The Pidgeon Process: Why Most Magnesium Is Made, Not Mined, in Batches
Magnesium is usually won from dolomite in a batch thermal reduction process that China scaled cheaply, not from a conventional continuous smelter.
Most of the world’s magnesium is produced by a specific thermal reduction method called the Pidgeon process, a real, distinctive chemistry that China scaled far more cheaply than anywhere else managed to.
The Pidgeon process reaction
Calcined dolomite is mixed with a reducing agent, usually ferrosilicon, and heated under vacuum, driving off magnesium vapour that condenses as crystalline metal:
Why China’s version became so much cheaper
China built large numbers of comparatively small, low-capital Pidgeon process plants, often co-located with cheap coal power and ferrosilicon supply, and scaled this specific production model faster and more cheaply than the larger, more capital-intensive electrolytic magnesium plants historically used in the West. This is a real, documented industrial-strategy outcome, not a mineral-resource advantage, since the dolomite feedstock itself is not geographically scarce, covered on this material’s geology page.
Sources: Pidgeon process chemistry and China’s production-cost advantage draw on standard extractive metallurgy references (USGS, International Magnesium Association); production figures reference the production data elsewhere on this site.