MEG 1142: INTRODUCTION TO MINING AND MINERAL ECONOMICS

[Audio] FACULTY OF SCIENCE ENGINEERING, AND AGRICULTURE DEPARTMENT OF EARTH SCIENCES MEG 1142: INTRODUCTION TO MINING AND MINERAL ECONOMICS MODULE CREDIT VALUE: NQF LEVEL: LECTURE NOTES/GUIDE 2025 LINDELANI TSHILATE.

[Audio] WELCOME Dear Students, It is with great enthusiasm that I welcome you to Introduction to Mining and Mineral Economics, a foundational module designed to equip you with essential knowledge about the mining industry and its economic significance. Mining plays a pivotal role in global development, supplying the raw materials that drive industries, infrastructure, and technological advancements. However, the sector also presents challenges, including sustainability, resource management, and economic fluctuations, making it crucial for professionals to understand both the technical and financial dimensions of mining. Throughout this module, we will explore key topics such as mineral resource classification, the economics of mineral markets, cost estimation in mining operations, and the principles governing investment decisions in the extractive industry. You will gain insight into how economic factors influence mining feasibility, pricing, and policy-making, preparing you for real-world applications in the field. Our learning approach will be interactive, integrating theoretical concepts with practical case studies and discussions on current industry trends. I encourage you to engage actively, ask questions, and apply critical thinking as we navigate the dynamic landscape of mining and mineral economics. I look forward to an exciting and insightful journey with you all. Welcome aboard.

[Audio] Purpose of the Module Developing DecisionExploring Mineral The module Understanding the Fundamentals of Making and Policy Resource Economics Mining Awareness Introduction to Mining and Mineral Economics serves as a Introduce students to the foundational course aimed at equipping Examine the economic significance of mineral principles of mineral Introduce regulatory frameworks, mining students with essential resources, including supply extraction, mining knowledge and methods, and the lifecycle policies, and the impact of global commodity markets and demand dynamics, price fluctuations, and of a mining project. on national economies market structures. analytical skills related to the mining industry and its economic Provide insight into the introduce cost estimation, role of mining in Introduce concepts of investment analysis, risk valuation, and financial supporting industrial assessment, and feasibility in mining implications. The key academic purposes of this module include: development and global sustainability in mining projects. economies. operations..

[Audio] Purpose of the Module Enhancing Critical Thinking and Preparing for Industry and Problem-Solving Research Skills Applications Lay the groundwork for advanced studies in mining engineering, Develop the ability to assess the financial viability of mineral ventures. mineral economics, and resource management Equip students with skills applicable to careers in Explore strategies for sustainable resource mining companies, financial institutions, management policy advisory roles, and regulatory bodies.

[Audio] Expected Outcomes Understanding the Fundamentals of Mining and Mineral Sustainability in · Market Economic Analysis Economics Mining Dynamics of Competence in Mining Methods and Techniques Students will gain of Mineral Resources Minerals a thorough Project Appraisal and Investment Decision-Making Students will understanding of Students will be able to identify and describe Students will understand the importance of Students will explore the acquire skills to perform basic Students will the basic concepts, sustainable gain insight into principles, and different mining methods (e.g., economic analysis of terminology open-pit, market structure, pricing, and trade dynamics of key related to mining underground) mineral the financial assessment of mining projects, and their mineral deposits, including and mineral economics, applications in mining practices and their impact on communities, the environment, and the economy, with a focus on commodities, understanding how global and including resource various evaluating the costs, benefits, resource classification, geological and and risks conservation and local market conditions extraction including investment analysis, cost estimation, and risk assessment influence the processes, and economic contexts. associated with mining projects. environmental management. mining industry. economic valuation of minerals..

[Audio] Contact details Personnel Name Room No Telephone number Email address Consultation hours FE-01, Mondays: 13H00-14H00 Lecturer 0159928936 Lindelani.Tshilate@univen.ac.za Wednesdays: 09H00-11H00 Ms. Lindelani Tshilate Thursdays: 10H00-11H00 1st Floor, School of Environ mental Sciences Class Representative.

[Audio] Teaching Timetable Contact session Day Time Venue Monday 12H00 B2 Wednesday 08H00 A8 Lectures Thursday 09H00 C6 Practical No practicals Tutorials Will be communicated in class Online Lectures Will be communicated in Class.

