Development and Validation of a Waste Rock Dumping Optimisation Model

摘要

Waste rock dumps represent among the largest remnant structures of open pit miningoperations. They can absorb a large proportion of the mine's operating costs, and can becostly to rehabilitate. Poor design, construction and rehabilitation of waste rock dumpscan produce a major safety risk and environmental hazard. There are many examplesworldwide where poor design and construction of waste rock dumps have resulted infailures causing considerable loss of life and widespread damage, or have resulted inerosion and seepage that have led to severe environmental pollution. The proper designand scheduling of waste rock dumps and haul routes can significantly reduce costs,minimise the possibility of failures, and avoid harming the environment. The first part ofthe paper discusses waste rock haulage costs and waste rock dump design in open pitmining operations, and describes the development and application of a waste rock dumpscheduling model using the Operations Research technique of Mixed IntegerProgramming (MIP). The model focuses on minimising the haulage cost for each blockof waste rock taken from the open pit and placed in the dump. Allowance is also madefor the selective placement of benign and reactive waste rock, based on an open pit blockmodel that delineates the different rock types. The second part of the paper employs theproposed model to schedule real mine site data. The findings and applicability of themethods are discussed in the final section of the paper.