AI-rewritten: This is a summary of an article from IEEE Spectrum, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

---

The Baogang Tailings Dam near Baotou, Inner Mongolia, is one of the world’s most polluted bodies of water. This 11-square-kilometer artificial lake holds toxic effluent from decades of rare-earth processing operations. Built in the late 1950s, it contains radioactive thorium resulting primarily from monazite ore processing. Due to this environmental disaster, China now does not permit stand-alone monazite mines.

Monazite is a key source for rare-earth elements like dysprosium and terbium. Most domestic monazite comes from the Bayan Obo complex, which produces nearly half of the world’s rare-earth ore annually. Roughly 30 to 40 percent of this ore is monazite, used to produce 170,000 tonnes of rare-earth metal last year. China also imports over 70,000 tonnes of monazite annually. Because concentrated monazite is radioactive Class 7 cargo, it can only be imported through four specific ports and often requires state-owned joint ventures.

However, many imported heavy mineral sands containing roughly 2 to 3 percent monazite bypass these controls. Companies import the sands, separate the monazite concentrate, and then process it. In 2025, the U.S. government invested $400 million in MP Materials to secure its Mountain Pass mine in California. Meanwhile, the U.S. government recently made a conditional loan commitment of up to $725 million to Energy Fuels for securing monazite supplies in Australia, Brazil, and Madagascar. Experts note that while Western nations view these moves as strategic supply chain efforts, China has been playing its game for decades by locking down rights to deposits abroad.