Harnessing magnetic fields for rare-earth complex crystallization–separations in aqueous solutions

Abstract

Magnetic crystallization was used as an energy-efficient technique for selective separation of paramagnetic rare-earth ions from lanthanum ions. An air-stable and simple RE-DOTA complex system was used to achieve separation in aqueous conditions.

Magnetic forces in paramagnetic fluids

“…This was first demonstrated for Mohr's salt [132] and later for nickel sulfate [133,134]. Magnetic field gradients have also been reported to enhance the separation of rare earths by crystallisation [135][136][137].…”

Rare Earths—The Answer to Everything

“…Use of different salts or double salts may yet improve differentiation, and an effective Nd/Dy crystallization separation has been provided to enable the recovery of these elements from magnets [18]. Magnetically assisted crystallization has been reported [19] and has been used in rare earth separations [20]. There has been a recent report of the use of machine learning to advance rare earth separation (Figure 5) [21].…”

On membrane-based approaches for rare earths separation and extraction – Recent developments

“…Bearing in mind such tremendous needs for REEs, other pathways away from the exploration and mining of natural resources should be considered. The alternative options should focus on improving recycling facilities and waste collection [41] (permanent magnets (Nd), fluorescent powders, television tubes, flat panel displays) [42][43][44][45][46][47][48][49], developing novel solid or liquid extraction systems [50][51][52][53][54][55], and implementing separation and bio-separation technologies [56][57][58][59][60][61][62]. At the European level recycling process is an essential solution owing to limited options for growing the primary supply.…”