CRITICAL MINERALSArtificial Geysers Can Compensate for Our Mineral Shortages
By imitating nature, it may be possible to recover seabed minerals by extracting hot water from the Earth’s crust. We can harvest green energy and be sensitive to the environment – all at the same time.
Seabed minerals: Here’s something you probably don’t know. The copper found in the Norwegian mines at Røros and Løkken, and which once made the country very wealthy, was formed from smoking ‘chimneys’ on the ocean floor.
In the Earth’s remote past, this copper was carried up through the crust by seawater that had originally been drawn downwards into the scorching depths. If we humans can learn to imitate part of this process, it may be possible to apply it to sensitively recover a variety of minerals from the oceans offshore Norway.
Or, in other words, of obtaining the ‘building blocks’ being called for by the green transition. At the same time, we can obtain valuable geothermal heat that we can convert into emissions-free energy.
From the scorching depths to the deck of a platform
In the heated debate currently raging about seabed minerals, now fuelled once again by WWF’s recent notification to sue the Norwegian state, many people have expressed their fear of negative ecological consequences resulting from the exploitation of these resources.
At SINTEF, we believe that seabed minerals should only be recovered if we can develop methods that minimise any negative environmental impacts. We are now in the process of identifying one such method.
Our idea is to transport the mineral-rich water and bypass the process of precipitation on the seabed, recovering the minerals directly from the scorching depths in the Earth’s crust from where they originate. Extraction will take place on the deck of an offshore platform.
Water Heated by Molten Rock
Below the sea surface, some distance from land, there are several locations where so-called black smoker geysers eject mineral-rich waters brought up from the depths of the crust.
This phenomenon is the result of water first having been drawn down into fractures in the volcanic rocks of the seabed and then all the way down into the mantle, which is the layer of molten rock lying beneath the crust. Here, the water is subject to intense heat and is able to take up particles of metals and minerals. These are exactly the materials we need to make our batteries, wind turbines and electric vehicle engines.
Then, the mineral-rich water rises from the mantle, through the crust, and up to the seabed, where it is ejected from the black smoker geysers.
