Net present value maximisation model for optimum cut-off grade policy of open pit mining operations

The optimum cut-off grade policy maximizes the net present value (NPV) of an open pit mining operation subject to the mining, processing, and refining capacity constraints. The traditional approaches to cut-off grade determination ignore the escalation of the economic parameters such as metal price...

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Main Authors: Asad, M., Topal, Erkan
Format: Journal Article
Published: South African Institute of Mining and Metallurgy 2011
Online Access:https://www.saimm.co.za/Journal/v111n11p741.pdf
http://hdl.handle.net/20.500.11937/13927
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author Asad, M.
Topal, Erkan
author_facet Asad, M.
Topal, Erkan
author_sort Asad, M.
building Curtin Institutional Repository
collection Online Access
description The optimum cut-off grade policy maximizes the net present value (NPV) of an open pit mining operation subject to the mining, processing, and refining capacity constraints. The traditional approaches to cut-off grade determination ignore the escalation of the economic parameters such as metal price and operating costs during life of an operation, and consequently lead to unrealistically higher values of the objective function. Further, the NPV of a mining operation declines due to the depletion of the available reserves, causing a decline in the optimum cut-off grade, i.e. higher cut-off grades in the early years of an operation and lower cut-off grades during the later years. Hence, low grade material mined in the earlier years may be stockpiled for processing during later years to offset the effect of escalating economic parameters on NPV. This paper demonstrates the combined impact of introducing economic parameters, escalation and stockpiling options into the cut-off grade optimization model. The model promises an enhancement in NPV as illustrated in a case study incorporating practical aspects of an open pit mining operation.
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institution Curtin University Malaysia
institution_category Local University
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publishDate 2011
publisher South African Institute of Mining and Metallurgy
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spelling curtin-20.500.11937-139272017-01-30T11:40:16Z Net present value maximisation model for optimum cut-off grade policy of open pit mining operations Asad, M. Topal, Erkan The optimum cut-off grade policy maximizes the net present value (NPV) of an open pit mining operation subject to the mining, processing, and refining capacity constraints. The traditional approaches to cut-off grade determination ignore the escalation of the economic parameters such as metal price and operating costs during life of an operation, and consequently lead to unrealistically higher values of the objective function. Further, the NPV of a mining operation declines due to the depletion of the available reserves, causing a decline in the optimum cut-off grade, i.e. higher cut-off grades in the early years of an operation and lower cut-off grades during the later years. Hence, low grade material mined in the earlier years may be stockpiled for processing during later years to offset the effect of escalating economic parameters on NPV. This paper demonstrates the combined impact of introducing economic parameters, escalation and stockpiling options into the cut-off grade optimization model. The model promises an enhancement in NPV as illustrated in a case study incorporating practical aspects of an open pit mining operation. 2011 Journal Article http://hdl.handle.net/20.500.11937/13927 https://www.saimm.co.za/Journal/v111n11p741.pdf South African Institute of Mining and Metallurgy fulltext
spellingShingle Asad, M.
Topal, Erkan
Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title_full Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title_fullStr Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title_full_unstemmed Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title_short Net present value maximisation model for optimum cut-off grade policy of open pit mining operations
title_sort net present value maximisation model for optimum cut-off grade policy of open pit mining operations
url https://www.saimm.co.za/Journal/v111n11p741.pdf
http://hdl.handle.net/20.500.11937/13927