Open pit mining, bench height, multicriteria decision making. Openpit mining is an operation in which blocks from the ground are dug to extract the ore contained in them, and in this process a deeper and. In the first steps we see strip mining techniques used from explosives, to surface scraping and bulldozing resulting in quite bland rock formations. The word is used to distinguish this type of mining from extractive methods that need tunneling into the earth. Sme mining engineering handbook 3rd edition knovel. The thickness that is, the height of the benches depends on the type of deposit, the mineral being mined, and the equipment being used. Openpit mining openpit mining, also known as opencast mining, opencut mining, and strip mining, means a process of digging out rock or minerals from the earth by their elimination from an open pit or borrow.
Dewatering techniques and applications open pit mining underground mining transition advantages and disadvantages costing, opex and capex legal requirements and permitting day 10. To assess this information and to extrapolate to the next twenty years, this approach has been reinforced using published. Underground mining in porgera employ a unique mining method known as avoca mining. Okubo encyclopedia of life support systems eolss figure 2. Worldwide, 40 percent of mining occurs at the surface, according to greenpeace international. However, blasting creates serious concerns for the mine operators and miners in terms of blast area security. However, surface mining can be more environmentallydamaging than subsurface mining. Openpit mining is the most common method used throughout the world for mineral mining and does not require extractive methods or tunnels. Open pit mining, mineral processing, materials handling.
Known also as opencast mining, openpit mining is the most common type of surface mining. Introduction as a definition in open pit mining, bench height is the vertical distance between crest and toe of the bench fourie and dohm, 1992. Mathematical optimization models and methods for openpit mining. Porgera underground mine and its mining methods basic. The mining rate is greater than 20,000 tonnes per day tpd but is usually much greater. Blasting is a great tool in fragmenting and loosening rock and other materials for easier handling and removal by mining equipment. Pit mining is more cost effective than shaft mining because more ore can be extracted and more quickly. If the deposit apexes below the surface, the overburden and barren capping overlying the ore must be removed in advance of openpit mining. Open pit mining does offer some advantages over traditional deep shaft mining. Openpit mines are used when deposits of commercially useful ore or rocks are found near the surface. Open cast mining involves the removal of ore from seams. In addition, the work can be used as a practical reference by professionals. Open pit mining mining methods 5 open pit mines are used to exploit low grade, shallow ore bodies. Optimized open pit mine design, pushbacks and the gap.
In 1978, the year the mine safety and health administration was established, 242 miners died in mining accidents. The unique waste handling needs, including tailings disposal, of contemporary oil. A mineral, with a few exceptions, is an inorganic substance occurring in nature that has a definite chemical composition and distinctive physical properties or molecular structure. At the strategic level, the ultimate pit limit upl problem, based on the seminal work of lerchs and grossmann 1965, provides a solution for the ultimate pit limit contours of a deposit with the objective of maximizing total pro. Shaft mining and open pit mining by victoria smith on prezi. Strip mining is the process of mining a seam of mineral by removing a long strip of overlying soil and rock.
Download complete pdf of the porgera underground mine and its mining method. Open pit mine planning and design, third edition mining. The ore is very near to the surface of the land but has one or more layers of rock and filth on top of it. This form of mining differs from extractive methods that require tunnelling into. Application of optimisation techniques in open pit mining. Optimization techniques in open pit mining, proceedings of australasian institute of mining and metallurgy 2918 1986, pp. This type of mining is particularly damaging to the environment because strategic minerals are often only available in small concentrations, which increases the amount of ore needed to be mined. In an open pit mine, loader types can include electric rope, hydraulic excavators including backhoe excavators, and frontend loaders also called wheel loaders er. Openpit mining deposits mined by openpit techniques are generally divided into horizontal layers called benches. The range of available machines and techniques can only be classed as universal, pacesetting and comprehensive. Assessing and monitoring open pit mine highwalls jami m. Openpit, opencast or open cut mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow this form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining. The steps in strip mining are similar to openpit mining. Openpit mining methods are applicable to mining ore deposits that apex at or near the surface.
