Data publication: Gallium bioionflotation using rhamnolipid: Influence of frother addition and foam properties

The current study investigated the application of rhamnolipid biosurfactant as an ion collector in bioionflotation. In a top-down approach, the influence of rhamnolipid on gallium (Ga) ion flotation and recovery were investigated followed by detailed studies on the influencing parameters and foam characterization. Rhamnolipid exhibits extensive foaming properties and foam produced by rhamnolipid alone has higher stability making it difficult to collect the flotation concentrates. An addition of 1,2-decanediol introduces instability to this foam and also aids in concentrate collection. Observations during the flotation studies resulted in a series of investigations on rhamnolipid properties such as aggregate size, surface tension, and foam characterization. These results indicated that the addition of Ga and/or 1,2-decanediol affected the molecular aggregation of rhamnolipid. Moreover, the surface activity, foamability, foam drainage, and foam coarsening/coalescence of the rhamnolipid changed in the presence of Ga and/or 1,2-decanediol. In a batch bioionflotation process, rhamnolipid was able to remove nearly 80% Ga at pH 7 in presence of 1,2-decanediol. However, upgrading was higher at pH 6 without 1,2-decanediol, which is important when considering the flotation recovery in presence of other metals. Such biosurfactants have a high potential for wide applications in ion flotation and further optimization of flotation parameters is essential.

本研究探讨了鼠李糖脂生物表面活性剂（rhamnolipid biosurfactant）作为离子捕收剂在生物离子浮选（bioionflotation）中的应用。采用自上而下的方法，首先考察了鼠李糖脂对镓（Ga）离子浮选及回收的影响，随后对影响参数和泡沫表征展开了详细研究。鼠李糖脂具有优异的发泡性能，且其单独产生的泡沫稳定性较高，导致浮选精矿难以收集。添加1,2-癸二醇可降低该泡沫的稳定性，同时有助于精矿的收集。浮选研究过程中的观察结果促使研究人员对鼠李糖脂的性质（如聚集体尺寸、表面张力和泡沫表征）进行了一系列深入研究。结果表明，镓离子和/或1,2-癸二醇的添加会影响鼠李糖脂的分子聚集行为。此外，在镓离子和/或1,2-癸二醇存在的情况下，鼠李糖脂的表面活性、发泡性、泡沫排液性及泡沫粗化/聚并行为均发生了改变。在批次生物离子浮选过程中，当pH值为7且存在1,2-癸二醇时，鼠李糖脂对镓离子的去除率可达近80%。然而，在pH值为6且无1,2-癸二醇的条件下，精矿品位提升更高，这对于考虑其他金属存在时的浮选回收具有重要意义。此类生物表面活性剂在离子浮选中具有广泛的应用潜力，进一步优化浮选参数至关重要。