FLOTATION
frothers
Gflotation= Gfinal- Ginitial = [sg - (sl+ lg)] A
sg = sl+ lgcos 
when  = 0o, cos = 1, Gflotation = 0, no flotation
when  = 90o, cos = 0, G = -lg. full flotation
Thus, flotation reagents can be classified into
a)
collector (decreases G)
b)
frother (no or negligable change of G)
c)
depressor (increases G)
Role of frother
1. Gas dispersion
2. Froth formation
3. Speeding up flotation
4. Improving selectivity of flotation (by interaction with collector)
f
l
o
t
4
frother structure with depth
froth
pulp
frother structure
H. Khoshdast, A. Sam, Flotation Frothers: Review of Their Classifications, Properties and Preparation, The Open Mineral
Processing Journal, 2011, 4, 25-44 25, 1874-8414/11 2011
Other classifications of frothers
H. Khoshdast, A. Sam, Flotation Frothers: Review of Their Classifications, Properties and Preparation, The Open Mineral
Processing Journal, 2011, 4, 25-44 25, 1874-8414/11 2011
Neutral frothers applied in flotation
Laskowski, 1988 (with some modifications)
Group
1. aliphatic alcohols
a) linear
b) branched
c) with additional group
2. Cyclic
a) linear
b) branched
3. Aromatic
4. Alkoxy-hydrocarbons
5. Polyglycols
Frother
from amyl to decanol
iso-amyl
methyloisobutylocarbinol
diacetone
cyclohexanol
terpineol
cresols
xylenols
1,1,3-trietoxybuthane
R(X)nOH
R=H lub CnH2n+1
X=EO (ethylene oxide), PO (propylene oxide)
BO (butylene oxide) from 3 to 7
Other classifications of frothers
Class
Surface active
Property of aqueous
solution
Liquid-gas
interactions at
flotation
concentrations
Form colloidal
solutions (fatty acids Stronly reduce water
amine, sulfonates,
surface tension
sulfates)
Change aqueous
Form true solutions
surface tension
(alcoholes)
Froth/foam
Form two (foam) and
three (froths) phase
systems
Form two (foam) and
three (froths) phase
systems
Organic compounds
forming true solutions
(ethyl acetal, ethyl
diacetone)
Do not change
aqueous surface
tension
Form only three phase
system (froth)
Inorganic electrolyties
Increase surface
tension of water
Form weak foams and
strong froths with
hydrophobic particles
Surface inactive
Frothers classification (Lekki and Laskowski, 1974)
Properties of frothers
CMC
80
surface tenion, mN/m
As ton e t al., 1983
MIBC
60
40
20
CMC
0
0.1
1
10
100
frother concentration, mmol/dm 3
1000
a
b
c
MIBC – metyloizobutylokarbinol
CMC – critical micellization concentration
Collector ions can be present in aqueous solution as free
ions(a), premicellar species, (b) spherical micelles (c).
Structures appear with increasing surfactant concentration in
aqueous solution. Symbol o denotes ion appositively charged
to surfactant ion
Properties of frothers
CCC
4.0
Tucke r e t al., 1994
1.6
3.5
DF250
bubble size, mm
Sauter mean bubble size, mm
2
3.0
CCC95
2.5
2.0
1.5
1.0
0.5
bubble
coalescence
0.0
0
0.02
minimum bubble size
0.04
0.06
frother concentration,
0.08
mmol/dm3
MIBC
1.2
0.8
0.4
0.1
Las kow sk i, 2004
CCC
0
0
4
8
12
16
frother concentration, ppm
Data of Finch, J.A., Nesset, J., Acuna, C., 2008, Role of frother on bubble
production and behaviour in flotation, Miner. Eng., 21, 949–957. CCC95
denotes 95% in Sauter mean bubble size reduction compared to mean
bubble size in water only. Plotted by Kowalczuk, Ind. Eng.Chem. Res.,
2013
20
in flotation important is dynamic surface tension
Atrafi et al., 2012, Mineral Eng., vol. 36-38, 138-144
CCC vs frother dose
106
selectivity of flotation a
105
C1P3
104
C1P5
C1P7
C2P5
103
C2P3
C3P3
C3P5
102
C4P1
C4P3
C4P5
101
100
0
20
CCC
40
60
80
100
120
frother concentration, ppm
Relationship between flotation selectivity coefficient a and concentration of CxPy frother.
