scholarly journals Incorporation of Geometallurgical Attributes and Geological Uncertainty into Long-Term Open-Pit Mine Planning

Minerals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 108 ◽  
Author(s):  
Nelson Morales ◽  
Sebastián Seguel ◽  
Alejandro Cáceres ◽  
Enrique Jélvez ◽  
Maximiliano Alarcón
Keyword(s):  
Production Scheduling ◽  
Programming Model ◽  
Mineral Resources ◽  
Mineral Deposit ◽  
Open Pit Mine ◽  
Mine Planning ◽  
Open Pit ◽  
Operational Parameters ◽  
Financial Outcomes

Long-term open-pit mine planning is a critical stage of a mining project that seeks to establish the best strategy for extracting mineral resources, based on the assumption of several economic, geological and operational parameters. Conventionally, during this process it is common to use deterministic resource models to estimate in situ ore grades and to assume average values for geometallurgical variables. These assumptions cause risks that may negatively impact on the planned production and finally on the project value. This paper addresses the long-term planning of an open-pit mine considering (i) the incorporation of geometallurgical models given by equiprobable scenarios that allow for the assessing of the spatial variability and the uncertainty of the mineral deposit, and (ii) the use of stochastic integer programming model for risk analysis in direct block scheduling, considering the scenarios simultaneously. The methodology comprises two stages: pit optimization to generate initial ultimate pit limit per scenario and then to define a single ultimate pit based on reliability, and stochastic life-of-mine production scheduling to define block extraction sequences within the reliability ultimate pit to maximize the expected discounted value and minimize the total cost of production objective deviations. To evaluate the effect of the geometallurgical information, both stages consider different optimization strategies that depend on the economic model to be used and the type of processing constraints established in the scheduling. The results show that geometallurgical data with their associated uncertainties can change the decisions regarding pit limits and production schedule and, consequently, to impact the financial outcomes.

scholarly journals Analysis of the variables: Commodity price and discount rate on long-term open pit mine planning

2021 ◽  
Vol 6 (2) ◽  
pp. 142-150
Author(s):  
Fontes MP ◽  
Koppe JC ◽  
Silva Neto JA
Keyword(s):  
Discount Rate ◽  
Net Present Value ◽  
Market Price ◽  
Commodity Price ◽  
Open Pit Mine ◽  
Mine Planning ◽  
Open Pit ◽  
Economic Criterion ◽  
Physical Constraints

Long-term open pit mine planning is a complex process which deals with numerous uncertainties, whether they are economical (commodity price, operational costs, production schedule, discount rate, inflation, among others); geological (grade distribution, density, hardness, etc); or physical constraints (property limits, environmental issues, legislation, etc). In this context, this paper aims to evaluate the effects of the variation of two important variables: commodity price and discount rate, with regard to the economic criterion, represented by the Net Present Value (NPV) of the mining business. Starting from a baseline value of US$ 80/t, the commodity (phosphate rock was used as a case study) price was varied within a 50% range, above and below the baseline value, obtained from historic values from the last 5 years. The discount rate values adopted in the analyses were 6%, 8%, 10%, 12%, 14%, 16%, 18% and 20%. The results showed increases in the market price yielded higher NPV and life of mine values. On the other hand, it was noted that increases in the discount rate can significantly alter the NPV, materially reducing the value of the mining undertaking. It is also worth noting that, in contrast to more robust approaches such as Real Options Theory (ROT), traditional Discounted Cash Flow (DCF) methods, such as NPV, assume variables, such as commodity price, to be fixed, which could either lead to the undervaluation or overvaluation of a project.

scholarly journals A practical, long-term production scheduling model in open pit mines using integer linear programming

2020 ◽  
Vol 120 (12) ◽  
Author(s):  
J. Gholamnejad ◽  
R. Lotfian ◽  
S. Kasmaeeyazdi
Keyword(s):  
Linear Programming ◽  
Mathematical Programming ◽  
Integer Linear Programming ◽  
Production Scheduling ◽  
Mine Planning ◽  
Open Pit ◽  
Mixed Integer ◽  
Small Scale ◽  
Mining Equipment

