Energy efficient scheduling of open-pit coal mine trucks (original) (raw)

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

Journal of the Southern African Institute of Mining and Metallurgy, 2020

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,...

A New Algorithm for the Open-Pit Mine Production Scheduling Problem

Operations Research, 2012

ABSTRACT For the purpose of production scheduling, open pit mines are discretized into three- dimensional arrays known as block models. Production scheduling consists in deciding which blocks should be extracted, when they should be extracted and how each ex- tracted block should be processed. Blocks which are on top should be extracted rst, and capacity constraints limit the production each time period. Since the 1960s it has been known that this problem can be modeled with integer programming. However, the large size of real instances (3-10 million blocks, 15-20 time periods) has made these models impractical for use in real planning applications, thus leading to the use of nu- merous heuristic methods. We propose a new decomposition method for the precedence- constrained knapsack problem, and show how we can use this to solve the LP relaxation of large production-scheduling formulations. Our computations show that we can solve, in minutes, the LP relaxation of real-sized mine-planning applications with up to 5 mil- lion blocks and 20 time periods. Combining this with a quick rounding algorithm based on topological sorting, we obtain solutions within less than 6% of optimality in seconds. A second heuristic step, based on local search, allow us to nd solutions within 3% in one hour on all instances considered. For most instances we obtain solutions within 1-2% of optimality if we let this heuristic run longer. Previous methods have only been able to tackle instances with up to 150,000 blocks and 15 time periods.

A Comparison between Various Dispatching Strategies for Truck-Shovel Productivity Optimization in Open Pit Mines

2019

In order to improve the efficiency of truck-shovel transportation systems and to decrease the relevant operational cost, an appropriate truck dispatching strategy should be utilized. In this paper, a modified Li model is used to cover heterogeneous fleet size. An extra goal of “minimizing the truck operating cost” was appended to the objective function of the modified Temeng model. Sungun Copper Mine transportation system was considered as a case study to evaluate the performance of three dispatching models: Extended Li model, Temeng model, and Developed Temeng model. In the different routes of mine transportation network, using these models the truck flow rates and the number of truck trips were determined. In order to implement these models, the CPLEX software was utilized. The results indicated that Extended Li model, Temeng model, and Developed Temeng model all improve the total production above 38%, 25%, and 25% respectively compared to the current mine production plan. Each of...

Dispatch Optimization Model for Haulage Equipment between Stopes Based on Mine Short-Term Resource Planning

Metals, 2021

The working environment of underground mines is complicated, making it difficult to construct an underground mine production plan. In response to the requirements for the preparation of a short-term production plan for underground mines, an optimization model for short-term resource planning was constructed, with the goal of maximizing the total revenue during the planning period. The artificial bee colony optimization algorithm is used to solve the model using MATLAB. According to the basic requirements of underground mine ore haulage and ore hoisting, a haulage equipment inter-stopes dispatch plan model was constructed, with the primary goal of minimizing the haulage equipment wait time. A non-dominated sorting genetic algorithm is used to solve the optimization model. An underground mine is examined using the two models, and the optimization results are compared and verified with the scheme obtained by using traditional optimization algorithms. Results show that based on the impr...