Reactions: How the US should approach rare earths

Letters to the editor

Rare earth projects

As the former technical director for the US subsidiary of Rhône-Poulenc’s successful venture to bring a rare earth purification plant to the US, I support the conclusion that using current well-established liquid-liquid extraction technology is the best short-term path to reestablishing a US manufacturing presence. This method lends itself well to the use of varying feedstocks.

In Freeport, Texas, the original site of Rhône-Poulenc’s facility, monazite ore was imported from Australia via its rare earth plant in La Rochelle, France. The ore was converted to a nitrate solution that was then separated and purified to "four nines" quality. This was done partly in Texas and in La Rochelle. The same type of process, optimized during a technology transfer between Rhône-Poulenc and China to handle a bastnaesite ore, is currently used in China.

So long as the feedstock to the liquid-liquid extraction process is of a certain purity, this high-tech, relatively straightforward continuous process will work, and it uses standard, nonexotic chemicals to deliver most of the rare earths.

There is no question that new, more tailored processes should continue to be developed, but in the short term, this is not an absolute necessity for the US to compete in the global rare earth market. The US and Canada are cooperating in a rare earth initiative from funding provided by the governments of both countries. I see no need to source rare earths form Ukraine, Greenland, or Russia when Canada sits on over 15 million metric tons of various ores and the US mine in Mountain Pass, California, has nearly 20 million metric tons of proven bastnaesite reserves.

Paul A. Bouis

Lexington, Virginia