Mineral Resources - Geology and Earth PDF

GEOLOGY and EARTH’S RESOURCES Layers of the Earth Some naturally occurring materials in the earth’s crust can be extracted and made into useful products in processes that provide economic benefits and jobs. Extracting and using these resources can disturb the land, erode soils, produce large...

GEOLOGY and EARTH’S RESOURCES Layers of the Earth Some naturally occurring materials in the earth’s crust can be extracted and made into useful products in processes that provide economic benefits and jobs. Extracting and using these resources can disturb the land, erode soils, produce large amounts of solid waste, and pollute the air, water, and soil.  The Earth’s Crust Composed of minerals and rocks Minerals are the building blocks of rocks Mineral is a naturally occurring, inorganic, solid element or compound with a definite chemical composition and a regular internal crystal structure.  Examples of minerals Mineral Quartz Hematite Diamond Halite Chemical SiO2 Fe2O3 C NaCl formula Elements in Si = silicon, O = Fe = iron, O = C = carbon Na = sodium, these minerals oxygen oxygen (two iron Cl = (two oxygen atoms for every chlorine atoms for every three oxygen one silicon atom) atoms) Crystal structures Na Cl Si O Fe O C  Metallic minerals  contain one or more metallic elements in their raw form.  usually obtained from rare, naturally formed concentrations known as mineral deposits.  these deposits consist of different metallic minerals where valuable metals can be extracted.  good conductors of heat and electricity  have high malleability and ductility and generally have luster  except for mercury, metallic minerals are solid at room temperature  are broken apart, melted, and processed chemically in order to extract useful metals such as a. copper in luzonite luzonite hematite b. iron in hematite c. chromium in chromite chromite d. manganese in manganese nodules e. gold in andesite host rock gold manganese nodules Classes of Minerals Metals consumed in greatest quantity by world industry ▪iron (740 M metric tons) ▪aluminum (40 M metric tons) ▪manganese (22.4 M metric tons), ▪copper and chromium (8 M metric tons each) ▪nickel (0.7 M metric tons) Non-Metallic Minerals  do not yield new products on melting  are often found embedded in young fold mountains and sedimentary rocks  are basically good insulators of electricity and heat  lack malleability and ductility and these minerals break down easily  do not have any shine or luster  What Are Mineral Resources? Naturally occurring materials in the earth’s crust that can be extracted and made into useful products in processes that provide economic benefits and jobs. Mineral deposit – area in which a particular mineral is concentrated. Ore – metal-yielding material; contains 2 parts: the ore mineral (metal) and waste mineral material (gangue) ◦ High-grade ore – large amount of desired metal ◦ Low-grade ore – small amount of the desired resource Minerals are the foundation of the construction, manufacturing and agricultural industries.  supports thousands of jobs  provides essential raw materials like construction roads and hospitals, building automobiles and houses, making computers and satellites, generating electricity, etc.  minerals and metals mining contribute to our economy.  contributes to the country's foreign-exchange earnings through exports  the industry provides additional revenues for the government through taxes and fees paid on mining and other related activities. The Life Cycle of a Metal Resource The extraction, processing, and use of mineral resources has a large environmental impact.  Natural Capital Degradation Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources Environmental effects Steps Disturbed land; mining accidents; health Mining hazards, mine waste dumping, oil spills and Exploration, blowouts; noise; extraction ugliness; heat Processing Solid wastes; radioactive material; air, water, and Transportation, soil pollution; noise; purification, safety and health manufacturing hazards; ugliness; heat Use Noise; ugliness; thermal water pollution; Transportation or pollution of air, water, transmission to individual and soil; solid and user, eventual use, and radioactive wastes; discarding safety and health hazards; heat The energy required to carry out each step causes additional pollution and environmental degradation Fig. 15-10, p. 344  Ways to Remove Mineral Deposits  Surface mining : shallow deposits removed  mechanized equipment strips away overburden(soil and rock overlay), discarded as waste called spoils  Used to extract 90% of the nonfuel mineral and rock resources and 6% of the coal  Subsurface mining  Deep deposits removed  Used to extract coal and metal ores  Types of Surface Mining Open Pit Mining Strip Mining Contour Mining Mountain Top Removal Open-Pit Mining Machines dig holes and remove ores, sand, gravel, and stone. Toxic groundwater can accumulate at the bottom. Figure 15-11 Panian Mine (Coalfield), Semirara Island in Caluya province of Antique Area Strip Mining Earth movers strips away overburden, and giant shovels removes mineral deposit. Often leaves highly erodible hills of rubble called spoil banks. Figure 15-12 Contour Strip Mining Used on hilly or mountainous terrain. Unless the land is restored, a wall of dirt is left in front of a highly erodible bank called a highwall. Figure 15-13  Mountaintop Removal Machinery removes the tops of mountains to expose coal. The resulting waste rock and dirt are dumped into the streams and valleys below. Mountaintop Coal Mining in West Virginia, U.S. Figure 15-14  DENR reported that the Philippines has an estimated PHP1.4 trillion in gold reserves  and an additional PHP7 trillion worth of