© Norm Sperling, November 1, 2010
The world's market for rare-Earth metals is now dominated - 97%! - by China. China says it will continue selling them, but neighboring Japan now suddenly seeks to buy from Viet Nam instead. A lot of high-tech consumers worry about how much they will be able to obtain, and for how long.
2 major sources have not been properly surveyed and exploited.
Many of those rare-Earth elements go into high-tech devices. Those devices wear out or become outmoded, are discarded, and go into dumps. We build up enormous dumps, filling valleys and building "Mount Trashmore"s.
When rare-Earth resources run out, or become scarce for ecological or political reasons, it should be more practical to mine old dumps and extract the needed elements from today's discards. Over centuries, I suspect that today's polluted dumps will be reclaimed, re-exploited, and re-consumed as resources.
At identifiable strata and pits in dumps, one can find the discards from datable years. And we know when certain chemicals were used. To facilitate reclamation, dumps should be mapped as accurately as practical in 4 dimensions. Zones should be labeled by dumping dates, and any other distinguishing characteristics, too. Time-lapse photos taken from standard vantage points should help the mapping. Seekers of a rare-Earth element can excavate the zones buried a few years after it was used, without having to slog expensively through unlikely zones.
To what degree is it practical to map older dumps? Many capped landfills are turned into parks after their initial organic outgassing subsides. How closely do their records of filling match new drill-core logs? How do those compare to ground-penetrating-radar scans?
Another waste source is ignored even more: mine tailings. Where nature concentrated a valuable mineral, well enough for miners to extract it, the discards simply got dumped. These mine tailings are often eyesores and sometimes accused of fouling their environment. It's time to take modern, high-quality chemical analyses of tailings from each mine. Surely something valuable will show up somewhere. Mineralogists and geochemists will discover new correlations.
Re-mining tailings has many advantages: they're already concentrated, they're already pulverized and therefore easy to process, and the (re-)remaindered tailings should be (re-)discarded in a much safer manner, which the newly-extracted fraction should pay for. Perhaps robots can stuff tailings that contain nothing likely to become valuable back into the depleted mines they came from, reducing the hazard of collapse.
Mapping dumps, and screening mine tailings, will produce new mineral resource locators - minURLs!