Environmental Management: Rocks and Minerals Practice Flashcards
Fundamentals and Principles of Environmental Management
Environmental Management is defined as a comprehensive field of knowledge and understanding regarding issues surrounding sustainable development and the specific ways in which the Earth’s resources are utilized. It acts as a systematic approach designed to balance various human activities with the essential needs of the natural environment. This discipline recognizes that human behavior toward the environment is fundamentally guided by the survival needs, perceptions, and values of individuals and society. There are several primary reasons for managing the environment, which include protecting diverse ecosystems, increasing the population Number, conserving non-renewable natural resources, reducing overall pollution levels, and promoting sustainable practices.
Characteristics and Internal Structure of the Earth
The planet Earth is characterized by several distinct physical attributes, including being a rocky planet with its own gravity and an atmosphere. It possesses a high density and is structured into distinct layers. The Crust is the outermost layer of the Earth's surface and is the environment where humans reside and where lighter elements are concentrated. The crust is further characterized by water bodies such as oceans, seas, and rivers, as well as the continents and all associated geographical phenomena. All accessible resources are found within this layer, which has a thickness of only a few kilometres. Beneath the crust lies the Mantle, which is positioned above the liquid outer core. The Mantle thickness is substantial, reaching more than kilometres. The Core itself is divided into two parts: the inner core and the outer core. The inner core consists of solid metal, specifically Iron and Nickel, while the outer core is comprised of liquid metals, particularly Iron.
Chapter : Rocks, Minerals, and Their Exploitation
Section focuses on the formation of rocks and their various classifications. Rocks are categorized into three primary types based on their method of origin. Igneous Rock is formed when liquid magma or lava, which are molten rocks, solidify through cooling either on the surface of the Earth or beneath it. Common examples include Granite and Basalt. The properties of igneous rocks are influenced by their cooling rate. When molten rocks cool quickly over a shorter period on the surface, small crystals are formed, which is a characteristic of Basalt. Conversely, when molten rocks cool slowly over a longer period beneath the surface, large particles are formed, as seen in Granite. Igneous rocks are generally characterized by the presence of crystals and are noted for being hard to break and hard to erode.
Sedimentary Rock is formed through the weathering and erosion of existing rocks found at the Earth's surface. These weathered fragments are then transported by agents such as water or wind and are eventually compacted and cemented into solid rock formations. Key examples of sedimentary rocks include Limestone, Sandstone, and Shale. These rocks have distinctive properties: their particles accumulate into visible layers, and the newest particles are always found on the top layer. Sedimentary rocks frequently contain fossils and are susceptible to erosion by weak acids. Furthermore, they are permeable to water. Metamorphic Rock is created when intense heat and pressure act upon existing rocks, causing chemical or physical changes, or both, in the crystals without the rock melting. Examples include Marble and Slate. These rocks exhibit multiple colors and shapes and may have specific colors due to the existence of certain minerals. They often feature light and dark bands of colors. The rock cycle illustrates that any type of rock can be changed into another type by applying the specific conditions of formation associated with that rock type.
Methodologies for Mineral Extraction and Detection
Section discusses the extraction of rocks and minerals from the Earth. Rocks may contain valuable minerals that are in high demand, and rocks containing specific elements are referred to as ores, such as iron ore or copper ore. The process of identifying these resources involves several methods. Prospection is the traditional process of examining the surface of rocks to look for minerals, but it is considered inaccurate and cannot be solely relied upon. Remote Sensing involves gathering data about an area using satellite signals or GPS. The way signals reflect indicates the presence of specific minerals. This method utilizes satellite photos or aerial photos taken by humans to examine the Earth's surface, and it is also helpful in determining the accessibility of an area and identifying natural habitats such as lakes or forests.
Radiation Detection is a highly accurate, fast, and relatively cheap method for detecting minerals compared to other techniques. It relies on the fact that mineral oxides possess a unique radiation signature for each element and can be used in any location. Geochemical Analysis involves the examination of samples collected from rocks, soil, and sediments. This method is used to check for the presence of specific elements, the purity of those elements, and the overall economic value of the ore. Geophysical Methods identify mineral ores by examining their physical properties through a series of vibrations or seismic waves sent through the Earth's surface. These vibrations create shock waves that travel into the rock layers and reflect back to sensors on the surface. These shock waves record different patterns depending on the specific minerals present in the rock layers.
Economic and Environmental Factors in Mining Decisions
Several factors affect the decision to begin mineral extraction. The Cost is a primary consideration, requiring a calculation of the extraction cost per unit to determine the potential profit. This may lead to changes in mining techniques, although higher-value deposits are often not affected by the specific technique used. Geology is the study of ore grade and the amount of accessible reserves underground; small deposits of high-grade ore are considered more valuable than large deposits of low-grade ore. Accessibility refers to the path to reach the mine and the difficulty of transporting or exporting ore to the nearest factory or port using trucks, trains, or ships. Difficult access can halt the mining process entirely, although processing the ore on-site before transport can reduce costs by decreasing the volume of material. An Environmental Impact Assessment (EIA) is a specialized study done on the mine area to minimize expected impacts on living organisms and their habitats and to plan for land restoration and waste storage, while also incorporating the public opinion of local people.
