The energy intensity for copper is the greatest on a gigajoule per metric ton (copper equivalent) basis.

The global mining industry must move away from legacy systems and processes if it is to meet the challenge of decarbonization, according to a new report that calculates mining’s share of global energy consumption and identifies ways the industry can aid the transition to net zero emissions.

The report, commissioned by the Weir Group plc, analyzes mine energy data from more than 40 published studies to give a comprehensive understanding of where energy is consumed in mining and minerals processing. It quantifies energy use for five commodities: copper, gold, iron ore, nickel and lithium. The energy intensities for each of the commodities totals 1.68 exajoules per year (EJ/y) or approximately 0.5% of energy consumption globally. Published information indicates that the entire mining industry consumes approximately 12 EJ/y or 3.5% of total final energy consumption globally.

The metals produced by mining are critical for enabling the global transition to low-carbon infrastructure. But 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, according to the report. The report suggests there are technologies available today that could make a significant difference. For example, it said comminution — i.e., crushing and grinding processes — is the single biggest user of energy at mine sites, typically accounting for 25% of mining’s final energy consumption. Comminution is a natural target for the most impactful energy savings opportunities, it continued.

“The mining industry is central to economic development globally, with critical minerals enabling the low-carbon transition required in the rest of the economy,” Weir Group CEO Jon Stanton said. “But, the environment in which it will operate in the future will be very different from the past, requiring comprehensive change and investment. In short, mining needs to become more sustainable and efficient if it is to provide essential resources the world needs for decarbonization while reducing its own environmental impact. This report is an important contribution to that debate, which we hope will spark thoughtful conversations around the world on the way forward.”

Small improvements in comminution technologies can lead to relatively large savings in both energy consumption and greenhouse gas emissions. For example, a 5% incremental improvement in energy efficiency across comminution could result in greenhouse gas emissions reductions of more than 30 million metric tons (mt) of carbon dioxide equivalent (CO2-e). 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 optimization, big data and artificial intelligence. In addition, if zero emissions energy sources are deployed for mining equipment — e.g., 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 urbanization and decarbonization. Copper, nickel, steel and lithium are core components of electricity transmission and storage, electric vehicles and renewable energy infrastructure. The move to a decarbonized 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, according to the report.

The independent Mining Energy Consumption 2021 report is available at www.energysavingsinmining.com.

 

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