Energy Resources

1. Energy Resources

2. Nuclear Power - Uranium • Uranium (U) – used for nuclear power • Has a Minimum Concentration Factor > 1000 • Source Rock – Igneous • U is leached (dissolved) into groundwater • Deposit Types • Sandstones that have been enriched with U minerals (groundwater enrichment) • U-bearing minerals in rock fractures • Placer Deposits

3. Hydroelectric and Tidal Power • Movement of water drives turbines • Dams – gravity key force • Tidal – tidal force, need a tidal range of > 8 m (nearly impractical)

4. Geothermal Energy • Temperature increases with depth ~ 3oC/ 100 m • Geothermal energy concentrated where magma is near the surface • Circulation of groundwater allows water to heat up • Hot groundwater drives turbines

5. Mineral Resources

6. Daily Questions • Within your groups, identify one task you all have completed today. Collectively think about the task and brainstorm. Produce a list of all of the mineral resources that were used in that task.

7. Some Important Minerals and there Uses • Galena [PbS] – source of lead – car batteries • Magnetite, Hematite [FexOy] – iron ore • Bauxite [Al2O3*2H2O] – aluminum ore • Chalcopyrite [CuFeS2] – copper ore • Quartz [SiO2] – glass and electronic components • Gypsum [CaSO4*2H2O] – sheetrock, plater of paris • Sphalerite [ZnS] – zinc ore • Calcite [CaCO3] – portland cement, soil conditioner, antacids • Garnet [Al2(SiO4)3+other metals] – abrasives • Olivine [(Fe,Mg)2SiO4] – silicon chips for computers • Sulfur [S] – insecticides, rubber tires, paints, papermaking, etc. • Halite [NaCl] – Table salt • Graphite [C] – lubricant, pencil lead • Feldspars [K,Ca,Na,Al, silicates] – porcelain, source of K • Any other element that is not a major component of a mineral • Gold [Au], Silver [Ag], Platinum [Pt], Titanium [ Ti], Tin [Sn], etc.

8. Reserves Natural resources that have been discovered& can be exploited profitably with existing technology Oil – 700 billion barrels Resources Deposits that we know or believe to exist, but that are not exploitable today because of technological, economical, or political reasons Oil – 2 trillion barrels Reserves vs. Resources

9. Total Resources High Discovered Undiscovered Proven Resources Hypothetical, speculative, or inferred resources Known resources (located but not measured) Unconceived Resources Potential Economical Threshold Degree of economic feasibility Recoverable resources (not likely to be economic in foreseeable future) Technological Threshold Nonrecoverable resources (present in the earth but not obtainable with present technology) Limit of crustal abundance Low High Low Degree of geologic assurance

10. Geochemically Abundant Elements (GAE) • Elements comprise > 0.1% (by weight) of the crust • Form as principal component in minerals within common rocks – i.e. iron (Fe) Fe2O3 • Form very large deposits • Form rock deposits

11. Geochemically Scarce Elements (GSE) • Elements that comprise < 0.1% (by weight) of the crust • Do not form as principal component in minerals within common rocks, usually occur as a substitute in rock forming minerals • Form small deposits • Ore minerals include sulfides, native elements, etc.

12. Will run out Abundant

13. Mineral Deposits • Elements need to be concentrated • Minimum Grade - minimum amount of element necessary to economically mine element • Minimum Concentration Factor (MCF) – Minimum Grade divided by the Crustal Abundance • GAE have MCF < 100 • GSE have MCF > 100

14. Comparison of Concentrations of Elements in the Earth’s Crust with Concentrations needed to operate a Commercial Mine

15. Process that concentrate elements • Igneous Processes • Hydrothermal • Magmatic • Sedimentary Processes • Mechanical • Chemical • Metamorphism Processes • Groundwater Processes

16. Hydrothermal Processes • Precipitation of metallic ions from hot, ion-rich fluid • Fluid could be • Magmatic • Groundwater • Oceanic water • Magmas heat up the water • Water flows into fractures, faults, joints, etc. where it cools and precipitates (deposits) the metals

17. Magmatic Processes • Gravity Settling • Dense, early-crystallizing minerals sink to the bottom of the magma chamber • Filter Pressing • Tectonic force compress a magma chamber and force the still-liquid portion into fractures, creating large crystals • These processes have produced large bodies of iron, chromium, titanium, and nickel

18. Sedimentary Processes • Clastic • Weathering of rock also weathers out elements of interest • Generally, the elements are heavy and are deposited when a streams competence is low. • Placer deposits, i.e. gold

19. Placer Gold

20. Sedimentary Processes • Chemical Precipitates • Water with high concentrations of elements is evaporated • Evaporation of water leaves the elements • Ex. Salts, Iron, etc.

21. Metamorphism • Alteration of rock concentrates the elements • The heat and pressure force out the GSE (“impurities”)

22. Weathering • Chemical weathering removes soluble material. • Ore material (elements of interest) are left behind in a concentrated residue.

23. Groundwater • Secondary enrichment • Groundwater dissolves and carries elements in solution • Chemical conditions change and the elements are precipitated (deposited) out. • Ex. Lead

24. Groundwater • Secondary enrichment • Groundwater dissolves and carries insignificant elements in solution • Insoluble elements of interest remain. • Ex. Aluminum

25. Ore Mineral • Ability to separate and readily process the metal (element) from the ore material. • Need to look at • The energy to process the material • The cost to process the material • The value of the metal • Basically, is it profitable to mine the metal?

26. Metals trapped in minerals (silicates) Mineralogical Barrier Metals the have been concentrated GSE GAE Fixed Costs Mineralogical Barrier • Increase in energy and cost associated with the production of GSE Energy and Cost per mass of metal $ Low Grade of metal (element) in rock High

27. Ways to overcome the mineralogical barrier • Improve technology • Recycle • Come up with cheap energy to break silicate bonds

28. Daily Assignment Place the following on the Venn Diagram • Gold • Oil • Coal • Iron • Copper • Gravel 5 4 1 2, 3, 6

29. Plate Tectonics and Resources