Supply and Demand also impact mining, as world demand fluctuates. High demand or low supply raises prices and increases revenue, making less profitable mining more viable. Conversely, low demand or high supply lowers the price, potentially causing the mining process to fail due to the overhead costs of extraction, transportation, and taxes. The Governmental Role is concerned with issuing licenses, providing agreements to miners, and checking the EIA. Taxes and other allowances must be considered when calculating the net profit of any mining venture.
Classifications and Techniques of Mining
Surface Mining is carried out when valuable deposits are located near the Earth's surface and is the most common method used in mining projects. Open Cast mining, which includes open-pit and open-cut methods, involves the removal of vegetation and topsoil, followed by breaking down rocks with explosives and machinery. The rocks and waste are then uploaded and moved away until the ore is reached and transported. This is the easiest and cheapest method. Quarrying is a specific type of surface mining used for extracting stone, sand, gravel, and other construction materials. Overburden describes the material removed during surface mining that is stored temporarily to be replaced once the land needs restoration. Strip Mining is a specialized form of surface mining used when a valuable mineral layer, such as coal, is present near the surface in the form of strips.
Deep and Shaft Mining, also known as sub-surface mining, is utilized when mineral deposits are too deep to be reached by surface methods. This process involves machines and miners digging in both vertical and horizontal directions. A vertical shaft is constructed to reach the rock layers, which is an expensive process. Loose rock and waste are brought to the surface, and minerals are transported by trains and trucks. The advantages of deep mining include the production of less waste, less damage to the surface land, and reduced noise pollution. However, it requires the introduction of oxygen into deep mines and involves high costs for waste removal and mineral uploading. There are also significant risks of fire, explosions, or the release of poisonous gases due to the chemicals used, as well as the risk of mine collapse during earthquakes or flooding from nearby water wells. Chemicals and waste may also pollute nearby aquifers and the surrounding environment.
Environmental and Economic Impacts of Mining
Section outlines the environmental impacts of extraction, which include ecological damage such as habitat loss and deforestation. This leads to a loss of shelter and food for animals. The accumulation of overburden on the ground can destroy habitats for prolonged periods, and storing waste over trees leads to further loss of vegetation. Pollution is another major impact. Noise pollution from explosives and machinery disturbs humans and animals and can lead to decreased biodiversity by disrupting animal reproduction or migration patterns. Water pollution occurs when toxic materials reach drinking, industrial, or agricultural water sources. Chemicals from mineral ores and mining wastes can also kill aquatic animals. Bioaccumulation is a process where living organisms absorb ions that accumulate in their bodies over time without being excreted. Biomagnification occurs when these ion concentrations increase at high rates through the food chain, which can lead to the death of top-level consumers. Land pollution results from toxic materials that kill plants or prevent cultivation for a long time. Air pollution from dust reduces air clarity and can cause health problems for humans and animals while reducing the efficiency of photosynthesis. Visual pollution is caused by land waste, tree clearing, and the presence of heavy machinery.
Economic impacts include the creation of jobs in mining and transportation, the generation of taxes for the government, and increased income for the country. Mining can lead to improvements in infrastructure such as roads, ports, and factories. Local populations may benefit from access to ores, and exporting minerals can increase foreign exchange. Mining provides raw materials for industries, leading to a better standard of life and improvements in public services like healthcare and education. Effective waste management is required to reduce the impact of mining on the local environment and can potentially increase profit if waste is utilized correctly.
Managing Extraction Impacts and Land Restoration
Section focuses on managing the results of mining. Safe Disposal of Waste involves storing and handling mine waste with care to prevent collapse and pollution. This includes monitoring waste chemical stability and preventing it from reaching surface or ground water. Land Restoration can be achieved by covering mine waste and overburden with soil and fertilizers to allow plants and trees to grow back. Bioremediation is the use of living microorganisms, such as bacteria or fish, to remove pollutants. Bacteria can absorb metals, and providing the right conditions for these organisms accelerates the bioaccumulation of toxins within them. Bioaccumulation involves the increase of pollutants in an organism, which is then removed to reduce the total concentration of pollutants in a field. Biomagnification refers to the transmission of these pollutants from one organism to another within a food chain.
Mining sites can also be converted into Lakes and Natural Reserves. Introducing trees and herbs provides a new habitat and helps maintain biodiversity. Mining holes can be filled with water to serve as reservoirs for irrigation or drinking, provided the rock lining is non-toxic and contains no oil waste. Alternatively, these holes can be used as Landfill Sites for safe waste, which is placed in alternating layers with sand. Bioremediation can then be used to remove waste once the landfill is full, and regular monitoring is required to check pollution levels.
Strategies for Sustainable Resource Management
Section defines a sustainable resource as a renewable resource that can last indefinitely, such as plants or animals. Sustainable development is defined as development that meets present needs without affecting the needs of future generations or polluting the environment. Strategies for the sustainable use of rocks and minerals include increasing extraction efficiency. This can be done by re-processing mine waste to recover minerals and reduce pollutants, or by using biological and chemical extraction methods. Improving the performance of mining machines and processing through new techniques, data analysis, software, and information sharing also increases efficiency. Furthermore, increasing the efficiency of mineral use involves recycling, which uses less energy than ore processing, as well as reducing waste, reusing elements, and reducing overall consumption to make resources last longer. Legislation plays a crucial role; laws must govern all steps of the mining process including before, during, and after extraction. Such laws encourage the reuse and recycling of waste and the determination of extraction quotas to limit environmental impacts and decrease extraction rates.