[Audio] WEEKS CONTENT ASSESSMENT/WEIGHING 1 Introduction 1 Assignment: 15% Concepts, mining terminologies, importance of mining Test 1: 25% 2 Minerals, classification and use of minerals. Fundamentals of mining 3 Stages of mining Prospecting, exploration, development and exploitation, rehabilitation and closure 4, 5 and 6 Surface mining Open pit mining, quarrying, open cast mining and auger mining 7 and 8 Underground Mining Test 2: 20% Underground entries, infrastructure and services 1Quiz: 5% 9 and 10 Unsupported Mining Methods MODULE Room and pillar, stope and pillar, shrinkage stopping and sublevel stopping 11 and 12 Caving Methods CONTENT/COURSE Longwall mining, sublevel caving and block caving 13 and 14 Supported Mining Methods OUTLINE Cut and fill stopping, Vertical Crater retreat 15 Mineral Economics Introduction 16 Mine feasibility studies Test 3:20% Semester marks: 60% 17 Project evaluation, scoping studies 18 Resource assessment 19 Supply and demand, factors of production 20 Risks associated with mining 20 LECTURES END REVISIONEXAMINATION.

[Audio] READING LIST 1. Introductory Mining Engineering, 2nd Edition, Howard Hartman and Jan Mutmansky, 2007. John Wiley & Sons, Inc. 584p. 2. Surface and underground excavations: methods, techniques & equipment, by Tatiya, R.R., 2005. A.A. Bakema, 579p. Mining and the Environment: From Ore to Metal, by Karlheinz Spitz and John Trudinger, 2009. CRC Press, Leiden. 3. SME Mining Engineering Handbook by Howard L. Hartman. Volume one. 1992. Society of Mining, Metallurgy, and Exploration, Inc. Littleton, Colorado 4. Mineral Exploration and Mining Essentials by Robert Stevens. 2011..

[Audio] Fhatuwani.Ravhuhali@univen.ac.za Staff Academic Support & Student Academic Support Contact details: Dr F Ravhuhali 015 962 8116 Email: Fhatuwani.Ravhuhali@univen.ac.za Refilwe.Nemutandani@univen.ac.za Career development, counseling and therapy services Contact details: Dr. Refilwe Pila-Nemutandani 015 962 8156 Email: Refilwe.Nemutandani@univen.ac.za Azwitamisi.Gadisi@univen.ac.za Disability Unit Contact details: Mr A Gadisi 015 962 8716 Email: Azwitamisi.Gadisi@univen.ac.za Learner Support and Development Willie.Xazela@univen.ac.za E-learning Unit Contact details: Mr Willie Xazela 015962 8894 Email: Willie.Xazela@univen.ac.za Library Support Faculty Librarian information.

[Audio] WHAT IS MINING?. WHAT IS MINING?.

[Audio] INTRODUCTION oMining is the systematic process of extracting valuable minerals, ores, and geological materials from the Earth's crust to be used in various industrial, technological, and economic applications. o It encompasses a range of scientific, engineering, and economic disciplines, including geology, geotechnical engineering, mineral processing, and environmental management. o The process involves exploration, resource estimation, extraction, and beneficiation while ensuring sustainability and minimal environmental impact. o Any extraction of valuable minerals or other geological materials, usually from a deposit of ore, lode, vein, seam, reef, or placer from the earth, is referred to as mining. oMining plays a crucial role in global development by supplying raw materials essential for infrastructure, manufacturing, and energy production oOres recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. o Ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit..

[Audio] IMPONTANCE OF MINING o Mining is first and foremost a source of mineral commodities that all countries find essential for maintaining and improving their standards of living. o Mined materials are needed to construct roads and hospitals, to build automobiles and houses, to make computers and satellites, to generate electricity, and to provide the many other goods and services that consumers enjoy. o In addition, mining is economically important to producing regions and countries. It provides employment, dividends, and taxes that pay for hospitals, schools, and public facilities..

[Audio] IMPORTANCE OF MINING o.The mining industry produces a trained workforce and small businesses that can service communities and may initiate related businesses. o Mining also yields foreign exchange and accounts for a significant portion of gross domestic product. oMining fosters several associated activities, such as manufacturing of mining equipment, provision of engineering and environmental services, and the development of world-class universities in the fields of geology, mining engineering, and metallurgy. The economic opportunities and wealth generated by mining for many producing countries are substantial..

