吸附剂协同作用的梯度模拟移动床提取卤水中硼锂的应用基础研究

China’s Saline lake brines contain a large amount of lithium and boron elements, being a valuable resource. Because the concentrations of both lithium and boron are very small and the concentrations of alkali metal and alkaline earth metal are very high in brine, it is more energy consumption and expensive to recover boron and lithium from brine using the existing separation methods, such as adsorption, extraction, crystallization et.al. In view of lithium and boron coexistence in brine, our research objective is to develop the novel coextraction technology of boron and lithium from brine using of the gradient simulation moving bed process with synergistic adsorption of adsorbents, in order to reduce the extraction cost and energy consumption for single product boron or lithium from brine, that will promote the effective utilization of both lithium and boron resources in brine. We shall focus on the following four research contents to attain our goal. ① Through the adjustment of the adsorbent structure, eluent matching and the design of the gradient elution and desorption mode, both dissolution loss and stability of adsorbents are avoided or improved significantly during the cyclic adsorption desorption prcesses for the lithium and boron extraction from brine. ② The simulated moving bed (SMB) process with synergistic adsorption of adsorbents, gradient elution mode and the reverse flow between liquid and adsorbents in the packed beds, is developed for the effective coextraction of lithium and boron from brine. ③ The mathematical model for the gradient SMB process is developed and the numerical solutions are obtained under gPROMs programming environment, and the SMB process optimization software package is developed. Based on simulation optimization and experimental verification, the theoretical system for the design and optimization of gradient simulated moving bed process is set up for the coextraction of both lithium and boron from brine. ④ Through comparison of extraction cost and energy consumption between single lithium or boron extraction and the coextraction of lithium and boron, the feasibility and effectiveness of gradient SMB process with synergistic adsorption of adsorbents are evaluated, and a novel method for the leffective recovery of lithium and boron from brine with large-scale is established.

我国盐湖卤水中含有大量硼锂有价元素，是宝贵的资源，但是硼锂品位低、碱金属和碱土金属含量高，导致硼锂提取成本和能耗较高。本课题i鉴于卤水中硼锂共存性，研发吸附剂协同作用的梯度模拟移动床新工艺联合提取卤水中硼锂，降低单一产品硼或锂提取成本和能耗,推进卤水中硼锂资源利用的产业化进程。研究重点聚焦①吸附剂结构调控、洗脱剂匹配以及梯度洗脱解吸模式协同作用解决实际工程应用中存在的硼锂吸附剂溶损及稳定性差问题；②构建模拟移动床提取硼锂新工艺，通过硼锂吸附剂协同作用、梯度洗脱模式、多塔内形成的液固相逆流流动实现卤水中硼锂共提取；③建立硼锂提取过程的数学模型，突破非线性动态吸附l数值求解难点，研发过程优化软件包，模拟优化与实验验证，形成梯度模拟移动床硼锂提取过程优化设计的理论体系；④比较单一产品硼或锂提取与硼锂共提取过程的成本与能耗，评价梯度模拟移动床工艺的可行性和有效性，建立大规模卤水中硼锂共提取新方法

近年来, 随着全球资源与环境问题的日益突出, 锂作为新世纪绿色能源的重要材料之一, 其开发应用广受关注。随着汽车锂动力电池的开发与应用，导致锂资源紧缺, 因此，作为一种重要的战略资源，锂资源开发与应用备受各国重视。我国锂矿资源匮乏，不能够满足工业生产需求。但是，我国盐湖卤水含大量锂有价元素，是宝贵的资源，且储量巨大，具有开发价值。然而，我国锂储量丰富的的盐湖卤水组分复杂，含多达59种以上元素，且Li与B、Cs、Br、K和Rb等有密切共生关系，卤水中锂品位低、鎂锂比高、碱金属和碱土金属含量高，导致锂提取成本和能耗高，限制其产业化进程。我国盐湖卤水也含大量硼有价元素，也是宝贵的资源。硼作为一种新型资源，其消耗量逐年增加，已成为现代工业中不可或缺的重要化工产品。然而，我国硼矿资源匮乏，也不能够满足工业生产需求。所以，从盐湖卤水中提取硼，意义重大。鉴于我国卤水中硼锂共存关系，我们提出同步提取卤水中硼锂概念，降低单一提取卤水中锂或硼的能耗和成本，提高市场竞争力，推进卤水中硼锂资源利用产业化进程。.在NSFC基金资助下，我们研制了高效纳米钛系锂离子筛提取卤水中锂，优选了葡甲胺硼特效树脂提取卤水中硼，揭示碱性树脂的胺基官能团强化钛系离子筛卤水提锂机制，提出葡甲胺硼特效树脂和钛系离子筛的协同作用同步提取卤水中的硼锂新思路。同时，鉴于盐湖卤水中硼锂共存性，研制的钛系锂离子筛与葡甲胺螯合树脂吸附与解吸条件基本相同，在中性或者弱碱性条件下对盐湖卤水中硼或锂高选择性吸附，吸附的硼锂均可以采用稀酸解吸，解吸得到的高浓度的硼锂水溶液，进一步加入盐酸结晶分离得到粗硼酸，加入碳酸锂得到粗碳酸锂，为卤水中硼锂共提取提供的充分条件。所以，我们研发了葡甲胺硼特效树脂和钛系离子筛的协同作用同步提取卤水中的硼锂的模拟移动床新工艺和多级连续搅拌槽式吸附器同步提取卤水中硼锂的新工艺，有效地降低卤水提取锂硼能耗和成本，推进卤水中硼锂资源利用产业化进程。