Crystallization process chemistry

crystallization phenomenon

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:- Supersaturated Nucleation. 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:- Purification Of Drug. Purification Of Seawater. Separation Of Alum Crystals. In Pharmaceutical Industries.

7. TYPES OF CRYSTALLIZATION There most frequently applied types of crystallization are following:- Evaporative Crystallization. Cooling Crystallization. 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:- Any type of mixture can be separated. Any quantity of mixture can be separated. Wider choice of mobile phase. Automation is possible. DISADVANTAGE:- Time consuming method. More amount of solvents are required, which are expensive. 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 _________________________________ Thank you