Lecture No 52_Description for Equipment for Leaching & Extraction.ppt

This describe the equipment used in Extraction

1. Lecture No: 52
DESCRIPTION OF EQUIPMENT
FOR LEACHING AND EXTRACTION

2. METHODS OF OPERATION
Leaching systems are distinguished by:
1.Operating cycle (batch, continuous, or multi-batch
intermediate)
2.Direction of streams (concurrent, countercurrent, or
hybrid flow)
3.Staging (single-state, multistage, or differentia-stage)
4.Method of contacting (sprayed percolation, immersed
percolation, or solids dispersion)
Meaning of Word ‘PERCOLATE’:
To move gradually through a surface containing tiny holes or spaces.
(Source: Oxford Advanced Dictionary)
Example: Water has percolated through the rocks

3. Classification of Leaching Equipments
Leaching Equipments are classified into two categories:
Equipments in which LEACHING
is accomplished by percolation
Equipments in which particulate
are dispersed into a liquid and
subsequently separated from it.
1 2
Aim
1. Leaching by percolation through stationary solid beds
2. Moving-bed leaching
3. Dispersed-solid leaching

4. Leaching by percolation through stationary
solids beds
 Equipment description
 Operation description
 Single Stage Operation
 Extraction Battery
 Diffusion Battery
Solvent In
Solid Bed
Perforated
False Bottom
Solvent Out
(With dissolved solute)
Extraction Battery

5. Moving-bed leaching
 Equipment description
 Operation description
Wet flake
hopper
Pure Solvent Half Miscella
Dry flakes
Full miscella
Paddle Conveyor
Bollman Extractor