Abstract: In this work, four types of solvent systems for boron recovery from salt lake brines including aliphatic alcohol (monohydric alcohol, diol, mixed alcohol), aromatic polyhydroxy compound, amine compound containing hydroxyl group and ionic liquid were systematically reviewed, focusing on the recent research and application progress. The extraction mechanism of boron by various extractant systems were highly summarized to clearly explain the effect of extractant structures on the extraction performance. The extraction performance of different extractants and the influence of coexisting ions on the extraction process were analyzed, and the future research and development direction of boron extraction from salt lake brines were discussed. The monohydric alcohol was suitable for extracting boric acid under the conditions of high salting-out and acidity. But it also had serious disadvantages including low extraction rate, and severe equipment corrosion. Diol had higher extraction efficiency than monohydric alcohol, but it was difficult to realize large-scale industrial production due to high viscosity, high solution loss and difficult stripping from the loaded organic phase. Therefore, the recycling performance of diol extractant was relatively poor. The mixed alcohol system was suitable for industrial application of boron extraction from acid salt lake brines because of its synergistic extraction effect and low cost, and can also reduce viscosity and solution loss. Other systems, such as hydroxyl-containing aromatic and amine compounds, had good extraction effects on boron from alkaline salt lake brines, but they were generally expensive and difficult for industrial application. Ionic liquid can be used for boron extraction and diluent because of its advantages such as low volatility, good chemical stability and designable structure, which had a certain application prospect.

Key words: boron, salt lake brine, solvent extraction, extraction system

摘要： 硼资源的开发利用对现代工业的发展具有重要作用。硼镁矿作为传统的硼资源，其储量和品位逐渐降低；而盐湖卤水中含有丰富的硼，占我国总储量的30%以上，盐湖硼资源的高效开发是解决我国高度依赖进口的有效途径。采用溶剂萃取法从盐湖卤水中提硼具有选择性好、效率高、成本低等特点，应用前景广阔。溶剂萃取的关键是萃取体系的选择，因此针对不同类型的盐湖，优选萃取性能好、水溶性小的萃取体系成为当前研究的热点。针对目前萃取工艺的应用以及近期研究开发的新型萃取体系，本工作综述了不同体系萃取硼的特点，包括脂肪醇(一元脂肪醇、二元脂肪醇和混合醇)、含羟基的芳香族化合物、含羟基的胺类化合物和离子液体四类萃取体系，重点总结了各类萃取体系萃取硼的机理，并概述了萃取剂结构对萃取性能的影响规律，分析了共存离子对萃取过程的影响，探讨了新型硼萃取剂的研发方向。其中脂肪醇中的一元醇需要在高酸度、强盐析下实现对硼酸的高效萃取。二元醇较一元醇的萃取效率更高，但二元醇黏度大、溶损高、反萃困难，萃取剂循环性能相对较差。混合醇体系能够降低有机相的黏度和水溶性，并且具有一定的协同萃取效应，成本低，适用于工业化应用。其他体系，如含羟基的芳香类和胺类化合物在碱性条件下对硼有较好的萃取效果，但一般价格较高，工业应用较为困难。离子液体由于其不易挥发、化学稳定性好、结构可设计性等优点应用于盐湖卤水萃取提硼，同时可作稀释剂，具有一定的应用前景。分析表明，混合醇作为经济高效的萃取体系在酸性盐湖卤水提硼中更具优势，有望大规模工业化应用。

关键词: 硼, 盐湖卤水, 萃取, 萃取体系