Wiluna Uranium Project Process Development AusIMM Adelaide AusIMM - - PowerPoint PPT Presentation

Wiluna Uranium Project Process Development AusIMM Adelaide AusIMM Adelaide

17 June 2010 17 June 2010

Dayle Kenny Eugene Dombrose Eugene Dombrose

Disclaimer

This presentation has been prepared by Toro Energy Limited (“Toro”). The information contained in this presentation is a professional opinion only and is given in good faith. Certain information in this document has been derived from third parties and though Toro has no reason to believe that it is not accurate, reliable or complete, it has not been independently audited or verified by Toro. Any forward-looking statements included in this document involve subjective judgement and analysis and are subject to uncertainties, risks and ti i f hi h t id th t l f d b k t T I ti l th k l f th d t f thi d t th contingencies, many of which are outside the control of, and maybe unknown to, Toro. In particular, they speak only as of the date of this document, they assume the success of Toro’s strategies, and they are subject to significant regulatory, business, competitive and economic uncertainties and risks. Actual future events may vary materially from the forward looking statements and the assumptions on which the forward looking statements are based. Recipients

• f this document (“Recipients”) are cautioned to not place undue reliance on such forward-looking statements.

Toro makes no representation or warranty as to the accuracy reliability or completeness of information in this document and does not take responsibility for Toro makes no representation or warranty as to the accuracy, reliability or completeness of information in this document and does not take responsibility for updating any information or correcting any error or omission which may become apparent after this document has been issued. To the extent permitted by law, Toro and its officers, employees, related bodies corporate and agents (“Agents”) disclaim all liability, direct, indirect or consequential (and whether or not arising out of the negligence, default or lack of care of Toro and/or any of its Agents) for any loss or damage suffered by a Recipient or other persons arising out of or in connection with any use or reliance on this presentation or information Recipient or other persons arising out of, or in connection with, any use or reliance on this presentation or information. All amounts in A$ unless stated otherwise. Competent Persons Statements: Competent Persons Statements: The information in this report that relates to Mineral Resources is based on information compiled by Mr Daniel Guibal who is a Fellow of the Australasian Institute of Mining and Metallurgy (AusIMM). Mr Guibal is a fulltime employee of SRK Consulting and has sufficient experience which is relevant to the style

• f mineralisation and type of deposit under consideration and to the activity he is undertaking to qualify as a Competent Persons as defined in the 2004

Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’. Mr Guibal consents to the inclusion in this

2

release of the matters based on his information in the form and context in which it appears.

Wiluna Uranium Project j

• Location, Environment
• Resource

Resource

• Project
• Res

rce

• Resource
• Mining
• Process Development

Process Development

3

Wiluna Uranium Project j

Location

4

Wiluna Uranium Project j

Environment

Land forms

• Delta System; calcrete flats, sand dunes,

samphire flats

• Lake bed, creek bed

Previous land use

• Heritage, Pastoral, Mining

g , , g

5

Wiluna Uranium Project j

Resource

• Calcrete / clay hosted carnotite mineralisation
• Within delta generally below the water table
• Within delta, generally below the water table
• Resource estimate using uniform conditioning
• Lake Way is predominantly assay data
• Centipede is all gamma data

Prospect Category Resource Million Grade U O Contained U O Contained Prospect Category Million Tonnes U3O8 ppm U3O8 Tonnes U3O8 Mlb Centipede

Measured 0.30 588 177 0.39

Centipede

Indicated 7.68 619 4,754 10.48

Centipede

Inferred 1.69 251 424 0.94

Total Centipede 9.68 553 5,355 11.81

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Lake Way

Inferred

10.53 543 5,714 12.60 Total Wiluna Project 20.21 548 11,070 24.40

Wiluna Uranium Project j

Mining

• Whittle optimisation of the Uniform Conditioned

Resource

• Selective mining with intensive grade control

Selective mining with intensive grade control

• Ore is below the water table

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Wiluna Uranium Project j

Process Development – Early T estwork Australian Nuclear Science and T echnology Organisation (ANSTO) in 2007. Observations included:

