Mineral Resources• Backbone of modern societies• Availability of mineral resources as a measure of the wealth of a society• Important in people’s daily life as well as in overall economy• Processed materials from minerals account for 5% of the U.S. GDP• Mineral resources are nonrenewable
Mineral Value• Direct value – Raw, recycles – Import, export• Indirect value – Processes• Value added – E.g., agriculture
Common Use of Mineral Products METALLIC HYDROCARBON NON-METALLIC
Mineral Resources and Reserves• Mineral resources: Usable economic commodity extracted from naturally formed material (elements, compounds, minerals, or rocks)• Reserve: Portion of a resource that is identified and currently available to be extracted legally and profitably• Defining factors: Geologic, technological, economic, and legal factors
Reserves vs. Resources• Reserves • Resources – Natural resources that – Deposits that we know have been discovered & or believe to exist, but can be exploited that are not exploitable profitably with existing today because of technology technological, economical, or political – Oil – 700 billion barrels reasons – Oil – 2 trillion barrels
Mineral Resources Problems• Nonrenewable resources – Finite amount of mineral resources and growing demands for the resources• Supply shortage due to global industrialization – More developed countries consuming disproportionate share of mineral resources• Erratic distribution of the resources and uneven consumption of the resources. – Highly developed countries use most of the resources; supply varies
Major Import Sources (Table 14.2)• Friends – Canada: Metals – United Kingdom: platinum, rare earths• Other – China: graphite, tin, tungsten… – South Africa : platinum, fluorspar – Chile: arsenic, iodine
Responses to Limited Availability• Find more sources• Find a substitute• Recycle• Use less and make more efficient use of what is available• Do without
Geology of Mineral Resources• Metallic ore: Useful metallic minerals that can be mined for a profit• Technology, economics, and politics• Concentration factor: Concentration necessary for profitable mining – Variable with types of metals – Variable over time
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 .
Plate Tectonics and Mineral Resources• Plate boundaries are related to the origins of many ore deposits• Plate tectonic processes (high temperature, high pressure, and partial melting) promote release and enrichment of metals along plate boundaries• Common metal ores along plate boundaries are Fe, Au, Cu, and Hg, etc.
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.
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
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.
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 MineElement Natural Concentration Required Enrichment Concentration in to Operate a commercial Factor Crust (% by Weight) mine (% by Weight) 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
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
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
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”)
Weathering• Chemical weathering removes soluble material.• Ore material (elements of interest) are left behind in a concentrated residue.
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 Metals trapped in minerals (silicates)Energy and Cost per mass of metal Mineralogical Barrier Metals the have been GSE concentrated $ GAE Fixed Costs Low Grade of metal (element) in rock High
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.Oil5 4 3.Coal 1 4.Iron 5.Copper 2, 3, 6 6.Gravel