The importance of hydrogeological testing in ISL ...€¦ · The importance of hydrogeological testing in ISL – Australian experience ... •Separate report 78 pages with hydrochemical

IAEA International Atomic Energy Agency

The importance of hydrogeological testing in

ISL – Australian experience

Peter Woods1 and Ben Jeuken2

1International Atomic Energy Agency, Vienna, Austria 2Groundwater Science, Adelaide, Australia

IAEA Technical Meeting on

Optimization of In Situ Leach (ISL) Uranium Mining Technology

Vienna International Centre, Vienna, Austria, 15-18 April 2013

IAEA

Does ISL mining need geology or hydrogeology?

• Both! Plus engineering, metallurgy, licensing and more

For ISL mining, groundwater studies and information are of vital importance

• Pumping of modified groundwater through the uranium-bearing aquifer is the mining method

• If the ore is there but hydrogeological conditions are not suitable, the uranium may not be economically or even physically extractable, and/or contamination of non-mining aquifers might occur

Woods & Jeuken 2013 ISL hydrogeological testing 2

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Some historic ISL hydrogeological investigations

in Australia

• Original Beverley (South Australia) studies (late 1990s)

• Regional and mining hydrogeology

• Pumping tests

• Field Leach Trial (central and northern orebodies)

• Honeymoon (South Australia)

• Small scale ‘push-pull’ test 1978

• Field Leach Trial facilities established early 1980s

• Larger FLT 1998-2000

• Multiple layers within main aquifer, surrounding aquifers described

• Additional drilling, data and computer modelling for final approval

documents 2008, updated 2010, leading to a Groundwater Management

Plan


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Some historic ISL hydrogeological investigations

• Manyingee (Western Australia)

• Discovered 1970s-1980s

• 2 pumping tests

• Field Leach Trial 5 months in 1985 (alkaline leach), produced 470 kg

UOC; although ‘because of permeability heterogeneity at the test

location the results were disappointing’, better results considered

possible (Bautin & Hallenstien 1997)

• New owner Paladin is ‘Working towards an In-Situ Recovery Field Trial’

(2012)

• Oobagooma (Western Australia)

• Discovered 1978-1983

• 1 pumping tests but did not go further at that time (ibid.)

• New beneficial owner Paladin is investigating further


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Case Study 1 – Beverley Mine Extension 2008

• Mine History

• 1969 deposit discovered

• 1982 first Environmental Impact Statement – project did not proceed

• 1998 New EIS and Supplement

• 1999 Environmental approvals

• 2000 First production

• 2006-08 Mine Lease Extension Application Approvals finalised November 2008


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Beverley Location

Approx. 550 km north of

Adelaide, South Australia

By company plane:

~1 hr from Adelaide

~1/2 hr from Pt Augusta


Graphic/Photo credits: Heathgate Resources

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Beverley Setting

Paralana

Hot Springs

Beverley

• Arid plain

adjacent to

the Flinders

Ranges

• Area used

for low

intensity

grazing of

cattle

WA

SA

NT

QLD

NSW

VIC

TAS


Graphic credit: Heathgate Resources

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Aspects of Beverley


Photo credits: Heathgate Resources/

Australian Geographic

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State of Hydrogeological Knowledge

• Prior to Operations • Nearly 1000 exploration holes for geological setting

• Numerous groundwater wells, both existing regionally and

specific to the project

• Several pumping tests

• At time of Lease Extension Application • Over 9,000 holes

• >100 monitor wells (plus several 100 production wells) with

>10,000 monitoring data

• 7 years experience with response of aquifer to operational

pumping


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Groundwater Situation - Beverley (Isolated ‘pod’ aquifers - palaeochannels)


Graphic credit: FLOW/ Heathgate Resources

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How the Beverley ISR mine works The ISR Mining Process:

1) Groundwater pumped to surface

(at start-up)

2) Small amount of acid

and oxidant added

3) Water pumped back

into aquifer

4) Uranium dissolved

5) Water pumped to

surface

6) Uranium recovered

by ion exchange (IX)

