Magnesium Metal: The Core Carrier of the Lightweight Revolution and Strategic New Materials

I. Core Definition of Magnesium Metallic magnesium (element symbol Mg) is the sixth most abundant metallic element in the Earth's crust. It belongs to the category of light metals, with a density of only 1.74 g/cm³ (approximately 2/3 that of aluminum and 1/4 that of steel), a melting point of 651℃, and a boiling point of 1107℃. Its core value lies in its "extreme lightweight + high specific strength + good processability + unique chemical activity." It can be used as a structural material to reduce equipment weight, and as a functional material for metallurgical reduction, energy storage, and other applications. It is a strategic metal connecting lightweight manufacturing, new energy, and high-end chemical industries, and is known as the "green engineering metal of the 21st century." II. Development History The industrial production of metallic magnesium began in 1886 when American scientist Hall and French scientist Heyrou simultaneously invented the electrolytic molten magnesium chloride process, marking the beginning of the magnesium industrial era. In the early 20th century, Germany first achieved large-scale production using the silicothermic process (Pidgeon process), and metallic magnesium began to be used in the aerospace field (such as for lightweighting aircraft parts during World War I). From the 1950s to the 1980s, the rise of the global automotive industry drove the growth in demand for magnesium alloys. Production processes were upgraded from open electrolytic cells to closed electrolytic cells and high-efficiency silicon thermal furnaces, significantly increasing capacity and product purity. Leveraging its dolomite resource advantages (accounting for 22% of global reserves and 85% of production), China became the world's largest magnesium producer in the 1990s. In recent years, the "dual-carbon" strategy and the upgrading of high-end manufacturing have driven industry transformation, accelerating the research and development of high-purity magnesium, nano-magnesium, and magnesium-based composite materials. Their applications in new energy vehicles, hydrogen storage, and 3C electronics continue to expand, significantly enhancing their strategic importance. III. Core Characteristics Analysis

(I) Core Functional Characteristics

The core advantages of metallic magnesium lie in its dual attributes of "lightweight + multifunctionality": As a structural material, its specific strength (strength/density ratio) far exceeds that of aluminum and steel, enabling equipment to be reduced in weight by 30%~50%, while possessing excellent die-casting, forging, and welding properties, making it suitable for forming complex components; as a functional material, it has extremely high chemical activity (standard electrode potential -2.37V), making it a high-quality metallurgical reducing agent (capable of reducing refractory metals such as titanium and zirconium), and possessing excellent hydrogen storage performance (magnesium hydride hydrogen storage density reaches 7.6wt%) and combustion characteristics (combustion temperature up to 3000℃), combining the integrated value of "structure and function". (II) Physical and Chemical Properties Pure magnesium has a silvery-white metallic luster, a soft texture, and good ductility, allowing it to be processed into various forms such as plates, profiles, and wires. It possesses excellent electrical and thermal conductivity (thermal conductivity 156 W/(m·K)), approaching that of aluminum. Chemically active, it readily forms a dense oxide film (MgO) on its surface at room temperature, preventing further oxidation of the internal magnesium. It exhibits good stability in dry environments. At high temperatures, it is easily combustible, producing magnesium oxide and magnesium nitride (Mg₃N₂). It reacts with acids and water (hot water) to release hydrogen, making it suitable for energy storage and chemical reaction scenarios. (III) Process Adaptability Metallic magnesium can be processed through various processes: die casting is suitable for the mass production of complex components such as automotive parts, offering high forming efficiency; forging can enhance the strength of magnesium alloys for use in high-end structural components; melt spinning technology can prepare magnesium-based amorphous alloys for use in precision electronic components; powder metallurgy can produce magnesium-based composite materials, expanding its functional applications. In addition, magnesium can form alloys with various metals such as aluminum, zinc, and lithium, and its strength, corrosion resistance, and other properties can be optimized through composition control to meet diverse needs. IV. Mainstream Production Processes

(I) Siliconothermic Process (Pidgeon Process, Mainstream Process)