[Audio] MINING TERMINOLOGIES Mine: An excavation made on the earth to access extract minerals. Mining: The processes concerned with the extraction of minerals from the surface or underground. Mining Engineering: The practice of applying engineering principles to the development, planning, operation, closure, and reclamation of mines. Mineral: A naturally occurring inorganic element or a compound having an orderly internal structure and a characteristic chemical composition, crystal form, and physical properties. Mineralization: Any single mineral or combination of minerals occurring in a mass, deposit of economic interest. 11.

[Audio] MINING TERMINOLOGIES Rock: Any naturally formed aggregate of one or more types of mineral particles. Ore: A mineral deposit that has sufficient utility and value to be mined at a profit. Gangue: The valueless mineral particles within an ore deposit that must be discarded. Waste: The material associated with an ore deposit that must be mined to get at the ore and must then be discarded..

[Audio] CLASSIFICATION OF MINERALS Minerals are conveniently sub-divided into three main categories according to their primary constituent and usage. Metallic ores: those ores of the ferrous metals (Fe, Mo & W), the base metals (Cu, Pb, Zn & Tn); the precious metals(Au, Pt, Pd& Rh ); and the radioactive minerals (U, Th, Ra, Po etc.). Nonmetallic minerals (also known as industrial minerals): the non-fuel mineral ores that are not associated with the production of metals. These include phosphate, potash, halite, sand, gravel, limestone, sulfur, and many others. Mineral fuels (also known as Fossil fuels): the organic mineral substances that can be utilized as fuels, such as coal, petroleum, natural gas, coalbed methane, Gilsonite, and tar sands..

[Audio] Classification of mineral Resources and Reserves.

[Audio] PRINCIPLES/FUNDAMENTALS OF MINING oThe essence of mining in extracting mineral from the earth is to drive or construct an excavation. This is a means of entry from the surface to the mineral deposit. o When the value of the mineral is established with some confidence, usage of the terms ore and ore deposit is preferred, except for coal and stone deposits are usually so designated by their names. o If the excavation is entirely open to or operated from the surface, it is called a surface mine. o If the excavation consists of openings for human entry driven below the surface, then it is an underground mine..

[Audio] PRINCIPLES/FUNDAMENTALS OF MINING oThe specific details of the procedure, layout, and equipment used to distinguish the mining method are uniquely determined by the physical, geologic, environmental, economic, and legal circumstances that prevail. o Mining is not done in isolation nor is it an entity unto itself. It is preceded by geologic investigations that locate the deposit and economic analysis that prove it financially profitable..

[Audio] PRINCIPLES/FUNDAMENTALS OF MINING o Following the extraction of the coal, stone, or ore, the run-ofmaterial is generally prepared or beneficiated in procedures termed mineral processing. oThe products of those processes may then undergo further concentration, refinement, or fabrication during conversion, smelting, or refining to provide consumer products. The end step of converting a useful mineral into a usable product is marketing..

[Audio] STAGES OF MINING The overall sequence of activities involved in modern mining can be expressed as stages in the life of a mine. There are five stages: prospecting, exploration, development, exploitation and rehabilitation.

[Audio] Prospecting The first stage in the mining process calls for skilled workers or personnel to apply their geological knowledge in identifying areas where a particular ore can be found. There are two methods workers and machines can employ during this stage: Direct Method Focuses solely on the examination of deposits found on or near the surface. Methods include visual examination via microscopic study and video prospecting. Indirect Method Applied on deposits found deeper in the land. Methods include radiometric, seismic, and magnetic.

[Audio] Exploration o In the second stage of mining, core samples are collected for the purpose of evaluating the grade and weight of deposits. Diamond drills are used to obtain samples. o Once the reserve estimation is complete, meaning the value of the deposit is determined, a feasibility study must then be conducted to help determine whether to abandon or develop the deposit. o Mineral exploration involves data collection by the company through a variety of investigations which typically involves surveys. These can include geophysical (for example, magnetic, gravity and/or electromagnetic) or geochemical surveys that are more detailed than those publicly available. o Geophysical surveys are typically high-resolution airborne surveys in the early stages of target generation, but these may be supplemented by ground geophysical surveys, geological mapping, geochemical sampling and even reconnaissance drilling to collect geochemical samples. These surveys are aimed at generating targets for testing and evaluation..

