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RESOURCES FROM THE EARTH Active mining projects for Mitsui & Co., Ltd. Renewable versus Nonrenewable resources… Nonrenewable resource is on that if replenished by natural processes, growth times are measured in millions of years rather than in annual seasons. A few more basic definitions: •Ore: an aggregate of minerals in which one or more minerals can be extracted profitably •Smelting: chemical process to remove metal from ore •Alloy: combination of 2 or more metals, i.e. Bronze = copper + tin •Metallic minerals: those from which metals such as Cu, Au, Fe, & Zn can be recovered by smelting. •Nonmetallic minerals: those used for their physical or chemical properties, that than for the chemical elements they contain. •Mineral Deposits: any volume of rock containing an enrichment of one or more minerals The basic supply of minerals is limited by three major factors: 1. Usable minerals are limited in abundance and locality within the Earth’s crust. No nation is self-sufficient where mineral supplies are concerned. 2. The quantity of a resource available is anyone country is never known with accuracy because the likelihood that new deposits will be discovered is difficult to assess. 3. Unlike fruit and vegetables, deposits of minerals are depleted by mining and are eventually exhausted. How are the reserves for a specific mineral increased? 1. A technological innovation that reduces the amount of iron ore lost during mining or smelting increases the effective stock of that resource. 2. The (partial) substitutability within the economy of virtually all resources for others is at the heart of the second method for increasing the effective stocks of natural resources. (conservation) 3. The third way we can increase our effective stocks of a natural resource is, of course, by technological changes that facilitate recycling. ORIGIN OF MINERAL DEPOSITS •Hydrothermal mineral deposits •Magmatic mineral deposits •Sedimentary mineral deposits •Placers •Residual mineral deposits HYDROTHERMAL MINERAL DEPOSITS Porphyry copper deposits are copper orebodies which are associated with porphyritic intrusive rocks and the fluids that accompany them during the transition and cooling from magma to rock. Circulating surface water or underground fluids may interact with the plutonic fluids. Successive envelopes of hydrothermal alteration typically enclose a core of ore minerals disseminated in often stockwork-forming hairline fractures and veins. MAGMATIC MINERAL DEPOSITS Magmatic Deposits are so named because they are genetically linked with the evolution of magmas emplaced into the crust (either continental or oceanic) and are spatially found within rock types derived from the crystallization of such magmas. The most important magmatic deposits are restricted to mafia and ultramafic rocks which represent the crystallization products of basaltic or ultramafic liquids. Chromite Pegmatite SEDIMENTARY MINERAL DEPOSITS Any concentration of minerals formed through processes of sedimentation. It has become common practice to refer to those minerals formed through precipitation of substances carried in solution—chemical sedimentary deposits rather than clastic sedimentary deposits. Stratabound Deposits occur when hydrothermal fluids invade and react with muddy sediments Placer deposits occur where barriers allow flowing water to carry away the suspended load of light weight particles, while trapping heavy particles. How heavy? Residual Mineral Deposits Substances that are concentrated by chemical weathering processes, i.e. bauxite. Metallogenic Provinces These are limited regions of the crust within which mineral deposits occur in unusually large numbers. Mineral deposits and plate tectonics Fossil Fuels: the remains of plants and animals in sedimentary rocks that can be used for fuel. Coalification: Compression and hardening over long periods of time, the processes by which coal is formed from plant materials. The final product has lost most of its volitiles and is highly inriched in carbon Petroleum Defined as gaseous, liquid, and semisolid naturally occurring substances that consist chiefly of hydrocarbons. Oil Traps Renewable Energy Sources Wind Solar Nuclear Geothermal Hydroelectric Biomass How is energy generated? There are four main stages: 1. the fuel is burned to boil water to make steam 2. the steam makes a turbine spin 3. the spinning turbine turns a generator which produces electricity 4. the electricity goes to the transformers to produce the correct voltage The energy needed to boil the water comes from fossil fuels or nuclear fuels. Renewable energy resources such as wind and wave power may drive the generators directly. 1. the fuel is burned to boil water to make steam 2. the steam makes a turbine spin 3. the spinning turbine turns a generator which produces electricity 4. the electricity goes to the transformers to produce the correct voltage Nuclear Power Generation Fission: a nuclear reaction in which the nucleus of an atom splits into smaller parts. Fusion: a nuclear reaction in which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus. Breeder reactor: is a nuclear reactor that generates new fissile material at a greater rate than it consumes such material. Pressurized water reactor: the primary coolant (water) is pumped under high pressure to the reactor core, then the heated water transfers thermal energy to a steam generator. Nuclear fuel cycle: The Nuclear Fuel Cycle