Closing the Loop: A Circular Economy Approach to Critical Mineral Sustainability

Michael Akindeju explores key circular economy strategies to reduce reliance on virgin resource extraction, and focuses on recovering gallium from electronics

CRITICAL and rare earth minerals are natural resources that have significant economic importance due to their essential role in manufacturing high-technology products, wearable electronics, renewable energy systems, and defence applications. These minerals such as gallium, indium, thallium, tantalum, cobalt, lithium, chromium, germanium, and graphite are currently used in diverse applications and in myriad industries.

However, the finite nature of many critical minerals necessitates a more sustainable approach to their use and management; and their supply is often constrained by geopolitical factors, environmental concerns, and limited availability (see Figure 1), making their efficient use and recycling critical for sustainable development. But what if we can work together to gradually and effectively reduce our reliance and over-dependence on new explorations and virgin materials by recovering and recycling portions from used materials instead?

Key considerations

Chemical engineers play a crucial role in developing and optimising processes to transform raw materials and waste streams into valuable products, with key considerations including:

• Economic feasibility: The process must be economically viable, considering the costs of raw materials, energy, labour, and equipment
• Environmental impact: It is essential to minimise environmental harm throughout the entire process
• Scalability: The process should be scalable to accommodate varying volumes of electronic waste
• Safety: Ensuring the safety of workers throughout the process by implementing appropriate safety measures, such as personal protective equipment and proper ventilation, is crucial

While technical challenges in mining and processing critical minerals can be addressed by chemical engineers through multidisciplinary collaboration, the greater hurdle lies in policy shifts to reduce reliance on virgin resources. Such shifts are vital for reducing mining’s environmental impact and addressing climate change, underscoring the need for a circular economy to meet the rising demand for critical minerals.

Transitioning to a circular economy

Traditionally, the extraction and use of critical minerals has followed a linear economic model characterised by resource extraction, manufacturing, usage, and disposal. This approach leads to resource depletion, environmental degradation, and significant waste generation.

The circular economy is gaining traction globally as a transformative model for sustainable development. Unlike the linear “take-make-dispose” approach, it aims to close the loop of product life cycles through resource efficiency, waste minimisation, and product reuse. This shift is crucial for critical and rare earth minerals, which have low recycling rates compared to traditional ores like iron and copper (see Tables 1–3).

Implementing circular-economy principles can help governments develop sustainable resource strategies and aid their carbon abatement goals. For instance, the UK’s Critical Minerals Strategy focuses on improving supply chain resilience, boosting domestic capabilities, and collaborating; the EU’s Critical Raw Materials Act aims to secure and sustainably supply critical raw materials, reduce dependencies, and promote supply chain sustainability; while Australia’s Critical Minerals Strategy 2023–2030 emphasises creating resilient supply chains, building sovereign capabilities, and supporting the clean energy transition. Further, by adopting these strategies, governments can enhance the sustainable management of critical minerals, supporting initiatives like the US Department of Energy’s focus on diversifying supply, developing substitutes, and enhancing reuse and recycling.

Circular economy strategies for chemical engineers

1. Resource efficiency and eco-design

Chemical engineers can by default embed resource efficiency and eco-design principles during scoping, front end engineering design, and EPCM phases for establishing operations for processing and deployment of critical minerals. This involves using fewer resources to achieve the same output through improved product design, manufacturing processes, and material selection. Eco-design aims to create products that are easier to repair, upgrade, and recycle. By designing products with longer lifespans and facilitating their disassembly, the circular economy reduces the demand for virgin materials and decreases waste generation. This aligns with the EU’s Circular Economy Action Plan¹ which promotes resource efficiency, waste reduction, and recycling, with specific targets for critical minerals.

