Magnesium: Characteristics
The lightest structural metal, and a fiercely reactive one
What this tab covers The supply and physical characteristics of the commodity. Supply: current production, inventories and stocks, capacity utilisation, geographic and producer concentration, how fast supply responds to price, the project pipeline and capital spending, and logistics and export flows. Material: the physical and chemical properties that set its grade, price and end uses (for example purity and conductivity for metals, API gravity, sulfur and energy content for fuels, moisture, protein and fibre quality for crops).Supply volume characteristics
| Characteristic | Figure | What it means | Source |
|---|---|---|---|
| Current production volume | about 1,100 kt primary metal (2025e); 21 Mt magnesite mined (2025e) | Primary metal output was flat at 1,080-1,100 kt in 2024-25. Secondary metal is large in some markets: the US recovered 110 kt from scrap in 2025, against 40 kt of primary consumption. | USGS MCS 2026, Magnesium Metal and Magnesium Compounds |
| Inventory and stock levels | not published | Producer stocks are withheld in the US and no exchange holds magnesium. The US stockpile plan listed 3,500 t of potential acquisitions for FY2025. Chinese producer inventories fell in 2025, which helped lift European prices in the third quarter. | USGS MCS 2026 |
| Capacity utilisation | about 61% world smelter utilisation (1,100 kt output on 1,800 kt capacity, 2025e); China about 64% (950 kt on 1,480 kt) | Spare capacity is almost all in China's Pidgeon plants, so China can raise output quickly when energy and emissions curbs allow. Outside China, the US Utah smelter has been idle since 2022. | USGS MCS 2026 (derived from production and capacity table) |
| Geographic and producer concentration | China about 86-88% of primary metal; top 3 (China, Russia, Brazil) about 95%; HHI about 7,700 (metal, 2025, derived). Magnesite: China 66.5%, HHI 4,571 (2024) | Shaanxi province (Fugu and Yulin) holds most Chinese smelters. China also had 60.3% of world HS 8104 exports by value in 2024. No top-5 company share is published; Chinese output is spread over dozens of small producers. | USGS MCS 2026; World Mining Data 2026; UN Comtrade 2024 |
| Supply elasticity | high in China in the short run, low elsewhere | Chinese Pidgeon plants are cheap to build and restart, so output responds within months to price, as after the 2021 energy-control spike. Western electrolytic plants take years and large capital to build, and the last US smelter went into Chapter 11 in September 2025. Raw material (dolomite, brines, seawater) is virtually unlimited. | USGS MCS 2026 |
| Project pipeline and CapEx | small non-Chinese projects; no large new capacity confirmed | A California company met the purity target at a pilot brine plant in July 2025 with $19.6 million of US Defense Production Act funding, and plans a commercial phase 1 plant in Arkansas. Australia shipped 14 kt from a trial magnesite pit in 2025. Latrobe Magnesium (Australia, fly ash) and Alliance Magnesium (Canada) are planned low-carbon projects. | USGS MCS 2026; Light Metal Age (2021) |
| Logistics and export flows | world HS 8104 trade about $2.1 billion exports (2024); China 60.3% of exports | Main importers by value were the US (18.4%), Canada (10.2%), Germany (7.8%) and India (5.5%). Ingot moves in containers from northern Chinese ports such as Tianjin. The chokepoint is policy, not transport: Chinese energy curbs and Western anti-dumping duties set who can buy. | UN Comtrade 2024; USGS MCS 2026 |
Material characteristics Metal / hard commodity
Magnesium sells on lightness and reactivity. It is the lightest structural metal, about two-thirds the density of aluminium, so die casters use it for car and electronics parts. Its strong chemical reactivity makes it the reductant for titanium and zirconium sponge and a desulphuriser for steel, but it also makes corrosion and impurity control central to price and grade.
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Purity / grade | Traded benchmark 99.9% ingot; ASTM B92 grades 9980A (99.80% Mg) to 9998A (99.98%) | Sets suitability for alloying aluminium can sheet and die casting; the Argus and Fastmarkets price basis is 99.9% | ASTM B92; Argus/Fastmarkets |
| Density | 1.74 g/cm3 (aluminium 2.70, steel 7.87) | The reason for use in vehicles and laptops: it gives the lowest part weight per volume of any structural metal | CRC Handbook of Chemistry and Physics |
| Tensile and yield strength (die-cast alloys) | AZ91D about 230 MPa tensile, 150-160 MPa yield; AM60B about 220 MPa tensile, 130 MPa yield with 6-8% elongation | Decides which parts it can replace; AM60 is chosen for crash-relevant parts such as steering-wheel frames for its ductility | ASTM B94 typical properties (indicative) |
| Corrosion-critical impurities | High-purity AZ91D: Fe at most 0.005%, Ni at most 0.002%, Cu at most 0.030% | Tiny amounts of iron, nickel and copper multiply salt-water corrosion, so impurity limits set alloy grade and price | ASTM B93/B94 |
| Melting point and castability | 650 C melting point; low heat content per volume | Allows fast die-casting cycles and long die life, but molten metal needs cover gas (SF6 or alternatives) against burning | CRC Handbook; IMA |
| Reactivity | Standard electrode potential -2.37 V | Makes it a strong reducing agent (Kroll process for titanium, zirconium, hafnium) and desulphuriser, and limits its use in wet, salty environments | CRC Handbook |
| Thermal conductivity and stiffness | about 156 W/m K; Young's modulus 45 GPa | Good heat spreading for electronics housings; low stiffness means thicker sections than steel | CRC Handbook |