Environmental Implications of Resource Security Strategies for Critical Minerals in Japan

By Tetsuo Tezuka

Environmental Implications of Resource Security Strategies for Critical Minerals in Japan

While it has been an ongoing concern from the early days of human history, in recent years there have been growing concerns that resource supply in the future will be vulnerable to supply restrictions, particularly for materials deemed as critical for economies or societies. Supply restrictions can occur for various reasons such as strikes, price spikes, long-term ore grade decline or political issues. Therefore, many countries have considered strategies for improving resource security in the face of perceived growth in uncertainty over supply, including approaches to alternative resource supply. In the assessment of critical minerals, environmental impacts have been a focus of a number of methodologies. In the case of resource security for critical minerals, there are a variety of potential strategies that might be used to reduce criticality from the supply risk perspective, but the environmental consequences of these strategies need to be evaluated.

Japan is a country that has widely been considered as particularly vulnerable to resource restriction, due to its heavy reliance on imported raw materials for fabricating metals to support its manufacturing export industries, with most of its historic mines having closed. For example, 100% of iron ore, copper, lead and zinc concentrates are imported. These materials are processed into metals, from which a variety of products, such as automobiles, electrical and electronic equipment are produced. A certain proportion of these products are exported outside Japan, which leads to these metals not being 100% recoverable in the domestic material cycle by recycling. Japan has traditionally developed a range of strategies to improve resource security—including upstream development in resource-producing countries, recycling, stockpiling and research and development of alternative (substitute) materials. However, these approaches still rely on a variety of uncontrollable factors, which leads to the conclusion that domestic mineral production would be attractive if the possibility arose.

Resource policy in resource importing countries has historically tended to focus on upstream development in resource producing countries and downstream improvements including research and development on substitute materials. Unconventional resources in the form of recycled materials have been focused on by some, but primary unconventional resources of deep ocean minerals remain beyond the practical scope of most resource security evaluation, due to the uncertainties in extractive economics. However, considering the uncertainty of resource supply in the future, relying on resource producing countries is not an optimal solution from the perspective of long-term resource security. In this context, domestic mineral production is an important alternative to consider for future supply.

Domestic mineral production in this study focused on deep ocean mining; however, there are other possible alternative resources for resource importing countries such as the reopening of mines that were previously closed due to ore grade decline, safety or economics under previous eras’ technology. It is possible that ore grades of closed mines may be higher than cut-off grades today, due to both the increase in prices and the improvement in technology. When countries whose resource policy previously changed from producing domestically to importing concentrate shift their policy again to restarting-mining, the issues of tailings, localized environmental impacts and energy consumption issues arise.

Since tailings, which possibly include harmful materials such as cadmium, arsenic or mercury, need to be stored in safe and stable environments and require long-term monitoring, this could be a significant issue to be traded-off against resource security benefits of domestic mining. The volume of tailings dams should be considered as well. Generally speaking, the lower the ore grade becomes, the more tailings are produced. When unconventional mining or redevelopment of closed mines occurs, ore grades are unlikely to be very high. Environmental impacts related to tailings storage need to be understood and evaluated. It should be noted that in the whole mineral supply chain, conventional processing produces more waste since deep ocean mining does not have waste rock. Because Japan does not import and process ore, waste rock and mill tailings from conventional mining become hidden waste streams. Considered from a global perspective, deep ocean mining may contribute to reduce waste from the mining process. Other solid wastes such as plastics or other minerals are not explicitly discussed in this study; however, how to deal with this kind of waste should also be considered—particularly when polymetallic ores or mingled recycling streams are considered. It is estimated that recycling will practically produce less waste than shown here, since this study does not consider recovery from waste except copper.

Energy consumption is another issue to be discussed. Energy consumption in resource importing countries includes transportation, smelting and refining, though roughly as much energy is consumed in resource exporting countries. As for recycling, since China will stop importing copper scrap by the end of 2018, the necessity for copper scrap recycling in domestic facilities will increase in Japan. Japan has long been struggling to secure its energy supply—especially after the nuclear power plant shut down in 2011. As recycling is further improved, Japan has to find alternative, secure energy resources to maintain its mineral production, along with the remainder of its economy. Japan has been trying to reduce energy demand for a long time, and while promoting mineral recycling may result in energy consumption decrease, and continue Japan’s declining energy demand trend, deep ocean mining would impact adversely on energy consumption. On the other hand, even if recycling were to become a dominant raw material supply stream, it still consumes imported energy. Renewable energy technology installation is therefore one of the requirements to achieve a more resource-secure society.

By minimizing energy consumption, CO2 emissions and waste disposal based on the capacity limitations of each supply source, it is indicated that installing processes that recover all materials from recycling on a priority basis will reduce these impacts significantly. If large-scale deep ocean mining extraction is conducted, it is obvious that this type of material supply can improve resource security significantly. However, as shown in the results, the optimal solution found in this study was utilizing deep ocean mining at a level of 30% of raw material supply if all metals are recovered from the ore, with the rest of demand filled by recycling. Even though there are some challenges, such as how to find more deep ocean hydrothermal ore (particularly higher-grade ore), it can be said that realizing domestic mineral production could help to achieve stable resource supply for Japan.


It can be concluded that: (1) domestic mineral production is one option to obtain resources so as to avoid vulnerability of external affairs. Supply controllability of domestic mineral production should be a key factor in evaluating the sustainability of supply; and (2), based on supply capacity, enterprises, installing recycling will improve resource security while also enabling better performance in terms of energy consumption, CO2 emissions and waste disposal. Considered within the framework of criticality, the combination of pressures from increasing demand globally with potential lags in primary supply could promote domestic mineral production. On the other hand, domestic production environmental implications could work to restrict their output or development, increasing the mineral criticality. For countries considering such options for reducing supply risk, the environmental considerations should also be factored in.



This is an excerpt of the journal article: Environmental Implications of Resource Security Strategies for Critical Minerals: A Case Study of Copper in Japan, by Ran Motoori, Benjamin C. McLellan and Tetsuo Tezuka. Published: October 9., 2018 in Minerals 2018, 8(12), 558; doi:10.3390/min8120558 under a Creative Commons Attribution License (CC BY 4.0). 

Tetsuo Tezuka

Dr. Tetsuo Tezuka is currently working with the Department of Socio-Environmental Energy Science, Graduate School of Energy Science, Kyoto University. He is the head of the “Energy Economics” Laboratory in Socio-Environmental Energy Science.