flotation kinetics a flotation model is similar to chemical kinetics dn/dt =-k 1 n 1 a - k 2 n 2 b n...
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FLOTATION KINETICSA flotation model is similar to chemical kinetics
dN/dt =-k1 N1a- k2 N2
b
N - species (1 and 2) concentration t- time k - rate constant(s)a, b – process order-negative sign indicates that the concentration is diminishing due to the loss of particles being floated. -exponents a and b signify the order of the process
Since flotation seems to depend only on particles concentration
dN/dt =-k1 N1a
Model Relation
Classic first order = [1 – exp (–k1t)]
Modified first order = {1 – 1/(k2t)[1 – exp (–k2t)]}
For reactor with ideal mixing = [1 – 1/(1 + t/k3)]*
Modified for gas–solid adsorption
= k4t/(1 + k4t)*
Kinetics of second order = ()2
k5t/(1 + k5t)
Modified second order = {1 – [ln (1 + k6t)]/(k6t)}
Two rate constants
= [1– { exp (–k7t) + (1 – ) exp(–k8t)}
Distributed rate constants = [1 – exp(–kt) f (k, 0) dk]
0
* Equivalent models because k3 = 1/k4. – flotation recovery after time t, – maximum recovery, – fraction of particles having lower flotation rate constant, k7, k – flotation rate constant.
Flotation kinetics models
Selected kinetic equations (ε – recovery of a component in separation product, εmax – maximum recovery of the same component in separation product, k – rate constant of separation, t – separation time
Model Formula
Zeroth-order model tkε (1)
First-order model tkeεε 1max (2)
First-order with rectangular distribution of floatabilities
tke
tkεε 1
11max
(3)
Fully mixed reactor model
k
tεε
1
11max
(4)
Improved gas/solid adsorption model
tk
tkεε
1max (5)
2
3 -order model
2
max
max
2
11
11
εtk
εε (6)
Second-order model tkε
tkεε
max
2max
1 (7)
Second-order model with rectangular of floatabilites
tk
tkεε 1ln
11max
(8)
A. Bakalarz, J. Drzymala, 2013, Interrelation of the Fuerstenau upgrading curve parameters with kinetics of separation, Physicochemical Problem of Mineral Processing, 49(2), 443-451
more
0
20
40
60
80
100
0 10 20 30
reco
very
of
a co
mpo
nent
in
conc
entr
ate,
ε, %
separation time, min
remaining components
component 1
Flotation kinetics of the whole mass and components
components (recovery vs time)
0
10
20
30
40
0 10 20 30
yiel
d of
con
cent
rate
, γ,
%
separation time, min
sum of kinetics of component 1 and
remaining components
Flotation results plotted as a relationship between recovery of each component in concentrate and separation time (a), yield of components forming concentrate vs. separation time (b)
product (yield vs time)
A. Bakalarz, J. Drzymala, 2013, Interrelation of the Fuerstenau upgrading curve parameters with kinetics of separation, Physicochemical Problem of Mineral Processing, 49(2), 443-451
0
20
40
60
80
100
0 10 20 30
reco
very
of
com
pone
nt 1
in
conc
entr
ate,
ε1,
c, %
separation time, min
component 1
0
20
40
60
80
100
0 20 40 60 80 100
reco
very
of
com
pone
nt 1
in
conc
entr
ate,
ε1,
c, %
recovery of component 2 in concentrate, ε2,c, %
ideal upgrading
idea
lup
grad
ing
Fuerstenau curve
0
20
40
60
80
100
0 10 20 30
reco
very
of
com
pone
nt 2
in
conc
entr
ate,
ε2,
c, %
separation time, min
component 2
a b
relation between flotation kinetics and upgrading curves
The kinetics of separation of feed components (a) provide separation results in the form of the Fuerstenau upgrading curve (b).A. Bakalarz, J. Drzymala, 2013, Interrelation of the Fuerstenau upgrading curve parameters with kinetics of separation, Physicochemical Problem of Mineral Processing, 49(2), 443-451
c,1
c,2
0 1 2
3 2
0 ,cεk,cε 21
100
2ln1
,cεk',cε
2)251(
111001
,cεk,cε
)2100(100
21
,cε
,cεk'
,cε
1
100
2ln1
,cεk,cε
k,cε
,cε100
210011001
2
100
2100ln51
111001
,cεk
,cε
1100
2100ln100
100
2100ln2100
1
,cεk
,cεk
,cε
2
3
2)251(
111001
,cεk',cε
2
100
2100ln51
111001
,cεk'
,cε
2
2100
)210010(1
111001
,cε
,cεk,cε
2
)2100(20
21
111001
,cε
,cεk',cε
2 )2100(100
21
,cε
,cεk
,cε
1100
2100ln100
100
2100ln2100
1
,cεk'
,cεk'
,cε
2
)2100(20
21
111001
,cε
,cεk,cε
100)1(2
2100
1
k,cε
,cεk
,cε
ugrading curves (here Fuerstenau’s) equations based on kinetics of flotation
c,1 recovery of component 1 in concentrate c,2 recovery of component 2 in concentrate
4
9
7
13
0
20
40
60
80
100
0 20 40 60 80 100
reco
very
of
com
pone
nt 1
in c
once
ntra
te, ε
1,c,
%
recovery of component 2 in concentrate, ε2,c, %
k=1.5
k=3
k=0.5
k=1
0
20
40
60
80
100
0 20 40 60 80 100
reco
very
of
com
pone
nt 1
in c
once
ntra
te, ε
1,c,
