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4. 1.Hydraulic Washing
3.Electromagnetic
separation
4.Leaching
Concentration
of Ore
2.Froth flotation

5. 1.Hydraulic
Washing
Some Important Notes

6. Useful for ores of heavy metals like Sn, Pb, Fe2
Light ores can not be concentrated3
Basic principle is density difference1
1.Hydraulic Washing

7. Crushed Ore
Jet of
water
1.Hydraulic Washing

8. Crushed Ore
Jet of
water
Procedure :
➢Jet of water is passed from
one side
➢Crushed ore is poured from
Hydraulic classifier
➢ Heavy ore particles gets
settled down
➢Lighter gangue particles
are washed away
1.Hydraulic Washing

9. FROTH FLOTATION
PROCESS
Some Important Notes

10. Used for sulphide ores of Cu, Zn, Fe and Pb1
Sulphide ore is wetted by oil and moves
upward in the form of froth
2
2.Froth flotation
Copper glance (Cu
2
S)
Iron pyrite (FeS
2
)
Zinc blend (ZnS)
Galena ( PbS )

11. Gangue particles are wetted by water and
settles down at bottom
3
2.Froth flotation
➢Why does S particle are wetted by oil not by water ?

Ans. ‘S’ has large size thus poor hydration

12. 2.Froth flotation

13. 2.Froth flotation
Procedure :
➢Finely powdered ore is mixed with water and pine oil
➢Mixture is agitated with compressed air
➢Ore particles rise to the surface along with froth
➢Gangue being wetted by water remain in water below the foam

14. Main parameters of
Froth Flotation

15. Potassium ethyl xanthate : To Enhance the non-wettability
of the mineral particles

Main parameters of Froth Flotation
❖Frothers
Pine oil or Eucalyptus oil :Oil should be less dense than H
2
O


❖Collectors

16. Main parameters of Froth Flotation
❖Froth stabilizers
i. Aniline,
NH
2
:

OH

CH
3

ii. Both the compounds are capable to show H-bonding
Cresol

17. Used when mixture of sulphide ore is present

NaCN, Na
2
CO
3

Example Mixture of galena ( PbS ) and Zinc blende ( ZnS )
PbS + NaCN
ZnS + NaCN Na
2
[Zn(CN)
4
]

Sodium tetra cyano zincate

❖Depressant
No reaction

18. PbS + NaCN
ZnS + NaCN Na
2
[Zn(CN)
4
]

Sodium tetra cyano zincate

Follow EAN rule

No reaction
➢This complex is wetted with water and prevented coming into the froth

19. ELECTROMAGNETIC
SEPARATION
Some Important Notes

20. Used if one of the ore or impurity is magnetic1
Magnetic particles are attracted and fall
nearer the magnetic roller.
2
3While non-magnetic particles fall
away from the roller
3.Electromagnetic separation

21. 3.Electromagnetic separation

22. LEACHING
Some Important Notes

23. Aluminium

Silver or Gold

Low grade copper

1

2

3

Leaching

When metal is more soluble than impurities present in its ore.

24. Leaching

Ag
2
S + 4NaCN → 2Na[Ag(CN)
2
] + Na
2
S

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