Mineral Resources

3-29-10 Mineral Resources How Do Mineral Resources and Geology Relate to the Human Experience? The arts, music, literature, and even the comics contain numerous references to geology and even the comics contain numerous references to geology and natural resources The struggle for control of natural resources such as oil, gas, gold, diamonds, copper, and iron, is a recurring theme in human history. Empires have risen and fallen based on the distribution and exploitation of natural resources Mineral Resources and Mining This is one of three employment main centers for geologists, and it is presently enjoying a boom. The other are: The Petroleum Industry The Environmental Industry Recent globalization markets and political change has had a drastic affect on the development and ownership of mineral resources. Today, Russia is one of the largest producers of oil. China is the largest importer or iron ore. What?s made of mineral resources? Walls, ceilings, floors Chairs, frame, desk Blackboard, projectors, screens Definitions A mineral resource is a concentration or occurrence of natural, solid, inorganic, or fossilized organic material in or on the Earth?s crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource(s) are known, estimated or interpreted from specific geological evidence and knowledge Mineral Naturally occurring inorganic crystalline solid Defined composition and characteristic properties Ore Mineral/rock containing metal that can be extracted profitably There are metallic, non-metallic, and energy mineral resources. Resources and Reserves A mineral Reserve is the economically mineable part of a measured or indicated mineral resource demonstrated by at least a Preliminary Feasibility Study. This Study must include adequate information on mining, processing, metallurgical, economic and other relevant factors that demonstrate, at the time of reporting, that economic extraction can be justified. A Mineral Reserve includes diluting materials and allowances for losses that may occur when the material is mined. Steps in obtaining mineral commodities Prospecting: finding places where ores occur Mine exploration and development: learn whether ore can be extracted economically Mining: extract ore from ground Beneficiation: separate ore minerals from other mined rock Refining: extract pure commodity from the ore mineral Transportation: carry commodity to market Marketing and Sales: find buyers and sell the commodity Mine Exploration (2) Define size, shape and grade or ore body Grade, G: mass of commodity per mass of ore/rock Drill cores, though expensive, can be used to determine underground extent of ore Estimate the mass of the commodity Design a profitable plan for mining. Analysis of requirements to startup mine Capital, transportation, labor, cost of processing, etc. Complying with governmental regulations Mitigating environmental damage Strategies for making profitability in a changing marketplace Surface mining: two types Open Pit mining Funnel shaped hole in ground, with ramp spiraling down along sides, allows moderately deep ore to be reached Strip Mining Blast, scoop off rock overburden, and then scoop out ore material. Fairly shallow Economics of strip mining depend on stripping ratio Large land area can be involved, especially for coal and bauxite Underground Mining The ore deposit is deep Ore body is steep Grade is high enough to cover costs Modern safety standards mean that most modern mines, at least those constructed by large corporations, are engineering marvels. They are expensive, and are not constructed unless the commodity sought is known to be present in profitable quantities and is recoverable. Mine Safety In U.S., stringent mining regulations have lead to a reduction in fatalities Demand for Mineral Resources Related to Population More people use more stuff Higher population leads to higher demands Related to Standard of Living Richer people use more stuff ?more developed countries? use more As standards of living improve in ?less developed countries? demand will rise more Overpopulation ? rapid depletion of nonrenewable and renewable resources - pollution Rock: An Aggregate of one or more minerals There are three major rock types: Igneous, Metamorphic, and Sedimentary Formation of Minerals Igneous (magmatic) processes Rocks that formed from cooling magma can be a resource for metals and useful minerals Deposits can be very old and take millions of years to form - some forming slowly as we speak Hydrothermal processes: heated groundwater near intrusions and plate boundaries creates different ores The metals combine with sulfur in these ?massive sulfide? or ?Sedex? deposits Formation of Minerals Sedimentary processes sediments: sand, gravel, clay evaporated seawater: brine, salt, gypsum ... rocks: iron ores, building stone, limestone may include radioactive minerals like uranium ores. Metamorphic processes slate, marble asbestos, talc, graphite Garnet, other gemstones Most tungsten deposits are in metamorphic rocks - no metamorphic rocks, no lightbulbs! Metamorphism occurs from the heat and pressure found in the cores a mountain range or near large igneous intrusions. Large amounts of erosion are needed to expose metamorphic rocks on the surface. Weathering and Groundwater Chemical weathering concentrates minerals Highly weathered residual soils Resistant minerals remain Laterite deposits are formed Commonly concentrate: Al ? bauxite Fe, Ni, Co Distribution of Mineral Resources Depends on geological processes/history Michigan wide variety of processes over last 2 billion years hydrothermal copper, massive sulfide sedimentary-metamorphic iron ores sand & gravel, gypsum, salt, clay... energy-oil, gas, coal Other countries mineral resources represent wealth political power related to resources Environmental Issues Pollution extraction (mining) of raw materials processing (to create useful material) Energy Use 20% U.S. energy use - mineral processing Dwindling Supplies remaining supplies are lower quality more energy needed to process; more waste Mining Processes and Problems Underground mines fumes, accidents, collapse, wastes Surface mines wastes, erosion, unsightly Tailings waste produced when ore mineral(s) separated from rest of rock Mining Problems Acid mine drainage many metal ores contain sulfur sulfur reacts with water and oxygen: H2O + O2 + S --> H2SO4 Sulfuric acid common where tailings exposed acidic water very reactive leaches metals... water pollution kills nearly all forms of life Extending Supplies Recycling reduce waste reduce demand for raw material Conservation use less -- lowers demand Substitution use something else ... (but what?s that made of?)