Strategic minerals are the cornerstone of national security and stable development. China's strategic mineral imports are highly dependent on maritime transport, and ensuring smooth maritime routes is crucial for safeguarding the security of strategic mineral imports. This study analyzes the overall pattern of China's strategic mineral imports and maritime routes. Taking the iron ore maritime import network as an example, the study evaluates the importance and failure impacts of key maritime routes, summarizes the risk sources of important maritime routes, and proposes corresponding security strategies. The research finds that China's strategic mineral imports are highly dependent on maritime routes. Based on the case study of iron ore maritime transport, the importance and failure impacts of maritime routes are identified. It is suggested to build differentiated and refined response strategies, focus on the protection of the Cape of Good Hope and the Lombok Strait transport corridor network, and pay attention to the safe navigation of large vessels. The risks of maritime routes for China's strategic minerals mainly come from three aspects: navigational passages, international disputes and war threats, and non-traditional security issues. In response, multi-domain response strategies can be implemented, including building multiple strategic pivot nodes, constructing a multidimensional early warning system and an alternative route response mechanism, strengthening the construction of cross-border rail‍–‍sea intermodal transport corridors, conducting preventive diplomatic work, improving the maritime security system, and implementing hierarchical and differentiated risk-response measures.

Praseodymium (Pr) is a critical mineral for the global clean energy industry. The global demand for Pr continues to increase. China possesses the largest proven reserves and highest production of Pr worldwide. However, a future Pr supply-demand gap still could occur in China. Developing a circular economy and promoting material recycling are considered as solutions to the potential supply constraints. This study adopts a material flow analysis method and combines it with the recycling input rate (RIR) indicator to estimate the potential quantities of the Pr recycling supply in China from 2011 to 2020. The key findings are as follows: (1) From 2011 to 2020, 7.902 × 10⁴ t Pr entered the anthropogenic cycle system in China from the supply side, of which 1.639 × 10⁴ t Pr originated from recycling; (2) 1.369 × 10⁴ t Pr was recycled from NdFeB magnet production scraps, with the RIR remaining stable at approximately 17%; (3) theoretically, 2.7 × 10³ t Pr could be recycled from end-of-life (EoL) products, and the RIR of EoL products could increase from 0.04% to 5.17%. In view of the major challenges in realizing Pr recycling from EoL products, this study proposes improvement strategies to promote Pr recycling in China. They include improving the extended producer responsibility of China, progressively establishing consumer responsibility for relevant products, and guiding the industry to formulate recycling-related technical specifications and industry standards.

Cobalt is an essential material for the development of the new energy industry. Based on the latest data regarding the cobalt resource industry of China and worldwide, this study analyzes the challenges faced by the development of China's cobalt resource industry from the aspects of cobalt resource endowment, supply-demand situation of cobalt concentrate and refined cobalt, and industry policy. China is the world's largest producer of refined cobalt and largest consumer of cobalt; however, its cobalt resources are extremely scarce and its ultra-high dependence on foreign countries and single source of imports have put China's cobalt resource security at risk. In response to the above problems, we propose the following countermeasures: (1) adopting effective measures to increase China's cobalt reserves; (2) diversifying cobalt import channels to ensure a stable access to overseas cobalt resources; (3) implementing supportive policies to help China-invested overseas enterprises stabilize their production; (4) establishing a cobalt reserve system to improve the cobalt resource guarantee capacity of China; (5) strengthening the comprehensive utilization technologies to increase the amount of available cobalt resources; and (6) emphasizing research of potential cobalt resources, such as sea-floor cobalt resources in ferromanganese nodules and crusts.

Nickel resources are vital for national economic development. As the largest consumer of nickel metal worldwide, China faces a scarcity of nickel metal raw materials which depend highly on imports. Therefore, it is necessary to achieve breakthroughs in nickel resource exploration, promote the comprehensive development and utilization of nickel resources, and broaden import channels, to ensure a secure and stable supply of nickel resources. Based on the analysis of the latest data of the nickel industry, this study reviews the nickel resource endowments and the status of nickel supply and demand in China and abroad, and summarizes the genetic types, spatiotemporal distribution, and prospecting potentials of nickel ore deposits. It also analyzes the issues facing the development and supply security of China's nickel resource industry, and proposes key technologies for nickel exploration as well as development paths for the comprehensive utilization of nickel resources. To ensure the stable supply and safe development of nickel resources in China, countermeasures are proposed from both international and domestic aspects. Internationally, it is necessary to stabilize the important nickel resource import markets represented by Indonesia and the Philippines, increase investment in mining projects overseas to enhance the international competitiveness of Chinese enterprises, and strengthen international cooperation to diversify the channels for nickel resource imports. Domestically, the following suggestions are proposed: (1) increasing nickel resource exploration, (2) promoting the comprehensive utilization of nickel resources to increase the utilization rate of recycled nickel resources, (3) optimizing traditional technical processes and adjusting the industrial structure, (4) strengthening nickel reserve bases to ensure effective increase in reserves; and (5) encouraging research on mining technologies of potential nickel ores such as ferromanganese nodules on the ocean floor.

