Material Insights · Understanding the Material World

Magnesium

The lightest structural metal, used in die castings, aluminium alloys and steel desulfurisation, and smelted mostly in China.

Battery & magnet · No. 31

  • EU strategic
  • EU critical 2023
  • US critical 2025
  • HHI 4,571 · highly concentrated
Battery & magnet · Foundation · Matter

When Chinese provinces rationed power in 2021, the world's magnesium supply tightened sharply and prices more than doubled.

Chart: Illustration: Magnesium

Where it comes from

Chart: Map of where it comes from

Magnesium is plentiful, about 2.48% of the upper crust. Metal is made from dolomite or magnesite, reduced with ferrosilicon in the coal-burning Pidgeon process that dominates in China.

Three things to know
  1. Magnesium is about two-thirds the density of aluminium, making it the lightest structural metal.
  2. Magnesium alloys are only about 1% of an average car's mass, held back by corrosion and forming problems.
  3. The only US primary magnesium smelter, in Utah, stopped in 2022, and its operator went bankrupt in 2025.
The journey
  1. 1 Raw materialDolomite, magnesite, brines or seawater
  2. 2 CalciningRoasted to magnesia, or brine to chloride
  3. 3 ReductionCoal-fired Pidgeon process or electrolysis
  4. 4 IngotPrimary metal, 99.8% magnesium
  5. 5 End usesDie castings and aluminium alloy additions
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