Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Rakehill Technologies, LLC, Benicia, California 94510, United States.
Environ Sci Technol. 2017 Nov 21;51(22):13481-13486. doi: 10.1021/acs.est.7b03464. Epub 2017 Nov 9.
We report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloride from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ∼91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. The present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.
我们报告了一种三阶段柱萃取工艺，用于从地热卤水中选择性地提取氯化锂。这项研究的目标是开发材料和加工技术，以提高从自然存在的地热和其他卤水提取和生产锂的经济性，用于储能应用。一种新型的吸附剂，锂铝层状双氢氧化物氯化物（LDH），通过 X 射线粉末衍射、扫描电子显微镜、电感耦合等离子体发射光谱（ICP-OES）和热重分析进行了合成和表征。柱萃取过程的每个循环都由三个步骤组成：（1）从卤水中负载吸附剂上的氯化锂；（2）中间洗涤以去除不需要的离子；（3）最终洗涤以卸出氯化锂离子。我们对洗脱液与进料中 Li 和竞争离子浓度的实验分析表明，我们优化的吸附剂可以实现约 91%的回收率，并且相对于 Na 离子具有出色的 Li 表观选择性（分别为 47.8），相对于 K 离子的选择性（分别为 212），在卤水中。本工作表明 LDH 是从卤水中选择性提取锂的有效吸附剂，从而为锂离子电池中有效应用锂盐提供了可能，从而导致锂供应链的根本转变。
