Energy Resources

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 Nuclear Power - Uranium

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)

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

Mineral Resources

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.

Some Important Minerals and there Uses Galena [PbS] – source of lead – car batteries Magnetite, Hematite [Fe x O y ] – iron ore Bauxite [Al 2 O 3 *2H 2 O] – aluminum ore Chalcopyrite [CuFeS 2 ] – copper ore Quartz [SiO 2 ] – glass and electronic components Gypsum [CaSO 4 *2H 2 O] – sheetrock, plater of paris Sphalerite [ZnS] – zinc ore Calcite [CaCO 3 ] – portland cement, soil conditioner, antacids Garnet [Al 2 (SiO 4 ) 3 +other metals] – abrasives Olivine [(Fe,Mg) 2 SiO 4 ] – 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.

Reserves vs. Resources Reserves discovered& exploited profitably –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

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

Elements comprise > 0.1% (by weight) of the crust Form as principal component in minerals within common rocks – i.e. iron (Fe) Fe 2 O 3 Form very large deposits Form rock deposits Geochemically Abundant Elements (GAE)

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.

Will run out Abundant

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

Comparison of Concentrations of Elements in the Earth’s Crust with Concentrations needed to operate a Commercial Mine ElementNatural Concentration in Crust (% by Weight) Concentration Required to Operate a commercial mine (% by Weight) Enrichment Factor Aluminum Iron Copper Nickel Zinc Uranium Lead Gold Mercury ,000

Process that concentrate elements Igneous Processes –Hydrothermal –Magmatic Sedimentary Processes –Mechanical –Chemical Metamorphism Processes Groundwater 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 Hydrothermal Processes

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

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

Placer Gold

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

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

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

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

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

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?

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

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

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

Plate Tectonics and Resources