Find it here: http://www.forbes.com/sites/timworstall/2013/03/15/an-odd-thought-thorium-reactors-would-make-tantalum-and-rare-earths-cheaper/
An Odd Thought: Thorium Reactors Would Make Tantalum And Rare Earths Cheaper
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A new reactor design has been announced, a molten salt one. In the discussions about it here the subject of thorium reactors comes up. And thorium reactors are indeed a very good idea and they do work. But it occurs to me that one of the effects of the adoption of thorium technology would be to make a series of other metals, like tantalum and the rare earths, rather cheaper.
Apologies, this is a little complex and comes from putting two plus two together as a result of something I'm doing in the day job at present.
When you go prospecting for minerals there are, of course, a number of elements that increase the value of whatever it is that you've found. Bits of gold add value to almost anything, high indium values increase the worth of zinc ore and so on. But there are also elements which reduce the value of what you find. And one of the biggest bugbears for the mining industry is thorium.
The problem being that it's not really used for anything. The total US annual consumption is about $400,000 worth a year for example. Maybe 4 tonnes or so. Worse, a lot of that value isn't actually in the metal at all: it's in the cost of the paperwork to move radioactive materials around. The one and only time I've ever shipped thorium to someone the metal itself was given to me for free: the $27,000 paid on getting the paperwork done was the real cost of the transaction.
So, if you find that you've got a reasonable looking tantalum containing mineral (like the euxenite I've currently got in the lab, or the fergusonite containing niobium) the first thing that you do is check the thorium levels in it. It will have some: but what you want to know is how much? For if the Th level is too high then the actual value of that mineral is negative. Yes, certainly, the tantalum (or niobium, or rare earths from monazite say) can all be extracted and that's fairly simple. But you've then got left over this thorium. A little bit, a tiny bit, that's not a problem. But if the Th levels in your wastes start to climb over about 0.5%, then you've got a problem. You've now got to dispose of this radioactive waste into a special facility. This is an expensive thing to do. And it can be more expensive than the value of any tantalum or rare earths that you're able to extract.
However, if thorium power stations ever started to be used then there would be an end market for that thorium. Even if you gave it to the nuclear guys that would still be vastly cheaper than trying to dispose of it or store it. Which leads to this slightly odd conclusion.
If we did start to use the thorium nuclear cycle in reactors one group of beneficiaries would be those who use tantalum, niobium, rare earths and so on. For it would open up the possibility of processing thorium heavy ores of those metals. Quite bizarrely thorium reactors would make electronics like smartphones a little bit cheaper.