Abstract

While continuing to operate mines which supply the critical minerals needed to decarbonize the economy, innovation is key to reduce any further effects of climate change on the planet. The responsible extraction of critical minerals is necessary for supporting the green transition. The mine operator’s ability to reduce carbon while expanding open pit mines will allow them to produce a differentiated product. This presentation will discuss the carbon reduction opportunities that can be achieved by steepening the slopes of an open pit mine.

Different pit slope design optimization methods will be covered, including DFN modeling to characterize rock mass bridging, ground support for weaker rock masses, and depressurization of pit slopes. These pit slope design optimization methods consider a variety of rock mass, structural geology, and hydrogeological conditions at different mine sites. In addition, this presentation will discuss how emerging technologies, such as automation of a mine site’s mobile fleet, tram assist, and other strategies can help reduce risk associated with steeper open pit slopes.

Steepening of an open pit slope by magnitudes as small as one degree in the overall slope angle can significantly reduce the carbon footprint at a mine site, by reducing the overall total volume of waste produced. Mobile fleet emissions, resulting from the combustion of fuel (typically diesel) is often the main source of carbon emissions at an open pit mine. Therefore, significantly reducing overall waste production will require much fewer haulage cycles to the waste rock dumps, reducing overall diesel consumption and associated carbon emissions. In most cases, the steepening of an open pit slope would result in an overall smaller mine footprint, which presents other possible carbon benefits, including shortened haulage distances, requiring less operating equipment to manage smaller waste dumps, and ultimately lessening the impact from carbon sink disturbance during the construction stage.

This presentation will provide an estimate of the percentage of carbon reductions per degree of pit slope steepening to quantify the relationship between the two variables.