As open pit mining of a mineral deposit deepens, the cost of extraction may increase up to a threshold where transitioning to mining through underground methods is more profitable. This paper provides an approach to determine an optimal depth at which a mine should transition from open pit to underground mining, based on managing technical risk.

1. The ore body is too deep to mine profitably by open pit. 2. The grades or quality of the orebody are high enough to cover costs. 3. Underground mining has a lower ground footprint than open pit …

The Yanqianshan iron mine is preparing to transform from an open-pit mine to an underground mine. We adopt the non-pillar sublevel caving approach to exploit the particularly thick steep ore bodies within the range from -183 m to …

Simultaneous extraction of ore reserves from open pitwall and the layer immediately adjacent to the open pit bottom results in higher volume of ore discharge in the limited bottom area, besides the bottom must be stable within the adjacent layer extraction interval. The authors select the pit bottom design with two-way alternate arrangement of …

Open-pit mining technology. Open-pit mining clearly offers a number of economic advantages over underground mining, especially now that mineral-processing technology has advanced to the stage where very low-grade ores can be treated profitably. 100 to 150 years ago, this was not the case, and mining was still much more selective.

In the study, a method based economical block models of OP and Ug to determine the Optimum Transition Depth (OTD) from Open-Pit (OP) to Underground (Ug) mining was introduced. The main idea was ...

1. Introduction. In recent years, more and more high-steep slopes were formed through years of open-pit mining around the world. Open pit to underground mining transition is normally resulted from exhausting of shallow resources [1], [2], [3], [29].This is quite dangerous as it may threaten the stability of high-steep slopes [49].In order to …

DOI: 10.1016/J.IJRMMS.2019.03.028 Corpus ID: 135092902; Use of an artificial crown pillar in transition from open pit to underground mining @article{Xu2019UseOA, title={Use of an artificial crown pillar in transition from open pit to underground mining}, author={Shuai Xu and Fidelis T. Suorineni and Long An and Yuanhui Li and Chang Yu Jin}, …

The primary methods used to extract minerals from the ground are: Underground miningSurface (open pit) miningPlacer mining The location and shape of the deposit, strength of the rock, ore grade, mining costs, and current market price of the commodity are some of the determining factors for selecting which mining method to use.Higher …

1. The ore body is too deep to mine profitably by open pit. 2. The grades or quality of the orebody are high enough to cover costs. 3. Underground mining has a lower ground footprint than open pit mining. The underground mining methods we use include room and pillar, narrow vein stoping and large-scale mechanised mining.

The transition from open pit to underground mining: An unsual slope failure mechanism at Palabora. In Proceedings of the International Symposium on Stability of Rock Slopes in Open Pit Mining and Civil Engineering, Cape Town, South Africa, 3–6 April 2006. [Google Scholar]

While both underground and open-pit mining is widely accepted mining processes, there is a greater inclination to further expand underground mining. This transition from open-pit to underground begins when open-pit mines are exhausted or inaccessible; meaning, they have either been depleted of minerals, rocks, and resources, …

Open-pit mining is a type of surface mining used to extract coal, gold, and other minerals. It creates immense water and air pollution, disfigures landscapes, …

Introduction. Open pit mining is defined as the method of extracting any near surface ore deposit using one or more horizontal benches to extract the ore while dumping overburden and tailings (waste) at a specified disposal site outside the final pit boundary. Open pit mining is used for the extraction of both metallic and nonme-tallic ores.

The ShiRenGou iron ore mine of Hebei Iron and Steel Group, China, transitioned from open pit to underground mining using sublevel open stoping based on the orebody geometry and ground conditions. In order to ensure open pit slope stability, the thickness of the crown pillar at ShiRenGou iron ore mine was set as 22 m. 29, 36 If the …

Mining - Strip, Open-Pit, Quarrying: It has been estimated that more than two-thirds of the world's yearly mineral production is extracted by surface mining. There are several types of surface mining, but the three most common are open-pit mining, strip mining, and quarrying. These differ from one another in the mine geometries created, the techniques …

Abstract Underground mining under an open-pit slope results in movement and instability of rock masses. However, most rock mass movement prediction methodologies are empirical and only suitable for underground mining. In this paper, a new theoretical methodology is proposed to predict the movement and instability of rock …

Underground mining is used when an economically viable deposit is situated sufficiently deep such that open pit mining is cost prohibitive. There exist …

The strategy for mining method selection plays an important role as it will directly affect the profit of the operation. Therefore, at this stage, the question is often 'Is the optimal mining method by open pit (OP), underground (UG) or …

Deposits close to the surface can be recovered using the open pit mining method. Underground mining methods are used for deep deposits. In some circumstances, ore may be mined by in situ recovery, a process that dissolves the uranium while still underground and then pumps a uranium-bearing solution to the surface. ... Open pit …

Open-pit mining, or open-cast 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 …

Open-pit mining, or opencast mining, is a surface mining technique used for large-scale operations. It involves extracting minerals from a pit by removing waste rock and overburden. Commonly used for minerals like copper, gold, and iron ore, requires heavy equipment such as trucks and shovels to efficiently extract the ore.

Generally, shallow deposits are mined through open-pit mining and where the deposits are extended to a substantial depth, there is a potential for a combination of open-pit and underground mining methods. In this case, mine planning and optimisation play a significant role in the decision-making.

Planning Considerations: The efficient transition from open pit mining to an underground operation requires extensive planning. For a large mining operation, planning could last as long as 20 years. The main factors and activities that need to be taken into account in the planning cycle are as follows: Definition of the ore body.

Mining: making the move from open pit to underground. As open pit copper mines reach their economic end of life, mine owners often consider the viability of transitioning to underground mining. How can they do this safely, economically and …

1 of 2. next ›. There are four main mining methods: underground, open surface (pit), placer, and in-situ mining. Underground mines are more expensive and are often used to reach deeper deposits. Surface mines are typically used for more shallow and less valuable deposits. Placer mining is used to sift out valuable metals from sediments in ...

Open pit and underground mining. Where orebodies lie close to the surface, they are usually accessed by open cut mining, involving a large pit and the removal of much overburden (overlying rock) as well as a lot …

The failure of underground goafs will change the structure and stress status of a rock mass. More seriously, such a failure can lead to large areas of rock mass collapse, greatly impacting the mine operations and personnel safety (Hoek and Brown 1980; Bye and Bell 2001; Chen et al. 2017).For mines that are transforming from open-pit to …