Slezak Presentation

Uranium Geology and Deposits, Exploration, Mining and Milling and Environmental IssuesSeminar on Nuclear Science and Technology for DiplomatsVienna, 6 – 8 February 2007: 

Uranium Geology and Deposits, Exploration, Mining and Milling and Environmental Issues Seminar on Nuclear Science and Technology for Diplomats Vienna, 6 – 8 February 2007 Jan Slezak, Uranium Resource Specialist Nuclear Fuel Cycle & Materials Section Division of Nuclear Fuel Cycle and Waste Technology

Introduction: 

Introduction Uranium Geology & Deposits Uranium Resources, Supply & Demand Uranium Exploration Uranium Mining Uranium Milling Associated Environmental Issues

Uranium: 

Uranium Uranium as an element The heaviest naturally occurring element (three main isotopes U-234, 235-0.71%, 238-99.28%) U+4 (reduced-insoluble) & U+6 (oxidized-soluble) Uranium minerals Oxides: uraninite (crystalline UO2-2.6), pitchblende (amorphous UO2-2.6) Silicates: coffinite (U(SiO4)1-x(OH)4x) Phosphates Organic complexes & other forms Uranium occurrence Uranium present almost everywhere, but in low concentrations Natural concentrations in rocks: 0.0X (alkalic) – X (acidic) ppm Concentration of uranium in the environment > URANIUM DEPOSIT

Uranium minerals: Autunite & Torbernite: 

Uranium minerals: Autunite & Torbernite

Uranium Geology & Deposits: 

Uranium Geology & Deposits Uranium Geology Source rock of uranium (X ppm) > process of removal > concentration in favorable conditions (X000 ppm) > ?URANIUM DEPOSIT Uranium occurrence: A naturally occurring, anomalous concentration of uranium Uranium deposit: A mass of naturally occurring mineral from which uranium could be exploited at present or in the future (under given economic conditions) 13 Geologic Types of Uranium Deposits Unconformity-related deposits (Canada, Australia) Sandstone deposits (all over the word) Hematite breccia complex deposits (only Australia – Olympic Dam) Vein deposits (all over the word) Intrusive deposits (Namibia)

Unconformity-Type Deposit: 

Unconformity-Type Deposit Outwash sand and gravel Till Ore-bearing till (cobble ore horizon) Ore body Shear zone Athabasca formation sandstone Pegmatoid Graphitic gneiss Biotite gneiss Block movement -450 -500 m level

Sandstone Deposit: 

Sandstone Deposit

Vein-Type Deposit: 

Vein-Type Deposit

Uranium ResourcesIdentified (Reasonably Assured + Inferred) Resources (in 1000 tonnes): 

Uranium Resources Identified (Reasonably Assured + Inferred) Resources (in 1000 tonnes)

Uranium Exploration: 

Uranium Exploration A complex process to find a uranium deposit – a defined model needed Three main methods used: Geological methods (remote sensing, geologic mapping, drilling, trenching etc.) Geochemical methods (sampling, analyses, advanced methods-dating, isotope studies) Geophysical methods (radiometric, geomagnetic, geoelectric, gravimetric, seicmic etc. methods and borehole logging)

Field Uranium Exploration: 

Field Uranium Exploration

Definitions: 

Definitions Mining The activity that removes from the earth’s crust the abnormal concentration of metal found in the deposit Mine An opening or excavation of the earth from which minerals are extracted

Type of Mining: 

Type of Mining Open pit Underground In-situ Leach (ISL)

Open Pit Mining: 

Open Pit Mining Mine working open to the surface Operation designed to extract minerals that lie close to the surface Waste is first removed, then the ore is broken and loaded

Open Pit Mine: 

Open Pit Mine

Underground Mining: 

Underground Mining Access Ramp or shaft or both Method Cut and fill Stope and Pillar Jet boring Raise Boring

Head Frame of Shaft: 

Head Frame of Shaft

Underground mine: 

Underground mine

Underground Stope: 

Underground Stope

In Situ Leaching : 

In Situ Leaching Production Monitor Wells Injection Wells Shallow Monitor Injection Pump Elution/ Precipitation Circuit O2 CO2 IX Columns Evaporation Ponds Electrical Power lines Monitor Wells Production Wells Deep Monitor Upper Aquifer Impermeable Zone Mineralized Aquifer Impermeable Zone Lower Aquifer Submersible Pump

In-Situ Leaching Wellfield: 

In-Situ Leaching Wellfield

Milling Process: 

Milling Process Size Reduction Leaching Solid - Liquid Separation Purification and Concentration Precipitation and Solid–Liquid Separation Drying

Milling Process Scheme: 

Milling Process Scheme

The Mill: 

The Mill

Yellow Cake: 

Yellow Cake

Uranium Production: 

Uranium Production 2004 40 263 tonnes U 2003 35 492 tonnes U

Mine Site at the End of Mining Operations: 

Mine Site at the End of Mining Operations

Rehabilitation of Mining Site: 

Rehabilitation of Mining Site

IAEA: 

IAEA …atoms for peace. Thank you for your attention