Mathematical Programming for Sequence Optimization in Block Cave Mining

• Author / Creator

  Pourrahimian, Yashar

• Production scheduling of any mining system has an enormous effect on the operation’s economics. The economics of today’s mining industry are such that the major mining companies are increasing the use of massive mining methods. Among the mining methods available, caving methods are favored because of their low cost and high production rates. Caving methods have become the underground bulk mining method of choice and are expected to continue as such in the foreseeable future. Scheduling a block cave mine is a matter of finding the goal that better represents the strategic planning vision subject to mine design, geomechanical, operational, and environmental constraints.
  The objective of this study is to develop, implement, and verify a theoretical optimization framework based on a mixed-integer linear programming (MILP) model for block-cave long-term production scheduling, whereby a mineral is extracted and prepared at a desired market specification, with the maximum economic return measured by NPV, and within acceptable technical and operational constraints.
  In this research, three MILP formulations are introduced for three levels of problem resolution (i) cluster level, (ii) drawpoint level, and (iii) drawpoint-and-slice level. These formulations can be used in two ways: (i) as a single-step method in which each of the formulations is used independently; (ii) as a multi-step method in which the solution of each step is used to reduce the number of variables in the next level and consequently to generate a practical block cave schedule in a reasonable amount of CPU runtime for large-scale problems.
  The main scientific contribution of this research on the body of knowledge is the development, implementation, and verification of a theoretical framework for long-term production schedule optimization of block-cave mines using MILP. This research directly contributes to creating new knowledge, understanding, and innovative technologies that are required to generate near-optimal life-of-mine production schedules for block-cave mining operations. The main industrial contribution of this research includes development and testing of a prototype open-source software application with the graphical user interface, DSBC.

• Subjects / Keywords

  • Production scheduling
  • Optimization
  • Block caving
  • CPLEX

• Graduation date

  Spring 2013

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R37S67

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.