solvent extraction By Dalpat singh

1. SOLVENT EXTRACTION
PRESENTED BY
DALPAT SINGH
PG-1
LACHOO MEMORIAL COLLEGE, JODHPUR
Submitted to-
Dr. Rekha sharma

2. SOLVENT EXTRACTION :-
• Introduction
•Working

3. INTRODUCTION-
• Solvent extraction (liquid-liquid extraction) is used to separate a solute
from a liquid (mostly aqueous solution) by an insoluble or immiscible
solvent (mostly organic solution).
• Separation is achieved when the solute is transferred from original
solution to the other liquid solution.
• Example:- recovery of acetic acid from aqueous solution by Ethyl
Acetate

4. MOSTLY THE SOLVENT EXTRACTION SYSTEM CONTAINS THREE
COMPONENTS:- (1). CARRIER SOLVENT (2).
EXTRACTING SOLVENT (3). SOLUTE
In this process, solvent rich product is called Extract And the
residual liquid from which solutes has been removed is the
Raffinate.

5. NERNST DISTRIBUTION LAW :-
This law states that the rate of migration of solute from one solution to
another solution is equal.
Or we can say that The concentration ratio of solute in two solvents is
constant at equilibrium.
(Ether)Suppose we dissolve a solute X in
aqueous and organic solvent then
the rate of migration of solute X is
equal from aqueous to organic or
organic to aqueous solvent.
Distribution coefficient KD = Corganic/C aqueous
Example:-

6. Limitations and conditions of Nernst distribution law:-
1. Constant temperature required :- Solubility depends on the
temperature so it should be constant.
2. Dilute Solution :- concentration of the solute must be low.
3. Same Molecular state :- Association or dissociation of solute in any
of solvent isn’t allowed.
4. Solute Reactivity:- Solute should not show any reaction with any of the
solvent.
5. Immiscibility of solvent :- The two solvent must be immiscible.

7. Types of solvent extraction :-
1. Simple extraction
2. Multiple extraction
• Simple extraction :- The Process of extraction in which total amount
of extracting solvent is carried in one successive step , called Simple
extraction.
Suppose ‘A’ gram of solute is in V1 mL of aqueous solvent and we add V2 mL
of organic solvent into it to extract solute.
If ‘x’ gram solute is extracted then according to distribution law-
Concentration of solute in organic solvent
Concentration of solute in aqueous solvent
= Kd

8. • Multiple extraction:- Extraction process in which small portion
of extracting solvent is used in two or more successive steps is
called multiple extraction
Suppose ‘A’ gram of solute is in aqueous solvent(100mL) and we add Organic
solvent(50mL) to extract it. In first step we add half volume of extracting solvent and if
‘A/2’ gram of solute extracted then (A/2) gram is still present in aqueous solvent.
Now we add other 50mL of organic solvent to complete the extraction
of solute. If ‘A/4’ gram of solute is extracted then
The total amount of solute extracted is equal to 75% of A gram.
Note:- Multiple extraction is
more efficient than the simple
extraction.

9. Methodology of solvent extraction:-
1. Batch Extraction (Separating funnel)
2. Back extraction
3. Continuous extraction
4. Counter current extraction (craig‘s apparatus)
5. Synergistic extraction
Craig‘s Apparatus

10. Advantages of solvent extraction:-
• It is simple,rapid,clean and convenient method.
• It is equally applicable on trace amount level or large amount
level of materials.
• It is widely used technique to separate the compounds of
organic systems.
• Suitability over a wide range of scale operations.
• We can extract metal ions and chilates also using synergistic
extraction.

11. Disadvantages of solvent extraction:-
• Tediousness process sometimes.
• In this technique, there is need to use high purity
solvent which make this expensive.
• Low selectivity of extracting solvents.
• In most of methods, handling samples with large
volumes is difficult.
• In synergistic extraction, formation of complex which
prevents the extraction is a problem.

12. Applications of Solvent extraction:-
1. Extraction of uranium and plutonium from nuclear spent fuel => to
extract uranium and plutonium,dissolve irradiated fuel into aqueous
nitric acid then mix it with the organic solvent (30% tri butyl phosphate
in kerosene).
Uranium and plutonium is transferred to organic
phase and after separating both phases. Treat the organic phase with
ferrous suphamate to separate uranium and plutonium. Plutonium is
present in aqueous solvent and uranium is in organic phase which is
extracted by back extraction.
2. Extraction of metal and chilates by forming complexes.
3. This process used to separate heat sensitive liquid solute.
4. It is used to recovery of antibiotics and proteins.
5. It is used to recover high boiling point components in inorganic industry.

13. Thank you.