This is currently the core process for global magnesium production, accounting for over 85% of global capacity. It uses dolomite (CaMg(CO₃)₂) as raw material, ferrosilicon as a reducing agent, and fluorite as a catalyst. The process involves three steps: 1) Dolomite calcination: calcination in a rotary kiln at 1100~1200℃ decomposes into magnesium oxide (MgO) and calcium oxide (CaO); 2) Vacuum reduction: the calcined dolomite, ferrosilicon, and fluorite are mixed in proportion, loaded into a reduction tank, and reacted at 1150~1200℃ under a vacuum of ≤10Pa. Silicon reduces magnesium oxide to generate magnesium vapor; 3) Condensation refining: the magnesium vapor is cooled by a condenser to obtain crude magnesium, which is then refined by flux or vacuum distillation to remove impurities such as iron, silicon, and calcium, yielding industrial magnesium with a purity ≥99.9%. This technology is mature and the raw materials are readily available, but the traditional process has high energy consumption (approximately 11,000-13,000 kWh of electricity per ton of magnesium) and high carbon emission intensity. (II) Electrolysis (Auxiliary Process) Mainly used for producing high-purity magnesium (purity ≥99.95%), accounting for 15% of global capacity, it is divided into magnesium chloride electrolysis and magnesium oxide electrolysis: 1) Magnesium chloride electrolysis: using anhydrous magnesium chloride (MgCl₂) as raw material, electrolysis is performed in an electrolytic cell at 700-750℃. Metallic magnesium is deposited at the cathode, and chlorine gas is generated at the anode (which can be recycled); 2) Magnesium oxide electrolysis: using calcined magnesite (MgO) as raw material, adding electrolytes such as cryolite, and electrolyzing at 900-1000℃ to produce metallic magnesium. This process produces high-purity products and has a high degree of continuous production, but the preparation of raw materials (anhydrous magnesium chloride) is difficult, and the equipment requires high corrosion resistance. It is suitable for layout in areas supporting chlor-alkali industries. (III) Technological Upgrading Directions With the upgrading of environmental protection and "dual carbon" requirements, the industry is accelerating technological innovation: First, green electricity coupled production, with companies in Inner Mongolia, Ningxia and other regions introducing wind and solar green electricity to drive electrolytic cells and reduction furnaces, reducing carbon emissions per ton of magnesium by more than 80% and saving 800-1000 yuan in electricity costs; Second, high-efficiency reduction technology, developing a "vertical reduction furnace + waste heat recovery" system, reducing energy consumption per ton of magnesium to below 9500 kWh, a reduction of 15%-20%; Third, high-purity refining technology, adopting a vacuum distillation-zone melting composite process to produce ultra-high purity magnesium (purity ≥99.999%), suitable for semiconductor and aerospace needs; Fourth, resource recycling, recovering magnesium alloy waste and salt lake magnesium resources (Qinghai salt lake magnesium reserves exceed 4 billion tons), developing an integrated salt lake magnesium extraction-electrolysis process to reduce resource dependence. V. Core Application Areas

