ABSTRACT

Geothermal power plants produce large amounts of high-temperature fluids from variable depths. These fluids can be enriched in lithium to up to 240 mg/L, rendering them an exploitable resource, not yet processed at industrial scale. The pressure on Li demand is expected to increase in the future, making the technical degradability of new Li resources indispensable. We examine Li-extraction methods from aqueous solutions systematically, dealing with evaporation, direct precipitation, membrane-related processes, solvent extraction, sorption, and ion exchange. Sorption and ion-exchange techniques are regarded to be the most promising methods with a high potential for the feasible lithium extraction. Therefore, Li sorption on different inorganic sorbents, in particular for the implementation into operating geothermal power plants, is evaluated. Inorganic sorbents, such as lithium–manganese oxide, titanium oxide, aluminum hydroxide, iron phosphate, clay minerals, and zeolite group minerals besides other sorbents, e.g. zirconium phosphate, tin antimonate, antimony oxide, tantalum oxide, and niobium oxide, are regarded. Promising inorganic sorbents for an environmentally friendly, efficient, and selective Li extraction are lithium–manganese oxide, iron phosphate, or zeolite. To evaluate the effectiveness of these sorbents to large-scale industrial Li₂CO₃ (or LiOH) production, we highlight their potential advantages and disadvantages in the application under geothermal operating conditions.

摘要

地热发电厂从不同深度产生大量高温流体。这些液体中的锂含量可高达 240 mg/L，使其成为一种可开发资源，尚未进行工业规模加工。未来锂需求压力有望加大，新锂资源的技术可降解性不可或缺。我们系统地研究了从水溶液中提取锂的方法，涉及蒸发、直接沉淀、膜相关过程、溶剂提取、吸附和离子交换。吸附和离子交换技术被认为是最有前途的方法，具有可行的锂提取的高潜力。因此，评估了锂在不同无机吸附剂上的吸附，特别是用于运行中的地热发电厂的实施。无机吸附剂，如锂锰氧化物、氧化钛、氢氧化铝、磷酸铁、粘土矿物和沸石族矿物，以及其他吸附剂，如磷酸锆、锑酸锡、氧化锑、氧化钽和氧化铌，都被考虑在内。用于环保、高效和选择性锂提取的有前途的无机吸附剂是锂锰氧化物、磷酸铁或沸石。评估这些吸附剂对大规模工业锂的有效性 和选择性锂提取是锂锰氧化物、磷酸铁或沸石。评估这些吸附剂对大规模工业锂的有效性 和选择性锂提取是锂锰氧化物、磷酸铁或沸石。评估这些吸附剂对大规模工业锂的有效性₂ CO ₃（或LiOH）的生产，我们强调它们在地热操作条件下应用的潜在优势和劣势。