ppm = g/dm. Note location of CCC. Kowalczuk, Ind. Eng.Chem. Res., 2013
HLB (Hydrophobic - Lipophilic balanse)
HLB = 7 + hydrophilic groups – lipophylic groups
Hydrophilic groups
-O1.3
-OH (free)
1.9
-OH (sorbitan ring) 0.5
-SO4Na
38.7
-COOK
21.1
-COONa
19.1
-COOH
2.1
-SO3(H) (sulfonate) ~11
-tertiary amin
9.4
-ester (free)
2.4
Lipophilic groups
-CH, –CH2–, CH3–, =CH– 0.475
-(CH2-CH2-CH2-O–)
0.15
Application of surfactants depending on their HLB
HLB
Application
1.5-3
Antifoaming reagents
3,5-6
Emulsification reagents
4-10
Frothers
7-9
Wetting reagent s
8-18
Emulsifikation reagents (oil in water)
13-15
Detergents
15-18
Solubilization reagents
CCC vs HLB
209.71 HLB MW 
CCC95 
105.14  800HLB MW 
5.0
CCC95, mmol/dm3
4.0
Aliphatic alcohols
Polypropylene glycol alkyl ethers
Polypropylene glycols
Commercial
3.0
2.0
1.0
0.0
0.000
0.020
0.040
0.060
0.080
0.100
0.120
HLB/MW
Kowalczuk, Ind. Eng.Chem. Res., 2013
DFI and other
800
4.0
0.6
500
400
300
0.4
0.2
max, %
600
80
40
200
1-CCC, mmole/dm3
1-CCC
Jw, =25%, cm/s
DFI, s dm3/mmole
700
Jw.=25%
120
 max
3.0
2.0
1.0
DFI ( )
100
0
0.0
0
0.0
0
2
4
6
8
10
12
14
16
nCeff
Comparison of different frothers properties (DI, CCC, Jw) and ability to mechanical flotation max.
They are similar (Szyszka et al., 2008)
Quartz flotation in the presence of different frothers (Szyszka et al., 2008)
Drzymala, unpublished , 2013
a (100   )
r 
 a
a – selectivity coefficient of flotation
 – useful component recovery in concentrate
r – non-useful components recovery in tailing
recovery of non-Cu components in tailing, Sno, %
100
a=101.3
20 g/Mg
90
30 g/Mg
50 g/Mg
80
alfa-terpineol
70
fractionated flotation
60
LUBIN copper ore
lab. tests, rep. 174
50
70
80
90
Cu recovery in concentrate, S, %
100
Drzymala, unpublished , 2013
Propylene glycol ethers
CnPm
Polypropylene
glycols Pm
Zhang, W.,
Nesset, J.E.,
Rao, R., Finch,
J.A., 2012,
Minerals, 2,
208–227.
Commercial
Frother
properties
Aliphatic alcohols Cn
Frother family
Type
n
1-Propanol
1-Butanol
1-Pentanol
1-Hexanol
1-Heptanol
1-Octanol
2-Propanol
2-Butanol
2-Pentanol
2-Hexanol
2-Heptanol
2-Octanol
3-Pentanol
3-Hexanol
Propylene glycol methyl ether
Propylene glycol propyl ether
Propylene glycol butyl ether
Di(propylene glycol) methyl ether
Di(propylene glycol) propyl ether
Di(propylene glycol) butyl ether
Tri(propylene glycol) methyl
ether
Tri(propylene glycol) propyl ether
Tri(propylene glycol) butyl ether
Di propylene glycol
Tri propylene glycol
Tetra propylene glycol
Poly propylene glycol 425
Poly propylene glycol 725
Poly propylene glycol 1000
FX120-01
DowFroth 250 DF250
DowFroth 1021 DF1021
FX160-05
FX160-01
F150
3
4
5
6
7
8
3
4
5
6
7
8
5
6
1
3
4
1
3
4
1
3
4
6
1
1
3
1
m
HLB
MW g/mol
CCC95,
mmol/dm3
1
1
1
2
2
2
7.48
7
6.53
6.05
5.58
5.1
7.48
7
6.53
6.05
5.58
5.1
6.53
6.05
8.28
7.33
6.85
8.13
7.18
6.7
60
74
88
102
116
130
60
74
88
102
116
130
88
102
90
118
132
148
176
190
3.933
0.851
0.284
0.108
0.069
0.062
5.117
1.041
0.341
0.108
0.078
0.062
0.466
0.127
0.489
0.246
0.159
0.176
0.091
0.063
7.98
7.03
6.55
9.25
9.125
9
8.625
8
7.375
6.05
7.83
7.48
7.11
7.86
8.625
206
234
248
134
192
250
425
725
1000
102
264
420
207
251
425
0.073
0.047
0.028
0.396
0.172
0.088
0.014
0.010
0.008
0.108
0.038
0.014
0.072
0.048
0.014
3
3
3
2
3
4
7
12
17
4
6.7
2.5
3.8
7