Chapter 1 - Modern (Classical) Fundamental Principles of Solvent Extraction

Abstract

This chapter presents modern theoretical considerations in SX (solvent extraction) techniques that are presented and are reviewed with a classification and grouping. Better understanding of the principles of SX allows the optimization of solute separations by SX technique. In addition, the chapter also provides what the factors that influence the effectiveness and selectivity of separation are and briefly analyzes them. SX is one of the favored separation techniques because of its simplicity, speed, and wide scope. By utilizing relatively simple equipment and requiring a few times to perform, extraction procedures offer much to the chemists and engineers. Using SX, important theoretical problems concerning the composition and stability of soluble as well as insoluble complexes can be solved. This quality is very useful especially for the cases when it is not possible to obtain reliable results by other methods. The SX process is usually described by a single net reaction, defined by the extraction constant Kex. Variations in Kex caused by modifications of the solvent system, such as changes in the temperature or aqueous ionic strength, by replacing one solvent by another, or by making substitutions in the extractant molecule, may be explained by careful consideration of the parameters of the system.