Some years back, in 2007 - which in NNadir time is about 150 billion tons of dumped dangerous fossil fuel ago (or in more traditional units of time, about 5 years ago) - I wrote a diary in this space about a fellow who was shot in the head in 1915, Henry Moseley, who made a very important discovery about the nature of matter, which explained some things that confused scientists around that time, in particular with regard to the fact that cobalt's atomic weight was higher than that of nickel, and that the atomic weight of tellurium exceeded that of iodine.
That diary is here:
A Very Fine Exploded Head: Henry Moseley and "Dangerous Nuclear Waste."
That diary was on the subject of a metal that is only found in almost undectable amounts in uranium ores, technetium.
I haven't commented, as I recall, in quite some time, on this remarkable element which despite its rarity in nature, is now available in metric ton quantities from used nuclear fuel. It's time for an update, since a lot is going on in technetium chemistry these days.
I was going to write a diary on lanthanide mining in Greenland - addressing the question of what our oil and gas drilling friends in Denmark intend to do with the side product of said mining - the naturally occurring element uranium - but I'm in a good mood tonight, despite everything, and would rather discuss something pleasant, technetium.
There has been a huge burst of work recently on the chemistry of technetium, and I thought I'd touch upon them.
Technetium, element 43, is the lightest element in the periodic table table that has only radioactive isotopes. No stable isotopes exist. Of the first 83 elements in the periodic table, only 79 have stable isotopes, promethium, technetium and bismuth are all radioactive, the latter so weakly so that its radioactivity was only recently discovered.
Promethium, like technetium, is a fission product, however the half-life of promethium isotopes - the most commonly available is Pm-147 which has a half-life of 2.6234 years - is so short that it is possible (and then at fairly high expense) to isolate a few kilograms at most. (Promethium has one longer lived isotope, Pm-145 but it is not commonly available from used nuclear fuel because it is not neutron rich. Thus Pm-145 is commonly made using accelerators as opposed to fission sources.)
By contrast, the half-life of technetium-99 - which represents a product of about 6% of nuclear fissions in the core of a nuclear reactor - has a half-life of 211,100 years and thus, as mentioned above, is available in multi-ton quantities.
Recently there has been quite a bit published on this metal and I thought I'd touch on some aspects of technetium metallurgy and chemistry.
Read More
