The Grey Lady seemed positively ecstatic about recent discoveries of mineral wealth in Afghanistan in an article that appeared yesterday. The finds include iron, copper, gold, and a host of other valuable materials valued at a cool $1 trillion. The most significant of them all may turn out to be lithium. Initial analysis indicates deposits at only one location as large as those of Bolivia, the country that now has the world’s largest known reserves.
Lithium has become increasingly important lately as a component of small but powerful batteries. It will become a lot more important if fusion energy ever becomes a reality. I don’t expect this to happen anytime soon. Even if the remaining scientific hurdles can be overcome, the engineering difficulties of maintaining the extreme conditions necessary for fusion reliably over the long periods necessary to extract useful electric power would be daunting. Fusion power would likely be too expensive to compete with alternative energy sources under the best of circumstances. However, that’s my opinion, and a good number of very intelligent scientists disagree with me. If they’re right, and the upcoming proof of principle experiments at the National Ignition Facility prove far more successful than I expect, or some scientific breakthrough enables us to tame fusion on much smaller and less costly machines, fusion power may yet become a reality.
In that case, lithium may play a far more substantial role in energy production than it ever could as a component of batteries. It could literally become the metallic “oil” of the future. The reason for that is the fact that the easiest fusion reaction to tame is that between two heavy isotopes of hydrogen; namely, deuterium and tritium. The “cross section” for the fusion reaction between these two isotopes, meaning the probability that it will occur under given conditions, becomes significant at substantially lower temperatures and pressures than competing candidates. The fly in the ointment is the availability of fuel material. Deuterium is abundant in nature. Tritium, however, is not. It must be produced artificially. The raw material is lithium.
It happens that the fusion reaction between deuterium and tritium results in the production of a helium nucleus and a very energetic neutron. This neutron can cause reactions in either of the two most common naturally occurring isotopes of lithium, Li-6 and Li-7, that produce tritium. Thus, the fusion reactions that may one day produce energy for electric power could also be leveraged to breed tritium if the reaction were made to take place in the vicinity of lithium, either in a surrounding blanket or one of several other more fanciful proposed arrangements.
As noted above, I don’t think that day is coming anytime soon. If it when it does, Afghanistan may well become the Saudi Arabia of a new technological era of energy production.