McCabe-Thiele procedure for Example

In extraction, the driving force is the difference between the concentration of the component being transferred, the solute, at the solid interface and in the bulk of the solvent stream. For liquid-hquid extraction, a double film must be considered, at the interface and in the bulk of the other stream. 

The rate of change in quantity of solution, dw/dt is given by the following equation 

In the simple case of batch extraction from a solid in a contact stage, a mass balance on the solute gives the equation  

Example 7.2 In a pilot scale test using a vessel Inn in volume, a solute was leached from an inert solid axid the water was 75 percent saturated in 10 seconds. 

in a full-scale unit, 1000 kg of the inert solid containing, as before, 25 percent by mass of the water-soluble component, is agitated with 100m of water, how long will it take for all the solute to dissolve, assuming conditions are equivalent to those in the pilot scale vessel Water is saturated with the solute at a concentration of 3.0 kgjvn .  

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