Department of Earth and Marine Science (DISTEM), University of Palermo, Via Archirafi 36, 90123 Palermo, Italy.
Geological Survey of Israel, 32 Yesha'yahu Leibowitz, Jerusalem 9371234, Israel; Institute of Earth Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel.
Sci Total Environ. 2023 Jun 1;875:162682. doi: 10.1016/j.scitotenv.2023.162682. Epub 2023 Mar 7.
The industrial extraction of Y and lanthanides (hereafter defined as Rare Earth Elements, REE) often requires the achievement of leaching procedures removing these metals from primary rocks and their transfer in aqueous leachates or incorporated in newly forming soluble solids. These procedures are the most dangerous to the environment in relation to the composition of leachates. Hence, the recognition of natural settings where these processes currently occur, represents a worthy challenge for learning how to carry out similar industrial procedures under natural and more eco-friendly conditions. Accordingly, the REE distribution was studied in the brine of Dead Sea, a terminal evaporating basin where brines dissolve atmospheric fallout particles and crystallise halite. Our results indicate that the shale-like fractionation of shale-normalised REE patterns in brines, inherited during the dissolution of atmospheric fallout, changes because of the halite crystallisation. This process leads to crystallising halite mainly enriched in elements from Sm to Ho (medium REE, MREE) and coexisting mother brines enriched in La and some other light REE (LREE). We suggest that the dissolution of atmospheric dust in brines corresponds to the REE extraction from primary silicate rocks, whereas halite crystallisation represents the REE transfer into a secondary more soluble deposit with reduced environmental health outcomes.
Y 和镧系元素（以下定义为稀土元素，REE）的工业提取通常需要进行浸出程序，从原岩中提取这些金属，并将其转移到水溶液浸出液中或掺入新形成的可溶性固体中。这些程序在浸出液的组成方面对环境最为危险。因此，识别这些过程目前发生的自然环境，代表了一项有价值的挑战，即学习如何在自然和更环保的条件下进行类似的工业程序。因此，我们研究了死海卤水（一个终端蒸发盆地）中的 REE 分布，其中卤水溶解大气沉降颗粒并结晶岩盐。我们的结果表明，由于岩盐结晶，在大气沉降物溶解过程中继承的页岩归一化REE 模式的页岩状分馏发生变化。这个过程导致结晶岩盐主要富集 Sm 到 Ho（中 REE，MREE），而共存的母液则富含 La 和其他一些轻 REE（LREE）。我们认为，大气尘埃在卤水中的溶解相当于从原硅酸岩中提取 REE，而岩盐结晶则代表 REE 转移到环境健康结果降低的二次更可溶解的沉积物中。
