ByAsmaa Saeed MohamedAmal Mohamed hussien

Esraa Zakria Kamel

Alexandria UniversityFaculty of Engineering

Liquid-liquid Extraction is a mass transfer

operation (Diffusion Controlled Operations) in

which the feed is contacted with an immiscible

or partially immiscible solvent that exhibits

preferential affinity towards one or more of the

components in the feed (called the solute).

• the feed is called the raffinate

stream after it begins to

lose the solute.

• the solvent is called

the extract stream when

it leaves the contactor.

LLEProcess

Feed

Solvent

Extract

Raffinate

A sketch of the basic process

1. Agitated column.2. Rotating shaft.3. Rotating disc.4. Stator ring.5. Liquid distributor.6. Variable speed motor.7. Light phase storage

tank.8. Heavy phase storage

tank.9. Centrifugal pump.10.Control valve.

The volumetric mass transfer coefficient (K` = KA) of the

extraction of copper sulphate from water with naphthenic acid

in a recirculating batch rotating disc contactor was obtained

using the equation: CCV

KA

dt

dCe

s

tV

KA

CC

CC

se

eo

ln

CC

CC

e

eo

ln

which upon integration yields:

K` is determined by plotting vs. t.

K` (cm3/sec) is used instead of K (cm/sec) as the interfacial mass transfer area between the two phases could not be calculated.

• the volumetric mass transfer coefficient for rotation disc contactor decreasing with decreasing with increasing concentration of copper sulphate.

• the volumetric mass transfer coefficient of rotation disc extractor increasing with increase

of :

1- the disc rotational speed.

2- degree of disc roughness.

3- the concentration of naphthenic acid.