Recovery of rare earth elements from acidic mine waters: An unknown secondary resource
Recovery of rare earth elements from acidic mine waters: An unknown secondary resource
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DOI：
10.1016/j.scitotenv.2021.152258
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发表时间：
2021-12-17
影响因子：
9.8
通讯作者：
Cortina, J. L.
中科院分区：
文献类型：
--
作者：
Hermassi, M.;Granados, M.;Cortina, J. L.
由于产生的大量废物和相关的高处理成本，酸性矿山排水（AMD）仍然被认为是采矿可持续性面临的最大挑战之一。关于可持续发展、循环经济和对稀土元素（REE）等战略元素的需求的新监管倡议可能会克服旨在开发低成本处理方案的传统研究倡议，并制定研究倡议，以确定将此类AMD视为潜在的二次资源的潜在利益。作为一个例子，本研究开发了一个三阶段过程的整合，其中REE从贱金属（如Fe， Al, Mn, Ca, Mg, Cd, Pb）中选择性分离，然后集中生产富含REE的副产品，回收为REE-磷酸盐。在pH值为3,6 +/- 0.2的条件下，通过全氧化生成Fe(III)，沉淀为schwertmanite，实现了铁（>99%）的选择性分离。然后用磺酸离子交换树脂从AMD中提取稀土，得到浓度为0.25 gREE/L的浓稀土硫酸溶液。最后，在优化的pH控制和总磷浓度条件下，通过磷酸盐溶液沉淀，实现了稀土元素与Al（III）、Ca（II）、Mg（II）和过渡元素（Cu、Zn、Ni）的选择性分离。XRD分析鉴定出低晶矿物。通过热处理，发现主要矿物为PrPO4(s)和Cheralite (CePO4(s)，其中Ce被La和Ca取代，Xenotime （YPO4(s)）为AlPO4(s), Ca,MgYPO4(s)也被鉴定出来。
Acidic mine Drainage (AMD) is still considered one of the greatest mining sustainability challenges due to the large volumes of wastes generated and the high associated treatment cost. New regulation initiatives on sustainable development, circular economy and the need for strategic elements as Rare Earth Elements (REE) may overcome the traditional research initiatives directed to developing low cost treatment options and to develop research initiatives to identify the potential benefit of considering such AMD as a potential secondary resource. As an example, this study develops the integration of a three-stage process where REE are selectively separated from base metals (e.g. Fe, Al, Mn, Ca, Mg, Cd, Pb) and then concentrate to produce a rich REE by-product recovered as REE-phosphates. Selective separation of Fe (>99%) was achieved by total oxidation to Fe(III) and subsequent precipitation as schwertmannite at pH 3,6 +/- 0.2. REE were then extracted from AMD using a sulfonic ion-exchange resin to produce concentrated REE sulfuric solutions up to 0.25 gREE/L. In a final stage selective separation of REE from Al(III), Ca(II) and Mg(II) and transitions elements (Cu, Zn, Ni) was achieved by precipitation with phosphate solutions under optimized pH control and total phosphate concentration. XRD analysis identified low-crystalline minerals. By using a thermal treatment the presence of PrPO4(s) and Cheralite (CePO4(s)) where Ce is substituted by La and Ca and Xenotime (YPO4(s)) were found as main minerals AlPO4(s) Ca,MgYPO4(s) were also identified.