What to know about China's cut-off of rare earth exports

In April, China stopped almost all shipments of critical minerals needed for cars, robots, wind turbines and other technology, writes Keith Bradsher from Beijing

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China has suspended almost all exports since April 4 of seven kinds of rare earth metals, as well as very powerful magnets made from three of them. The halt has caused increasingly severe shortages that threaten to close many factories in the United States and Europe.

Why are these metals so needed, why has China stopped exporting them and, crucially, what happens next?

There are 17 types of metals known as rare earths, which are found near the bottom of the periodic table. Most of them are not actually very rare — they are all over the world, though seldom in large enough ore deposits to be mined efficiently.

They are called rare because it is very difficult to separate them from each other. Breaking the chemical bonds that bind them in nature can require more than 100 stages of processing and large quantities of powerful acids.

China mines 70% of the world’s rare earths. Myanmar, Australia and the United States mine most of the rest. But China does the chemical processing for 90% of the world’s rare earths because it refines all of its own ore and also practically all of Myanmar's and nearly half of US production.

China's dominance is greatest for seven rare earths that it has mostly stopped exporting since early April: dysprosium, gadolinium, lutetium, samarium, scandium, terbium and yttrium. These are mined almost exclusively in China and Myanmar and are among the hardest to separate chemically. For metals like dysprosium and terbium, so-called heavy rare earths that are used for heat-resistant magnets, China’s refineries produce up to 99.9% of the world’s supply.

China has some of the world’s best deposits of heavy rare earths. These are found in a band of ore that is particularly rich in a valley near Longnan in south-central China, extending west into northernmost Myanmar.

HEAVY RARE EARTH MINING