scholarly journals Integrated Parametric Graph Closure and Branch-and-Cut Algorithm for Open Pit Mine Scheduling under Uncertainty

Mining ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 32-51
Author(s):  
Devendra Joshi ◽  
Amol Paithankar ◽  
Snehamoy Chatterjee ◽  
Sk Md Equeenuddin
Keyword(s):  
Production Scheduling ◽  
Resource Constraints ◽  
Deterministic Model ◽  
Open Pit Mine ◽  
Branch And Cut ◽  
Open Pit ◽  
Computational Time ◽  
Scheduling Problems ◽  
Stochastic Production ◽  
Stochastic Production Scheduling

Open pit mine production scheduling is a computationally expensive large-scale mixed-integer linear programming problem. This research develops a computationally efficient algorithm to solve open pit production scheduling problems under uncertain geological parameters. The proposed solution approach for production scheduling is a two-stage process. The stochastic production scheduling problem is iteratively solved in the first stage after relaxing resource constraints using a parametric graph closure algorithm. Finally, the branch-and-cut algorithm is applied to respect the resource constraints, which might be violated during the first stage of the algorithm. Six small-scale production scheduling problems from iron and copper mines were used to validate the proposed stochastic production scheduling model. The results demonstrated that the proposed method could significantly improve the computational time with a reasonable optimality gap (the maximum gap is 4%). In addition, the proposed stochastic method is tested using industrial-scale copper data and compared with its deterministic model. The results show that the net present value for the stochastic model improved by 6% compared to the deterministic model.

scholarly journals Production Scheduling of Open Pit Mine Using Sequential Branch-and-Cut and Longest Path Algorithm: An Application from an African Copper Mine

2020 ◽  
Vol 53 (5) ◽  
pp. 629-636
Author(s):  
Devendra Joshi ◽  
Susanta Kumar Satpathy
Keyword(s):  
Production Scheduling ◽  
Feasible Solution ◽  
Resource Constraints ◽  
Open Pit Mine ◽  
Branch And Cut ◽  
Open Pit ◽  
Computational Time ◽  
Mine Production ◽  
Mine Production Scheduling ◽  
Longest Path

Open pit mine production scheduling assigns mining blocks in different production periods for maximising profits after satisfying geotechnical and operational constraints. In this paper, two Open pit mine production scheduling models were applied in an African copper deposit. The first model is a traditional model with more tight resource constraints; the second model is a more robust model where resource constraints are relaxed by penalizing the objective function. Both the models were solved using two step algorithms: (a) year wise production scheduling using a sequential branch-and-cut algorithm; and (b) an iterative longest path algorithm to improve the solution generated from branch-and-cut. Results demonstrated that due to the tight constraints in Model 1, the optimizer was unable to generate a feasible solution after the first period, therefore the lower limit metal production constraint was eliminated to generate a feasible solution; however, Model 2 was able to generate a feasible solution for all periods. Results show that both the models generated nearly the same amount of ore, waste, metal content, and mine life. Model 2 generates relatively more net present value as compared to Model 1, whereas, the computational time required for solving the scheduling problem is relatively less for Model 1 than for Model 2.

Linear models for stockpiling in open-pit mine production scheduling problems

2017 ◽  
Vol 260 (1) ◽  
pp. 212-221 ◽  
Author(s):  
Eduardo Moreno ◽  
Mojtaba Rezakhah ◽  
Alexandra Newman ◽  
Felipe Ferreira
Keyword(s):  
Production Scheduling ◽  
Linear Models ◽  
Open Pit Mine ◽  
Open Pit ◽  
Scheduling Problems ◽  
Mine Production ◽  
Mine Production Scheduling

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.

Improving performance of open-pit mine production scheduling problem under grade uncertainty by hybrid algorithms

2020 ◽  
Vol 27 (9) ◽  
pp. 2479-2493
Author(s):  
Kamyar Tolouei ◽  
Ehsan Moosavi ◽  
Amir Hossein Bangian Tabrizi ◽  
Peyman Afzal ◽  
Abbas Aghajani Bazzazi
Keyword(s):  
Production Scheduling ◽  
Hybrid Algorithms ◽  
Open Pit Mine ◽  
Open Pit ◽  
Scheduling Problem ◽  
Mine Production ◽  
Mine Production Scheduling ◽  
Grade Uncertainty
Sign in / Sign up

Export Citation Format

Share Document