run of mine ore upgrading: proof of concept plant …

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RUN OF MINE ORE UPGRADING: PROOF OF CONCEPT PLANT FOR XRF ORE SORTING Anglo American Platinum: Concentrator Technology

Ruan Fouchee, Chris Rule, Ernst Swart

SAG Conference, Vancouver, BC, Canada

September 2015

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CONTENTS

• Ore Pre-Concentration

• Sorting Technology

• XRF sorters

• Test Work

• Proof of Concept Plant

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CONTENTS



• XRF sorters

• Test Work


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WHY PRE-CONCENTRATE?

The Resource

• Grades

– Change in resource type

– Resource grades over time

– ROM dilution due to:

Narrow seams

Mining efficiency

Mechanised mining - wider stoping

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The Costs

• Utilities

– Efficiency

– Demand / Finer grinds

– Developing countries

– MAJOR cost for comminution

– Disproportional inflation

128

82.29

225

-5.49

9.14 1.46 0.85

55.47

38.40

111

0

50

100

150

200

250

In-situ Drill & Blast Load-Haul-Dump Crush Screen SAG Mill Ball Mill Total Energy

Ene

rgy

Inte

nsi

ty (

kWh

/oz)

Energy Intensity per unit Metal

Current Circuit

Circuit with Upgraded Feed

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The PGM Industry Over the Last 6 Years

R/$:

+40%

6y of Mining

Inflation:

+50 to +70%

(CPI: +40%)

10-30% profit in 2009 just

to break even in 2015

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Loss Making

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Loss Making

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• Operations:

“Mill the ounces, not the waste”

Lower unit metal cost

Efficiency, flexibility

Waste dilution reversed

Milling efficiency

Flotation recovery

• Projects:

– Waste removal can:

Decrease CAPEX (smaller plants)

Optimise strategy (multiple mines, 1 plant)

Turn a non-starter into a viable project

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The Bigger Picture

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CONTENTS



• XRF sorters

• Test Work


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SORTING TECHNOLOGY

Overview

• Ore must be amenable to sorting

– Macro-liberation

– Measurement

• Not new

– As old as mining itself

– Technology is making sorting more widespread

– Driven by demand for resource

• Scale is important!

Selectivity

Throughput

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SORTING TECHNOLOGY

Anglo American Work on ROM Upgrading

• 2000 – 2005:

– AAP – First work on sorting

– Commodas MicroSort plant built

oOptical measurement, light sensitive

oHigh maintenance air pulse ejection

• 2010 – present:

– AA Research – detailed evaluation and

comparison of various analysers; ongoing

– AAP / Rados collaboration – Mintek programme

o Tested on all AAP ore sources

o Successfully upgraded MicroSort waste

o Proof of Concept plant at Mogalakwena

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SORTING TECHNOLOGY

Competing Technologies and the Technology of a Process

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SORTING TECHNOLOGY

Competing Technologies and the Technology of a Process

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SORTING TECHNOLOGY

Space Map

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CONTENTS



• XRF sorters

• Test Work


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XRF SORTING

The Theory

• Deciding what to measure

– Concentrations

– Accuracy

• Proxy Measurement

– Cu, Ni and Cr

– Correlation?

• Surface measurement

– Representative of the whole

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CONTENTS



• XRF sorters

• Test Work


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MINTEK TEST WORK

Full Scale Batches

• Measurement: XRF vs Assay

– Rocks vs briquettes; XRF validated

• Grade vs Recovery test work

– Repeat at different thresholds

– 3 size fractions investigated:

+30-50mm, +50-100mm and +100-150mm

– ADJUSTABLE operating point

• Lab success across the group, except Unki:

Platreef

Merensky

UG2

Waste

MSZ (Unki)

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MINTEK TEST WORK

Summary of Results

85%

2.24

0.59

1.51

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CONTENTS



• XRF sorters

• Test Work


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PROOF OF CONCEPT PLANT

4 Sorters Treating 30ktpm

• Objectives:

– Profitable applied research

– Verify Mintek Results

– Validate process design parameters

– Quantify maintenance aspects

• Plant Operation:

– Adjustable discard grade (Cu-Ni threshold)

– Ties in with existing contract crusher

– Set up to treat batched strategic stockpiles

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First Results

• Key Performance Indicator:

– Discard grade <0.5g/t

– Controlled by fixed Cu threshold

• Sample vs Actual:

– PGM : Cu ratio is ~2.4x higher

– PGM “payload” is higher with measured Cu

0.5

1.0

0

0.5

1

1.5

2

2.5

Daily Results: Discard 4E (g/t)

4E_CAV G/T TAIL

Tail Target

Disc Avg

10.8

24.4

0.0

10.0

20.0

30.0

40.0

50.0

60.0

Daily Results: 4E / Cu ratio

Discard

4E/Cu Mintek

4E/Cu avg

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Comparison against Mintek report

0.57

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

00.5

11.5

22.5

33.5

44.5

55.5

66.5

77.5

88.5

99.510

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

PG

M R

eco

very

to

Co

nce

ntr

ate

(%)

Gra

de

(2P

GE+

Au

g/t

)

Concentrate Mass (%)

Mintek Platreef -150+30mm Data (lines) vs Daily Assay Data (circles)

Mintek Conc Grade Mintek Discard Grade MOSP Disc Grade

MOSP Conc Grade Mintek PGM Recovery MOSP PGM Recovery

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Upgrade Modelling (ore type and setup dependent)

y = 0.9151x-1.238

R² = 0.9327

y = 1.1389x-1.984

R² = 1

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

100.0%

1 1.2 1.4 1.6 1.8

Enrichment Ratio vs Mass Yield

MOSP Model

Mintek Model

y = 0.5236x0.26

R² = 0.2965

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

80.0%

90.0%

0.00 1.00 2.00 3.00 4.00 5.00

Mass Yield as a function of Head Grade

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Next Focus Area: Stockpile Re-mining

0

50,000,000

100,000,000

150,000,000

200,000,000

250,000,000

300,000,000

350,000,000

400,000,000

450,000,000

20

12

20

15

20

18

20

21

20

24

20

27

20

30

20

33

20

36

20

39

20

42

20

45

20

48

20

51

20

54

20

57

20

60

20

63

20

66

20

69

20

72

20

75

20

78

20

81

20

84

20

87

20

90

20

93

20

96

20

99

21

02

21

05

21

08

Stockpile Status - Level 1

HGO - S/P MGO - S/P LGO - S/P VLGO - S/P

HGO

MGO

LGO

VLGO

Waste

Plant Feed

Stockpiled

Stockpiled

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CONCLUSION

Anglo American Platinum have effectively converted

lab scale batch test success into profitable applied

research in a Proof-of-Concept sorting plant at

Mogalakwena.

The technology promises to bring a step-change to

an industry in desperate need of radical intervention

to return the majority of operations to profitability.

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THANK YOU

run of mine ore upgrading: proof of concept plant …

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