Magnesium is located at the 12th position on the periodic table, with a density of 1.74g/cm3, approximately 2/3 of aluminum and 1/4 of steel, making it an ideal lightweight material. Magnesium alloy is an alloy composed of magnesium as the base and other elements added, with the main alloying elements including aluminum, zinc, manganese, silicon, zirconium, etc.
Magnesium alloy has excellent application performance and is currently the lightest practical metal structural material. It has advantages such as high specific strength and stiffness, good seismic and noise reduction performance, good die-casting forming performance, corrosion resistance, and excellent electromagnetic shielding performance. It is also easy to recycle and reuse, and is widely used in fields such as automotive parts, 3C products, biomedical, aerospace, and building materials.
The magnesium industry chain is as follows:
② Magnesium production situation
Magnesium resources are abundant in the Earth’s crust, mainly distributed in magnesium ores (such as dolomite and magnesite), salt lakes, seawater, and other resources. At present, the main methods for magnesium smelting include electrolysis and thermal reduction.
The principle of electrolytic magnesium smelting is to electrolyze and melt anhydrous magnesium chloride at high temperature, causing it to decompose into metallic magnesium and chlorine gas. The electrolysis method has the advantage of low energy consumption, and currently more than 80% of metal magnesium in developed countries is produced through electrolysis. However, the unit investment of the electrolysis method is relatively high, and the by-product chlorine gas is a toxic and high-risk product, which is not suitable for large-scale storage and transportation.
The principle of hot reduction method for magnesium smelting is to reduce magnesium oxide through silicon under high temperature and vacuum conditions, in the presence of calcium oxide, to generate magnesium vapor, which is separated from the solid dicalcium silicate (2CaO ‘ SiO2) generated by the reaction, and then condensed to obtain crystalline magnesium. The hot reduction magnesium smelting process has the advantages of short process, low investment, fast plant construction, low cost, high purity of finished magnesium, and can directly use resource rich dolomite as raw material. However, during the production process of thermal reduction method, resource and energy consumption are relatively high, and pollution is relatively serious.
China has abundant resources of dolomite ore, therefore the thermal reduction method is an important method for producing primary magnesium in China. With the growth of market demand for raw magnesium, the scale of magnesium smelting enterprises in China has rapidly expanded, and since 1998, China’s raw magnesium production has always ranked first in the world. According to the 2021 China Magnesium Industry Development Report by China Magnesium Industry Network,
In 2021, China’s original magnesium production was 948800 tons, and the production of magnesium alloys (including magnesium particles and magnesium powder) was 451900 tons. According to data from Minsheng Securities Research Institute, China‘s original magnesium production in 2022 was 900000 tons, accounting for 91.00% of global production.
Our country has sufficient raw magnesium production capacity and ample competition. After years of technological innovation, the production costs of magnesium smelting enterprises in China have been effectively reduced, and they have a certain price advantage. Under competitive pressure, a considerable part of the production capacity of foreign magnesium smelting manufacturers has been closed, and the share of China‘s original magnesium and magnesium products in the international market continues to expand. At present, China is the world‘s largest exporter of primary magnesium. According to the export data of various magnesium products in China from January to December 2022 on China Magnesium Industry Network, the total export of various magnesium products in China in 2022 was 49.77
