Centuries of mining extraction and exploration have made the identification of economically viable mineral deposits more difficult to find. In the future, mining exploration will have to develop better extraction methods, such as to exploit lower concentration deposits; the technology exists, but more intense technology can also be costlier. It is more than just a question of economics, exploiting lower concentration deposits also costs more in terms of energy, a less viable proposition, considering the related problem of scarcer fossil fuel prospects. The world may not be all that far away from the scenario presented in the Hollywood blockbuster ‘Avatar’. It will be quite a challenge for modern society having to learn to cope with more expensive resources; therefore, the search for alternatives should be encouraged. While there has been talk of mining on asteroids, the moon or even Mars – and one day, as suggested by the history of human progress, this will certainly be possible – the sea offers potentially huge resources closer to home. There is plenty of sea and much of it hides billions of tons of mineral resources. Undersea oil exploration is a well developed technology, even at the staggering depths in excess of 5,000 meters. Therefore, the problem as to whether or not the oceans can be turned into economically viable sources for minerals is clearly worth exploring. Some techniques, many years into the future, suggest the extraction of ions dissolved in sea water; however, in the shorter term, sea mining technology will be an extension or evolution of conventional extraction techniques.

The oceans contain minerals that could even be extracted without the need for drilling and the other energy intensive techniques that are used on land. Indeed, at least three companies are currently engaged in developing underwater phosphate mining at depths ranging from 200 to 600 meters using a dredging technique, avoiding any kind of drilling. The phosphate is extracted by dredging the sea floor. The dark sand or sludge is collected and transported by boats, linked to the main dredging ship, to the shore, where it would be stockpiled and made available for shipment. Such is the demand for phosphate, especially in the long term, that undersea phosphate makes economic and business sense. In New Zealand, Neptune Minerals a US company with experience in the exploration for of sulphides off the coast of New Zealand is helping Chatham Phosphate in the development of an offshore phosphate project. Chatham Rock has just completed a two week environmental data gathering ‘cruise’ in the site area and it is preparing to launch another cruise to study the best methods to mine the phosphate, which occurs in what will be one the deepest underwater mining projects in the world. The extraction plan envisages vacuuming the top layer of sediment that contains rock phosphate.

Phosphate, however, is similar to salt and non toxic and, as important as phosphate is to agriculture and a handful of other applications such as battery manufacturing, deep sea mining has been proposed for more complex minerals such as rare earths. Indeed, every time that Sino-Japanese relations flare up, the latest episode being especially intense as Japan has moved to nationalize the Senkaku / Diayou Islands, claimed by both China and Japan, the media is eager to report that Japan has discovered a massive rare earths deposit off one if its islands, the conveniently named Minamitorishima. The deposit is more than attractive, 6.8 million tons of REE’s rich in that especially elusive of rare earths, dysprosium, and in quantities that humble the most prolific of Chinese mines. The question remains, however, as to the viability of the project. The depth of the deposit is at some 6,000 meters or 20,000 feet; this is not exactly your Uncle Hiroshi’s weekend fishing trip. The Japanese scientists, who discovered the deposit, have estimated that a mere square kilometer of surface could yield a fifth of the current world annual consumption of rare earths. Nevertheless, even Godzilla would have a hard time extracting anything at 6,000 meters. The scientists have claimed that the extraction method would simply consist of pumping the material at the bottom the sea and then extract the REE from the mud. But this simple explanation fails to convince; REE processing is expensive and complex; deep sea mining would merely add enormous costs. Still, companies such as Nautilus Minerals, which is developing an underwater high grade copper and gold mining project off the coast of Papua New Guinea, claim that underwater REE extraction is no more complicated than underwater oil extraction.

This may be true, if the REE deposit in question were truly dominated by dysprosium, which is the one ‘rare’ element of the ‘rare earth’ series. Moreover, the deposit would have to be close to production stage. Herein lays the problem, the development period for the proposed Minamitorishima REE project is far too long; it could take decades to develop this project. The Nautilus Minerals marine mining project, should it actually reach the production stage – we will know soon enough as the Company expects extraction to begin in 2013 – will signal whether or not underwater mining projects that involve more activity than dredging are technologically and economically viable. Yet, it would be too easy to simply dismiss underwater mining, relegating it to the science fiction of Jules Verne, after all the French writer also predicted landing a man on the moon. Eventually, underwater mining will be a reality, despite the difficulties posed by the tremendous pressure, the low temperature and the darkness; a slew of new equipment will have to be designed, – just as new equipment had to be designed to explore space. Regardless of the challenge, if there is one thing that history has taught us is that human ingenuity will prevail; the technology, the timing and the market conditions just have to be right. Perhaps, in the REE space, we have not yet reached any one of those three stages yet, but mining technology will eventually catch up to Jules Verne, of that there is no doubt.