(I) Lightweight Manufacturing (Traditional Core Area)
Globally, over 60% of magnesium is used in the manufacture of lightweight structural components, making it a key material for the aerospace and automotive industries. In the aerospace field, magnesium alloys are used to manufacture components such as aircraft landing gear, engine casings, and satellite supports, reducing aircraft weight by 10% to 20% and increasing range and payload capacity. For example, the Boeing 787 uses up to 4% magnesium alloy. In the automotive industry, magnesium alloys are used in components such as engine blocks, gearbox housings, and steering wheel frames, achieving vehicle lightweighting and reducing fuel consumption and carbon emissions (for every 100kg reduction in weight, fuel consumption is reduced by 0.5 to 0.8L per 100km). In the 3C electronics field, magnesium alloys are used in laptop casings and mobile phone frames, combining thinness and impact resistance, and their market share continues to increase. (II) Metallurgical and Chemical Industries (Important Application Scenarios) Magnesium is a high-quality metallurgical reducing agent used in the Kraul process for the production of refractory metals such as titanium, zirconium, and hafnium. Its reduction efficiency is higher than that of aluminum and silicon, and the product has a lower impurity content. In the steel industry, magnesium powder is used for desulfurization of molten steel (with a desulfurization rate of over 95%), improving steel quality. In the chemical industry, magnesium is used to produce organomagnesia compounds (such as Grignard reagents), serving as a catalyst and reducing agent in organic synthesis reactions. Furthermore, magnesium powder can be used to manufacture fireworks, signal flares, and flame-retardant materials, utilizing its luminous combustion properties. (III) Emerging High-End Fields (Growth Engines) In the new energy field, magnesium is the core carrier of hydrogen storage materials. Magnesium-based hydrogen storage alloys (such as Mg₂NiH₄) are used for hydrogen energy storage and transportation and fuel cell support, suitable for new energy vehicles and distributed energy storage scenarios. Magnesium-ion batteries, with their high safety and low cost advantages, have become a potential alternative to lithium-ion batteries, and the research and development of cathode materials has entered the pilot stage. In the medical field, magnesium-based biodegradable alloys (such as Mg-Ca-Zn alloys) are used for fracture fixation screws and vascular stents, which can gradually degrade in the human body, avoiding secondary surgery. In the military field, magnesium alloys are used to manufacture missile bodies and lightweight components for armored vehicles, improving mobility and survivability. VI. Market Development Trends (I) Rapid Demand Growth and Prominent High-End Gap In 2024, China's magnesium production capacity was approximately 1.2 million tons, accounting for 85% of the global market, with a market size exceeding 18 billion yuan. It is expected that the average annual compound growth rate will remain at 9.0%~10.5% over the next five years, leading the growth rate in the light metals industry. Among them, the demand for high-purity magnesium (purity ≥99.99%) and magnesium-based composite materials is growing the fastest, with its share increasing from 12.6% in 2024 to over 27% in 2029. Currently, the domestic supply and demand gap for ultra-high purity magnesium (≥99.999%) is 0.8 million tons, with an import dependency of about 40%, mainly relying on imports from the United States and Japan. New energy vehicles, hydrogen storage, and aerospace are becoming the core driving forces for demand. (II) Optimization of production capacity structure and coordinated regional layout Global magnesium production capacity is highly concentrated in China, with domestic production capacity mainly distributed in Shanxi (the main dolomite producing area), Inner Mongolia, Ningxia, and Shaanxi. Affected by energy consumption control and environmental protection policies, traditional high-energy-consuming Pidgeon process production capacity is gradually being phased out. Inner Mongolia, Qinghai, and other regions are taking over incremental production capacity by virtue of their advantages in green electricity and salt lake resources, forming a three-pronged layout of "dolomite producing area + green electricity base + salt lake resources". Industry concentration continues to increase, with the top ten companies accounting for 68.3% of the total capacity. Leading companies such as Shanxi Yinguang, Ningxia Taiyang Magnesium Industry, and Inner Mongolia Yunhai Metal have built competitive barriers through the integration of the "resource-smelting-processing" industrial chain, while small and medium-sized enterprises focus on magnesium alloy processing or niche application scenarios. (III) Green and low-carbon driven, technological innovation becomes the core barrier The "dual-carbon" strategy promotes the industry's low-carbon transformation, with green electricity production and energy-saving processes becoming the core directions. The policy requires that all production capacity that does not meet the energy efficiency benchmark (comprehensive energy consumption per ton of magnesium ≤ 8500 kWh) be phased out by 2025, forcing companies to increase investment in technological transformation. The popularization rate of waste heat recovery and intelligent control technologies is expected to increase from 45% in 2024 to 70% in 2027. In the medium and long term, the research and industrial application of integrated magnesium extraction technology from salt lakes, green electricity electrolysis, and magnesium-based new materials (hydrogen storage alloys, bio-alloys) will reshape the industry landscape, and integrated solutions of "materials + process + application" will become the core of corporate competition. (IV) Price Fluctuations and Strategic Layout The price of magnesium metal is affected by multiple factors: upstream factors such as dolomite (average price in 2024 was RMB 280/ton, an increase of 12.0%), ferrosilicon (accounting for 30%~35% of the cost of the Pidgeon process), and energy price fluctuations directly affect production costs; downstream factors such as the operating rate of the automotive industry, new energy policies, and aerospace orders influence demand; and environmental standards and green electricity policies affect supply elasticity. Due to its irreplaceable role in lightweight manufacturing and the new energy industry chain, magnesium metal has been included in the key mineral lists of many countries. As a major global producer, Chinese companies are strengthening their reserves of dolomite and salt lake resources and aligning with green electricity, while simultaneously increasing investment in high-end product R&D to break through technological bottlenecks in ultra-high purity magnesium and magnesium-based composite materials, thereby enhancing their global influence in the industry chain.