Claudio Acuna
-
Upload
richard-gutierrez -
Category
Documents
-
view
225 -
download
0
Transcript of Claudio Acuna
-
7/30/2019 Claudio Acuna
1/18
EFFECT OF FROTHER
ON THE SELECTIVITY OF FLOTATION
Claudio Acua and Mario Gamboa
Procemin 2011 Claudio [email protected]
em ca ng neer ng epartment, n ves a at ca e orte
S. Ramachandra Rao
Department of Mining and Materials Engineering, McGill University
-
7/30/2019 Claudio Acuna
2/18
INTRODUCTION: Flotation Mechanisms
entrainmentfine particles carried by water
true flotationHydrophobic particles collecteselectively by bubbles
-
7/30/2019 Claudio Acuna
3/18
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)
-
7/30/2019 Claudio Acuna
4/18
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
-
7/30/2019 Claudio Acuna
5/18
Water recovery and entrainment
Controlling water recoveryentrainment can be controlled
bubble Hydrophobic particleHydrophilic particle
"water layer"
Frother molecular structure
-
7/30/2019 Claudio Acuna
6/18
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
-
7/30/2019 Claudio Acuna
7/18
Water recovery and entrainment
Can be controlled either by manipulating frothertype/concentration or varying gas hold-up
-
7/30/2019 Claudio Acuna
8/18
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
-
7/30/2019 Claudio Acuna
9/18
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)
-
7/30/2019 Claudio Acuna
10/18
Results: Effect of frother concentration
2-Ethilhexanol, froth depth 7cm.
-
7/30/2019 Claudio Acuna
11/18
Results Jwo: Effect of frother type
15, 30, 50 ppm
-
7/30/2019 Claudio Acuna
12/18
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
-
7/30/2019 Claudio Acuna
13/18
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
-
7/30/2019 Claudio Acuna
14/18
-
7/30/2019 Claudio Acuna
15/18
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.
-
7/30/2019 Claudio Acuna
16/18
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
.
-
7/30/2019 Claudio Acuna
17/18
Acknowledgments
CONICYT, Fondecyt Project 11090269.
CYTEC Chile Limitada, providing reagents andtechnical support.
-
7/30/2019 Claudio Acuna
18/18
RESULTADOS
%Re finos v/s %Re agua