%
recovery of component 2 in concentrate, ε2,c, %
k=5
k=2
k=0.4
k=1
Theoretical shape of the separation data in the Fuerstenau plot
0
20
40
60
80
100
0 20 40 60 80 100
reco
very
of
com
pone
nt 1
in c
once
ntra
te, ε
1,c,
%
recovery of component 2 in concentrate, ε2,c, %
k=0.005
k=0.5
k=0.02
k=1
4 97
0
20
40
60
80
100
0 20 40 60 80 100
reco
very
of
com
pone
nt 1
in c
once
ntra
te, ε
1,c,
%
recovery of component 2 in concentrate, ε2,c, %
k=3
k=0.5k=0.2
k=1
13
*for a suitable equation see previous slide (more plots in A. Bakalarz, J. Drzymala, 2013, Interrelation of the Fuerstenau upgrading curve parameters with kinetics of separation, Physicochemical Problem of Mineral Processing, 49(2), 443-451
*
Remeber: for characterizing separation results we need either two parameter or a law governing separation and then you can use one parameter which can be called selectivity as in these plots selectivity k
An example of separation results approximation using the Fuerstenau plot
plant 3, trial 1 a=102.28
0 20 40 60 80 100
r
0
20
40
60
80
100
= a(100-r)/(a-r)
Polish copper ore – lab tests with xanthate
0 20 40 60 80 100
component 2 in product 2, %
0
20
40
60
80
100
(c
om
po
ne
nt
1 in
pro
du
ct
1)%
ideal upgrading
F = (89/89)
no upgrading a=~1000
a=100
a=~110
Homework
Calculate the rate constant and order of a set of yield flotation data
Microlaboratory cellsLaboratory cells Laboratory machines Industrial machines
Mechanical Pneumo-mechanical PneumaticPressurized (DAF)Other (sparged hydrocyclone, ASH)
gas
magnetic stirrer
porous glass
water level
froth product
x
gas
deflector
stirrer
flotaton product
water level
porous glass
Other laboratory flotation devicesa) cylindrical cell equipped with magnetic stirrer (Fuerstenau, 1964)b) laboratory flotation device of Partridge and Smith, 1971
Laboratory cells
air
drive
Laboratory Mechanobr flotation machine
Laboratory Denver flotation machine
EIMCO Product Leaflets, 2000
Industrial flotation
Flotation machines are used individually and as a group (bank)
Svedala Product Handbook, 1996
Flotation machines are rectangular and circular
Constructions and impellers of flotation machines are different
DenverMechanobrFagergreen (WEMCO-EIMCO)
DENVER
Wemco-Fagergreen (V=0.085 ÷ 85m3)
Kelly E.G., Spottiswood D.J., Introduction to mineral processing. J.Wiley& Sons, N.Jork 1985
Wemco-Fagergreen (WEMCO-EIMCO) mechanical flotation machines
EIMCO Product Leaflets, 2000
Denver Agitair Metso RCS (Metso Minerals) Outotec (Outokumpu) X-Cell (FLSmidth Minerals) Humbolt-Wedag IMN Gliwice
Wills B.A., Mineral processing technology. Pergamon Press
1983
Fragment of mechano-pneumatic flotation machine (continueous, multi-impeller tankless Denver D-R
Pneumo-mechanic multi-tank (15m3 each)
(Aker FM – Humbold Wedag)
Humbold-Wedag Product Leaflets, 1998
feed
taili
ng
Maszyna jednowirnikowa
Maszyna przepływowa
wielowirnikowa
Pneumo-mechanical flotation machines IMN
New machines: large volume and output, saving energy
New machines: large volume and output, saving energy
Flotation technologies. Outotec Leaflets 2007
Historyczny rozwój pojemności maszyn flotacyjnych
Outokumpu Oy Leaflets 2000
(Outokumpu OK-100, V= 100m3
TankCell 300 300m3
Flotation technologies, Outotec Oyj. Leaflets 2007
© 2012 Outotec Oyj. www.outotec.com
Outotec TankCell 500 (500m3)
RCS™ (Reactor Cell System) from 5 to 200 m3 (Metso Minerals/Svedala)
1-radial flow of slurry to tank wall
2-primary slurry stream to benith impeller
3-secondary recirculation towards upper part of tank
Basics in mineral processing. Metso Minerals 2003
RCS™ (Reactor Cell System) from 5 to 200 m3 (Metso Minerals)
Basics in mineral processing. Metso Minerals 2003
RCS™ (Reactor Cell System) from 260 m3 (Metso Minerals)
pneumo-machanic XCELL (FLSmidth Minerals)
XCELL™ Flotation Machines. FLSmidth Mineralss brochure 2008.
FLOTATION COLUMNS
Metso Outotec (Outokumpu)
Jameson Cell Imhoflot Pneuflot (Humbolt-Wedag)
Injection Jameson Cell
Pneumatic PNEUFLOT
Pneumatic flotation with PNEUFLOT® cells HUMBOLDT WEDAG leaflet 2009
Pneumatic cell Imhoflot. Maelgwyn Mineral Service leaflet 4/06 Chile 2006
Multi-injection Imhoflot 3 (centrifugal flotation)
concentrate
tailing
feed pump tailing pump
feed reagents
compressed air
feed
air plus suspension
Siemens SIMINE Hybrid Flot
Metals and Mining, Siemens VAI, No. 1, 2011
Injection columnInjection column
Dissolved air flotation (DAF)
Dissolved air flotation (DAF)
Flotation, ZWR Polkowice