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Future mineral demand
Published in Natalia Yakovleva, Edmund Nickless, Routledge Handbook of the Extractive Industries and Sustainable Development, 2022
Patrice Christmann, Elias T. Ayuk, Antonio M. A. Pedro, S. Vijay Kumar
Mining activities can easily trigger conflicts with the populations that are impacted by such activities. Large-scale open-pit mining meets ever growing opposition from potentially affected local populations and/or out of broader environmental concerns. In recent years, several large-scale mining projects have been delayed for many years, with much uncertainty about the date they may receive the necessary permits to start their operations. Some of the most prominent cases are Minas Congas (Peru, a gold deposit), Pebble (Alaska, USA; a copper, gold, molybdenum and silver deposit), Schaft Creek (British Columbia; a copper, gold, molybdenum and silver deposit) and the Panguna project (Bougainville Island, Papua New Guinea; a copper, gold and silver deposit). The latter was an operating mine for 17 years, up to 1989 when its operations came to a stop due to the civil war triggered by this operation (Hammond, 2012), probably the worst social drama related to 20th-century mining activities. Mining has not resumed yet (January 2021) despite the remaining resource of 4.6 Mt Cu (Bougainville Copper Limited, 2013) still making it one of the world’s largest copper deposits.
Mining Methods Vary Widely
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Iron, stone, gravel and many other minerals and ores are extracted by open pit mining, in which a hole is excavated into the Earth’s surface. Overburden, if present, is stripped and placed outside the pit area to uncover the mineral deposit. The pit excavation usually produces additional large volumes of waste rock that need to be removed to provide access to the ore and to create stable slopes. The ore is usually separated from waste materials (either overburden or adjacent host rock) within the pit during excavation. Rock fragmentation (drilling and blasting) and laboratory testing of samples recovered during the drilling program in preparation for blasting allows the mining engineer to classify waste rock and ore for selective disposal or treatment. It is at this stage that the detailed characteristics of orebody become apparent.
Natural Diamond
Published in Mark A. Prelas, Galina Popovici, Louis K. Bigelow, Handbook of Industrial Diamonds and Diamond Films, 2018
Henry O. A. Meyer, Michael Seal
Open-pit mining is generally more cost effective and profitable than underground mining. For this reason all kimberlite and lamproite pipes are initially developed as open-pit mines and only later, often after several years, is underground development started. The usual method in developing an open-pit mine is first to cut back a series of stepped benches in the country rock immediately surrounding the pipe. This is all waste material but is necessary in order to avoid collapse of the pit walls. The ore is removed by blasting and trucked to the surface via spiral ramps which utilize the benches constituting the walls. As the pit progressively becomes deeper so the benches in the pit walls have to be cut back in order to retain slope stability. Nevertheless, there comes a point when the cost of cutting back the waste benches is more than the economics of underground mining and at this point the open-pit has run its useful life. Prior to this, however, mine management will have been planning for underground extraction and will have already sunk a shaft at the edge of the pipe and may have undertaken initial development work for the underground activity. Thus the changeover from open-pit to underground mine is a progressive change and designed to minimize interruption of production.
Experimental Investigation of the Effect of Ultrasound on Lixiviant Ion Migration in In-Situ Recovery Processing
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Elahe Karami, Laura Kuhar, Andrej Bona, Aleksandar N. Nikoloski
Gold and copper deposits tend to have grades of less than 1 g/t or 0.62%, respectively. Traditional mining methods, such as open pit mining or underground mining, are used to extract ore from these mineral deposits. Conventional mining methods are becoming more challenging, in part because they require physical excavation, which can be extremely energy-intensive and expensive. Gangue minerals must be removed during mining operations, which results in significant waste production. It is also costly to move and store the extracted rocks afterward. As a result, the sustainability of current mining techniques in ore deposits such as gold and copper is declining, which has necessitated the development of new techniques. One alternative option is in-situ recovery (ISR), which involves using a lixiviant solution to remove metals from valuable minerals without rock excavation.
Optimizing pushback design considering minimum mining width for open pit strategic planning
Published in Engineering Optimization, 2022
Pierre Nancel-Penard, Nelson Morales
To address the fundamental problem of open pit mine design, mine planners rely on a discretization of the ore deposit into a 3-D array of blocks with attributes such as ore grades, tonnages and recoveries, among others, forming a database called the block model. The block model, together with geotechnical constraints related to the pit wall slopes and long-term economic parameters (such as costs and commodity prices) are the basic inputs for open pit strategic mine planning. From these data, the mine is designed and blocks are scheduled for extraction and processing or sent to waste dumps. As these decisions must be made to maximize the economic value of the mine, planners rely on models and algorithms to optimize profit. The first step to designing an open pit mine is computing the ultimate pit or final pit, which determines the limits of the economic envelope. It identifies which blocks should be mined and which ones should be left in the ground (Dagdelen 2001).
Review of Solution Methodologies for Open Pit Mine Production Scheduling Problem
Published in International Journal of Mining, Reclamation and Environment, 2021
Karo Fathollahzadeh, Mohammad Waqar Ali Asad, Elham Mardaneh, Mehmet Cigla
Surface mining is applicable for mineral resources or orebodies that exist at relatively shallow depths. However, surface mines require waste stripping or the extraction of overlying waste to gain access to the underlying ore or valuable material that generates profit. Therefore, for the orebodies that exist at great depths, waste stripping requirements may reach extreme limits, such that surface mining is no longer considered economic; in these circumstances, the process of underground mining becomes the only option. This confirms that even though the spatial (size, shape, depth and orientation) properties of an orebody play a significant role in the selection of a mining method, the strategic decision between surface vs. underground mining is mainly derived through the economics of a mining operation. If surface mining becomes the method of choice, then the development of reserves and infrastructure commences for a surface mining method that is appropriate to the mineral commodity under consideration [2]. Open pit mining refers to the large-scale (in terms of production) surface mining of metallic (copper, gold, iron, etc.) and non-metallic (limestone, etc.) resources. Figure 1 presents a 3D view of a copper mineralisation or orebody model in the context of an open pit mining operation.