Mining goes 20,000 leagues under the sea
Metal Tech News Weekly Edition – February 12, 2020
Last updated 6/27/2020 at 5:15am
Reminiscent of Jules Verne's 20,000 Leagues Under the Sea, a small submersible scours the inky depths of the ocean, not in search of seams of coal, but towering spires created by thermal vents. The remotely operated sub's lights splash across the cluster of vents that spew mineral rich plumes of super-heated water from deep in the earth into the chill of the ocean depths.
The ROV moves into position, its clawed arm reaching out and breaking off a sample of mineral rich rock near the top of one of the vents, before stowing it away to be brought back to the surface and analyzed.
Gold, cobalt, lithium, nickel and rare earth metals can be found near these thermal vents which form deep in the earth. As the water explodes to the surface, it carries tiny droplets of molten metals and minerals. When they hit the cold of the ocean water, they cool quickly and drop off, some forming the vents themselves, others piling up on the ocean floor.
Many geologists believe that the sulfides and other rare earth metals found in the continental crust likely formed millions of years ago in this same way in the depths of the ocean before sliding under and becoming a part of the terrestrial deposits mined today.
As readily available terrestrial deposits of these metals used in green energy are used up, other sources need to be found and harvested. With the rise in demand and cost of these metals soaring, as well in advances in technology, deep sea mining is becoming more viable.
New methods of extracting material from thousands of feet of underwater are being invented as companies map and purchase large claims to mineral rights in oceans around the world. They are spending millions of dollars creating dredges that can suck up material and deliver it to a processing ship. They are designing remote submersibles that scrape and grind the top layers of sediment to be shipped to the surface. Some are even looking for machines that can process the material on the ocean floor sending up only separated ore.
The oceanic crust is only three miles thick at its thinnest point compared to the continental crust that can be thirty miles thick. This means the deeper in the ocean you can get, the closer you are to the source of these metals. It also means the oceanic crust is weaker and more likely to allow materials to seep up to through the ocean floor.
More is known about the surface of the Moon than the bone crushing depths of our own oceans. This makes working conditions hostile and dangerous at best. Technologies developed to make deep sea mining safer are also lending themselves to help researchers prepare for off terrestrial mining.
So the next time you pick up your phone, turn on your television, hop in your electric car or see a wind turbine going up, know that the materials used to make these technologies may have come not from an open pit mine, but a tiny submersible deep in the ocean.