The ore grade is a core indicator for measuring the economic value of minerals, and its online detection capability is related to the economic benefits, environmental impact, and production intelligence level of a mining enterprise. This study discusses the application value and classification of online detection technologies for ore grade and summarizes the research and application progress of these technologies in terms of the following technical directions: radioactive, optical, electromagnetic, and machine-vision detection. Challenges faced by the development of related technologies are identified at the technical research and practical application levels. Challenges at the technical research level include (1) accuracy bottlenecks and interference factors, (2) difficulties in signal analysis and optimization, and (3) model construction and data dependency. Challenges at the practical application level include (1) radiation safety and cost-effectiveness, (2) technological breakthroughs adapted to diverse ore characteristics, and (3) stable operation and real-time feedback in harsh environments. The study further elaborates on the future development directions of online detection technologies for ore grade. Future efforts should focus on breakthroughs in exploring the forefront of multimodal fusion and intelligent perception technologies, iterating and upgrading intelligent perception and data processing algorithms, developing miniaturized/remote/intelligent equipment, and constructing and optimizing real-time dynamic monitoring network systems. Moreover, emerging technologies, such as deep learning for promoting the fusion analysis of micro and macro features, quantum computing and bioinspired algorithms, as well as intelligent sensor networks and the Internet of Things technology, are summarized. Furthermore, active actions are recommended in the following aspects: (1) technological innovation and equipment upgrading, (2) standards formulation and standardization construction, (3) deepening of the industry–education–research–application cooperation mechanism, (4) talent cultivation and team building, and (5) international cooperation and resource sharing, thereby promoting the intelligent and efficient development and utilization of mineral resources.

Platinum group metals (PGMs) are indispensable for the automobile, petrochemical, energy, and national defense industries. However, the mineral resources of PGMs are extremely scarce in China, and the contradiction is prominent between the supply and demand of the resources. Therefore, recycling PGMs becomes an important measure to ensure the safe supply of PGMs and support the high-quality development of related industries. This study analyzes the supply and application of PGMs, clarifies the supply and demand trend of the PGMs market, and sorts out the recycling technologies of PGMs. The hydrometallurgical process includes cyanidation as well as hydrogen chloride combined oxidant method. The pyrometallurgical process includes capture by lead, copper, matte, and iron. The research and application of the pyro-hydro-metallurgical recycling process for PGMs are elaborated from the aspects of the roasting-leaching, iron capture-acid leaching, and low-temperature iron capture-electrolysis-centrifugal extraction processes. The low-temperature iron capture-electrolysis-centrifugal extraction process follows the research idea of low-temperature iron capture. Through the design of slags with a low melting point, the iron capture temperature is reduced from beyond 1800 ℃ to around 1400 ℃. The enriched Fe-PGM alloy is further enriched by electrolysis, and Pd, Pt, and Rh are successively obtained through centrifugal extraction and purification, realizing the short-process separation and purification of PGMs. This process has the advantages of green, high efficiency, and low cost. Focusing on the high-quality development of the PGM recycling industry, we propose the following suggestions: (1) conducting basic research and technical breakthroughs centering the entire process of PGM enrichment, separation and purification, as well as pollution prevention and control; (2) accelerating the construction of a full-chain standards system for PGM recycling and a green and low-carbon industrial ecological environment; and (3) improving the Internet Plus capabilities through the entire business links to realize the intellectualization of the whole recycling-processing-reuse process.

New energy industries, such as wind and photovoltaic (PV) power generation, are key to supporting the carbon peaking and carbon neutrality goals of China. The installed capacity of wind and PV power in China is the largest worldwide; therefore, it is necessary to secure the supply of key metal materials and conduct a more accurate management of emerging solid wastes. This study sets different development scenarios based on the historical data and planning objectives of wind and PV power industries of China. It assesses the demand, waste, and supply of key metals in China's new energy industry using a life distribution model of wind and PV power generation equipment, and focuses on identifying the supply pressure of silver, copper, gallium, silver, steel, and neodymium, thereby providing a basic support for realizing the green and low-carbon development of the energy industry by 2060. In the baseline scenario, the decommissioned volume of the wind and PV power generation industries will reach 4.6 GW and 28.3 GW in 2035, respectively; and the total decommissioned volume (by mass) of both wind and PV power generation equipment will reach 2.54 ×10⁶ t and 1.048 ×10⁷ t in 2035 and 2060, respectively. In terms of the supply of key metals for the new energy industry during 2030‒2060, iron and steel have a low supply risk (≤5%), neodymium has a medium-high supply risk (25%‒50%), copper and silver have a high supply risk (50%‒100%), and the supply of gallium and indium are at an extremely high risk owing to their excessive peak demand. To improve the security and diversity of the supply chain of the new energy industry, it is necessary to ensure the sustainable supply of metal mineral resources and promote material recycling and efficient use. Furthermore, we propose the following recommendations: (1) treating decommissioned equipment for wind and PV power generation as waste electrical and electronic products, (2) incorporating wind and PV power generation enterprises into the Catalogue of Classified Management of Pollutant Discharge Permits for Stationary Pollution Sources, (3) improving the distributed new-energy solid-waste recycling system, and (4) developing recycling technologies for emerging solid wastes.