non-metallic reserves. Getting More Minerals from the Ocean Hydrothermal deposits form when mineral-rich superheated water shoots out of vents in solidified magma on the ocean floor. Figure 15-17 Why Philippines is rich in mineral deposits? The Philippines is blessed with metal and mineral deposits due to its geology. The islands are on the top of underwater mountains that were formed due to the molten rocks from the interior of the earth, which created the ideal setting of a variety of valuable minerals. The Philippines is situated along a well-defined belt of volcanoes called the Circum-Pacific Rim of Fire where the process of volcanism and plate convergence resulted in the formation of abundant and important metallic mineral deposits of gold, copper, iron, chromite, nickel, cobalt and platinum. The Philippines considered as one of the countries most endowed with metallic resources in the world, ranks in the top 6 for gold, nickel, copper and chromite and has the potential to be top 10 largest mining power in the world. Today, mining companies are charged a 4% excise tax; a 5% reservation royalty; a 1% indigenous people’s royalty; and 30% corporate income tax, on top of VAT. Over and above these taxes, mining companies are also required to appropriate 1.5% of their annual operating cost for social development and management programs.  9 Adverse Effects of Mining on Environment 1. It leads to the emission of dust, suspended particle and gases generated by explosion, transportation and processing which cause air pollution. 2. Release of harmful trace element e.g., Co, Pb, Cd etc. leads to the contamination of surface water. 3. Underground water is also contaminated due to seepage and infiltration of leached drainage. 4. Mining leads to the degradation of soil quality, fertility and makes it toxic. 5. Natural vegetation get adversely effected due to leached race element. 6. The major consequences of mining is the deforestation which results in loss of flora and fauna. 7. It directly affect the ecosystem and its stability as many species are killed due to toxicity of water and soil and loss of habitat. 8. Mining results in the wastage of land as it neither remains suitable for industrial use nor for agricultural purposes. 9. Mining directly results in the loss of landscape and beauty of surrounding.  Mining Waste Subsidence is a phenomenon where the surface collapses directly above a subsurface mine. Spoils are the unwanted rock and other waste left over after mining either on the surface or subsurface Tailings are the materials left over after the process of separating the valuable fraction from the worthless fraction of an ore. Gangue are waste materials from the ores which produces tailings Smelting is heating the ore in order to separate desired metals; without proper equipment, it releases sulfur dioxide and suspended particles damaging vegetation and acidifying soils  Mining Impacts Metal ores are smelted or treated with (potentially toxic) chemicals to extract the desired metal. Gold Processing Gold is treated with a Cyanide compound which produces a Gold-Cyanide complex which is soluble Problem: Hydrogen Cyanide gas is toxic to human and may cause death if exposed to high enough doses. Figure 15-15 DENR Administrative Order No. 96- 40 December 19, 1996 SUBJECT: Revised Implementing Rules and Regulations of Republic Act No. 7942, Otherwise Known as the "Philippine Mining Act of 1995"  What to do with the waste Incorporate the mine waste into ◦ Concrete for buildings ◦ Backfill for roads ◦ Extraction of other minerals The Alliance for Responsible Mining (ARM) was established in 2004 and is a leading global expert on artisanal and small-scale mining (ASM). We work to transform the ASM sector into a socially and environmentally responsible activity, while improving the quality of life of artisanal miners, their families and communities.  Natural Hazards Potentially damaging natural phenomena that may occur within specific period of time in a given area that may cause danger to people, structures or economic assets and which may lead to a disaster Kinds of Natural Hazards A. Hydro Meteorological hazards B. Geological hazards C. Astronomical hazards Dynamic processes move matter within the earth and on its surface, and can cause volcanic eruptions, earthquakes, tsunamis, erosion, floods, and landslides.  Geological hazards are common in areas with high tectonic activity and presence of active volcanoes.  Different risk reduction and mitigating measures should be in placed to reduce the negative impacts of these hazards.  The photo on the right side is the risk of earthquakes in the Philippines produced by the Manila Observatory and DENR.  The dark colored areas indicate high risk to earthquakes.  EARTHQUAK E  is the result of a sudden release of energy in the Earth's crust that creates seismic waves is a weak to violent shaking of the ground produced by the sudden movement of rock materials below the earth’s surface also known as a quake, tremor, temblor or seismic activity Tectonic earthquakes are produced by sudden movement along faults and plate boundaries Volcanic earthquakes induced by rising lava or magma beneath active volcanoes Magnitude it is calculated from earthquakes recorded by an instrument called seismograph focus or hypocenter- earthquake's point of initial rupture Epicenter- point at ground level directly above the hypocenter How can geological hazards be prevented? Awareness, education, preparedness, and prediction and warning systems can reduce the disruptive impacts of a natural disaster on communities. Mitigation measures such as adoption of zoning, land- use practices, and building codes are needed to prevent or reduce actual damage from hazards.