Critical Materials

The following sections are included:

• Foreword to the World Scientific Series on Current Energy Issues
• Acknowledgement
• Contents

A growing world population and rising levels of prosperity are driving up the global demand for energy and materials and are increasing the negative impact on the environment. Challenges related to energy use, materials consumption, and climate change are closely intertwined. On the one hand, producing materials consumes about 21% of global energy use and is responsible for about the same percentage of carbon emitted to the atmosphere. On the other hand, the transition from a fossil to a non-fossil electricity mix — to mitigate climate change — would result in a much higher usage of metals. The increase in the usage of metals would range from a few percent to a factor of a thousand for certain metals. Concerns over the future security of the supply of raw materials has led to the identification of critical raw materials for the USA, Japan, and the EU. As part of the World Scientific Series on Current Energy Issues, this book is focused on ‘Critical Materials’…

Raw Materials are an important commodity for most economies in the world. Due to a combination of population growth, economic developments, and quality of life expectations, resource nationalism centred around the availability and control of raw materials has the attention of the highest political levels worldwide, fuelling the geopolitical usage of materials for other purposes.

Geopolitics and energy markets have a close relationship, as the outbreak of geopolitical tension has traditionally caused fluctuations in the oil price. Similarly, politically motivated disruptions in the supply of natural gas have caused security concerns and shortages. Much has changed however since the mid-20^th century. The development of unconventional fuel types such as shale gas and oil in the United States (U.S.) has meant that the U.S. has morphed into a major energy producer. Particularly the onset of shale oil has had a major impact on the international oil market. Similarly, the onset of Liquefied Natural Gas (LNG) has caused gas markets to be more globally connected. A third major disruptive change in global energy has been the rapid increase in renewable sources of energy since half-way through the past decade. This chapter presents an analysis of how the role of geopolitics in energy markets has changed over time and why political upheaval has a markedly different impact today than it has had throughout history.

The global quest for intermittent renewable energy sources (wind, solar), consumer goods (mobile phones, notebooks), and electrification of the transport sector (electric vehicles), requires a strong increase in the use of rechargeable energy storages devices, such as batteries. Hence, novel types of rechargeable batteries are to be found that are cost-effective, consist of environmentally friendly materials and non-critical materials, and deliver a high performance in terms of energy density and power, during a long cycle and service life, taking current legislation laws into account. Here we concentrate on various types of batteries and their materials, their typical sectors of application, and their forecast, including potential market share. It turns out that metals will still remain the predominant type of battery material, irrespective of the choice of battery system. From the required materials that are important for future rechargeable batteries, a number are critical in terms of scarcity, geopolitics, supply risk, competition with the food industry, carbon footprint, and/or ethical mining. With respect to the critical elements, particularly once those concern scarcity and supply risks, recycling is of utmost relevance, and needs to be regarded as an industrial sector of paramount importance.

The tensions around limits to growth versus tech will fix it are, today, as prominent as ever in the debates around critical materials. Changes in the demand and supply of materials has regularly led to periods of material supply problems. This chapter provides an overview of the development of critical materials from the mid-20^th into the early 21^st century. The overview begins with, in the U.S., the development of critical materials policy in World War II and the Cold War years, the oil crisis of the 1970s and the subsequent evolution into the early years of the 21^st century. Critical materials thinking has been defined through war, the cold war and then concerns over energy availability and environmental impacts. This chapter shows how the historical military-energy framework for assessing critical materials has evolved into critical materials approaches to help address the challenges of energy, materials and the environment in the 21^st century.

Criticality can be defined as “the quality, state, or degree of being of the highest importance”, but how can we understand what is meant by “highest importance”? In this chapter we define and describe a multi-parameter approach to the criticality issue that involves (as do the efforts of other researchers and governments) a variety of geological, economic, technological, environmental, and social concerns. Our results suggest that the highest level of concern should be for metals whose processing and use involves extensive separation from parent ores, high levels of embodied energy, little opportunity for substitution, and low levels of recyclability. Improved approaches to material use should thus involve the preferential utilization of non-critical materials, attention to the potential for material reuse at the design stage, and a focus on increasing the efficiency of recycling.

For many companies understanding the environmental impacts of their products and operations is steadily rising upwards in their business agenda…

Past events and predictions suggest the need for a methodology to assess the criticality of raw materials to national economies. Existing criticality methodologies were combined to develop a raw materials criticality methodology for the Dutch economy, considering materials embedded in intermediate or finished goods as well. Indicators are described according to their relevance for assessment of risk for supply security, financial damage or reputational damage for companies. The impact aspect is based on value added in exported domestically produced goods.

For product designers, the world has traditionally been one of resource abundance. Introducing them to a resource-constrained world thus requires new design strategies. This chapter explores how embedding circular economy principles into design practice and education could help product designers take critical material problems into account. We introduce four product design strategies that address materials criticality: (1) avoiding and (2) minimizing the use of critical materials, (3) designing products for prolonged use and reuse, and (4) designing products for recycling. The ‘circular’ strategies (3) and (4) are elaborated, as these sit most firmly within the remit of product design. This leads to a typology of circular product design that redefines product and material lifetime in terms of obsolescence, and introduces a range of approaches to resist, postpone or reverse product and material obsolescence. The typology establishes the basis for the field of circular product design, bringing together design approaches that were until this date unconnected and paving the way for the development of detailed design methods.

