Solvex: A database for the selection and appraisal of solvent extraction reagents

The design of a solvent extraction process can cause considerable problems regarding the choice of reagents. Reagent selection is based upon the evaluation of many criteria, for example the ability of a reagent to transfer a metal selectively across the aqueous/organic interface in both directions and the ability of the extractant/diluent mixture to perform efficiently in terms of reaction rates and stabilities. Other factors are also important such as reagent availability, cost, capacity and toxicity. Manufacturers, world wide, are continuously seeking new and improved reagents and so the already large range is steadily growing, adding to the dilemma. In response to these problems the Solvent Extraction Database, SOLVEX, was developed at Warren Spring Laboratory, in association with the Minerals Industry Research Organisation. It offers a single comprehensive source of reliable, quantitative information compiled into a single, standard format. A large part of the database consists of performance data which is essential to the process designer. The recent addition of a graphical interface has greatly enhanced the ability of the system to allow the efficiency of different systems to be compared and evaluated. SOLVEX also stores data concerned with the physical properties of the reagents and physicochemical data such as specific gravity, solubility, interfacial tension, viscosity and toxicity. There are also comprehensive sections on commercial information and references. This paper describes the database and the graphical interface and discusses the advantages it can offer process engineers and manufacturers alike.