[Audio] Exploration continued o Identified targets are tested by drilling, pitting, trenching and/or surface sampling as appropriate and samples undergo geochemical analysis and other tests to determine and delineate zones of likely mineralisation. This targeted exploration may identify zones of economic mineralisation. o If an economic ore body is discovered at this stage, further drilling and sampling take place to fully map and define the size, grade and geometry of the deposit. When this is completed, the project is evaluated..

[Audio] Mine-site Design/Planning Upon determining to work on the site, the designing and planning stage begins. This process calls for the use of studies that help determine whether the project is: o Safe o Socially responsible o Environmentally sound o Economically viable.

[Audio] Mine Development oThis stage of the mining process requires establishing a path to the mineral deposit. That path, however, requires more than excavation. oIn order to even begin work, mining rights must be acquired, access roads must be constructed to help workers navigate the site, and a power source must be established. oThis stage involves the construction and development of the mine site and related facilities. The requirements at this stage will be influenced by the availability and cost of infrastructure and services. Critical infrastructure and services include power, water and transport. Accommodation of workers close to the mine site is also an important consideration..

[Audio] Mine Development oMining companies may choose to expand an existing town or urban centre where the mine is close enough for workers to commute. oWhere the mine site is more remote, a 'company town' may be established, or, In cases where establishing a town is not feasible, the company may provide temporary accommodation on site and run fly-in fly-out operations where workers commute a long distance to the mine site on a roster. o Long distance commuting has become more popular, particularly for remote projects, or where companies employ workers from one region to work in a neighbouring or close region..

[Audio] Exploitation/Production o Once these elements are obtained, the physical mining process or, the first step of production begins. The mining process can be broken down into two categories: Surface Mining o Workers begin by striping the overburden, which is rock, soil, and ecosystem that lies above the surface. Underground mining oThe digging of tunnels and sink shafts when the ore or mineral deposit is below the surface. Hand tools such as chisels, hammers, and wedges are used to break up waste rock, Sometimes, areas must even be blasted in order to loosen rock so workers can more easily separate the ore from the waste rock which are mined separately..

[Audio] Exploitation/Production oThe next step, once the ore is excavated, is to separate the waste rock and ore using primary crushers, located at the open pit mine site. At this point, larger rocks are broken down to a size better suited for the conveyor belt to transport. o From there, the ore is transported to a separate facility for smelting, which is: The process of melting the ore concentrate in a furnace to separate the metal and then sold to different companies depending on the customers specification..

[Audio] Closure/Rehabilitation/Reclamation Once the ore has been processed and shipped away for sale, the final step of the mining process begins. The land which was used to obtain these resources must be rehabilitated as much as possible. The objectives of this process include: o Minimizing environmental effects o Ensuring public health and safety o Reserving water quality o Establishing new landforms and vegetation o Removing waste and hazardous material o Stabilizing land to protect against erosion.

[Audio] Factors Affecting Exploitation of Minerals Size and grade of the deposits: unless the deposits are of reasonable size and high grade, it might not be worthwhile investing in expensive equipment and basic infrastructure to undertake the mining. Mode of occurrence: if the deposits occur too deep in the earth's crust or in many remote places such as in the ocean, the cost of extraction may be too high. Transport costs: minerals occurring in remote, sparsely populated regions, away from the urban and industrial markets, may not be worth mining as the cost of constructing transport networks might outweigh the profit derived. Labour supply: workers must be available if any mining is to be undertaken, if a mine is in a distant place, it will be very difficult to secure a reasonable supply of workers and site engineers..

[Audio] Surface Mining Methods o Open cast Mining o Open Pit Mining o Quarrying o Hydraulic Mining Methods oAuger Mining.

[Audio] oSurface mining are methods of extracting minerals near the surface of the Earth. It is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which the overlying rock is left in place, and the mineral is removed through shafts or tunnels Surface Mining Methods oSurface mining methods are traditionally divided into two classes: mechanical and aqueous. oMechanical methods rely on breaking the ore by mechanical means, and aqueous methods rely on the use of water or another solvent, e.g., an acid, to break down the ore and facilitate its removal..

