Uncovering Value in Tailings

Aaron Szumilak

November 2013

Study Overview

FMG Desand process Initial WHIMS tests performed – CYC O/F, UFC O/F, SPT, THK U/F

High level financials and project benefits

Live onsite 2tph pilot program findings

WHIMS vendor comparison

Global Iron grades – Comparison between continents

How Wet High Intensity Magnetic Separation works & Identifying the best value for your investment

Global Iron Grades - Hematite

Brazilian Itabirite

Australian Hematite

Indian Fines Hematite

Head

• 42-46% Fe

• 16-20% SiO2 / 0.2-0.8% Al203

Product

• 62-68% Fe

• 1-5% SiO2 / 0.1-0.2% Al203

Tails

• 8-16% Fe

• 34-42% SiO2 / 0.5-1% Al203

Head

• 55-63% Fe

• 4-9% SiO2 / 1.5-5% Al203

Product

• 57-63% Fe

• 2-5% SiO2 / 1-3.5% Al203

Tails

• 42-55% Fe

• 8-16% SiO2 / 5-10% Al203

Head

• 47-56% Fe

• 4-10% SiO2 / 2-5% Al203

Product

• 56-62% Fe

• 1-5% SiO2 / 0.5-2.0% Al203

Tails

• 26-45% Fe

• 22-36% SiO2 / 4-15% Al203

General FMG Process Flowsheet

Flowsheet by J. Clout, Iron Ore 2013

WHIMS Scoping Study

• Tailings from each unit process

were evaluated

• WHIMS concentrate yields from

6%- 30%

• Increased overall desand

upgrades by treating tails with

WHIMS

• Up to a 9% absolute increase in

Fe

• Up to a 7% absolute decrease in

SiO2

• Up to a 3% absolute decrease in

Al2O3

Flowsheet by J. Clout, Iron Ore 2013

Where’s the best value – Processing Options

1) Thickener U/F

• ~1000 tph, ~50% solids, ~1250 m3/hr

• Contains high amounts of slimes from CYC O/F

• ~16% mass recovery via WHIMS

• Final grades and concentrate quality possibly a concern

1) Upflow Classifier U/F

• ~525 tph, ~9% solids, ~5,000 m3/hr

• Low slime content

• ~30% mass recovery via WHIMS

• Final grades and concentrate quality acceptable

Both options scavenge ~ 160tph of concentrate and contribute an

additional 10% yield to the desand process

How a WHIMS Works

WHIMS Key Operating Parameters

• Gauss = Magnetic Field Intensity • ~900G – Magnetite

• ~6000G – Hematite

• >10,000G – Goethite

• >12,000G – Iron Carbonates

• Rotor RPM = Resonance Time in the Matrix • Increasing RPM = Higher Throughput, lower recovery

• Decreasing RPM = Lower Throughput, higher recovery

• % Solids (w/w) in the feed • > % Solids = greater available mass to recover

• Balance between magnetic yield and entrainment of gangue

• Matrix Gap • Dependant on top size of the feed – typically 3X larger than feed top

size. Will affect field intensity at a given amperage

• Wash Water • Product removal & aids the removal of entrained gangue

2 tph Readings WHIMS Pilot Plant

Only treating UFC O/F

• 10,000G

• 1,200 l/min of non-mag wash water

• 1,800 l/min of mag wash water

• ~40% solids

2 tph Results

Pilot Plant Summary

• Average Yield of 50%

• Average Concentrate Grade

• 59% Fe

• 4.5% SiO2

• 2.2% Al2O3

• Increased overall circuit upgrades by treating

tails via WHIMS

• Up to a 8% absolute increase in Fe

• Up to a 6% absolute decrease in SiO2

• Up to a 3% absolute decrease in Al2O3

Vendor Comparison

20 identical samples in triplicate tested with three vendors Jones – Mbe (ex KHD Humboldt Wedag)

Gaustec – Allmineral

Readings – Mineral Technologies

Vendor Comparison Study Summary

Yield % Fe % SiO2 % Al2O3 %

Gaustec 73.55 58.78 5.12 2.49

Readings 36.59 61.40 3.80 1.90

Jones 62.58 59.10 4.54 2.42

Test Operating Conditions

• 10,000G

• Mids & Mags combined

• ~1200 l/min of wash water

• 40% Feed Solids

• 1.5mm Matrix

Actual Plant – Process Considerations

Key Process Considerations

• % Solids of WHIMS Feed

• % of ferromagnetic material –

LIMS protection

• Oversize in WHIMS Feed – Trash

Screens

• Clean wash water

• Aim to minimize slimes in the

feed

• Area over WHIMS is clear

• Falling Debris

• Maintenance Access

Financial Considerations

• Treating volumes = $$$

• Long equipment lead times

• Brownfields tie in can be costly

• Product recovery & grades are mineralogy dependant

Financials - 50% Engineering Accuracy

Treating 525tph at 9% solids (-150µm)

• CAPEX • ~$30M AUD installed

• OPEX • Plant: ~$8/t

• NPV & IRR • ~$250M & ~170%

• Based on a 10 yr project & $100US/t

• Payback • ~1.5 years based on zero production in the first year

• Margin • ~$70/t

Project Benefits

• Improve upgrades and help lower strip ratios

• Increased revenue

• Improving both production tonnes and final grades

• WHIMS add on improves desand circuit yield from 42% to

56%

• Improves overall desand circuit upgrades producing a higher

quality final product

• Lower C1 cost by ~$0.35/t

• Potential for a new product stream • Potential to produce pellet feed product

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