Microfluidic technology has attracted great interest across industry and academia. Its engineering characteristics, through miniaturization, can enhance mass- and heat transfer rates together with allowing operation at high concentrations. Combining this technology with a green designer solvent is one of the most recent advances in separation processes. Ionic liquids have negligible volatility and flammability and have an exceptionally large chemical diversity space, which these days can be better utilised through solvent modelling. Ionic liquids have been demonstrated to increase the efficiency and selectivity of extraction by orders of magnitude.

Different types of microfluidic devices have been designed until now, and among those, the segmented flow with alternate regular slugs is the most prominent. Helical coiling can further intensify the internal recirculation by convection, which is the motor of the advanced mass transfer. This is done by liberating Dean forces. A device that leverages such mass transfer intensification in the best possible way is the Coiled flow inverter (CFI) (Saxena Nigam, 1984) [1]. The coil periodicity is just 4 turnings, and then the winding direction is inversed, e.g. changed from clockwise to counter-clockwise, and this is repeated multiple times. The CFI extraction performance is typically much better than for a straight and a non-inverted helical capillary.

Separation of metals using liquid–liquid extraction methodology is an important research subject of large economical relevance. The common types of equipment in metal extraction have some disadvantages such as long mixing time and huge plant footprint for the coalescence of the multi-phase, which might take very long due to emulsion formation. In this regard, microfluidic devices and ionic liquids provide an alternative as more compact, more efficient, and faster technology. This review shall help researchers to understand the recent improvement in metal extraction processes, and what the addition of disruptive technology can add to an industrial transformation.

微流体技术已引起整个行业和学术界的极大兴趣。通过小型化，其工程特性可以提高传质和传热速率，并允许在高浓度下运行。将该技术与绿色环保型溶剂相结合是分离工艺的最新进展之一。离子液体的挥发性和可燃性可忽略不计，并且具有异常大的化学多样性空间，这些天可以通过溶剂建模更好地利用。离子液体已被证明可以将萃取的效率和选择性提高几个数量级。

迄今为止，已经设计出了不同类型的微流体装置，其中，以交替的规则段塞组成的分段流动最为突出。螺旋盘绕可以通过对流进一步增强内部再循环，这是高级传质的动力。这是通过解放迪恩部队来完成的。能够最好地利用这种传质强化的设备是螺旋流换流器（CFI）（Saxena Nigam，1984）[1]。线圈周期仅为4圈，然后将绕组方向反转（例如，从顺时针方向更改为逆时针方向），并重复多次。CFI提取性能通常要比直形和同向螺旋形毛细管好得多。

使用液-液萃取方法分离金属是具有重大经济意义的重要研究课题。金属提取中常见的设备类型具有一些缺点，例如混合时间长和多相合并所需的巨大工厂占地面积，这可能会由于形成乳液而花费很长时间。在这方面，微流体装置和离子液体提供了一种更紧凑，更有效和更快的技术。这项审查将帮助研究人员了解金属提取工艺的最新进展，以及添加破坏性技术可以为工业转型带来哪些好处。