This document summarizes a lecture on solvent extraction and separation techniques presented by Dr. Vandana B. Khobragade. The lecture covered topics including types of solvent extraction such as solvating, cationic exchange, anionic exchange, and chelating extraction. Specific techniques discussed included Soxhlet extraction, classification of separation processes, and types of separation processes like centrifugation, filtration, distillation, and membrane separations. Novel separation techniques like supercritical fluid extraction and ion exchange chromatography were also summarized.

1. ONLINE VALUE BASED COURSE ON
“CHEMICAL HANDLING AND LABORATORY
SAFeTY”
FOR UG AND PG STUDENTS OF CHEMISTRY

2. Organized By
Department Of Chemistry
Shri Shivaji Science College Amravati

3. Lecture
On
“ SOLVENT EXTRACTION
AND
SEPERATION TECHNIQUES”
Presented By
Dr. Vandana B. Khobragade
Assistant Professor

4. CONTENT
 Introduction
 Solvent Extraction
 Types of Solvent Extraction
 Soxhlet Extractor
 Applications
 Separation techniques
 Classification of Separation Process
 Types of separation processes
 Novel separation techniques

5. Solvent Extraction
• Solvent Extraction , also known as liquid-liquid extraction ,
is a method to separate compound based on their relative
solubilities in two different immiscible liquids , usually water
and an organic solvent.
• Extraction involves the separation of medicinally active portions of
animal or plant tissues from the inactive components through the
use of selective solvents.
• The solvent extraction was first developed as a tool of
analytical chemistry.
• Every metallic element of the periodic table could be virtually
separated by this process.
• Back in 1940’s , S.E. was primarily used to separate nuclear and
rare earth elements.
• However, availability of inexpensive and effective reagents led to
the establishment of large scale S.E. processes for extraction of
non-ferrous metals from hydrometallurgical leach liquors.

6. • Solvent Extraction, consists of transferring one (or
more) solute(s) contained in a feed solution to
another immiscible liquid(solvent).
• The solvent that is enriched in solute(s)is called Extract &
the feed solution that is depleted of solute (s) is called
Raffinate

7. Types of Solvent Extraction
SOLVATING EXTRACTION
CATIONIC EXCHANGE
ANIONIC EXCHANGE
CHELATING EXTRACTION

8. 1.SOLVATING EXTRACTION
• Solvent used
Tri Butyl Phosphate (TBP)
Tri Octyl Phosphine Oxide(TOPO)
Methyl Iso Butyl Ketones(MIBK)
• Application:
Extraction/Separation of Lead , Zinc , Uranium, Iron ,
Cadmium, Hafnium , Zirconium & Plutonium.

9. 2. CATIONIC EXCHANGE
• Solvents used
1)Di-2-ethylhexy Phosphoric Acid(D2EHPA)
2) Naphthenic Acid
3) Versatic Acid
• Application:
Extraction/Separation of Copper, Zinc,
Nickel, Cobalt, Silver

10. 3. ANIONIC EXCHANGE
• Solvents used ,
1) Primary Amines(RNH2)
2) Secondary Amines(R2NH)
3) Tertiary Amines(R3N)
• Application:
Extraction/Separation of Uranium,
Thorium, Vanadium, Cobalt.

11. 4.CHELATINGEXTRACTION
• Solvent used ,
1) Lix63 , Lix65
2) Kelex 100
• Application:
Extraction/Separation of Copper , Nickel, Cobalt.

12. SOXHLETAPPARATUS
• It was invented in 1879 by a scientist named Franz von
Soxhlet.
• ASoxhlet extractor is lab equipment designed for processing
certain kinds of solids.
• These devices allow for continuous treatment of a sample with a
solvent over a period of hours or days to extract compounds of
interest.
• Typically, a Soxhlet extraction is only required where the
desired compound has a limited solubility in a solvent, and the
impurity is insoluble in that solvent.
• It has been frequently used for the extraction of lipids in
agricultural chemistry.

