Extraction of lithium from oilfield waste-water brine

从盐水中提取锂通常是通过去除镁、钙和钡来实现的，镁、钙和钡与锂具有相似的化学行为，然后在池塘中进行太阳能蒸发以浓缩和沉淀锂化合物。尽管这种方法成本相对较低，操作简单，但在阿尔伯塔省这样的寒冷地区，大量的水蒸发既不经济可行，也不环保。在这个项目中，我们将研究使用非常规方法从盐水中提取锂，基于锂离子的选择性清除，而不诉诸太阳能蒸发池。磷酸三丁酯（TBP）是为数不多的锂萃取剂之一，在核化学中被广泛用于处理乏燃料。在我们的研究中，第一个目标是全面表征盐水的地球化学特征。第二个目标是通过TBP直接从盐水中提取锂，采用两种方法：(1)利用TBP作为溶剂，然后通过剥离锂来回收TBP；(2)将TBP与有机颗粒杂交，并将其置于吸附柱中，选择性地从盐水中隔离锂。该吸附剂可在浓酸中再生，有效解吸锂离子。虽然已有大量文献报道TBP在核废料处理中作为萃取剂，但关于TBP作为锂清除剂的研究很少，大部分研究都是将TBP在有机溶剂中稀释后作为溶剂萃取剂使用。我们的工作成果不仅可以为我们的行业合作伙伴提供新的技术来解决从盐水中提取锂的问题，还可以为从盐水中选择性分离锂的研究打开一扇新的窗口。

Lithium extraction from brine is conventionally achieved by the removal of magnesium, calcium, and barium,which have similar chemical behaviors to lithium, followed by solar evaporation in a pond to concentrate andprecipitate lithium compounds. Although this approach benefits from a relatively low-cost and simpleoperation, evaporation of large volumes of water in cold regions such as Alberta is neither economicallyfeasible nor environmentally benign. In this project, we will investigate lithium extraction from brine waterusing unconventional approaches, predicated on the selective scavenging of lithium ions without resorting tosolar evaporation ponds. One of the few identified lithium extractants is tributyl phosphate (TBP), which hasbeen used widely in nuclear chemistry to process spent nuclear fuel. In our study, the first objective is to fullycharacterize the geochemistry of the brines. The second objective is to extract lithium directly from the brine byTBP using two approaches: (1) utilizing TBP as a solvent, followed by recycling TBP by stripping the lithiumfrom it, and (2) hybridizing TBP with organic particles and employing them in a sorption column to selectivelysequester lithium from the brine. The sorbent can be regenerated in a concentrated acid to efficiently desorb thelithium ions. Although there is ample literature surrounding TBP as extractant in nuclear waste treatment, thereare few studies dedicated to TBP as lithium scavenger, in most of which TBP is diluted in an organic solventand used as a solvent extractant. The results from our work could not only equip our industry partner with anew technique to address lithium extraction from brine but also open a new window into the research on theselective sequestering of lithium from brine.