Leaching triangular diagrams

FIG. 18 81 Composition diagrams for leaching calculations a) right-triangular diagram (h) modified Ponchon-Savarit diagram,... 

Equilibrium relations in leaching usually are simpler than in liquid-liquid equilibria, or perhaps only appear so because few measurements have been published. The solution phase normally contains no entrained solids so its composition appears on the hypotenuse of a triangular diagram like that of Example 14.8. Data for the raffinate phase may be measured as the holdup of solution by the solid, K lb solution/lb dry (oil-free) solid, as a function of the concentration of the solution, y lb oil/lb solution. The correspond-... 

Triangular diagrams, such as Fig. 10.5-1, can be uned to cany am equilibrium-stage leaching calculations in the same way that analogous calculations are ceiried out for ternary liquid-liquid extractions.1 3 Other coordinate systems, for example, Janecke coordinates, can also be used for such calculations. 

The sohd matrix consists of macropores (voids between particles of the bed) and micropores (voids within the particles). The transfer compound B (solute) is typically concentrated in the micropores. During leaching process the solvent penetrates into all pores and mixes with substance B in the micropores. At equihbrium state the hquid in the macropores has the same concentration as the liquid in the micropores. Therefore, the ratio of solute to solvent B/L ) has the same value in the raffinate and the extract. In this case, all tie lines, which represent the distribution equilibriiun, emerge from the S -comer of the triangular diagram in Fig. 6.1-3. Supposed that only the liquid in the macropores can be removed from the matrix by... 

Apply the triangular diagram analysis to leaching problems with variable flow rates. 

C4. Develop the procedures for single-stage and cross-flow systems for leaching using a triangular diagram... 

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