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Effect of polyacrylic acid in restoring

chalcopyrite an molybdenite flotation

Ian Wark Research InstituteAustralian Research Council Special Research Centre

For Particle and Material Interfaces

Maria Sinche Gonzalez, D. Fornasiero

and M. Zanin

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Water in mineral processing

Dissolved ases

water

Organic compounds(reagents, micro-organism) Suspended solids

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0.5

0.6

0.7

0.8

0.9

threcovery

0.55

0.6

0.65

0.7

0.750.8

0.85

Overall

recovery

Water quality in flotation

0.4 0.5 0.6 0.7 0.8 0.9

0.1

0.2

0.3

0.4

Collection zone recovery

Fr

o

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

.

Water quality can affect both

froth zone and collectionzone

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Metal ions in solution may depress the

sulphide minerals

- Collection Zone Issues -

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HypothesisMI in solution can:

Precipitate as hydroxide on the surface of Cp and Mo particles,

reducing the overall hydrophobicity and contact angle

Reduce the surface charge of Cp and Mo particles to less negative,

The addition of a charged organic dispersant (PAA) may be beneficial

in preventing/reversing metal ion deposition on the surface of Cp

and Mo

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Al3+

Mg2+

Mn2+

Ca2+

Al3+

Mg2+

Mn2+

Ca2+

Metal hydroxide may form in solution at

typical plant pH (9.3)

pH of hydroxide formation:

FeMn

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MoS2 is negatively charged

MI adsorption reduces the negative

charge and improves floatability

BUT

Increases potential to aggregate with

negatively charged gangue particles

MoSMoS22

MoSMoS22++

CaCa2+2+

MoSMoS22+SiO+SiO22

MoSMoS22+Ca+Ca2+2++SiO+SiO22

MI may favor slime coatings on molybdenite

Zanin et Al., 2010AMIRA P260E

7

Can dispersants counteract ??

Raghavan & Hsu (1984)

MoS2+

--

+

+

-

+

-

SiO2

Ca2+ adsorbed

at the edges

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Experimental approach

amplifier

computer

Single minerals: Chalcopyrite -75+38 um

Molybdenite -250+150 um

zeta potential(Malvern Zetasizer Nano)

detachment force

(related to CA)batch flotation

50 Hz

Effect of Fe, Al and Mn

investigated

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40

60

80

100

veMorecovery%

No metal ionsFeAlMn

Mn

Flotation response in the presence of MI

Chalcopyrite Molybdenite

40

60

80

100

veCurecovery%

No metal ionsFeAlMn

Al Fe

0

20

0 1 2 3 4 5 6 7 8 9

Cumulati

Time (min)

Fe

Effect of metal ions (10-4 M) on chalcopyrite and molybdenite recovery as a

function of flotation time at pH 9.3 ([KNO3] =10-2 M)

0

20

0 1 2 3 4 5 6 7 8 9

Cumul

ati

Time (min)

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Cum

ulativeMo

recovery%

10

20

30

40

50

60

70

80

Cum

ulativeMo

recovery%

10

20

30

40

50

60

70

80

Cum

ulativeCu

recovery%

20

30

40

50

60

70

80

90

Cum

ulativeCu

recovery%

20

30

40

50

60

70

80

90

Effect of metal ions and PAA in flotationChalcopyrite Molybdenite

No

m

etalions

Fe3x10-5

/

8.2x10-7

Fe10-4

/

0

Fe10-4

/4.1x10-7

Al3x10-5

/

4.1x10-7

Al3x10-5

/0

Al10-4

/0

Mn

2x10-5

/4.1x10-7

Fe3x10-5/0

Fe10-4

/2.1x10-7

Al3x10-5

/

8.2x10-7

Al10-4

/

2.1x10-7

Al10-4

/

10-6

Mn

2x10-5/0

Mn

10-4

/0

Mn

10-4

/2.1x10-7

Mn

10-4

/4.1x10-7

Fe3x10-5

/

1.2x10-6

Metal ions (M) / PAA (M)

0

No

m

etalions

Fe3x10-5

/

8.2x10-7

Fe10-4

/

0

Fe10-4

/4.1x10-7

Al3x10-5

/

4.1x10-7

Al3x10-5

/0

Al10-4

/0

Mn

2x10-5

/4.1x10-7

Fe3x10-5/0

Fe10-4

/2.1x10-7

Al3x10-5

/

8.2x10-7

Al10-4

/

2.1x10-7

Al10-4

/

10-6

Mn

2x10-5/0

Mn

10-4

/0

Mn

10-4

/2.1x10-7

Mn

10-4

/4.1x10-7

Fe3x10-5

/

1.2x10-6

Metal ions (M) / PAA (M)

0

No

m

etalions

Fe2x10-5/0

Fe2x10-5

/2.1x10-6

Fe2x10-4

/0

Fe2x10-4

/1.1x10-6

Fe2x10-4

/2.1x10-6

Al2x10-5

/

2.1x10-6

Al2x10-5

/

0

Al2x10-5

/

5x10-5

Al10-4/

0

Al10-4

/

2.1x10-6

Al10-4

/

5x10-5

Metal ions (M) / PAA (M)

