3. 1 Definition Of leaching.
2
Example Of Leaching Process.
3
Principle Of Leaching Process.
4
Uses Of Leaching
4. Is a process of mass transfer that
occurs by extracting a substance from
a solid material that has come into
contact with a liquid.
In leaching, the liquid is very important as it
facilitates the ability to remove (or extract) a
given substance from a solid matrix (i.e.
material).
5. A simple example is the making of green tea.
Now, relate the component used in the green tea to our
definition.
1- the green tea bag is our solid mixture.
2- the green to be extracted is our desired substance.
3- and the hot water is our liquid source.
6.
7. 1- to add hot water to a cup.
2- and now, steep the green tea bag into it.
3- not only the color changes but also the green is extracted from the
bag into the cup.
4- and after steeping some the take a sip from the cup there is not only
hot water but a delicious green tea.
Making tea is an ideal example of how leaching works.
The process goes like that:
8. Leaching can be batch, semi batch, or continuous. It usually
operates at an elevated temperature to increase the solubility of
the solute in the solvent.
Feed to leaching system typically is solid, consisting of basically
insoluble carrier material and a (Usually desirable) soluble
compound. The feed usually must be prepared by grinding or
chopping. It is then mixed with a liquid solvent.
The desired material dissolves (to some extent) and so leaves when
the liquid is drawn off as overflow.
9. Typical uses include:
In the metals industry for removing mineral from ores (acid
solvents).
Int the sugar industry for removing sugar from beets (water is
solvent).
In the oilseeds industry for removing oil from soybeans, etc.
(hexan or similar organic solvents).
