Leaching and Liquid-Liquid Extraction Flashcards
Extractor that has been used effectively in antibiotics and vitamins recovery
Podbielnak Extractor
In a mixer-settler liquid-liquid extraction column, it comprises of a thin bed of substances of extended surface having high porosity that helps in increasing the bubble size entering the settler and the settling rate of the bubbles.
Coalescer
Extractor used to treat radioactive nuclear waste.
Pulsed column extractor
Extractor used for the extraction of uranium and gold ores in mineral processing.
Pachuka Tanks
Extractor used for the extraction of oil from oilseed.
Bollman extractor
Solvent used in leaching sugar from sugar beets.
Hot water
Commonly used liquid solvent in vegetable oil industry.
Hexane
Basis of the liquid-liquid extraction
Solubility difference
Extracting solvent is cheaply and abundantly available
In a counter-current extractor, what happens to the extraction efficiency as the axial mixing increases?
It decreases since undesired components are also extracted (extraction is most efficient is the solvent gently circulates the solids).
In multistage extraction or washing, what configuration is more efficient compared to using a single large extraction?
Repeated small washing (to save solvent cost)
Distillation recovers the target solute and the solvent, which can be recycled to another extractor. Why does the solvent used in liquid extraction should not have high latent heat of vaporization?
Its recovery cost by distillation may be prohibitively high since more energy is required for solvent with high latent heat.
Why do viscous liquid components not advisable to use in liquid-liquid extraction?
Mass transfer is low in viscous fluids, resulting in low extraction efficiency.
In counter-current liquid extractor like the pulsed-liquid columns, how were the two liquids introduced in the column?
The lighter liquid is pumped from the bottom to top at any desired rate.
The heavier liquid is introduced at the top and flow to the bottom via gravity.
Note: Heavier liquid is not pumped as it requires greater power (higher operation cost)
When the solvent dissolves very little solute, then ______.
large quantity of solvent is required to extract the solute
Leaching of coarse solid lumps
Percolation
