Total mass balance for Example

The final extract contains 40% of oil so the final overflow can be given by  

The final underflow will contain 8% of total oil. Therefore, total oil in final 

There are 85 Kg of soUd in the underflow which will retain 0.4 + 85 = 34 kg of solution. Therefore, total underflow is given by  

Solvent in the final underflow = 34-1.2= 32.8 kg. Solvent in the extract= 20.7 kg. Therefore, total solvent is given by  

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. 

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