Simultaneous stochastic optimisation of mining complexes: integrating waste management and progressive reclamation with encapsulation

Effective waste rock management is crucial for long-term mining planning. Ignoring the role of potentially acid-generating (PAG) waste rock requires significant treatment costs incurred to mitigate acid rock drainage (ARD). Encapsulation of PAG material can prevent or mitigate ARD by limiting exposure. Traditional practices don’t optimise production schedules while addressing this risk. This work integrates waste management and reclamation using encapsulation into a simultaneous stochastic optimisation framework. Uncertainties in acid generation are addressed using geostatistical simulations of the rock’s geochemical properties. A case study at a copper-gold mining complex increases the encapsulation by 41.3% with 1.6% decrease in NPV.