JL: Yes, of course. The point is China is still the only HREE producer because of the cost structure. Heavy rare earths occur almost everywhere in the world in extremely low-grade deposits. In China, for example, HREEs come from the so-called ionic adsorption clays, which are just a few hundred parts per million. Now luckily for the Chinese, mining ionic adsorption clays is not nearly as expensive as underground or even surface mining of hard rock material.
For example, if I have 50 parts per million of dysprosium in ionic adsorption clays, I need to process 1 million tons (1 Mt) of clay to get 50 tons of dysprosium. By comparison, if I move 1 Mt of rock at Mountain Pass, California, I will produce 50–80 Kt of REEs. In China, I'm going to get 50 tons of dysprosium. The Chinese do this on an immense scale, producing as much as 15 Kt of these materials, of which only 8 Kt to 10 Kt tons are the REE-related element yttrium. The Chinese are washing millions and millions of tons of clay.
China is the only place that produces HREEs from ionic adsorption clays. That happened as dysprosium-modified magnets became extremely useful and necessary.
TMR: Is that due to demand for permanent magnets for electric cars?
JL: Right. Magnets used in extreme environments of hot and cold need to be modified with dysprosium and terbium so that they don't permanently lose their magnetization when they go through a heat cycle.
Quite frankly, if these elements had been found anywhere else in the world, they probably wouldn't have been developed. The world is fortunate that they were found in such a low labor cost, but highly developed country.
Ionic adsorption clays exist in Vietnam, Thailand, Cambodia, Indonesia, Malaysia. They haven't been developed there for many reasons. Some are ethical reasons. Ionic adsorption clay mining is extremely dirty environmentally and very difficult to contain.
A significant source of this material was discovered in Thailand right under a resort area a couple of years ago. The Thai government said it didn't give a damn what anybody thought, nobody was going to start ionic adsorption clay processing next to the swimming pool in a country where tourism is the number one revenue source.
The Vietnamese have a wide variety of rare earth sources, hard rock, as well as ionic adsorption clay, but dealing with the country has been impossible so far.