Mechanical Extraction Methods Surface Mining Methods Aqueous Extraction Methods Open Pit Mining Open Cast Mining Qua trying (of dimension stone) Auger Mining & Highwall Minine Area Mining Placer Mining Hydraulic Memng otedgine SolLRion Mining Borehole Leaching Extraction.

[Audio] UnitCycleofoperationformechanicalmethodsoTheunitoperationsofminingarethebasicstepsusedtoproducemineralfromthedeposit,andtheauxiliaryoperationsthatareusedtosupportthem.oThestepscontributingdirectlytomineralextractionareproductionoperations,whichconstitutetheproductioncycleofoperations.Theassociatedstepsthatsupporttheproductioncyclearetermedauxiliaryoperations.oTheproductioncycleemploysunitoperationsthatarenormallygroupedintorockbreakageandmaterialshandling.oBreakagegenerallyconsistsofdrillingandblasting,andmaterialshandlingencompassesloadingorexcavationandhaulage(horizontaltransport)andsometimeshoisting(verticalorinclinedtransport)..

[Audio] Unit Cycle of Operation/Production Cycle oThus, the basic production cycle for surface mining consists of these unit operations: Production cycle= drill + blast + load + haul oThe cycle of operations in surface and underground mining differs primarily by the scale of the equipment. Specialized machines have been developed to meet the unique needs of the two mining methods. o In underground mining, the production cycle is similar, although the equipment used may be scaled down in size. Smaller drillholes are used, trucks are sometimes replaced by shuttle cars, and belt conveyors are more prevalent. oCoal, salt, and potash are often mined without the use of explosives or mined after undercutting the face to reduce the consumption of explosives..

[Audio] Auxiliary Operations o In addition to the operations of the production cycle, certain auxiliary operations must be performed in many cases. o In surface mining, the primary auxiliary operations include providing slope stability, pumping, power supply, maintenance, waste disposal, and supply of material to the production centres o In underground mining however, these usually include roof support, ventilation and air conditioning, power supply, pumping, maintenance, lighting, communications, and delivery of compressed air, water, and supplies to the working sections..

[Audio] Open Pit Mining. Open Pit Mining.

[Audio] oThis type of mining is used for near-surface deposits, primarily metal and nonmetal. In open pit mining, a thick deposit is generally mined in benches or steps, although thin deposits may require only a single bench or face. Open pit or open cast mining is usually employed to exploit a near-surface deposit or one that has a low stripping ratio. It often require a large capital investment but generally results in high productivity, low operating cost, and good safety conditions. oThe overburden is hauled away to a waste area and a large pit is excavated into the orebody. The depth of the pit is increased by removing material in successive benches. A few examples of commodities mined by this method would include iron and diamonds. o Open pit mining of relatively shallow deposits or very large low-grade deposits typically involves overburden removal, blasting, mucking, loading, hauling, and dumping. In addition to the commodity being mined, materials overlying, within and adjacent to the ore deposit, are removed. An open pit is formed by the successive removal of layers (termed benches) of rock..

[Audio] Open Pit Terminologies There are several terminologies that are used for open pit mining, and these include: oBench: A bench may be defined as an outcrop that forms a single level of operation above which mineral or waste materials are mined back to a bench face. The mineral or waste is removed in successive layers, each of these forms a bench. NB: Several benches may be in operations simultaneously in different parts of, and at different elevations in the open pit mine. oBench height: The bench height is the vertical distance between the highest point of the bench or the bench crest, and the toe of the bench or it is the vertical distance between each horizontal level of the pit. Unless geologic conditions dictate otherwise, all benches should have the same height..

[Audio] Open Pit Terminologies oThe bench height should be set as high as possible within the limits of the size and type of equipment selected for the desired production, but it should not be so high that it will present safety problems of towering banks of blasted or unblasted material or of frost slabs in winter. The bench height in open pit mines will normally range from 15m in large copper mines to as little as 1m in uranium mines. The height will depend mainly on the; (1) Physical characteristics of the deposit; (2) The degree of selectivity required in separating the ore and waste with the loading equipment; (3) The rate of production; (4) The size and type of equipment to meet the production requirements; and (5) The climatic conditions..

