This work reports the semiquantitative laboratory chemical procedures developed for some Rare Earth Elements (REE) extraction and concentration from coal bottom ash (BA), including recycling the recovered valuable components. This preliminary assessment applied in case of 25 coal BA samples of Ceplea Valley landfill of Romania describes the chemical methods by using digestion with nitric acid coupled with microemulsion assisted extraction procedure. The enrichment of REE by concentrated nitric acid followed by water washing proved to be an adequate approach since water recovers 29.42% of metals comparing to that extracted by the total phase (ac + aq). The REE concentration process achieved by precipitation with NaOH, at different pH values, shows to be almost completely in the fraction at pH ≈ 0 and 3. The statistical outlook coefficient C_outl shows that evaluation of REE concentration in acid/aqueous solution falls into the “promising” field for their recovery by chemical procedures. Optimal microextraction was obtained by coupling microemulsion Winsor II ternary system consisting in Brij 30/AcOEt:AcOBu/metal ions solution, with citric acid as complexing agent. Results confirm that recovery of lanthanides as nanoparticles from microemulsion system yields over 85%. Optical characterization of oxide nanoparticles suggested applications such as for energy efficient buildings, photo-catalysts for water remediation or thin films for photonic optical devices. The ash residue can be also recycled as an alternative raw material for building materials production.

这项工作报告了为从煤底灰 (BA) 中提取和浓缩某些稀土元素 (REE) 开发的半定量实验室化学程序，包括回收回收的有价值成分。该初步评估适用于罗马尼亚 Ceplea Valley 垃圾填埋场的 25 个煤 BA 样品，描述了使用硝酸消化结合微乳液辅助提取程序的化学方法。用浓硝酸浓缩 REE 然后水洗被证明是一种合适的方法，因为与总相 ( ac + aq)提取的金属相比，水回收了 29.42% 的金属）。在不同 pH 值下用 NaOH 沉淀实现的 REE 浓缩过程显示几乎完全在 pH ≈ 0 和 3 的分数中。 统计前景系数 C _outl表明酸/水溶液中 REE 浓度的评估属于“有希望”的领域，因为它们通过化学程序进行回收。通过偶联微乳液 Winsor II 三元体系获得最佳微萃取，该体系由 Brij 30/AcOEt:AcOBu/金属离子溶液组成，柠檬酸作为络合剂。结果证实，镧系元素从微乳液系统中作为纳米颗粒的回收率超过 85%。氧化物纳米粒子的光学表征表明其可用于节能建筑、用于水修复的光催化剂或用于光子光学器件的薄膜。灰渣也可回收作为建材生产的替代原料。