2. Extended producer responsibility

Extended Producer Responsibility (EPR) policies should be enforced. EPR holds manufacturers accountable for the entire life cycle of their products, including end-of-life management. This policy incentivises producers to design products that are easier to recycle and encourages the development of take-back programmes. In the context of critical minerals, EPR can significantly drive the recycling of electronic waste, a major source of these valuable elements. By integrating EPR, chemical engineers can contribute to more sustainable product designs and efficient recycling processes, supporting the circular economy.

3. Urban mining and secondary raw materials

Decentralised hubs for urban mining should be created. This essential practice involves extracting valuable materials from electronic waste, old appliances, and other discarded products which would reduce the need for primary resource extraction and mitigate the environmental impact of mining activities. Urban mining can play a crucial role in the circular economy by recovering critical minerals from secondary sources and reintegrating them into the production cycle. For example, Japan is stepping up imports of used electronic devices from the Association of Southeast Asian Nations² in order to promote the development of urban mining.

4. Recycling technologies and innovations

Advancements in recycling technologies are vital for cost-effective and efficient recovery of critical minerals from complex products. This will include innovative hydrometallurgical and pyrometallurgical process techniques to improve extraction rates and the purity of recycled materials. Additionally, research into bio-metallurgy and other environmentally friendly methods holds promise for sustainable recycling practices. As part of its sustainability efforts, Apple’s Daisy robot disassembles iPhones to recover rare earth elements and cobalt, aiming to create a closed-loop supply chain.³

5. Material substitution and product innovation

Where possible, chemical engineers should consider material substitution, which involves replacing critical minerals with more abundant and less environmentally impactful alternatives. This approach can reduce the pressure on critical mineral supply chains and decrease the environmental footprint of products. For example, advancements in battery technologies are exploring alternatives to cobalt and other critical elements, and enhancement for bio-solar cells.

Challenges and barriers to implementation

While the circular economy offers significant benefits for the sustainable management of critical minerals, several challenges and barriers must be addressed.

1. Technical and economic feasibility

Implementing circular-economy practices requires substantial investments in research, development, infrastructure, and technology. Recycling certain critical minerals from complex products can be technically challenging, and the economic viability of these processes often depends on market conditions and policy support. Chemical engineers must innovate to make these processes both technically and economically viable.

2. Regulatory and policy frameworks

Effective regulatory and policy frameworks are essential for transitioning to a circular economy, especially for critical minerals. Governments must implement policies that promote resource efficiency, support recycling initiatives, and incentivise sustainable product design. This could involve a government body managing decentralised urban mining hubs. International collaboration is also crucial due to the global nature of critical mineral supply chains.

3. Consumer awareness and behaviour

Consumer behaviour significantly impacts the success of circular-economy initiatives. Raising awareness about recycling and sustainable consumption can encourage participation in take-back programmes and the choice of longer-lasting products. Educating consumers about the environmental impact of their purchasing decisions is essential for driving demand for circular economy products.

4. Supply chain complexity

The supply chains for critical minerals are complex, involving multiple stakeholders, including miners, manufacturers, recyclers, and consumers. Coordinating efforts across these diverse actors and ensuring transparency and traceability in supply chains can be challenging. Effective collaboration and information sharing are necessary to optimise resource use and minimise waste.

Conclusion

Circular economy offers a comprehensive strategy for managing critical minerals, addressing issues like resource depletion, environmental harm, and waste generation. By promoting resource efficiency, recycling, and sustainable product design, this approach can create a more resilient and sustainable future for critical mineral availability. Although challenges persist, the potential benefits make it a vital part of global efforts to achieve sustainable development and alleviate resource scarcity. Adopting a circular-economy approach for critical minerals processing and recovery is an opportunity to drive innovation, economic growth, and environmental stewardship. This effort demands strong political commitment from governments and active engagement from the private sector, as demonstrated by MKPro’s innovative recovery of gallium from waste electronics (above).

References

1. EU Circular Economy Action Plan: https://bit.ly/40Luo5A
2. The Japan News: Japan Plans to Support ‘Urban Mining’: https://bit.ly/4goj3hO
3. Apple recycling: https://bit.ly/4hweIKO