7) Water recycled (back

to 2)

Woods & Jeuken 2013 ISL hydrogeological testing Graphic credit: Heathgate Resources

IAEA

Studies done for the extension application

• Consultant review of historic mining and

monitoring information, and revision of

conceptual model to include minor, deeper

aquifers of limited extent, one of which was

later mined – 131 pages including graphs

• Pumping tests at three locations in distinct

aquifers, with multiple observation wells

• Separate report 78 pages with hydrochemical data

and graphs, compiled by in-house hydrogeologists


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Results of additional hydrogeological studies

• Historical data allowed connections/lack of

connection between areas of mined aquifers to be

more fully described

• Lack of connection to overlying and underlying

aquifers of better quality confirmed

• Pumping tests demonstrated limited extent of new

minor aquifers proposed for mining

• Poor groundwater quality confirmed


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Beverley Expansion: Hydrogeological Conclusion

• A robust understanding of the local and

regional hydrogeology, coupled with stringent

groundwater management practices ensures

that there is no credible risk from mining at

Beverley to groundwater users in the district

including the Great Artesian Basin

• Hydrogeological issues are a key focus of

environmental management, monitoring and

reporting for Heathgate – they need to get it

right and be able to demonstrate that


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Case Study 2 – Beverley North 2011

• Mine History

• 2007 deposits discovered

• 2008 baseline studies commenced

• Different aquifer system! • Older aquifer, part of a large but sluggish regional

system

• Water less saline, although still with high radionuclides and fluoride meaning it did not meet guidelines for stock or irrigation use

• Great Artesian Basin aquifer absent; underlying aquifer is in fractured rock basement


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Case Study 2 – Beverley North 2011

• Hydrogeological Studies • Data review and census of all available pastoral wells in

the district (water levels, water quality)

• Pumping test, hydrogeological/geochemical modelling

• 2008-11 Staged applications and approvals • hydrogeological testing (no modification of groundwater

chemistry)

• Field Leach Trial with introduction of mining solution and extraction of uranium

• Full mining approvals, FLT expanded to become first satellite plant (Pepegoona)

• Second satellite plant established (Pannikan)


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Baseline Environmental Investigations

17

Pre-mining groundwater monitoring

Aquifer pumping test –

water dam

Pumping test (nearby)

Regional

pastoral well

with solar pump

Photo credits: Heathgate Resources Woods & Jeuken 2013 ISL hydrogeological testing

IAEA Regional Groundwater Conceptual Model – 3-D source: SKM report reproduced in Heathgate Public Environment Report

Woods & Jeuken 2013 ISL hydrogeological testing

18

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Pepegoona Deposit

(Beverley North)

Published long sections

This and following slide

from SKM’s regional

hydrogeology report

published with the Beverley

North MLP/PER

(Heathgate 2010)

4 Mile East Deposit

Beverley Deposit (projected)

Hydrogeology of Beverley North


19

source: SKM report reproduced in Heathgate Public Environment Report

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Regional Groundwater Flow – Eyre Formation Aquifer Similar maps done for 3 other local aquifers


source: SKM report reproduced in Heathgate Public Environment Report

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Pepegoona Hydrostratigraphy

• Willawortina/Namba Formation

• Surface to ~175 m below ground level (bgl)

• Boundary is difficult to pick at Pepegoona

• Either dry or no significant sandy layers (aquifer lenses)

• Eyre Formation Sands

• ~175 – 250 m bgl

• Pumping test completed – 5 m screen, 120 m2/d

• Bulldog Shale

• ~250 – 335 m bgl

• Fractured Rock Basement ~335 m bgl


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Beverley North Schematic

Source: Heathgate Resources Woods & Jeuken 2013 ISL hydrogeological testing

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Hydrogeological Setting – flow paths

