December 15, 2011
Gradually, people are starting to put the two sides of the equation together – thorium and rare earths; two seemingly disparate sectors, the former an apparent salve for the maligned nuclear space, the latter a nascent sector in the west looking to challenge China’s dominance by creating a functioning rare earths supply chain for end-users.
Rare earth expert Anthony Mariano – one of the high-profile go-to consultants in the rare earth space – spoke at length this week about going back to the future, if you will, by revisiting the beach and river placer sands that contain monazite, which is where rare earth mining really began.
As he describes it in a recent interview with the The Gold Report, “beach sand and river placer monazite occurs in plentiful supply in many countries outside of China. The rare earth oxide (REO) content of monazite is approximately 70 weight percent (wt%) and the distribution has a better intermediate REE content than bastnasite.”
Bastnasite is the world’s source at this time, and has been historically, for the light rare earth elements. (Read: China’s Bayan Obo mine, Molycorp’s Mountain Pass mine).
A few decades ago, when Molycorp and Solvay’s Rhodia (then known as Rhone-Poulenc) were providing the bulk of the REEs to the marketplace, Rhône-Poulenc received all of its REEs from beach sands in Australia and South Africa.
“It transported the monazite sands to France and eventually compiled an unusual quantity of thorium. The French government forbade the company from continuing this, so it switched over to bastnasite and left the monazite. The physical and chemical processing of monazite is well-known and can be handled, but the problem is what to do with the thorium after it is extracted,” he told the Gold Report.
(Thorium, by the way, is a natural radioactive chemical element, one discovered in 1828 and named after Thor, the Norse god of thunder. It’s estimated to be about three times more abundant than uranium and is, in fact, a by-product when rare earths are extracted from monazite sands. It was formerly used as a light source in gas mantles and as an alloying material, but these applications declined as concerns over its radioactivity increased.)
“The current perceived challenge to mining monazite is the presence of thorium in the structure. If the thorium disposal problem can be solved economically, monazite mining can provide all of the necessary light and medium atomic number REEs to the marketplace without dependence on China,” Mariano said.
He pointed to companies such as Medallion Resources and privately held Mining Ventures Brasil Ltda. – two companies that see a lot of positives in mining monazite, in large part because a lot of the processing has already occurred from natural crushing.
He said crushing represents 61% of the cost when talking about mining hard rock. Conversely, virtually no crushing is involved in mining beach sands. And there are large monazite tailings from existing beach sand mining operations, which are available for exploitation.
That’s what Medallion Resources is focusing on at the moment.
Mariano said thorium can be controlled, but if the public doesn’t understand this, it’s going to be very difficult to start any mining operation in which the mineral has a substantial amount of thorium in its structure.
Some kind of education program would be the obvious next step and there are a number of upstart thorium-minded nuclear companies out there that could push the nuclear sector toward thorium- and away from uranium-based reactors in the future.
It won’t happen anytime soon, even though some believe thorium use in reactors should have happened decades ago.
NOTE: Raremetalblog will be interviewing one or two of the strongest thorium advocates out there today, in large part to get some perspective on how the two sectors can possibly be aligned in order to resolve the thorium issue for players in both sectors.