The new Fundamental Tree Algorithm for production scheduling of open pit mines

The problem of annual production scheduling in surface mining consists of determining an optimal sequence of extracting the mineralized material from the ground. The main objective of the optimization process is usually to maximize the total Net Present Value of the operation. Production scheduling is typically a mixed integer programming (MIP) type problem. However, the large number of integer variables required in formulating the problem makes it impossible to solve. To overcome this obstacle, a new algorithm termed ‘Fundamental Tree Algorithm’ is developed based on linear programming to aggregate blocks of material and decrease the number of integer variables and the number of constraints required within the MIP formulation. This paper proposes the new Fundamental Tree Algorithm in optimizing production scheduling in surface mining. A case study on a large copper deposit summarized in the paper shows substantial economic benefit of the proposed algorithm compared to existing methods.