• Flow pathways based

on Modflow numerical

groundwater model

• Standard industry model

calibrated against actual

data

Source: SKM/Heathgate Resources Woods & Jeuken 2013 ISL hydrogeological testing

23

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Groundwater Management

• Lateral Groundwater migration is relatively

slow approximately

• 15-24 m/year in and around the orebody

• Drops to 7 m/year towards Lake Frome

• Management Strategies

• Bleed stream – extract more than is injected

• Monitoring and adjustment of pumping rates

• Enhanced natural attenuation for closure


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Pepegoona Attenuation Study (1)

• Findings/Conclusions (incorporating wellfield flush)

• Range of potential impact on groundwater uranium content limited to some 200 m from FLT area for full mining (FLT will be significantly smaller)

[Reactive transport model prediction based on lab test findings/data – incl. all significant

chemical constituents]

• Predictive tool for MNA

ISR

Source: UIT/Heathgate Resources Woods & Jeuken 2013 ISL hydrogeological testing 25

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Pepegoona Attenuation Study (2)

• Findings/Conclusions (incorporating wellfield flush)

• pH returned to ~ 7 within 700m for full mining

ISR

Source: UIT/Heathgate Resources Woods & Jeuken 2013 ISL hydrogeological testing 26

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Beverley North: Hydrogeological Conclusion

• A robust understanding of the local and regional

hydrogeology was required – 4 aquifers of interest

• Hydrogeological flow and hydrochemical

modelling was required

• A staged approach used including a Field Leach

Trial in the first mining area – but not the second

• As with Beverley, hydrogeological issues are a

key focus of environmental management and

monitoring


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Other recent ISL hydrogeological investigations (1)

• Oban (South Australia)

• Discovered 1978-1983

• Pumping tests from 2

existing bores 2008

• Modelling including particle

tracking of a 5-spot ISL

pattern and solute transport

• Field Leach Trial 2010 –

initial pattern, then pairs of

wells

• Acid and oxidant

breakthrough observed but

no significant U

• Under review

Photo credit: Curnamona Energy Woods & Jeuken 2013 ISL hydrogeological testing 28

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Recent ISL hydrogeological investigations (2)

• Mullaquana/Blackbush (South Australia)

• Hydrogeology from geological drilling, regional information and nests of

investigation wells at 7 sites, 2 test production wells

• 5-day aquifer tests on test production wells 2010

• Bench chemical testing of drill core to test for natural attenuation

• Circulation trial in ISR pattern (tracer NaBr added) 2011

• Approval for Field Leach Trial, being considered while further

exploration is undertaken

• Testing of ion exchange

resins suitable for

high-Cl waters

Photo credit: Uranium SA


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Conclusions (1)

• A robust understanding of the local and

regional geology and hydrogeology is required

• Consider lithology and permeability of ore

relative to surrounding aquifer

• Do a thorough literature review if data exists

• Field data (water levels and groundwater

quality) for existing wells should be compiled

• Now review and decide if the next stage is

warranted Woods & Jeuken 2013 ISL hydrogeological testing 30

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Conclusions (2)

• Pumping tests, combined with studies on cores

• e.g. grain size distribution, presence of clay/lignites,

• Review and decide if further work warranted

• Groundwater circulation test (often skipped)

• Field Leach Trial

• ‘push – pull’ on single wells, or preferably

• Pair(s) or pattern(s)

• Review and decide if further work warranted –

sometimes the first test is inconclusive

• The FLT equipment may or may not be suitable to

form the basis of a production phase Woods & Jeuken 2013 ISL hydrogeological testing 31

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Conclusions (3)

• Be aware of potential environmental effects once

chemicals (acid or alkaline) are involved

• Be sure to tie in with mineralogy, 3-D geology and

extraction technology (but that’s another talk or 3)

• And if it’s all good

• Get approvals

• Mine safely,

• Mine responsibly!


