ABSTRACT
I. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
II. Extraction Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
III. Reactive Equilibria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
IV. Reactive Mass Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
A. Mass Transfer without Electrical Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
B. Mass Transfer with Electrical Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473
1. Surfactants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475
2. External Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479
V. Liquid-Liquid Hydrodynamics in Electric Fields . . . . . . . . . . . . . . . . . . . . . . . . . 483
VI. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488
The first extraction processes were with solid extraction gaining perfumes, waxes, and pharma-
ceutical active oils in an operation quite similar to a modern Soxhlet apparatus. An extraction
pot with an age of about B.C. 3500 was found 250 km north of Bagdad and extraction instructions
were documented by a Sumerian text of B.C. 2100 [1]. The next major improvements were in the
medieval age with new solvents like ethanol, mineral acids, and amalgams used to extract and
purify metals. The first extraction of a metal was reported by Peligot [2] who used diethylether
to extract uranyl nitrate which gave a basis to uranium extraction within the “Manhattan”
project in the 1940s [3]. Reactive solvent extraction was then a niche for pyrometallurgically diffi-
cult to separate metals (Nb/Ta, Zr/Hf) till the 1960s, when there was a breakthrough with copper extraction. Liquid ion exchanger (LIX) chemicals [4] were size-selective extractants for separation
of copper from iron, allowing copper recovery from low-grade ores after a sulfate leaching process.
Meanwhile, the use of LIXs has expanded to a large variety of ionic species and neutral solutes in
hydrometallurgical, environmental, petrochemical, chemical and biochemical industries [5-9].
