The mining industry is facing mounting pressures to secure essential metals for a future driven by electricity. As demand for metals like copper rises, companies are exploring alternative methods to source these materials. One notable approach is re-mining, which involves extracting valuable metals from mining waste, known as tailings. This strategy is gaining traction as traditional mining investments struggle to keep pace with the urgent requirements for a sustainable energy transition.
Duncan Winblad, the chief executive of Anglo American, highlighted the urgency of this situation in a Bloomberg interview three years ago. He expressed concerns about the future supply of copper, stating, “I genuinely don’t see where all of this copper is going to come from at this point in time.” Winblad also noted that while there are significant copper resources globally, the time required to bring these resources to market is often underestimated.
Long lead times in mining present a formidable challenge in the quest for net-zero emissions, as outlined in the Paris Agreement. Despite some market awareness of these challenges, copper prices have not incentivized large-scale investments in new mining projects. Consequently, mining companies are increasingly focusing on re-mining to tap into existing waste deposits.
Re-Mining: An Innovative Solution
Tailings, the waste produced during mining operations, contain recoverable metals that can be utilized similarly to newly mined materials. According to research by the Fraunhofer Institute, approximately 100 million tons of copper are currently stored in tailings dams from mining activities conducted between 1910 and 2010. The annual production of tailings is substantial, amounting to around 7 billion tons globally. Although the metal content in these tailings can be quite low—ranging from 0.1% to 0.5% for older mines and under 0.1% for modern ones—there is a growing consensus that recovering these metals could help meet the demands of the energy transition.
Several companies are actively investigating the commercial viability of metal recovery from tailings. For instance, Hudbay Minerals is exploring copper recovery from the Flin Flon mine, which closed in 2022 but still contains substantial amounts of recoverable copper and zinc. Similarly, Cobalt Blue Holdings, an Australian company, is assessing a project to extract sulfur from pyrite tailings following the closure of a local copper smelter. Additionally, Hindustan Zinc recently approved an investment to build a reprocessing plant at the Rampura Agucha mine, which is recognized as the world’s largest zinc mine, with a capacity of 10 million tons per year.
The Economic Barriers to Re-Mining
The concept of re-mining aligns well with the principles of a circular economy, which aims to minimize waste while securing necessary materials. However, the primary obstacle to widespread adoption of this approach lies in technology and economic feasibility. To make the extraction of residual metals from tailings profitable, the costs associated with the process must be sufficiently low.
Currently, international copper prices do not provide a compelling incentive for investors. Despite forecasts indicating soaring demand and potential shortages, prices have remained relatively stagnant. As a result, while re-mining presents a promising opportunity, it may take time before significant progress is made in draining tailings dams and recovering the valuable metals contained within them.
As the mining industry navigates these challenges, the focus on innovative recovery methods like re-mining could play a crucial role in meeting the increasing demand for metals necessary for a sustainable future.