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Photo credit: Heathgate Resources

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With special acknowledgement of our former employer Heathgate

Resources. Current affiliations:

Peter Woods

Team Leader, Raw Materials and Resources Sub-programme

[email protected]

Nuclear Fuel Cycle & Materials Section

Division of Nuclear Fuel Cycle and Waste Technology

Department of Nuclear Energy, IAEA, Vienna

Ben Jeuken

Principal Hydrogeologist, Groundwater Science

[email protected]

Adelaide, South Australia

Thank you for your attention


IAEA

Further reading – mining companies, IAEA

• Curnamona Energy http://www.curnamona-energy.com.au/

• Heathgate Resources http://heathgate.com.au

• Paladin Energy http://www.paladinenergy.com.au/

• Uranium One http://www.uranium1.com/index.php/en/mining-operations/australia/honeymoon-

mine

• Uranium SA www.uraniumsa.com.au

• IAEA 2010 Best Practice in Environmental Management of Uranium Mining IAEA Nuclear

Energy Series NF-T-1.2

• IAEA 2005 Guidebook on environmental impact assessment for in situ leach mining projects.

IAEA-TECDOC-1428.

• IAEA 2004 Recent developments in uranium resources and production with emphasis on in situ

leach mining. IAEA-TECDOC-1396.

• IAEA 2001 Manual of acid in situ leach uranium mining technology. IAEA-TECDOC-1239.

• IAEA 1997 Environmental Impact Assessment for Uranium Mine, Mill and In Situ Leach

Projects IAEA-TECDOC-979


http://www.curnamona-energy.com.au/

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Further reading – selected publications

• Anon. (2013) Fact Sheet Uranium One Honeymoon Mine. Australasian Mining and Metallurgical Operating

Practices (3rd Ed), Monograph 28 (Australas. Inst. Min. Metall., Melbourne, Australia) 2:1819-1822.

• Bautin, F., & Hallenstein, C. (1997, October) Plans for uranium mining by COGEMA. In ANA 97 Conference on

Nuclear Science & Engineering in Australia pp. 20-24.

• Birch, G.R., Every, C.R., Märten, H.G., Marsland-Smith, A.B., Phillips, R., Woods, P.H. (2013) Beverley

Uranium Mines, Heathgate Resources. Australasian Mining and Metallurgical Operating Practices (3rd Ed.),

AusIMM Monograph 28 (Australas. Inst. Min. Metall., Melbourne, Australia) 2:1799-1818.

• Commonwealth of Australia (2010), Australia’s in situ recovery uranium mining best practice guide, Department

of Resources, Energy and Tourism, Canberra, Australia

• Märten, H., Phillips, R., Woods, P. (2012) New uranium ISR satellites at Beverley North, South Australia, The

New Uranium Mining Boom, (Proc. Int. Conf. Uranium Mining and Hydrogeology VI, Freiberg, Germany, 18-22

Sep. 2011) (Merkel, B., Schipek, M., Eds): Springer Berlin, Heidelberg pp23-30.

• Kalka, H., Märten, H., Woods, P. (2011) ISR mine closure concepts, Proc. WISSYM2011 - Wismut Symp.

Sustainability and Long-term Aspects of the Remediation of U Mine and Milling Sites, Ronneburg, Germany,

25-27 May 2011. Wismut GmBH, Chemitz, Germany pp201-215.

• Penney, R. (2012) Australian sandstone-hosted uranium deposits, Appl. Earth Sci. 121 (2):65-75.

• Samphire Uranium (2011) Retention Lease Proposal on Mineral Claim 4280 for a Uranium In-situ Recovery

Field Trial. Uranium SA, Adelaide, Australia

• URS Australia Pty Ltd (2007) Mining Proposal for Proposed Extension of Beverley Mine, Heathgate Resources

Pty Ltd, Adelaide, Australia.

• URS Australia Pty Ltd (2010) Beverley North Project Mining Lease Proposal and Draft Public Environment

Report, Heathgate Resources Pty Ltd, Adelaide, Australia.


Documents

The importance of hydrogeological testing in ISL ...€¦ · The importance of hydrogeological testing in ISL – Australian experience ... •Separate report 78 pages with hydrochemical