Introduction
Monazite is a reddish-brown phosphate mineral that is widely distributed around the globe, often found in “mineral sands” alongside zircon and titanium minerals on ancient coastlines. For decades, it was the primary source of rare earths before Bastnäsite took over in the 1960s.
Composition & Chemistry
Formula: (Ce, La, Nd, Th)PO4
Monazite is chemically more robust than Bastnäsite, requiring more aggressive “cracking” (usually with high-temperature caustic soda) to extract the elements. However, it often carries a better balance of Neodymium and Praseodymium than Bastnäsite.
The Thorium Challenge
The defining feature of Monazite is radioactivity. The crystal structure of Monazite is perfect for holding Thorium-sometimes up to 10% or more. This makes Monazite a potential energy source for future Thorium nuclear reactors, but currently, it classifies the ore as radioactive material (NORM), complicating logistics and waste disposal.
Major Sources
Australia (Mount Weld), India, Brazil, and parts of the USA are rich in Monazite. It is often a byproduct of Titanium mining.