The substitution of critical alloying elements in metals is a strategy to reduce the criticality of materials. Nano-steels are a novel grade of advanced high-strength steels that are suited for application in the chassis and suspension of cars and as fire-resistant steel in high-rise buildings. The high strength and ductility per unit mass make the nano-steels resource-efficient and reduce vehicle weight while maintaining crash worthiness. The excellent mechanical properties of certain nano-steels rely on the addition of small amounts (up to 0.1 wt.%) of Niobium as alloying element to the steel. Niobium is considered to be a critical raw material by the European Union due to its high economic importance as an alloying element in advanced, high-strength steel grades and due to the high supply risk related to the high degree of monopolistic production within the supply chain. This chapter describes the fundamental materials science that is needed for the substitution of the critical alloying element Niobium by Vanadium as an alloying element in nano-steels.

In a resource-constrained world, the demand for new renewable resources becomes a must. Two of the rapidly developed technologies are photovoltaic applications to act as efficient sources of solar energy, and touch screen-dependent communication technologies. Both require the use of transparent conducting layers that achieve the main requirements of very high conductivity and very high transparency. In this chapter, we describe our efforts to use carbon nanomaterials, specifically graphene, as transparent conducting electrodes. Graphene sheet resistance was reduced, while keeping its transparency high enough to be suitable for the two mentioned applications. The lowest value achieved was 22 Ω/square at 90% transparency which is close enough to the values of the conventional currently used transparent electrodes.

Sustainability is often defined as: the ability to continue a defined behavior indefinitely. However, considering the nature of mining operations, this cannot be meant with the phrase “Sustainability in Mining”. Sustainability in the mining industry should be understood in the same way as sustainability in environmental science: meeting the resources and services needs of current and future generations without compromising the health of the ecosystems that provide them. A number of aspects of this are addressed in this chapter: use of energy, use of water, land disruption, reducing waste (involving solid waste, liquid waste, and gaseous waste), acid rock drainage when dealing with sulfide minerals, and restoring environmental functions at mine sites after mining has been completed. To do everything in an environmentally sound way is costly, but in the end necessary. Regarding this, it is concluded that governmental regulations concerning emission of waste, storage of waste and re-use of the land after mining are essential to provide a sustainable form of mining and mineral processing.

In order to recycle or re-use products that contain Critical Raw Materials (CRMs), these products have to be collected from consumers and professional organizations (e.g. businesses) first. Waste Electrical and Electronic Equipment (WEEE) is collected for economical, environmental, and public health and safety reasons. Lessons can be learned from the collection of WEEE, such as how to influence and stimulate consumers to collect WEEE separate from other waste, and how to stimulate and train companies in separating waste.

Efficient mechanical and sensor-based separation of mixed solid waste into valuable secondary materials is a critical step in recycling and in the preservation of primary resources. To position the associated research field, we discuss backgrounds and links to societal and political developments within and outside the classical waste chain. An encompassing theory detailing separation processes is briefly introduced and explained using appealing examples. The roles of science and industry in the development of innovative technologies is clarified, finishing with examples of physical principles that are behind many contemporary separation technologies. Throughout, scientific challenges and technological advances are identified.

Metals are important engineering materials, and are produced from non-renewable natural resources. This chapter starts with the criticality and scarcity issue of metals and metal resources. Then various available extraction and refining technologies and processes are introduced for primary production and recycling of metals. The principles of pyrometallurgy, hydrometallurgy and electro-metallurgy (electrowinning and electro-refining) are described for primary production of metals. The applications of metallurgical technologies to metals recovery from secondary resources (metal scrap and waste residues), i.e. recycling of metals, are discussed. As the last part, the extraction and recycling of cobalt, one of the most critical metals, is given as an example to illustrate how different metallurgical technologies are used and combined to extract a metal from different types of raw materials.

The management of bauxite residue (BR) is a major issue for the aluminum industry because of its high alkalinity and the large volumes generated. Therefore, the recovery of rare earth elements (REEs) with or without other metals from BR and utilization of the generated residue can contribute to a solution on the management problem of BR and it can be one of the options to meet the demand of REEs. In view of the above, the selective recovery of REEs over major elements such as iron by direct acid leaching was studied initially. From the leaching results, either the recovery of REEs was low or the dissolution of iron was high. To address that, iron was removed from BR by smelting. The slag generated after smelting was leached with mineral acids. The selectivity of REEs over iron was greatly improved. However, the high level of alumina presence in BR required a large amount of fluxes thereby increasing the energy consumption in smelting. Hence, the removal (and recovery) of alumina from BR by sodium carbonate roasting was carried out. The sample, after alumina removal, was smelted and the REEs were successfully recovered from slag by leaching with mineral acids. An alternative process, called sulfation–roasting–leaching, was also developed by which the REEs can be selectively leached. The scandium recovery, however, was low. Preliminary energy and economic analysis showed that alkali roasting–smelting–leaching and sulfation–roasting–leaching were the most promising processes for the treatment of BR.

The following sections are included:

• Author Biographies
• Index