Determination of optimised cut-off grade utilising non-linear programming

Abstract

One of the most fundamental problems in a mining operation is how to recognise an optimum cut-off grade, which defines the grade for discriminating between ore and waste in an ore body, including ore that is extracted at different periods over a mine life period. Therefore, the identification of an optimised cut-off grade (COG) is a crucial function which has to be monitored during the mine life. The main aim of this study is to propose a modified optimum COG model in order to maximise the profit value (PV) for mining projects. Maximising the PV of a mining operation, which is a nonlinear programming, is subject to different constraints involving a general grade distribution within a deposit and three stages of production namely mining, concentrating and refining. The proposed computer-based model is more effective in long-term planning of the open pit mines. To provide a better understanding of the algorithm efficiency, a numerical example is given and subsequently solved based on the Lane algorithm. In order to achieve this, the LINGO software was employed.

Application of an Inverse Distance Weighted Anisotropic Method for Rock Quality Designation distribution in Eastern Kahang deposit, Central Iran

“…The Kahang deposit was modelled with 489,927 voxels and each voxel has a dimension of 4 m × 4 m × 10 m, corresponding the project dimensions of 600, 660 and 780 m, in the X, Y and Z directions, respectively. This has been done using statistical characteristics of the deposit geometrical particulars consisting of mean, median and median absolute deviation (MAD) [27,31,45,46]. For validation purposes between raw and estimated data, jackknife analysis was utilised.…”

A new global optimum solution model based on multi-value dynamic programming for the cut-off grade optimization in a surface mining complex

“…The application of mathematical programming to open-pit mine planning traces back to the 1960𝑠. Acknowledging the limitations of Lane's approach, a few attempts have been made to overcome them through an alternative analytical framework of optimization (Azimi et al, 2012;Dagdelen & Kawahata, 2008;Ganguli et al, 2011;Yasrebi et al, 2015). The basics of Lane's (Lane, 1964(Lane, , 1988 technique have been expanded in most optimization approaches.…”

A sequentially advancing algorithm based on multi-value dynamic programming for the cut-off grade optimization in open-pit metalliferous deposits

“…The application of mathematical programming to open-pit mine planning traces back to the 1960𝑠. Acknowledging the limitations of Lane's approach, a few attempts have been made to overcome them through an alternative analytical framework of optimization [20][21][22][23]. The basics of Lane's [16,17] technique have been expanded in most optimization approaches.…”