Solid – Liquid Extraction ( Leaching )
OUTLINES
Introduction to leaching.
Leaching equipments.
Principles of Continuous
Countercurrent Leaching.
How to CALCULATE material balance and number of ideal stages for multistage leaching.
INTRODUCTION TO LEACHING
Leaching / solid extraction – methods of removing one constituent from a solid by means of a liquid solvent.
Examples:
1. Making coffee from ground coffee beans and tea from tea leaves.
(The complex mixture of chemicals that give coffee and tea their odor, taste, and physiological effects are leached from the solid by hot water)
2. Extraction of oil from soybean flakes
3. Extraction of coconut milk from coconut
The amount of soluble material removed is often greater than in ordinary filtration washing.
The coarse, hard or granular feed solids may disintegrate in pulp or mush when their content of soluble material is removed.
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