The two industries ranked together as the primary or basic industries of early civilization. Some pits operate at a rate of more than 100,000 tpd. Graph g with dummy node x0 and arcs added from the dummy node x0 to all other nodes. The working conditions are safer for the miners because there is no risk of cave in or toxic gas. Geotechnical considerations open pit audit guide page 3 of 28 1 mine planning and design mine planning and design point standard guideline 1. Underground mines are more expensive and are often used to reach deeper deposits. The typical large open pit mining operation that has been in production for 10 years and more is operating under conditions that could not possibly have been foreseen by the original planners of. Application of optimization techniques in open pit mining, proc. Although there are mine shafts all around the world, most shaft mines are located in south africa because it has so many diamond and gold deposits. Openpit mining is the process of extracting rock or minerals from the earth through their removal from an open pit or borrow. The fimiston open pit, known as the super pit, located in kalgoorlie in western australia. In a hard rock mine, the bottom of the pit would be the lowest level elevation that mining would be conducted on the ore being mined. The open pit design and scheduling problem is a largescale optimization problem that has attracted considerable attention during the last 40 years the development of the knowhow to improve economics of open pit mining projects through the use of mathematical optimization techniques goes back to early 1960s.
Open pit mining mining methods hydraulic gassification opencast mining open cut mining surface or strip mining final pit. In many cases, logging of trees and clearcutting or burning of vegetation above the ore deposit may precede removal of the overburden. Open pit mine planning and design is an excellent textbook for courses in surface mine design, open pit design, geological and excavation engineering, and in advanced open pit mine planning and design. Mine dewatering and water management at barrick goldstrike. Google scholar caccetta, l, giannini, lm and kelsey, p. Shaft mines hold the record for being the deepest mines in the world. Surface mines are typically used for more shallow and less valuable deposits. This form of mining differs from extractive methods that require tunnelling into the earth, such as long wall mining. Open pit mining or strip mining is an extraction process for ore or fossil fuels that takes place at the surface of a mining site. Open pit mining techniquessurface minesrock or mineral.
Each one of these problems is very complex, so the operation of a large openpit mine is an enormously difficult task. Throughout this paper, we consider a \loader to be any type of high productivity excavating equipment, which may include a mining loader, shovel or excavator. Modern day heap leaching, which has a relatively low level of energy consumption, is for example. Surface mining machinery glossary bibliography biographical sketches summary this chapter deals with surface mining. Shallow, flat coal deposits are mined by surface processes, which are. In 2003, the deepest mine was the east rand mine at 3585 m. Geotechnical considerations in open pit mines version 1. Another example of very large open pit is given by these images taken. It is clear from the definition of our graph g that a graph closure in g represents a physically feasible pit, if not, then a block not in our closure violating the slope. In a open pit coal mine, the pit bottom would be the bottom mined coal seam elevation, since it is usually feasible to extract multiple seams when surface mining coal.
Surface mining methods dominate the world production of minerals. Openpit, opencast or open cut mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow. The removal of this material is known as stripping. Open pit mines are used to exploit low grade, shallow ore bodies. Surface miningplanning and design of open pit mining presentation pdf available march 2010 with 18,876 reads how we measure reads. Open pit mining, where material is excavated from an open pit, is one of the most common forms of mining for strategic minerals. Compared with underground mining, surface mining is much more efficient.
Informative presentation you came across to know about open pit mining. Branch and cut methods for mixed integer linear programming. Selection of practical bench height in open pit mining. The typical large open pit mining operation that has been in production for 10 years and more is operating under conditions that could not possibly have been foreseen by the orig inal planners of. The word is used to distinguish this type of mining from. Loaders lift the ore or waste material onto the trucks for removal from the mine. This unique course enables you to learn the basic theory of open pit mine design and the application thereof, whilst having the chance to interact with experts in the field. Strip mining, openpit mining, surface mining, mining. Placer mining is used to sift out valuable metals from sediments in river channels, beach sands, or other environments. Strip mining is a practical type of mining when the ore body that is to be extracted is near the surface. Epa hardrock mining conference 2012 flow model projection 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5100 5200 0 50 100 150 200 250 300 350 400 stage in feet amsl recovery time in year simulated pit stage groundwaet r level pit water stage postmining pit lake recovery simulated maximum. These images are from the largest open pit gold mine in australia. Determination of optimum bench height is a major concern in most open pit mines.
Mining, process of extracting useful minerals from the surface of the earth, including the seas. Sme mining engineering handbook 3rd edition details. Change in production and productivity of us coal mines the higher productivity for open pit mining equipment also lowers costs. This project was completed mainly through the use of questionnaire sent to subcontractors in almost each country of the eu. Unesco eolss sample chapters civil engineering vol. Heap leaching is a tried and tested mining technique enabling the processing of different kinds of ores which could not otherwise be exploited under viable economic conditions. As open pit operations contributes a big junk of the mines production, the underground operations also contrite considerable amount of high grade gold. Training the people who work in the mining industry and retraining annually helps reduce deaths, injuries and illnesses. Openpit mining is the process of extracting rock or minerals from the earth through their removal from an open pit.
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