The global mining industry must move away from legacy systems and processes if it is to meet the challenge of decarbonisation.
This is according to a new report, commissioned by engineering company Weir Group, which calculates mining’s share of global energy consumption and identifies ways the industry can contribute to the transition to net zero emissions.
The report analyses mine energy data from over 40 published studies focused on five commodities – copper, gold, iron-ore, nickel and lithium – and provides an understanding of where energy is consumed in mining and minerals processing.
It shows that the total amount of power used in hard-rock mining is equal to about 3.5% of global energy use.
The metals produced by the mining sector are critical for enabling the global transition to low-carbon infrastructure, the report notes.
However, without action, energy use in mining itself is set to trend higher in the coming years as demand increases for metals like copper, nickel and zinc.
The report suggests, however, that there are technologies available that could make a significant difference in reversing this trend.
For example, it highlights that comminution – that is, crushing and grinding processes – is the single biggest user of energy at mine sites, typically accounting for 25% of mining’s final energy consumption.
Extended across all hard-rock mining, this is equivalent to the power used by 221-million typical UK homes, or about 1% of total consumption globally.
Comminution is, therefore, a natural target for the most impactful energy savings opportunities, the report highlights.
Small improvements in comminution technologies could lead to relatively large savings in both energy consumption and greenhouse-gas (GHG) emissions, it posits.
For example, a 5% incremental improvement in energy efficiency across comminution could result in GHG emissions reductions of more than 30-million tonnes of carbon dioxide-equivalent.
The replacement of traditional comminution equipment with new grinding technology also reduces indirect emissions in the mining value chain, for example, by removing the need for the manufacture of emission-intensive steel grinding balls.
Of the remaining energy consumption by the mining industry, diesel in varied forms of mobile equipment accounts for 46%, electricity in mining (ventilation) 15% and other electricity 14%.
Other significant opportunities identified by the report for reducing mining’s energy consumption include optimisation, big data and artificial intelligence.
In addition, if zero emissions energy sources are deployed for mining equipment – for example, renewable energy, energy storage and alternative fuels – then the industry may well be able to achieve zero emissions, leaving a relatively small role for offsets and carbon credits to play.
The report comes as the mining industry is under ever-greater pressure to produce essential minerals that support some of the biggest global structural trends, from population growth to urbanisation and decarbonisation.
Copper, nickel, steel and lithium are core components of electricity transmission and storage, electric vehicles and renewable energy infrastructure. The move to a decarbonised economy will result in increased primary consumption of these mined commodities, even after factoring for recycling, so it is important that mining itself becomes more sustainable, the report indicates.