There are three unique scenarios that represent open pit and underground interaction: Scenario 1 – Open pit transitioning to underground: This is the most likely to occur in …
Open-pit mining is a surface mining technique that involves extracting minerals from ore deposits near the topsoil. Unlike conventional underground mining methods, these operations are extensive projects …
Open pit mining method is one of the surface mining methods that has a traditional cone-shaped excavation and is usually employed to exploit a near-surface, nonselective and low-grade zones deposits. It often results in high productivity and requires large capital investments, low operating costs, and good safety conditions. The main …
1 Introduction. The transition from open pit (OP) to underground (UG) methods requires a large capital cost for development and potential delays in production but can provide access to a large …
Underground hard-rock mining accounts for 40 percent of global mining operations but only 12 percent of run-of-mine (ROM) production. 1 Underground mines also tend to be more targeted, more costly, and less productive than open-pit mines. Because the choice of which underground method to deploy is predominantly driven by the …
Simultaneous operations of open pit and underground macroblock caving. The Chuquicamata transition business case is to maintain the current production rate of 140,000 t/d, as shown in Fig. 9, requiring simultaneous open pit and underground macroblock operations. This is to be achieved within an 18-month period (July 2019 to …
This paper proposes a mixed-integer programming model to obtain the optimal transition point and the transition period from open-pit to underground mining, …
The macro-micro mining response of the surrounding rock and overlying strata towards the transformation from open-pit to underground mining is examined in the present study, based on the engineering background of the Jinning phosphate mine (Yunnan Phosphate Chemical Group Co., Ltd.) via simulations involving similar …
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Open Pit to Underground - Transition and Interaction. Many ore deposits have considerable vertical extent which is not always known at the time of commencement of mining. In many of these cases, initial mining is by opencast methods, and as ore reserves are proved to greater depths, the pits are often planned to go deeper than had been ...
The first method for determining transition depth from open-pit to underground was the "Allowable Stripping Ratio", which is a relation between the exploitation cost of 1 ton of ore in underground (and in open-pit) and the removal cost of waste in relation to 1 ton of ore extracting by open-pit [16, 17].
The entry from the surface to an underground mine may be through a horizontal or vertical tunnel, known as an adit, shaft or decline. Underground mining is practical when: The …
The decision to exploit a mineral deposit that can be extracted by open pit and/or underground mining involves consideration of the following options: (a) independent open pit extraction; (b ...
The Sangan mine locates in north eastern of Iran in Khorasan province. According to the primitive designs, about 50 million tons of ore are to be extracted from an open pit with a maximum depth of 260 m. In this case, the remained portion of ore beneath the open pit would be extracted by an underground mining method.
In Fig. 2, level A represents the primitive open pit bottom that is traditionally calculated without considering the production scheduling of the underground portion (commonly used as the basis for open pit mining); level B represents the optimum transition depth (suggested in this study); and level C stands for the smallest beneficial pit (not ...
As open-pit mining progresses, the depth of extraction and stripping ratio increase, eventually reaching a point where the cost of open-pit mining equals that of underground mining (Bakhtavar et ...
A novel opportunity cost approach is presented, allowing it to take into account a crown pillar, and it is shown how the new approach can be best applied through the unconventional application of an existing mine optimisation tool. Many Ore Reserves are harvested by a combination of open pit and underground mining methods. In these …
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 mining. When uranium ore is found near the surface, generally less than 100 metres deep, it is typically extracted by open pit mining.
Open pit, underground methods or both of them are selected depending on the geometry properties of the deposit, its position with respect to the surface and so on. Many deposits can be mined entirely with surface methods; others must be worked underground from the very beginning. Still other deposits can be mined first as open pits but must be ...
How can open pit copper mines transition to underground mining safely, economically and without impacting existing production? Find out more.
SRK carried out a scoping study on an existing open pit operation (12 Mtpa) that is soon to be reaching a depth where the mine will need to transition to a large-scale underground mining method.The goal was to provide production continuity at a rate that will still be suitable to maximise use of the existing surface processing facilities.
We see the open pit, black, encroaching on the underground mine, gray, in the transition zone. We present a new model and corresponding solution techniques to …
There are many deposits that have the potential to be mined by a combined method of open-pit and underground. In this manner, the most sensitive problem is the determination of the optimal transition depth from open-pit to underground or vice versa. To calculate this depth, a model based on block economic values of open-pit and …
Open-pit to underground mining is a common and complex mining system engineering project, in which the rock mass stability issues caused by combined mining disturbances are a hot topic of concern for many scholars [1,2,3].The mechanical characteristics of rock masses under the disturbances of open-pit to underground …
Open pit mining is preferable for recovering weathered and more shallow resources, and it can lead to access points to underground mines. Why and when would mining open pit move to underground? Begin by …
The transition from open pit (OP) to underground (UG) operation is one of the challenging mining engineering issues. Mines that have the potential to transition from OP mining to UG mining will ...
The mined materials from underground are either transported to the surface via trucks or via cable belt to be delivered to the processing plant. In contrast to open-pit or other surface mines where the materials are hauled by trucks directly from the pit. Having said all of this, surface mining methods are obviously relatively easier that's ...
The Operational Land Imager (OLI) on Landsat 8 acquired this image of the Palabora mine on July 2, 2019. It is South Africa's largest open-pit mine, measuring almost 2 kilometers wide. It is about half the width of the world's largest open-pit mine, which is at Bingham Canyon in Utah. Copper mining began at Palabora in 1965, and by 1967 the ...
Open pit mining refers to mining directly on the ground surface, thereby producing an open pit. This method is practical and cost-effective when the uranium ore is located near the surface (e.g., within 100 m). Underground mining and ISL methods may be considered for sites that have uranium ores at deeper depths.
Open pit blasting at Ernest Henry Mining has the potential to cause damage to nearby underground workings. This paper is a case study of the blast vibration management project that was conducted ...
The objective of mine planning and design, whether for surface or underground mining methods, is to develop an annual strategy for ore extraction while maximizing the net present value (NPV) of the operation (Mahdi and Morteza 2013).As open-pit mining progresses, the depth of extraction and stripping ratio increase, …