13. SOXHLETAPPARATUS
1: Stirrer bar
2: Still pot (the still pot
should not be overfilled
and the volume of solvent
in the still pot should be
3 to 4 times the volume of
the soxhlet chamber)
3: Distillation path
4: Thimble
5: Solid
6: Siphon top
7: Siphon exit
8: Expansion adapter
9: Condenser
10:Cooling water in
11:Cooling water out

14. SOXHLETAPPARATUS

15. Selection of Organic Solvent
 High extraction capacity
 Selectivity
 Easily Stripped
 Immiscible in aqueous phase
 Sufficient density difference
with the aq. phase
 Low Viscosity
 Non toxic
 Non explosive
 Cheap
Generally used Solvents
Water
Ether
Chloroform
Aliphatic alcohols
Glycerine

16. Today the process of Solvent Extraction is widely applied in
miscellaneous fields of Science and Technology
Analytical Chemistry
Extraction of Rare-earths &PGM
Waste water treatment
Mineral oil treatment & dewaxing
Food industry(essential oilextraction)
Perfume industry(fragrance extraction)
Pharmaceutical industry
Application

17. INTRODUCTION of separation techniques
 Separation is simply the process of dividing material into its
component parts.
 Separation techniques are essentially methods of purification.
 Homogeneous and heterogeneous mixtures can
be separated into their components by several physical methods
 The choice of separation techniques is based on the type of
mixture and difference in the chemical properties of the
constituents of a mixture.

18. Based on the nature or physical mechanism of separation, various
separation processes can be classified into,
1)Mechanical separations: separations based on size and/or density
differences of different components in a mixture, for separation of
solid from liquid (e.g. filtration and centrifugation).
2)Diffusional separations (mass transfer operations): separations
based on molecular movement toward a favourable phase, for
separation of dissolved components (e.g. distillation, absorption,
extraction). (“Mass transfer is the transfer of solute molecules from
one point to anther or from one phase to another.”)
3)Membrane separations: use of a semipermeable membrane to
separate molecules with difference in size or some other properties.
CLASSIFICATION OF SEPARATION PROCESS

19. VARIOUS TYPES OF SEPARATION PROCESSES ARE:
 Separating Funnel
 Centrifugation
 Evaporation
 Crystallization
 Magnetic separation
 Filtration
 Sedimentation
 Distillation
 Membrane Separations
 Chromatography

20. Separating Funnel:
A separating funnel is used for the separation of components of a
mixture between two immiscible liquid phases. One phase is the
aqueous phase and the other phase is an organic solvent. This
separation is based on the differences in the densities of the
liquids. The liquid having more density forms the lower layer
and the liquid having less density forms the upper layer.
Applications:
 To separate a mixture of oil and water.
 To separate a mixture of kerosene oil
and water.
SEPARATING FUNNEL

21. Centrifugation:
centrifugation is the process of separation of insoluble materials
from a liquid where normal filtration does not work well. The
centrifugation is based on the size, shape, and density of the
particles, viscosity of the medium, and the speed of rotation. The
principle is that the denser particles are forced to the bottom and
the lighter particles stay at the top when spun rapidly.
CENTRIFUGATION

22. The apparatus used for centrifugation is called a centrifuge. The
centrifuge consists of a centrifuge tube holder called rotor.
Classification of Centrifuge
1. Low speed Centrifuge
2.Hight Speed Centrifuge
3. Ultra Centrifuge

23. Evaporation :
The general definition of evaporation is the loss or disappearance
of a liquid due to vaporization. In the process industry,
evaporation process is to concentrate a solution (of a non-volatile
solute) or to separate a volatile solvent from a non-volatile solute,
by vaporizing and removing part of the solvent (mostly water). In
an evaporation process, the liquid solution is usually heated to
boiling by steam.
EVAPORATION

24. Magnetic separation is a process in which magnetically
susceptible material is extracted from a mixture using a magnetic
force. This separation technique can be useful in mining iron as it
is attracted to a magnet.
MAGNETIC SEPARATION

25. Filtration is the mechanical separation of solid particles from a
fluid by passing the fluid through a filtering medium,on which
the solids are deposited. The most common filtering medium is
fabric cloth with strong mechanical properties.
Filtration is any of various mechanical, physical or biological
operations that separate solids from fluids (liquids or gases) by
adding a medium through which only the fluid can pass.
FILTRATION

26.  Hot filtration method is mainly used to separate solids from a
hot solution.
 Cold Filtration method is the use of ice bath in order to rapidly
cool down the solution to be crystallized rather than leaving it
out to cool it down slowly in the room temperature
 Vacuum Filtration technique is most preferred for small batch
of solution in order to quickly dry out small crystals. This
method requires a Büchner funnel, filter paper of smaller
diameter than the funnel, Büchner flask, and rubber tubing to
connect to vacuum source.

