A Mine-to-Crusher Model to Minimize Costs at a Truckless Open-Pit Iron Mine in Brazil

Abstract

Innovation has an important role in improving the productivity, safety and sustainability of mining operations. Historically, ore transport was done by diesel trucks, but with the commitment to reduce CO2 emissions and increase mine safety, mining companies have invested in innovative, more sustainable ore transport technologies. The innovative truckless system, with the intensive use of belt conveyors to transport the ore from the mine to the processing plant, represents a huge project and capital investment. However, operation costs are lower when considering the decrease of fuel use and also maintenance expenses. This paper presents an economic analysis of a mine-to-crusher model to estimate and minimize the operating expenses of an open-pit iron mine located in northern Brazil. The activities at this truckless mine consist of drilling and blasting, loading and primary crushing. In this study, the calibration of the mine-to-crusher model was based on rock fragmentation from the blasting phase. The costs of each mine operation phase were estimated for an optimum 80% passing size (P80). The calibration was conducted with the values of technical and economic parameters in 2019. By considering the structural lithologies of canga and jaspillites, we concluded that the P80 value that minimizes costs might be in the range from 0.31 to 0.34 m.