Application of a semi-automatic method for optimal ramp design

Abstract

The problem of strategic open pit planning involves several stages, including (1) pushback optimization, (2) open-pit design, and (3) production planning. To address stages (1) and (3), mine planners rely on different software optimization to assist them in making the best choices within the boundaries of these tools. However, for (2) this task, which consists of designing the actual ramps and slopes of the pit, is mostly manual, hence time-consuming and highly dependent on the expertise of the planner. In this work, we use a previously introduced mathematical model to assist the design of ramps in open pit mines. The model starts with a pre-defined pushback (in terms of blocks) and generates a “corrected” envelop which is as close as possible to the original one, but with space for designing a phase that includes ramps. To carry out this work, an analysis of the application of the assisted design of ramps in four mining operation is carried out and compared with the use of the current design methodology. This way, the differences between the operational models of both methodologies and the final pit for every case study are sought through economic benefit and the number of reserves. When applying both design methodologies, it has been obtained as a result that in all cases of studies, with the method of assisted ramp design, a slight improvement in the economic benefit is achieved.