Crystallization is the process of obtaining crystals of a pure substance from its hot, saturated solution. It involves a physical change as no new substances are formed - only a change from liquid to solid state. Crystallization is used to purify naturally occurring impure substances and obtain them in pure crystalline form. There are three main steps: supersaturation of the solution, nucleation where crystal seeds form, and crystal growth. Common applications include purification of drugs, seawater, and in separating substances like alum in industries. Types of crystallization include evaporative, cooling, and reactive crystallization.

1. CRYSTALLIZATION

2. INTRODUCTION
The process of obtaining crystals of a soluble substance from its hot saturated
solution is called crystallization.
Crystallization is only a physical change because no new substances are formed during
the process-it involves only a change in physical state.
Crystallization is used to obtain pure substances from naturally occurring impure
substances.

3. DEFINATION
• Crystallization can be defined as a solidification of
a liquid substance into highly structured solid
whose atoms or molecules are placed in a well
defined three dimensional crystal lattice.
• The smallest individual part of crystal is called
unit.
• The crystal is made up of million of such unit
cells.

4. CRYSTALLIZATION PROCESS
• Crystallization occur in three major steps which are following:-
1. Supersaturated
2. Nucleation.
3. Crystal growth.

5. The impure solid is
dissolved in solvent.
The solution is heated
to evaporate most of
the solvent. The hot solution is
allowed to cool, the solid
appears as pure crystals.
The cold solution is poured off to
obtain the crystals. The crystals
my be dried by pressing them
between shsets of filter paper.

6. APPLICATIONS
• Following are some of the applications of crystallizations:-
1. Purification Of Drug.
2. Purification Of Seawater.
3. Separation Of Alum Crystals.
4. In Pharmaceutical Industries.

7. TYPES OF CRYSTALLIZATION
• There most frequently applied types of crystallization are following:-
1. Evaporative Crystallization.
2. Cooling Crystallization.
3. Reactive Crystallization.

8. EXAMPLES
• Ice and snow flakes are great
examples of crystallization of
water.
• Another interesting example is the
crystallization of honey.When bees
regurgitate honey into the
honeycomb, it is liquid.

9. Advantages & Disadvantages
• ADVANTAGES:-
1. Any type of mixture can be
separated.
2. Any quantity of mixture can be
separated.
3. Wider choice of mobile phase.
4. Automation is possible.
• DISADVANTAGE:-
1. Time consuming method.
2. More amount of solvents are
required, which are expensive.
3. Automation technique makes
complication.

10. Conclusion
• Basic concept of crystallization like supersaturation metastable crystallization
zone, crystallization nucleation and growth were discussed
• Nano particles can be produced from these process at higher supersaturation
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