• Entrained chlorides readily removed by water washing
• Entrained chlorides readily removed by water washing
• Upgrading by scrubbing and screening not possible
• Uranium extraction amenable to acid and alkaline leaching
• Uranium extraction amenable to acid and alkaline leaching
• High acid consumption (700 kg/t)
• Tailings difficult to settle
• Tailings difficult to settle
• High recovery from low chloride pregnant liquor achieved

using RIP using RIP

• Column alkaline leach achieved 70% extraction in 17 weeks

Wiluna Uranium Project j

Process Development – Early T estwork T est Outcomes

• Head grade of sample about double average resource grade
• Head grade of sample about double average resource grade
• Test results deemed indicative only but adequate for PFS level

study of following options: study of following options:

• Option A – CCD Chloride Wash, Agitated Leach and RIP
• Option B – Dump Chloride Wash, Dump Leach, and IX
• Option C – ROM Chloride Wash, Agitated Leach and RIP
• Option D Agitated Leach and Direct Precipitation
• Option D – Agitated Leach and Direct Precipitation

Option D studied at conceptual level only and assumed direct precipitation Option D studied at conceptual level only and assumed direct precipitation

• f SDU

Wiluna Uranium Project j

Process Development – 2008 Prelim Feasibility Study 2008 PFS - Summary of Results:

Option A CCD Wash RIP Option B Dump Leach IX Option C ROM Wash RIP Option D Direct Precipitation RIP IX RIP Throughput Mt/a 1.5 2.0 1.5 1.5 Production t/a U3O8 661 648 661 661 Recovery % 86.8 70.0 86.8 86.8 Capital Cost M$A 305.4 195.7 274.6 247 O i C $A/ O 51 0 36 1 48 1 43 1 Operating Cost $A/t Ore 51.0 36.1 48.1 43.1 Operating Cost $A/lb U3O8 52.5 50.6 49.5 44.0 Water Requirement GL/a 3.4 1.5 2.3 2.9 q

Wiluna Uranium Project j

Process Development – SDU T ests and 2008 Options Study T ests at Ammtec demonstrated effective precipitation of SDU from high Chloride low, Uranium solutions leading g , g to study of following options:

• Agitated Leach and direct precipitation of SDU
• Heap Leach and direct precipitation of SDU

Heap Leach and direct precipitation of SDU

Wiluna Uranium Project j

Process Development – 2009 Optimisation Study Supporting testwork on blended sample included: S bbi d i

• Scrubbing and screening
• Comminution
• Leaching
• Leaching
• T

emperatures 90 to 150oC

• Various Carbonate/Bicarbonate concentrations
• Grind sizes up to all passing 1mm
• Chloride levels up to 70 g/L
• SDU precipitation at chloride levels up to 70 g/L
• Mineralogy

Wiluna Uranium Project j

Process Development – 2009 Optimisation Study Summary of Results

Option D Conventional Leach Option E Heap Leach Throughput Mt/a 1.3 1.6 Production t/a U3O8 615 616 Recovery % 86 0 70 0 Recovery % 86.0 70.0 Capital Cost M$A 257.9 163.9 Operating Cost $A/t Ore 48.41 35.09 Ore Operating Cost $A/lb U3O8 46.43 41.35 W t R i t 1 7 0 7 Water Requirement GL/a 1.7 0.7

Wiluna Uranium Project j

Process Development – 2009 Optimisation Study Heap Leach v Agitated Tank Leach – Other Considerations Advantages Advantages

• Lower operating and capital costs
• Residues easier to handle
• Residues easier to handle
• Requires less water
• Technically simpler circuit requiring less skilled operators

Technically simpler circuit requiring less skilled operators Disadvantages

• Slower leach kinetics and lower extraction
• Little scope for controlling process once underway
• Not widely used technology, especially with direct precipitation
• Delayed revenue stream

