06 Mejoramiento Calidad Catodica Planta San Francisco

8/22/2019 06 Mejoramiento Calidad Catodica Planta San Francisco

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IMPROVING CATHODE QUALITYAT HIGH CURRENT DENSITY ATSAN FRANCISCO EW PLANT

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J. Flores; K. Muoz & G. Zrate

XIII Seminario Tcnico Cytec 2010


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IMPROVING CATHODE QUALITY AT HIGH CURRENTDENSITY AT SAN FRANCISCO EW PLANT

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Julio Flores: Cathodes Plants SuperintendentKatherine Muoz: Chief Operations SX-EW

Gabriel Zrate: Metallurgist Senior Corporative

Seminario Tcnico Cytec 2010


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CONTENTS

GENERAL INFORMATIONSELE

CATHODE QUALITY

3

NEW GUAR REAGENT

TESTWORK

RESULTS

CONCLUSIONS


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GENERAL INFORMATION

The plant produces about 37 Kton/year of cathode in San Francisco and

around 10 Kton/year of cathode in Los Bronces EW Plant.

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In addition, the unit is equipped with a copper sulphate pentahydrate

equivalents to 3 Kton/year of fine copper.

ROM ore is dumped with grades below the cut-off grade for the

concetrator: 0.15 0.75%Cu tot and 80% chalcopyrite (bioleaching

process)


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200 m3/h

COPPER SULPHATE

SULPHATEPLANT


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SELE (SELECTIVE ENHANCED EW)

Tecnologies developed by New Tech CopperCorporation

San Francisco Plant is the first plant that has

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mp emen e s c ean ecno ogy nnova on

Kind of basket that is introduced in the

electrolyte cell about EW process

Fiberglass Reinforced Plastic (FRP) structure

Allows electrodes to maintain a fix position,

avoiding short-circuits, that improves process

efficiency and quality


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CATHODE QUALITY BACKGROUND

Current Density (A/m2), I (A) vs Period

350

400

450

500

(A/m2)

45

50

55

60

65

10

100

150

200

250

300

2002 2003 2004 2005 2006 2007 2008 2009 2010

Curr.Den

s.

15

20

25

30

35

40 I(A)

|

Period 2002 2003 2004 2005 2006 2007 2008 2009 2010

I (A) 22,3 36,1 37,9 44,3 48,5 51,4 48,4 54,2 58,0

Curr. Dens. (A/m2) 183 296 311 363 393 406 384 430 460

Prod. (t) 11,7 16,8 21,7 27,1 30,5 34,1 33,2 36,6 2,9


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CATHODE QUALITYUP TO FEBRUARY 2010

Ao %Off grade Curr.Dens. (A/m2)

2005 19 363

2006 27 393

2007 28 406

2008 53 384

2009 60 430

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Higher %off grade is due to much higher cathode weight than required, specially

at the highest current density

Have an ambicious action plan

Improve and implement best practices operational and housekeeping EW plant

Cathode plant and Metallurgical Department, decided to test a new guar reagent

(C) in order to improve cathode quality


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Parameters to Keep Quality San Francisco Plant

Temperature of Washing Water to Cathodes [C] > 75

Temperature of Washing Water Chamber to Cathodes [C] > 70

Temperature Hot Water Tank [C] > 40

Temperature Electrolyte Income Cell [C] > 55

Poor Electrolyte Cu+2 [gpl] > 39

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Poor Electrolyte H+ [gpl] 165 to 180

pH of Washing Water Chamber to Cathodes > 6

Pressure of Washing Water Cathodes [Psi] > 80

Especific Flow Rate to Cells [m3/hr/m2] > 0.2

Weight Laminate to Harvest [Kg] 33 to 37

Frecuency to Cleaning Same Cell [month] max 12

Dosification Guar Reagent [gr/t Cu fine] > 90 % Curr.Density

Dosification Cobalt Sulphate [ppm] > 80 % Curr.Density

Poor Electrolyte Cl [ppm] 10 to 20

Poor Electrolyte Mn [ppm] max 90


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COMPARISON DIFFERENTS REAGENTS"A" "B" "C"

