12.9. EQUILIBRIUM RELATIONS AND SINGLE-STAGE LEACHING
12.9A. Equilibrium Relations in Leaching
To analyze single-stage and countercurrent-stage leaching, an operating-line equation or material-balance relation and the equilibrium relations between the two streams are needed, as in liquid–liquid extraction. It is assumed that the solute-free solid is insoluble in the solvent. In leaching, assuming there is sufficient solvent present so that all the solute in the entering solid can be dissolved into the liquid, equilibrium is reached when the solute is dissolved. Hence, all the solute is completely dissolved in the first stage. There usually is sufficient time for this to occur in the first stage.
It is also assumed that there is ...