Optimizing open-pit block scheduling with exposed ore reserve

!�24$1/1 A crucial problem in the open pit mining industry is to determine the optimal block scheduling, defining how the orebody will be sequenced for exploitation. An orebody is often comprised of several thousand or million blocks and the scheduling models for this structure are very complex, giving rise to very large combinatorial linear problems. Operational mine plans are usually produced on a yearly basis and further scheduling is attempted to provide monthly, weekly, and daily schedules. A portion of the ore reserve is said to be exposed if it is readily available for extraction at the start of the period. In this paper, an integer programming (IP) model is presented to generate pit designs under exposed ore reserve requirements, as an extension of the classical optimization models for mine planning. For this purpose, we introduce a set of new binary variables, representing which blocks can be declared as exposed ore reserve, in addition to the extraction and processing decisions. The model has been coded and tested in a set of standard instances, showing very encouraging results in the generation of operational block schedules.

[1]  Christopher Fricke.  Applications of integer programming in open pit mining , 2006 .

[2]  H. Askari-Nasab,et al.  Two-stage clustering algorithm for block aggregation in open pit mines , 2011 .

[3]  Eduardo Moreno,et al.  A New Algorithm for the Open-Pit Mine Production Scheduling Problem , 2012, Oper. Res..

[4]  J. Picard.  Maximal Closure of a Graph and Applications to Combinatorial Problems , 1976 .

[5]  K. Dagdelen,et al.  Fundamental tree algorithm in optimising production scheduling for open pit mine design , 2005 .

[6]  Alexandra M. Newman,et al.  A Review of Operations Research in Mine Planning , 2010, Interfaces.

[7]  Alexandra M. Newman,et al.  MineLib: a library of open pit mining problems , 2013, Ann. Oper. Res..

[8]  Louis Caccetta,et al.  Application of Optimisation Techniques in Open Pit Mining , 2007 .

[9]  Henry Amankwah.  Mathematical Optimization Models and Methods for Open-Pit Mining , 2011 .

[10]  M. P. Gaupp,et al.  Methods for Improving the Tractability of the Block Sequencing Problem for Open Pit Mining , 2008 .

[11]  Torbjörn Larsson,et al.  A maximum flow formulation of a multi-period open-pit mining problem , 2014, Oper. Res..

[12]  Natashia Boland,et al.  A strengthened formulation and cutting planes for the open pit mine production scheduling problem , 2010, Comput. Oper. Res..

[13]  Juan Peypouquet,et al.  Aggregation heuristic for the open-pit block scheduling problem , 2016, Eur. J. Oper. Res..

[14]  Ambros M. Gleixner,et al.  LP-based disaggregation approaches to solving the open pit mining production scheduling problem with block processing selectivity , 2009, Comput. Oper. Res..

[15]  Thys B Johnson,et al.  OPTIMUM OPEN PIT MINE PRODUCTION SCHEDULING , 1968 .

[16]  Alexandra M. Newman,et al.  A sliding time window heuristic for open pit mine block sequencing , 2011, Optim. Lett..

[17]  Lou Caccetta,et al.  An Application of Branch and Cut to Open Pit Mine Scheduling , 2003, J. Glob. Optim..

[18]  Daniel Bienstock,et al.  Solving LP Relaxations of Large-Scale Precedence Constrained Problems , 2010, IPCO.

[19]  Alexandra M. Newman,et al.  Tailored Lagrangian Relaxation for the open pit block sequencing problem , 2014, Ann. Oper. Res..

[20]  Dorit S. Hochbaum,et al.  Performance Analysis and Best Implementations of Old and New Algorithms for the Open-Pit Mining Problem , 2000, Oper. Res..

[21]  L. M. Giannini.  Optimum design of open pit mines , 1991, Bulletin of the Australian Mathematical Society.

[22]  W. Hustrulid,et al.  Open Pit Mine Planning and Design , 2015 .

[23]  Juan Peypouquet,et al.  Heuristics for the open-pit block scheduling problem , 2013 .