Mining Goes Digital – Mueller et al. (Eds)
© 2019 Taylor & Francis Group, London, ISBN 978-0-367-33604-2
402
Framework of optimal operational indices for the open pit mines
production scheduling problems
M.R. Moghaddam & E. Moosavi
Department of Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
ABSTRACT: Understanding the ways in which production scheduling have been done is
critical to analyzing existing production scheduling systems and finding ways to improve
them. This paper addresses the problem of developing an optimization structure to aid the
operational decision-making of scheduling activities in a real-world mining operation. For
this purpose, after a brief description of the problem, there is a brief summary of recent
advances in constrained—production scheduling optimization for open pit mines. Our contribution in this paper include proposing a production scheduling framework to optimize
some data integration issues according to different planning levels. With the correspondence of a better data—based optimization among production scheduling process, we aim
to decline some currently used well-established practices to provide more stable and reliable
plans This paper not only reviews the range of concepts and approaches used to improve
production scheduling but also demonstrates their timeless importance.
Keywords: Production scheduling, open pit mine, Data-based optimization
1 INTRODUCTION
Mining operations begin with exploration of the area that has the potential for mining and
continue with exploratory works throughout the region, such as digging, mapping, and geological interpretation. If the open method is confirmed for extraction, the mineral model is
expanded through the numerical modeling methods, and mineral reserves are classified into
zones that are eventually blocked into millions of 3-D rectangular blocks (Osanloo 2005).
The ore element, grade and other necessary information are collected through drilling boreholes in each block and used for economic evaluation of the blocks. Then the mineral mass
model, which includes ore distribution and its expected economic value, is used to determine
the ultimate pit limit to identify the economic value of the mine.
Production in open pit mines is planned to determine the mine optimal extraction pattern
to not only enjoy of the highest economic profit, but also to meet the physical and operational constraints including:
− Extraction capacity constraint,
− Processing plant capacity constraint,
− Processing plant grade(s) constraint,
− Slope angle constraint.
In other words, annual production scheduling is a decision-making problem in which blocks
within the pit limit must be extracted so that the highest net present value (NPV) can be
obtained, considering the existing constraints. On the other word, the problem is to find the
most appropriate way to extract blocks in a volume that can result in the highest amount of
NPV. There are many blocks within the ultimate pit limit, for which annual production scheduling should be performed. But production cannot be planned without knowing the ultimate
pit limit; in fact, production scheduling requires the economic value of the blocks, calculation of which requires knowledge of the cut-off grades. The relationship among production
© 2019 Taylor & Francis Group, London, ISBN 978-0-367-33604-2
402
Framework of optimal operational indices for the open pit mines
production scheduling problems
M.R. Moghaddam & E. Moosavi
Department of Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
ABSTRACT: Understanding the ways in which production scheduling have been done is
critical to analyzing existing production scheduling systems and finding ways to improve
them. This paper addresses the problem of developing an optimization structure to aid the
operational decision-making of scheduling activities in a real-world mining operation. For
this purpose, after a brief description of the problem, there is a brief summary of recent
advances in constrained—production scheduling optimization for open pit mines. Our contribution in this paper include proposing a production scheduling framework to optimize
some data integration issues according to different planning levels. With the correspondence of a better data—based optimization among production scheduling process, we aim
to decline some currently used well-established practices to provide more stable and reliable
plans This paper not only reviews the range of concepts and approaches used to improve
production scheduling but also demonstrates their timeless importance.
Keywords: Production scheduling, open pit mine, Data-based optimization
1 INTRODUCTION
Mining operations begin with exploration of the area that has the potential for mining and
continue with exploratory works throughout the region, such as digging, mapping, and geological interpretation. If the open method is confirmed for extraction, the mineral model is
expanded through the numerical modeling methods, and mineral reserves are classified into
zones that are eventually blocked into millions of 3-D rectangular blocks (Osanloo 2005).
The ore element, grade and other necessary information are collected through drilling boreholes in each block and used for economic evaluation of the blocks. Then the mineral mass
model, which includes ore distribution and its expected economic value, is used to determine
the ultimate pit limit to identify the economic value of the mine.
Production in open pit mines is planned to determine the mine optimal extraction pattern
to not only enjoy of the highest economic profit, but also to meet the physical and operational constraints including:
− Extraction capacity constraint,
− Processing plant capacity constraint,
− Processing plant grade(s) constraint,
− Slope angle constraint.
In other words, annual production scheduling is a decision-making problem in which blocks
within the pit limit must be extracted so that the highest net present value (NPV) can be
obtained, considering the existing constraints. On the other word, the problem is to find the
most appropriate way to extract blocks in a volume that can result in the highest amount of
NPV. There are many blocks within the ultimate pit limit, for which annual production scheduling should be performed. But production cannot be planned without knowing the ultimate
pit limit; in fact, production scheduling requires the economic value of the blocks, calculation of which requires knowledge of the cut-off grades. The relationship among production