Instance: mclaughlin

1. Contents:
2. Information
3. File downloads
4. Solution files
   1. UPIT
   2. CPIT
   3. PCPSP
5. References

Information:

Description:

McLaughlin defunct gold mine located in CA, USA.

Block model:

2'140'342 blocks of size 25x25x20ft

Precedences computed with a 45 degrees pit slope (8 levels)

Blockfile columns detail:

id x y z blockvalue ton destination Au(oz/ton)

Blockvalue computation

UPIT & CPIT: precomputed using apriori destination

PCPSP: Computed using $900/oz (Au Price), $1.32/ton (mining cost), $19/ton (proc.cost) 90% (recovery)

Discount rate = 0.15

Type of Constraints:

C0 Capacity constraint (Mill): Total processed tonnage <= 3.3M tons

File downloads:

• .blocks file: mclaughlin.blocks
  
• .prec file: mclaughlin.prec
• .upit file: mclaughlin.upit
• .cpit file: mclaughlin.cpit
• .pcpsp file: mclaughlin.pcpsp

Download the Minelib data format specification.

Solution files:

UPIT

Download: mclaughlin_upit.sol

Objective value: 1,495,886,962

Computed using Hochbaum's pseudoflow algorithm. [*]

CPIT

Download: mclaughlin_cpit_gmunoz120723.sol

Objective value: 1,073,327,197 (LP GAP 0.5%)

Provided by Gonzalo Muñoz, and obtained from the LP relaxation using a modified TopoSort heuristic. [*]

Download: mclaughlin.LPcpit

LP relaxation solution (not feasible)

Objective value: 1,079,024,268

Computed using a modified version of Bienstock & Zuckerberg algorithm. [*]

PCPSP

Download: mclaughlin_pcpsp_gmunoz120723.sol

Objective value: 1,510,126,435 (LP GAP 0.2%)

Provided by Gonzalo Muñoz, and obtained from the LP relaxation using a modified TopoSort heuristic.[*]

Download: mclaughlin.LPpcpsp

LP relaxation solution (not feasible)

Objective value: 1,512,971,680

Computed using a modified version of Bienstock & Zuckerberg algorithm.[*]

References:

• Daniel Bienstock, Mark Zuckerberg (2010), Solving LP Relaxations of Large-Scale Precedence Constrained Problems. IPCO 2010: 1-14
• Dorit S. Hochbaum (2008), The Pseudoflow Algorithm: A New Algorithm for the Maximum-Flow Problem. Operations Research 56(4): 992-1009
  
• Gonzalo Muñoz (2012), Modelos de optimizacion lineal entera y aplicaciones a la mineria. Master thesis, Dept. Mathematical Engineering, Universidad de Chile.