Introduction
Apatite is the world’s source of phosphorus fertilizer. It is mined on a scale that dwarfs all rare earth mining combined. Interestingly, some apatite deposits (especially those in Russia and Brazil) contain 0.5% to 1% rare earth oxides.
Composition & Chemistry
Formula: Ca5(PO4)3(F,Cl,OH)
During fertilizer production, the rock is dissolved in sulfuric acid. The rare earths typically end up in the waste product known as “phosphogypsum.” There are mountains of this waste sitting at fertilizer plants globally.
Future Potential
If an economic method to extract REEs from the phosphoric acid production stream is perfected, Apatite could theoretically supply the entire world’s demand for Light Rare Earths without opening a single new mine. This is the “Holy Grail” of green supply chains.