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EFFECT OF FROTHER

ON THE SELECTIVITY OF FLOTATION

Claudio Acua and Mario Gamboa

Procemin 2011 Claudio Acuacacuna@ucn.cl

em ca ng neer ng epartment, n ves a at ca e orte

S. Ramachandra Rao

Department of Mining and Materials Engineering, McGill University

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INTRODUCTION: Flotation Mechanisms

entrainmentfine particles carried by water

true flotationHydrophobic particles collecteselectively by bubbles

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INTRODUCTION: Flotation

entrainmentfine particles carried by water(hydrophobic or hydrophilic)

Positive effectin case of valuable mineral

(increase recovery) Negative effectHydrophilic or not valuable(grade reduction)

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Water recovery and entrainment

frother

mg/L

%

solids5 166 27

2.5 1630

40

5m

QUAR

TZ

,%

Adapted from, Trahar, Int. J. Min. Proc. 8:289-327, 1981

10 20 30 40 50 60

10

20

WATER RECOVERY, %

RECOVERY

-

slope ~ 0.7

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Water recovery and entrainment

Controlling water recoveryentrainment can be controlled

bubble Hydrophobic particleHydrophilic particle

"water layer"

Frother molecular structure

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Water recovery and gas holdup

0.3

0.4

0.5

,cm

/s

Pentanol

Hept, Hex , MIBC,DF200

Octanol, Ethoxy, DF250F150

0

0.1

0.2

10 15 20 25 30 35 g, %

Jwo

Adapted from: Finch, Gelinas, Moyo. Min. Eng. 19: 726-733, 2006

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Water recovery and entrainment

Can be controlled either by manipulating frothertype/concentration or varying gas hold-up

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Evaluate at pilot scale the effect of frother typeon hydrophilic particles.

Establish operating recommendations to control

Objectives

en ra nmen roug ro er se ec on

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Experimental set up

Pilot column (3 m height alto and 7,5 cm )

Differential pressure transmitters

Peristaltic pumpsMass flow meter

Quartz / ta water s stem:

Solid content 10% (only silica)

Particle size (100% under 80 microns)

Frothers (Cytec):

MIBC (methil isobutil carbinol)

2-Ethilhexanol

Polyglycol blend (OREPREP F 570)

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Results: Effect of frother concentration

2-Ethilhexanol, froth depth 7cm.

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Results Jwo: Effect of frother type

15, 30, 50 ppm

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Effect of frother type on entrainment

6

8

10

12

recovery,

%

0

2

4

8 9 10 11 12

Gas holdup, %

Qurz

t

Polyglycols, 80 ppm

MIBC 80 ppm

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Effect of frother type and water layer

How does frother molecular structuredetermine the amount of water carried to the

froth?

from, J. Finch, Short Course, 2005

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Conclusions (Summary: Moyo &Trahar)

Each frother has a characteristic Jwo (superficialwater velocity) vs. gas holdup curve.

The superficial water velocity in the concentrate isassociated with the recovery of hydrophilic particles

.

Since frother type affects the amount of waterreported to the concentrate, the recovery of

hydrophilic particles is also affected.

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Conclusions

The water recovery and the recovery of hydrophilicparticles is related to the frother structure andmolecular weight.

The results suggest that frother type could influencethe rade-recover curve. The more water the

frother carries to the concentrate, the more theflotation by entrainment and lower the grade for agiven recovery.

Frother type appears to be another variable toimprove flotation selectivity

.

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Acknowledgments

CONICYT, Fondecyt Project 11090269.

CYTEC Chile Limitada, providing reagents andtechnical support.

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RESULTADOS

%Re finos v/s %Re agua