STEADY-STATE LOCAL LINEARIZATION OF THE COUNTERCURRENT MULTISTAGE EXTRACTION PROCESS FOR METAL-IONS

Steady-state local linearization of the countercurrent multistage solv ent extraction process for metal ions with cation exchange reagents ha s been carried out on the basis of the differential forms of (i) the e quilibrium relation and (ii) the material balance for the metal ion, i n each stage. The result is presented as a normal form total different ial equations for the respective stages expressing the relation of the metal ion molarities in the aqueous phase to the operational paramete rs capable of independent continuous variation. These equations have b een validated by comparing their numerical solutions for a model syste m with those by the conventional simulation method. These equations, t hus, provide a new simulation method enabling one to efficiently draw a precise diagram expressing the effect of one operational parameter o n the process performance.