Clean hydrogen potential for carbon-neutral copper mining

Abstract

Increasing electrification and extensive expansion of renewable energy technologies bring about expectations of increased demand for copper and a corresponding increase in the total energy consumption for copper mining. This manuscript gives the first comprehensive overview of current energy consumption in copper mining and suggests avenues toward carbon neutrality. In the present work, we estimate the future amount of copper needed for clean energy transition-related technologies, focusing on the U.S. market and the leading role of Arizona (AZ) in copper mining. Particularly, we evaluate hydrogen's potential to displace diesel in haulage, for use in high-grade heat generation in smelting and fire-refining (anode) furnaces, and as a chemical feedstock in anode furnaces, by conducting a techno-economic assessment for replacing fossil fuels with clean hydrogen. Lastly, we examine the challenges and opportunities associated with integrating hydrogen in copper mining. Our analysis shows a likely sizeable increase in future copper demand just for clean energy technologies by a maximum factor of 4.6 by 2035 and by a factor of 7.0 by 2050. We also found that there is an economic opportunity to replace diesel with clean hydrogen at the current hydrogen production costs with the help of production tax credits (PTC) for clean hydrogen in the U.S. Inflation Reduction Act (IRA) adopted in August 2022. Additionally, we show that carbon taxation is not an effective measure for copper mining to switch from fossil fuels to hydrogen. Overall, this manuscript contributes to the discussion about transitioning mining to carbon neutrality and identifies specific areas of opportunity.