Lance Projects Lance Projects Alternate Lixiviant Chemistry - - PowerPoint PPT Presentation

Lance Projects Alternate Lixiviant Chemistry

July 28, 2017

Lance Projects Alternate Lixiviant Chemistry

July 28, 2017

Community Energy

Agenda

• Low pH lixiviant

– Discussion of reason for request – Results of lab testing – Recovery and Restoration

• Permitting process
• Update on Agreement State Timeline and how it

affects permitting action

• Discuss path forward

2

Community Energy

The Issue

• Alkaline leach not effective on Lance Projects

mineralization

• Current head grade and resource recovery below

expectations – to date best recovery at 40%

• 54 Mlb Wyoming uranium resource at risk
• Testing of low pH lixiviants extremely successful

3

Community Energy

Precedent

• Two acid leach pilot tests in Wyoming circa late

1970’s

– Nine Mile Lake – Reno Creek

• ISR Copper in Arizona

– San Manuel – Florence – Globe – Miami Unit

• Australia
• Kazakhstan

– Several attenuation demonstrations

4

Community Energy

Mineral Occurrence

• Extensive petrology work has identified difference

between uranium mineralization in older, Cretaceous age Lance Deposits and Tertiary age deposits

• Uranium mineralization in the Powder River Basin

and other Tertiary traditionally occurs interstitially

5

Community Energy

Interstitial Uranium Mineralization

6

Community Energy

Lance Deposits Mineralization

7

• Uranium mineralization predominately Uranophane

as opposed to more common uraninite or coffenite

• Some traditional interstitial mineralization
• High percentage of mineralization occurs occluded

within secondary chert

• Alkaline lixiviant unable to fully contact occluded

uranium

Community Energy

Lance Interstitial Uranium Mineralization

8

Community Energy

Lance “Chert Occluded” Mineralization

9

Community Energy

Laboratory Testing of Low pH Lixiviants

• Strata has tested several low pH lixiviants with very

good initial results

• Dilute sulfuric acid leach very effective
• Citric acid with oxidizer also effective
• 90 – 95% recovery in 20 pore volumes (PV)

compared to 40% recovery with alkaline lixiviant

• Initial restoration testing very positive

10

Community Energy

Low pH: 95% Recovery in 20 Pore Volumes

11

Community Energy

Alkaline: 40% Recovery in 20 Pore Volumes

12

Community Energy

Other Low pH Lixiviants

13

Community Energy

Restoration Simulation Results

14

Community Energy

Changes to Permit to Mine

• Low pH leaching within capacity of current facility
• Plant operations minimal impact
• Excursion monitoring parameters may change
• Restoration standards remain the same

– Restoration techniques may change

• Ground water restoration impact on bonding

15

Community Energy

Regulatory Context

• No prohibition to low pH lixiviants
• LQD Regulatory Approach

– R & D Testing License – Non Significant Revision – Significant Revision

• Materials license

– Post Agreement State amendment

• WQD Regulatory Implications / Other

16

Community Energy

Path Forward

• LQD feedback on concept and regulatory approach
• Further laboratory testing by Strata of leaching and

restoration

• Strata prepares White Paper for LQD

– Historical & international experience – Detail effects on Permit to Mine – Summarize safety and environmental implications

17