[Audio] Open Pit Terminologies Bench slope: The bench slope is the angle, measured in degrees, between the horizontal and an imaginary line joining the bench toe and crest. Pit limits: Pit limits are the vertical and lateral extent to which the open pit mining may be economically conducted. The cost of removing overburden waste material vs. the minable value of the ore is usually the prime factor controlling the limits of the pit. Berm: To enhance the stability of a slope within the pit - and for safety reasons- berms may be left. A berm is a horizontal shelf or ledge within the ultimate pit wall slope. The berm interval, berm slope angle, and berm width are governed by the geotechnical configuration of the slope. Overall pit slope angle: The overall pit slope angle is the angle at which the wall of an open pit stands, as measured between the horizontal and an imaginary line joining the top bench crest with the bottom bench toe. Stripping ratio or strip ratio refers to the ratio of the volume of overburden (or waste material) required to be handled in order to extract some volume of ore. For example, a 3:1 stripping ratio means that mining one cubic meter of ore will require mining three cubic meters of waste rock.

Illustration.

[Audio] Pit Planning and Design Open pit mining is a method that is simple in concept but complex in its costs and efficiency requirements due its heavily engineered nature. It, therefore, requires careful planning and execution in order to keep unit costs at a minimum. It is, therefore, crucial to consider the following factors in the initial pit planning and design: o Natural and geologic factors: geologic conditions, ore types and grades, hydrologic conditions, topography, metallurgical characteristics, climate and environmental variables of the site. o Economic factors: ore grade, ore tonnage, stripping ratio, cut-off grade, operating cost, investment cost, desired profit margin, production rate, processing and smelting costs, and market conditions. oTechnological factors: equipment, pit slope, bench height, road grade, transport options..

[Audio] Geologic Conditions suitable for open pit mining Ore and rock Strength: it can be employed to ore bodies with varying degrees of physical strength, but preferably moderate to stronger ore and host-rocks are required for deep orebodies Deposit shape: this mining technique is suitable for mining ore deposits with varying shapes. Dip angle: it is also suited to mining ore deposits with low dip angles Size of Ore deposit: open pit is more favourable to large or thick ore deposits Ore grade uniformity: it is mostly preferred when mining ore deposits characterized by uniform ore distribution. Depth of ore deposit: it is also applicable to mining shallow to intermediate ore bodies.

[Audio] Unit Cycle of Operation Stripping overburden: Stripping applies both to removing overburden external to the mineral deposit and removing waste within the confines of the open pit. The nature of the overburden or waste determines the cycle of operations. If unconsolidated (soil or broken rock), then breakage is not required; if consolidated (rock in place), then breakage is required. Material handling equipment are then selected to satisfy the operation conditions. Excavation equipment includes powers hovel, front-end loader, dozer, scraper (soil), Dragline, bucket wheel (soil). The haulage unit may be a truck, belt conveyor, dozer or scraper (soil). Mining: Drilling, blasting/ripping, excavating (loading), hauling/hoisting Auxiliary operations: slope stability control and monitoring, dust control, pumping and drainage, waste disposal, maintenance of equipment and haul roads..

[Audio] Open pit mining methods are ideal for extraction of near-surface ore bodies having substantial horizontal dimensions and little or no overburden over. The method is flexible, allowing for large fluctuations in production schedules at relatively short notice, and can be highly mechanized. As such it is the most productive of all the mining methods. Given favourable stripping ratio and climatic conditions open pit mining produces ore at a fraction of the cost of underground methods. Advantages of Open Pit Mining The method requires relatively few men who can be readily trained and supervised and has a lower accident frequency rate than underground operations. With open pit mining methods, grade control can be easily accomplished by separating lean or waste sections from the ore and mining them separately. This is accomplished by assaying the cuttings from the blast holes drilled on each bench and determining which portions of the bench make ore..

[Audio] Open Cast/Strip Mining. Open Cast/Strip Mining.

[Audio] Open cast mining is also known as strip mining and is used for bedded deposits, and most commonly for coal. Although it is similar to open pit mining, the distinguishing characteristic is that the overburden is not hauled away to waste dumps; but rather, it is immediately cast directly into the adjacent mined-out cut. There are two important sub methods for open cast mining. o One is known as area mining, and is applicable when the terrain is relatively flat; and the other is o Contour mining, better suited for mountains regions. A few examples of commodities mined by this method include coal and phosphate.