In response to concerns over greenhouse gas (GHG) emissions and an imposed cost in some jurisdictions, many mining houses have committed to reductions in their GHG emissions. However, mining faces particular challenges in this regard, notably from increasing strip ratios. Furthermore, mining activity around the globe is not expected to decrease in the foreseeable future as mineral demand is driven up by the aspirations of rapidly-developing nations. Novel approaches will thus be needed if any reductions in energy consumption and GHG emissions of mining are to be achieved.
This paper presents some directions for the mining industry to pursue in reducing their GHG impact, focusing on the difference that blasting methods can make. Importantly, large productivity and revenue gains can also be realised from these methods.
Key directions considered here include optimising resource recovery and quality through:
reducing coal damage and loss from throw blasting
recovering thin coal seams
producing cleaner coal with less dilution.
Blast design can also significantly improve the productivity of surface mining by:
improving muck pile shaping
improving mine equipment productivity
We show how a particular blasting method can eliminate coal loss in overburden throw blasting and can lead to large increases in coalmine profitability. Thin seams that were previously wasted can also be recovered with this method. Furthermore, the method has been implemented to combine several separate drill and blast cycles into a single cycle, leading to productivity gains.
An illustrative example is given to show how increased coal recovery can increase revenues and more than offset any potential GHG emissions liabilities. Overall mine energy and GHG emission intensities can thus be reduced.
Goswami, T and Brent, G, 2015. Blasting approaches to increase mine productivity and reduce greenhouse gas emissions in surface coal mining, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 635–644 (The Australasian Institute of Mining and Metallurgy: Melbourne).