LIX reagents

G. A. Kordosky, The Chemistry of Metals Recovery Using LIX-Reagents. 1973, Mines Branch General Mills. 

The necessity of using a hydrocarbon as the solvent in the reactions discussed thus far raised the problem of using a home-made lithium reagent, since these derivatives are best made from a halogen/lithiiun exchange in an ethereal solvent. This difficulty may be circumvented if pentane, hexane, or cumene is added to the RLi,LiX reagent, prepared in ether, but a larger amoimt of sparteine has to be added, since the diamine coordinates efficiently with the lithiiun halide. The best way is to start from an alkyl chloride, so that liCl already precipitates in ether, and to piunp off this solvent after the addition of ciunene under these conditions, a 1 1 ratio of sparteine Rli can be used [27]. 

A-6-(t-Dodecylamido)-2-pyridinecarboxylic acid (t-DAPA) is a newly synthesized carrier, proposed as an alternative to LIX reagents (known to be very selective toward Cu(II)) to overcome problems related to their cost and poor physicochemical stability. However, the fact that t-DAPA is not commercially available and very little is known about its stability raises the question whether it will become an attractive alternative to LIX reagents [28,29]. Its high selectivity for Cu(II), Zn(II), and Ni(II) can be explained by the high affinity of the carboxylic group and the pyridine moiety for these metals, although it is more selective for Cu(II) at low pH values. 

Cognis Corp. Undated. The chemistry of metals recovery using LIX reagents, MID Bluebook. 

House, J. E. 1989. The development of the LIX reagents. Miner. Metall. Proc. 6(2) l-6. Hurtado-Guzman, C. and Menacho, J. M. 2003. Oxime degradation chemistry in copper solvent extraction plants. In Proceedings hydrometallurgy of copper modelling, impurity control and solvent extraction, vol. 6, book 2, eds. PA. Rivieros, D. G. Dixon, D. 

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