Wiluna Uranium Project j

Process Development – 2009 Optimisation Study Conclusions and Recommendations

• Financial evaluation confirmed heap leach as preferred option

R i i l l h l

• Retain conventional leach as alternate
• Commence comprehensive heap leach test program to

confirm study assumptions

Wiluna Uranium Project j

Process Development – Heap Leach T est Program T est program:

• Agglomeration and percolation
• Agglomeration and percolation
• Bottle rolls
• Small columns to establish conditions
• Small columns to confirm conditions on main ore types

Small columns to confirm conditions on main ore types

• Medium scale columns to accommodate coarser ore
• Large scale (6m) columns for pilot testing in closed circuit
• Trial heap on site (4,500 tonnes)

(Tests in blue have been completed or underway)

Wiluna Uranium Project j

Process Development – Heap Leach Based on agglomeration and bottle roll results two small column tests started under following conditions: g

• Blended ore type
• 10 kg/t cement as binder

10 kg/t cement as binder

• Mixture of Na2CO3 and NaHCO3
• PLS collected at day’s end assayed and reagents adjusted
• PLS collected at days end, assayed and reagents adjusted
• One test at10 L/m2/hour and other at 20 L/m2/hr

Wiluna Uranium Project j

Process Development – Heap Leach

Wiluna Uranium Project j

Process Development – Heap Leach

Wiluna Uranium Project j

Process Development – Heap Leach Changes in conditions to break the plateaus included: 1 R i h l

• 1. Resting the column
• 2. Increasing mV

3 I i bi b

• 3. Increasing bicarbonate
• 4. Increasing solid : solution ratio, by:

I 2 l h l d PLS I. 2-stage leach, recycled PLS II. Taller column, 4.5m

Fi 3 i d i i i l b ll f l 4 1 d 4 2 First 3 tried in existing columns but all unsuccessful 4.1 and 4.2 required separate tests. Removed samples from the columns for analysis.

Wiluna Uranium Project j

Process Development – Heap Leach

Wiluna Uranium Project j

Process Development – Heap Leach

Wiluna Uranium Project j

Process Development – Heap Leach 2-Stage Leach:

• PLS from previous leach at 155 to 190 ppm U added to

p pp fresh ore

• After 47 days, output of U less than inputs

y p p 4.5m Column:

• 18 days taken to stabilise reagents, 10 L/m2/h
• After 36 days, PLS just under 80 ppm U and extraction just
• ver 2%
• Too early for firm conclusions

Wiluna Uranium Project j

Process Development – Heap Leach Research

• Parker Centre Curtain University:
• CSIRO Minerals – XRF and EPMA analysis of samples taken

CSIRO Minerals XRF and EPMA analysis of samples taken from columns

• Murdoch University (School of Chemical and Mathematical
• Murdoch University (School of Chemical and Mathematical

Sciences) – theoretical thermodynamic modelling

• Dr David Klessa theoretical thermodynamic modelling
• Dr David Klessa - theoretical thermodynamic modelling

Wiluna Uranium Project j

Process Development – Heap Leach Research Preliminary Findings CSIRO d d f hi h U l b i hi

• CSIRO detected areas of high U, low carbonate, within

partially leached carnotite carcass Th d d ll l b l

• Thermodynamic modelling suggests carnotite solubility

exceeded

• Carnotite solubility theory requires confirmation by peer

review and laboratory testing

Wiluna Uranium Project j

Process Development – Heap Leach Implications

• Review of compatibility between heap leach and direct
• Review of compatibility between heap leach and direct

precipitation of uranium from pregnant liquor

• L

h t t bl id d th U t i

• Leach rates are acceptable provided the U tenor in

leachant is maintained at low levels H l h i h IX i i id d hl id

• Heap leach with IX remains an option provided chloride

is removed by washing ore prior to leaching

Thank you for your attention