Recently in the papers, it was reported that mud and sediment in certain parts of the Pacific, including parts around New Zealand, were surprisingly rich in materials called ‘rare earth minerals.’
Okay, first of all, what is a rare earth mineral? As the name suggests, these materials are chemical elements which are relatively rare on the Earth. More specifically, it refers to elements numbers 21, 39, and 57 through 71. What is interesting about these materials is that they have different electronic and magnetic properties to most other elements, which gives them applications in all sorts of electronics, ceramics, and other high tech devices. In my own research for example, I am looking at rare earth elements to find coupled electric, magnetic and physical vibrations.
There is definitely a market for these things, which seems likely only to expand in the future. So news that we may have some rich deposits of rare-earths to draw on is good news. However, all of this latest find is in seabed mud, which is underwater. And we all know how safe undersea mining is, don’t we? Deepwater Horizon revealed some of the poor practices in place even in large-scale operations, and there has been strong opposition from the public and from local and iwi groups to a Petrobras proposal to start undersea oil extraction in New Zealand.
I had a bit of a search, and found some documents detailing the presence of rare earth minerals on land in New Zealand, to see what deposits existed above water. It turns out that there are a few sites in mainland New Zealand which contain relatively high yields of rare earths—between two and four times more abundant than the average yield for the right type of rock. Unfortunately, like much of New Zealand’s mineral wealth, most of it is under our Native forest and conservation estate. Most of the promising sites are on the West coast of the South Island, although there are some deposits in the Canterbury plains, and the lower East coast. One other alternative is the rare earths found in beach sands. One advantage of the beach sand deposits is that they also contain ilmenite and gold. So if any one of these mining operations was to begin, then the other two could use the by-product of the first for a lower overall cost.
Overall it seems like while New Zealand does have some promising rare-earth deposits, wherever we go for them, there are some problems to be overcome in order to extract them. It may become worthwhile to do so anyway, but only if we intend to produce manufactured goods such as electronics, ceramics[1] and turbines out of them. Simply digging them up and selling them off to someone else seems like a raw deal for us.