Copper sits within the centre of the global energy transition. Yet producing this critical mineral is actually an increasingly energy-intensive process.
As demand surges for electrification technologies such as electric vehicles (EVs), batteries, and renewable power systems, the industry faces a rather difficult paradox: the metal necessary to decarbonise the world is itself carbon intensive to extract.
That tension was a key theme discussed at this year’s Electric Mine Conference in Lisbon, Portugal, where CRU Group’s director of energy transition Simon Price explained that copper mining is emerging as one of the most energy-demanding parts of the critical minerals supply chain.
CRU is a commodity business intelligence provider covering the production of metals, mining, and fertilisers, as well as their critical role in the transition to electrification. CRU provides market analysis, independent price assessments, transparent methodologies, consultancy, and events.
According to CRU’s analysis, copper mining currently generates around 80 million tonnes of CO2 per year. While relatively small in comparison to steelmaking’s 4-billion-tonne footprint, the figure is significant given copper’s role in enabling electrification.
Unlike steel and aluminium, where most emissions occur downstream during smelting and processing, Price points out that copper’s emissions are overwhelmingly concentrated at the mine site itself.
The reason, he says, is scale.
Emissions intensity increasing
CRU estimates that producing roughly 24 million tonnes of mined copper each year required the movement of 12 billion tonnes of material.
For reference, in a rock-to-metal ratio that equates to 500:1 — a ratio higher than commodities such as iron ore or aluminium, which typically sit in a 10–20:1 ratio.
“As every year passes, generally we are processing commodities more and more highly,” Price explains, pointing to declining ore grades across major copper regions, such as Chile and Peru.
Lower grades essentially means more rock must be moved, hauled, and processed to produce the same amount of copper. As a result, diesel consumption, electricity demand, and overall emissions intensity increases.
According to Science Direct, copper ore grades range typically between 0.5% and 1% — making production highly energy intensive. In fact, copper production ranks third in specific energy consumption among major primary metals.
Copper production is also an important source of air pollutants. Science Direct reports that at an actual flash copper smelter plant with a production capacity of 100,000 tonnes annually, only 25% of energy consumption goes into production, while the balance is used for environmental control.
Speaking to Mining.com.au, International Council on Mining and Metals (ICMM) Director of Environment Dana Cartwright says the industry cannot ignore that mining is an energy-intensive industry.
“Our recent research shows that scope one and two emissions from mining and metal processing together account for around 11% of global emissions, placing the sector as the sixth-largest source of global GHG emissions,” Cartwright says.
“Of that 11%, around 3% comes from actual mining activities.”
Cartwright notes that while this figure may seem small from a global perspective, it is where mining companies have an opportunity to reduce operational emissions.
Copper consequences
At the Electric Mine Conference, CRU’s Price says that the industry is already seeing the consequences from operational emissions.
CRU forecasts that, despite efficiency gains and electrification efforts, diesel consumption in Chilean copper alone could rise by 10% by 2030 if operations continue under current models.
At the same time, copper demand is being reshaped by the very technologies driving decarbonisation.
Copper is a key enabler of the energy transition, where the metal is not only embedded in everyday life but is essential across power grids, renewable generation, EVs, and battery systems, among other things.
CRU’s modelling shows global electricity generation could double by 2050, while installed power capacity may increase fourfold or more — creating additional demand for copper-intensive infrastructure.
This growing demand is also being accelerated by the pace of electrification and the rapid expansion and use of artificial intelligence (AI), as previously reported.
An S&P Global study forecasts total installed capacity for all data centres could reach roughly 550 gigawatts by 2040 — more than five times higher than 2022 levels. Concurrently, global defence spending could double to US$6 trillion ($8.47 trillion) by 2040, amid heightened geopolitical tensions.
Together, these sectors are expected to triple by 2040, representing a combined 4 million tonnes of additional demand.
Chilean copper
In the case of the world’s largest copper producer, Chile, fuel consumption at copper processing plants and electricity generation facilities supplying the industry account for a significant share of emissions.
According to a research paper published by the University of Chile’s Department of Mechanical Engineering, these activities account for 6.4% of emissions from fuel consumption and 9.2% from electricity use among total energy consumers.
The University of Chile highlights that the most fuel-intensive components of an integrated copper operation are smelting and refining.
Smelting copper concentrate involves two main stages: heating and converting. Emissions from the smelting process result from burning fossil fuels to heat the furnace to such high temperatures.
Refining, or electrorefining, is then used to produce high-quality copper cathodes. This is required for electrical industries, where 45% of copper is used, according to Carbon Credits.
The University of Chile also highlights the growing environmental importance of local sulphur dioxide (SO2) emissions.
In the smelting-converting process of chalcopyrite — a copper iron sulphide mineral — about 2 tonnes of SO2 are produced per tonne of copper, according to US data.
The University of Chile reports that in 1996, Chilean production of fine copper from smelters was 1.259 million tonnes, while the SO2 emitted was 1.775 million tonnes. In addition, 1.384 million tonnes of sulphuric acid was produced in acid plants from 900,000 tonnes of SO2.
These figures mean that from a rock-to-metal ratio, this equates to 2:1 for Chile.
Chilean copper SO2 emissions due to the use of fuels represent 8.2% of the total SO2 emissions of stationary energy sources. Stationary energy sources refers to electricity and heat at fixed locations such as homes, businesses, and the electrical grid.
The geographical area where one of the largest smelters — producing 300,000 tonnes of refined copper per year — is located was declared by the Chilean Government in 1994 to be SO2 saturated.
To address this challenge, copper smelters are installing plants that capture SO₂ gas and produce sulphuric acid, which is in high demand for hydrometallurgical processes.
The convergence of copper mining, declining ore grades, and decarbonisation is now forcing miners to rethink how the critical mineral is produced.
Electrified haulage, trolley assist systems, renewable power integration, and battery storage are increasingly being viewed as operational necessities in a sector facing rising energy costs, grid constraints, and mounting pressure to decarbonise.
In the second part of this copper series, Mining.com.au will examine how mining companies and technology providers are responding to this challenge.
Write to Aaliyah Rogan at Mining.com.au
Images: Mining.com.au & Unsplash