0

No

m

etalions

Fe2x10-5/0

Fe2x10-5

/2.1x10-6

Fe2x10-4

/0

Fe2x10-4

/1.1x10-6

Fe2x10-4

/2.1x10-6

Al2x10-5

/

2.1x10-6

Al2x10-5

/

0

Al2x10-5

/

5x10-5

Al10-4/

0

Al10-4

/

2.1x10-6

Al10-4

/

5x10-5

Metal ions (M) / PAA (M)

0

Effect of PAA on chalcopyrite and molybdenite recovery in presence of

Fe, Al and Mn ions (pH 9.3)

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-20

-10

0

10

20

30

potential(mV)

(2)

(3)

(1)

b

-20

-10

0

10

20

30

potential(mV)

(2)

(3)

a

Zeta potential in the presence of MI

Chalcopyrite Molybdenite

Zeta potential of Mo, Cp and freshly prepared Fe(OH)3 10-4 and PAA, pH =9.3

-70

-60

-50

-40

-30

0 1 2 3 4 5 6 7 8 9 10 11

z

et

pH

Cp

Cp + PAA 10-5 M

Fe(OH)3 10-4M

Fe(OH)3 10-4 M + PAA 10-5 M

Cp + Fe(OH)3 10-4M

Cp + Fe(OH)3 10-4 M +PAA 10-5 M

-70

-60

-50

-40

-30

0 1 2 3 4 5 6 7 8 9 10 11

z

et

pH

MoMo +PAA 10-5 MFe(OH)3 10-4MFe(OH)3 10-4M + PAA 10-5 MMo + Fe(OH)3 10-4MMo + Fe(OH)3 10-4 M +PAA 10-5 M

(1)

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Measurement of the detachment force

Xu et Al., 2010AMIRA P260E

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5.0E-06

1.0E-05

1.5E-05

2.0E-05

2.5E-05

3.0E-05

3.5E-05

Detachmen

tforce(N)

aIncreasingcollector

IncreasingPAA

5.0E-06

1.0E-05

1.5E-05

2.0E-05

2.5E-05

3.0E-05

IncreasingPAA

etachmentForce(N)

Particle-bubble detachment force: Fe nitrate and PAA

Chalcopyrite Molybdenite

0/

0/1

0/

0/

0.

5

0/

0/

0

2x10-5/

0/

0

2x10-5/

0/

0.

5

2x10-5/

2..

1x10-06/

0.

5

2x10-5/

4.

2x10-06/

0.50.0E+00

Fe ion concentration (M)/ PAA concentration (M) /collector concentration

0/

0

/0

.5

3x10-5/

0/

0.

5

3x10-5/

8.

2x10-07/0.

5

6x10-5

/0/

0.

5

6x10-5/

8.

2x10-07/0.5

6x10-5/

1.

2x10-06/0.

50.0E+00

Fe ion concentration (M)/ PAA concentration (M) /

collector concentration

Detachment force for chalcopyrite and molybdenite particle-bubble in thepresence of Fe nitrate and PAA, at pH 9.3

(*1= 2 g/t SIPX for CuFeS2, and *1= 22 g/t diesel oil for MoS2)

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Particle-bubble detachment force: Al nitrate and PAA

5.0E-06

1.0E-05

1.5E-05

2.0E-05

2.5E-05

5.0E-06

1.0E-05

1.5E-05

2.0E-05

2.5E-05

3.0E-05b

IncreasingPAA

Chalcopyrite Molybdenite

2x10-5/

4.

2x10-06/

0

.5

2x10-5/

0/

0

.5

2x10-5/

6.2

x10-6

/0

.5

0/

0/

0

.5

0.0E+00

Al ion concentration (M)/ PAA concentration(M) /collector concentration

0/

0/

0

.5

3x10-5/

0

/0

.5

6x10-5/

0/

0

.5

6x10-5

/8.

2x10-07/

0

.5

6x10-5

/1.

6x10-06/

0.50.0E+00

Al ion concentration (M)/ PAA concentration(M) /collector concentration

Detachment force for chalcopyrite and molybdenite particle-bubble in thepresence of Al nitrate and PAA, at pH 9.3

(*1= 2 g/t SIPX for CuFeS2, and *1= 22 g/t diesel oil for MoS2)

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Conclusions

Al and Fe ions decrease CuFeS2 and MoS2 flotation recovery,zeta potential and attachment force.

Changes in zeta potential suggest adsorption/precipitation ofmetal hydroxide on the mineral surface of CuFeS2 and MoS2decreasing particles hydrophobicity.

po yacry c ac restore t e otat on o c a copyr te

and molybdenite when Fe, Al and Mn were present at

concentration

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Acknowledgements

The authors acknowledge the financial support of:

Australian Research Council (ARC)

Sponsors of the AMIRA International P260E project

Thank you!