A landfill based approach to surface mine design

Abstract

Surface mining operations extract a large quantity of waste material, which is generally disposed into a dump area. This waste can cause a series of environmental problems ranging from landscape deterioration to acidic water generation and water pollution. Therefore, mine waste management is a significant task in mining operations. As known, in strip mining, the overburden is not transported to waste dumps but disposed directly into adjacent strip which was mined out. This concept can be adapted for mine planning of relatively horizontal deposits through a mixed integer programming (MIP) model. The main idea behind this work is that, in one pit, production voids created in early year of mining are used for waste landfilling in late years of production. In other words, in addition to external dumping, a landfilling option within the same pit is proposed for mine design optimization. The problem is formulated as maximization of the net present value (NPV) of the mining project under the constraints of access, landfill waste handling, mining and processing capacities. A case study using a data set was carried out to see the performance of the proposed approach. The findings showed that this approach could be used in waste management incorporating a landfilling option into mine planning. As a result, material handling costs decrease, and environmental compliance increases due to less external waste quantity.