Artificial Geysers Can Compensate for Our Mineral Shortages
Electricity from Steam
At SINTEF, we are working on the idea of imitating part of this process by constructing artificial geysers. Firstly, by drilling wells for sending seawater down into the mantle – and then others for transporting the mineral-rich water back to the surface.
This water will be transported in pipes up to platforms where the particles will be separated.
The pressure at the Earth’s surface will cause the water to boil. Our idea is to use the steam to generate electricity, which will then be sent onshore. The revenues from selling the electricity will be used to pay for parts of the mineral recovery process.
Discovered in the 1970s
SINTEF has been here before – demonstrating that imitating nature can be a very fruitful venture. Specifically, that the properties of underwater shales are ideal for dealing with abandoned oil wells.
The phenomenon that we are seeking to imitate today – these ‘black smokers’ on the seabed – was discovered in the 1970s in an area of the Pacific Ocean at the boundary between two tectonic plates.
Many underwater geysers of this type have been identified on the Mid-Atlantic Ridge in Norwegian waters. These are locations where molten magma still occurs close to the seabed. Some of them are probably still active today.
Sulphide minerals
The smoker chimneys are made up of particles that are precipitated when the hot, mineral-rich water is ejected from the geysers into the cold seawater. Other fractions of the ejected mass of particles have sunk to the seabed, forming great mounds of gravel at the base of the chimneys.
As time passes, many of the chimneys stop ejecting. They seal up and die, tipping over onto the ‘piles of gravel’.
These gravel piles represent the biggest and most concentrated occurrences of sulphide minerals on the seabed. The sulphide family is one of the two main groups of seabed minerals known from Norwegian oceans.
Key Metals
According to the Norwegian Offshore Directorate, the natural geysers have deposited minerals containing key metals such as zinc, cobalt, nickel, vanadium, tungsten and silver. Not to mention copper, which occurs in concentrations much greater than those we encounter in mines onshore.
Our idea assumes that humans will succeed in drilling wells that can withstand the temperatures they will encounter close to bodies of molten rock. Experts are already working on this problem..
“Our concept will not be put into practice tomorrow, but it may not be too far into the future either. The timing will depend on the efforts that we are prepared to put into developing the idea. We still need more data about the subsurface, combined with some smart technological innovations.
Supply Security for the Green Transition
If our idea succeeds, this will help the European Parliament, the Norwegian government and everyone else who is looking to safeguard supply security for the green transition.
We have great faith that our concept represents a sensitive and realistic approach to minerals recovery, and are looking forward to continuing with its development.
Bhargav Boddupalli is a research scientist at SINTEF. Lars Sørum is Research Director at SINTEF. The article is published courtesy of the Norwegian SciTech News. Norwegian SciTech News, and its counterpart, Gemini.no, publish up-to-date research news from the Norwegian University of Science and Technology (NTNU), Norway’s main science and engineering university, and SINTEF, Scandinavia’s largest independent research group.
