Energy Resources. Uranium (U) – used for nuclear power Has a Minimum Concentration Factor > 1000 Source Rock – Igneous U is leached (dissolved) into groundwater.

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 ~ 3oC/ 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 [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.

Reserves vs. Resources

• Reserves– Natural resources that

have been discovereddiscovered && can be exploited exploited profitablyprofitably 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

Deg

ree

of e

cono

mic

fea

sibi

lity

Limit of crustal abundance

Technological Threshold

Potential Economical Threshold

High

High

Low

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) Fe2O3

• 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

Element Natural Concentration in Crust (% by Weight)

Concentration Required to Operate a commercial mine (% by Weight)

Enrichment Factor

Aluminum 8 24-32 3-4

Iron 5.8 40 6-7

Copper 0.0058 0.46-0.58 80-100

Nickel 0.0072 1.08 150

Zinc 0.0082 2.46 300

Uranium 0.00016 0.19 1200

Lead 0.00010 0.2 2000

Gold 0.0000002 0.0008 4000

Mercury 0.000002 0.2 100,000

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 Costper mass of

metal

$

Grade of metal (element) in rock HighLow

GAEGSE

Mineralogical Barrier

FixedCosts

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

Place the following on the Venn Diagram

1.Gold

2.Oil

3.Coal

4.Iron

5.Copper

6.Gravel

15

2, 3, 6

4

Plate Tectonics and Resources