27. Sedimentation
Sedimentation relies on gravity to separate suspended solids
from fluids. It is accomplished by decreasing the velocity of the
fluid being treated to a point below which the particles will no
longer remain in suspension. When the velocity no longer
supports the transport of the particles, gravity will remove them
from the flow.
SEDIMENTATION

28. DISTILLATION
• Distillation is a process of separating the component or
substances from a liquid mixture by selective evaporation and
Condensation.
• The application of distillation can roughlybe divided in two
groups : laboratory scale, industrial distillation.

29. The main difference between laboratory scale distillation and
industrial distillation is that laboratory scale distillation is often
performed batch-wise, whereas industrial distillation often occurs
continuously.
Type of distillation
 Simple distillation.
 Fractional distillation.
 Steam distillation.
 Vacuum distillation.

30. Membrane Separations
Separation by the use of membranes has been increasingly used in
the chemical and bioprocess industry. In membrane separation, the
membrane acts as a semipermeable barrier which only allows for
certain molecules to pass through it
1. Ultrafiltration
Ultrafiltration (UF) is used for the separation of macromolecules
(polymers) such as proteins, with molecular weights 1000-50,000.
It is a high-pressure membrane process, up to 145 psi (10 bar).
MEMBRANE SEPARATION

31.  Molecular weight of particles : 103
- 105 Pore size: 20 –
1000A0
 Pressure: 6 – 8 atm.
 Transport Mechanism: Convection (main) + diffusion
 Example: Filtration of protein, Red blood cells,
polymers, etc.

32. 2. Reverse osmosis
Osmosis (as a natural phenomenon) is the flow (diffusion) of water
molecules through a semi-permeable membrane from low-solute
concentration side to high-solute concentration side of the
membrane.
Reverse osmosis is the use of high pressure to force the flow of
solvent (e.g., water) molecules in the reverse direction of osmotic
pressure. Applications of reverse osmosis include: water
purification, sterilization, dewatering and the separation of
components in a mixture

34. The separation processes those are not conventional and routine
fall under this category. Therefore, some of the equilibrium and
rate governed separation processes are included this.
Some of the processes are identified as,
(i) Membrane based separation processes
(ii) Chromatographic separation processes
(iii) Supercritical Fluid Extraction
(iv) Electric field assisted separation processes
(v) Ion exchange processes, etc.
NOVEL SEPARATION PROCESSES

35.  Chromatographic Separation Processes:-
i. Chromatography is an extremely powerful analytical tool for
separating and analyzing complex mixture.
ii. Different types of chromatographic techniques such as column
chromatography, TLC, paper chromatography, and gas
chromatography.
Fig:- Chromatography Separation Technique

36. Applications:
 To separate colors in a dye.
 To separate pigments from natural colors.
 To separate drugs from blood.

37.  Paper chromatography is one of the important
chromatographic methods. Paper chromatography uses paper as the
stationary phase and a liquid solvent as the mobile phase. In paper
chromatography, the sample is placed on a spot on the paper and
the paper is carefully dipped into a solvent. The solvent rises up the
paper due to capillary action and the components of the mixture rise
up at different rates and thus are separated from one another.
Fig:- Paper Chromatography

38. Supercritical Fluid Extraction
 Supercritical Fluid Extraction (SFE) is the process of separating
one component (the extractant) from another (the matrix)
using supercritical fluids as the extracting solvent. Extraction is
usually from a solid matrix, but can also be from liquids.
 Carbon dioxide (CO2) is the most used supercritical fluid,
sometimes modified by co-solvents such as ethanol or methanol.
Extraction conditions for supercritical carbon dioxide are above
the critical temperature of 31 °C and critical pressure of 74 bar.
 The system must contain a pump for the CO2, a pressure cell to
contain the sample, a means of maintaining pressure in the system
and a collecting vessel.

39.  The liquid is pumped to a heating zone, where it is heated to
supercritical conditions. It then passes into the extraction vessel,
where it rapidly diffuses into the solid matrix and dissolves the
material to be extracted. The dissolved material is swept from the
extraction cell into a separator at lower pressure, and the extracted
material settles out. The CO2 can then be cooled, re-compressed
and recycled, or discharged to atmosphere.

40.  Ion Exchange Chromatography
The most popular method for the purification of proteins. IEC can
be divided into two different sub types.
a. Cation exchange chromatography positively charged molecules
are attracted to a negatively charged.
b. Anion exchange chromatography, negatively charged molecules
are attracted to a positively charged.
After the molecule of interest has been adsorbed, the column
is washed to remove any residual unbound species from the solid
phase.

41. Application :
 Used for biopurification
 Used in downstream processing platforms.

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