Studying the kinetics of important solvent extraction reactions and identifying the rate limiting step has led to system modifications to achieve dramatically improved results. This work served to verify that chemical reactions and not mass transfer were the system bottlenecks for important systems already studied. Future research will produce rate data for additional systems and lead to general development to point to general methods to improve other systems in the difficult platinum group. In addition to quantitative measurements with a series of complex extraction agents, hollow fiber membrane filter assemblies will be studied to achieve alternative methods for separation.