SYNOPSIS Long-term production scheduling is a major step in open pit mine planning and design. It aims to maximize the net present value (NPV) of the cash flows from a mining project while satisfying all the operational constraints, such as grade blending, ore production, mining capacity, and pit slope during each scheduling period. Long-term plans not only determine the cash flow generated over the mine life, but are also the basis for medium- and short-term production scheduling. Mathematical programming methods, such as linear programming, mixed integer linear programming, dynamic programming, and graph theory, have shown to be well suited for optimization of mine production scheduling. However, the long-term plans generated by the mathematical formulations mostly create a scattered block extraction order on several benches that cannot be implemented in practice. The reason is the excessive movement of mining equipment between benches in a single scheduling period. In this paper, an alternative integer linear programming (ILP) formulation is presented for long-term production scheduling that reduced the number of active benches in any scheduling period. Numerical results of the proposed model on a small-scale open pit gold mine show a 34% reduction in the average number of working benches in a given scheduling period. Keywords: long-term production scheduling, mathematical programming, practical plans, equipment movements.

scholarly journals Estimating criteria for mining profitability predicting

2020 ◽  
Vol 12 (4) ◽  
pp. 511-518
Author(s):  
S. P. Reshetnyak ◽  
D. A. Vedrova
Keyword(s):  
Underground Mining ◽  
Mineral Resources ◽  
Mineral Deposit ◽  
Open Pit ◽  
Capital Investments ◽  
Factors Affecting ◽  
Economic Support ◽  
Regional Centers

The development of mineral resources deposits, whether it is open pit or underground mining, involves a large amount of initial investment, much of which is spent on building the infrastructure of the future enterprise. Capital investments will be the greater, the farther the deposit is located from regional centers, settlements, the more complex the structure of the deposit itself is. Modern market economy reality makes the question of equity distribution opportunities on mining one of the most pressing. Participation in the tender for the license acquisition, despite the antitrust policy of the state in this area, can be afforded mostly only by representatives of large businesses, while small regional companies are left to deal with less attractive deposits in terms of investment in the development. The authors of the article have analyzed and ranked the main factors affecting the profitability of mineral deposit development during the period prior to its commissioning, with the aim of offering a method of economic support and incentives for business representatives who are ready to take specific mining risks. Based on the considered factors, a classification of deposits according to the profitability of mining was developed, the use of which can give a more accurate description of the proposed subsoil use areas by the level of necessary investments in the construction of a mining enterprise. The authors have proposed an economic mechanism to stimulate regional subsoil users who are ready to develop deposits of mineral resources that are risky in terms of long-term investment. A refund ratio is proposed – which part of the license cost for subsoil use is supposed to be returned, during the construction of the enterprise period, before it reaches its planned capacity.

scholarly journals An Optimum Deployment Algorithm of Camera Networks for Open-Pit Mine Slope Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1148
Author(s):  
Hua Zhang ◽  
Pengjie Tao ◽  
Xiaoliang Meng ◽  
Mengbiao Liu ◽  
Xinxia Liu
Keyword(s):  
Focal Length ◽  
Field Tests ◽  
Mineral Resources ◽  
Video Camera ◽  
Open Pit Mine ◽  
Mine Safety ◽  
Open Pit ◽  
Prototype System ◽  
Mine Slope ◽  
Slope Monitoring

With the growth in demand for mineral resources and the increase in open-pit mine safety and production accidents, the intelligent monitoring of open-pit mine safety and production is becoming more and more important. In this paper, we elaborate on the idea of combining the technologies of photogrammetry and camera sensor networks to make full use of open-pit mine video camera resources. We propose the Optimum Camera Deployment algorithm for open-pit mine slope monitoring (OCD4M) to meet the requirements of a high overlap of photogrammetry and full coverage of monitoring. The OCD4M algorithm is validated and analyzed with the simulated conditions of quantity, view angle, and focal length of cameras, at different monitoring distances. To demonstrate the availability and effectiveness of the algorithm, we conducted field tests and developed the mine safety monitoring prototype system which can alert people to slope collapse risks. The simulation’s experimental results show that the algorithm can effectively calculate the optimum quantity of cameras and corresponding coordinates with an accuracy of 30 cm at 500 m (for a given camera). Additionally, the field tests show that the algorithm can effectively guide the deployment of mine cameras and carry out 3D inspection tasks.

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