching efficiency with three different eluents and (iv) the market potential of the elements as commodities are evaluated.

Results and conclusions

Aqua regia digestion was found to be sufficient to evaluated the recovery potential; except for the mass constituents Al, Si, Sn, Ti and the trace components Cr, Hf, Nb, U and W, for which HF-containing digestions delivered better recoveries. On different time scales, ashes were very homogenous and HCl- as well as H₂SO₄-supported leaching delivered, satisfying results within an hour (exceptions are, e.g., Bi and Sb). By applying characterisation factors of the life cycle assessment impact category “Resource depletion—minerals and metals” supplemented by the list of critical raw materials of the EU: Ag, Bi, Cd, Ga, In and Sb are most interesting elements to be recovered in future activities.

中文翻译：

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城市垃圾焚烧飞灰：从多要素方法到市场潜力评估。

背景

城市固体废物焚烧产生的飞灰含有大量（技术关键）元素。回收铜或锌的工艺已经在实践中，但仍然难以评估灰烬的全部二次资源潜力。原因之一是缺乏用于详细市场分析的全球可比分析基础。为了解决这个问题，(i) 提供了关于如何在通过 ICP-OES 和 ICP-MS 进行微波辅助消解后分析 65 种元素的建议，(ii) 评估焚烧厂的异质性（小时到年周期），（ iii) 三种不同洗脱液的浸出效率和 (iv) 评估元素作为商品的市场潜力。

结果和结论

发现王水消化足以评估回收潜力；除了质量成分 Al、Si、Sn、Ti 和痕量成分 Cr、Hf、Nb、U 和 W，对于这些成分，含 HF 的消解提供了更好的回收率。在不同的时间尺度上，灰烬非常均匀，并且 HCl 和 H ₂ SO ₄支持的浸出交付，在一小时内得到令人满意的结果（例外是，例如，Bi 和 Sb）。通过应用生命周期评估影响类别“资源枯竭-矿物和金属”的表征因素，并辅以欧盟的关键原材料清单：Ag、Bi、Cd、Ga、In 和 Sb 是最值得回收的元素未来的活动。