DESCRIPTION Guar Galactomannon PolymerDerivate

Guar Galactomannon PolymerDerivate

Low molecular weight

carbohydrate, dextrin type,

oligosaccharide group

SOLVENT Water Water Water

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WATER VOLUMEN FOR 250 GR/TON8 m

3

8 m

3 4 m3

SOLUBILITY 95% 85% 99%

DISSOLUTION T > 25C > 25 > 5C

DISSOLUTION TIME 2 hours 12 hours 0,5 hours

HIDRATATION 12 hours 12 hours Not required

AGITATION Mechanical Mechanical Mechanical or Neumatic


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"A" "B" "C"

EFFECTOS ON SX None None None

OPERATIONALS PROBLEMSLow temperatures tend to form

gel

Easy form gel to blocks pumps

and pipesNone

CATHODE DEPOSIT ESTRUCTURE Columnar Non defined Columnar

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CATHODES NODULATION Ocassional Frequent None

CATHODE LOOK Opaque Opaque Bright

ACID MIST DPRESS None None 10%

CURRENT DENSITY < 400 A/m2 < 350 A/m2 < 500 A/m2

MEASUREMENT METHOD None None Yes


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INDUSTRIAL TEST PROCEDURE (430 g/t)

First week (25%) : 4 kg C + 11 kg A (per shift)

Second week (50%) : 7.5 kg C + 7.5 kg A (per shift)

Third week 75% : 11 k C + 4 k A er shift

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Fourth week (100%) : 15 kg C + 0 kg A (per shift)

Preparation tank : C addes first with water at < 55C, agitation

for 30 min and then Guar is added


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RESULTS

Main parameters were graphed between April and June 22nd of 2010

Cathode ualit was evaluated usin S content

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Current Density vs Period

430

450

2)

17

350

370

390

Mar-10 Apr-10 May-10 May-10 Jun-10 Jul-10

Date

(Amp/


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Flow Electrolyte Feed Cells vs Period

1800

1900

2000

18

1300

1400

1500

1600

1700


Date

(m3/h)


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Copper in Electrolytes vs Period

50

55

60

l

19

20

25

30

35

40


Date

Cu+2 g

Cu Poor

Cu Rich


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Temperatures in EW Plant vs Period

70

80

90

20

30

40

50

60


Date

TC

TRich electrolyte to cells

TWashing w ater


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Average Content of Sulfur into Cathodes vs Period

30

35

40

45

)

21

0

5

10

15

2025


Date

S(pp


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Cathode Quality Distribution vs Period

60

70

80

90100

e(Sppm)

22

0

10

20

30

4050

Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-10

Date

%Cathodegra

%Special %Total Grade A %Of f grade


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Average week S content before the test was 6.9 and 22.4 ppm and 14

ppm as median.

After test avera e S content was 2.9 and 9.3 m and 6.3 as median.

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Tendence of S content into cathode is to get values < 5 ppm

According to the graphs, current density and electrolyte flowrate

decreased after started test. They have opposite effects and overall effect

is neutralized


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CONCLUSIONS

Highest current density in copper EW plant, increase off grade quality in

cathodes and increase possibilty to have unsafe operation

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eep ng opera ona an me a urg ca parame ers, ensurance goo

quality and safety operation

Necessary have a metallurgical senior external advisor

Decision to test a new guar reagent early this year (C), is a good

complement for help to improve quality cathode, reducing S content


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In order to validate the results obtained, it has been recommended to

continue with 100% addition of C to EW plant, and follow so close sulfur

content and any effect that residual product may have on the SX plant

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Necessary test differents tecnologies to improve cathode quality

operating high current density


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Thank you!

Documents

06 Mejoramiento Calidad Catodica Planta San Francisco