The supply of minerals critical to electronics manufacturing—such as cobalt, nickel, copper, manganese, silver, gold, zinc, and lithium—is not endless, and with each passing year the demand for them increases.
Through a combination of several technologies, from remotely-operated vehicles to novel mapping techniques, some are delving into the Earth's crust on the bottom of our oceans to mine for these precious minerals.
Here are some of the ways we're sending tech into one of the harshest environments on earth, deep, quiet, and alone.
A Ticking Clock: Pressures on the Supply of Minerals
There are some estimates that current sources of these minerals will only last another 40 to 50 years.
Pressures on these supplies are multifaceted:
- There is a rising demand for lithium batteries, especially in the electrical vehicle market.
- There hasn’t been truly significant investment in the global mining industry despite increasing demand for these materials.
- Electronics recycling is often poorly organized and inefficient.
- There a lack of global policy that could help coordinate mineral resources.
This is critical because a shortage of these minerals would drive up costs for the supplies that are currently available on the market, which would then raise the price of the devices they enable to exist. When electronics begin to cost more, innovation can be inhibited and can slow the growth or adoption of new technologies. Things like solar panels, batteries, or even electronic wiring, could become costly.
There are already proposed solutions, but one that is interesting—both because it raises some contentious issues and because it’s technologically challenging—is the mining of deep sea beds.
There is evidence that there may be deposits of minerals along the ocean floor that could help fuel demands for an additional 40 years (and then hopefully in 80 years, we will have much better solutions available). However, it’s still not a straightforward venture to tackle.
Where Are Precious Minerals Found?
The minerals largely sought after for electronics production, are largely found in three forms around the world’s oceans: polymetallic sulphides, cobalt-rich crusts, and polymetallic nodules.
From top: polymetallic nodules, colbat-rich crusts, and sulphides. Image courtesy of Frontiers.
Cobalt-rich crusts are found between 500-1,000 m below sea level in nearly every ocean on Earth. However, the crusts in the central Pacific ocean offer the best promise for mineable sources. These crusts are rich in manganese and iron in particular, with some traces of copper, platinum, nickel, and cobalt. However, to mine the crusts, they must be removed from the rocky substrates they are attached to.
Polymetallic sulphides are found mostly around active or dormant hydrothermal vents around the crusts of Earth’s tectonic plates at a depth of about 1,000-4,000 m below sea level. The waters in these areas can be as hot as 400C, and acidic with a pH between 2 and 3. It is thought that these sulphides are rich in copper, gold, silver, and zinc in quantities and qualities that make them suitable for mining.
The deepest, polymetallic nodules, are found scattered across abyssal plains which can be as deep as 6,000 m below sea level. As the name suggests, these nodules are "chunks" of minerals that form over millions of years and are made up of manganese, copper, cobalt, and other important minerals.
Image used courtesy of Frontiers.
A typical undersea mining operation will involve vehicles for excavation, ones for removal/transport, and then surface level storage/processing. Additionally, there will be vehicles for exploration and preparations.
Technological Challenges of the Sea Bed Environment
It is clear that each of the proposed sources of sea bed minerals presents challenges to access. Underwater mining requires some technologies that already exist, but new expeditions will also need ones that still need to be developed. Looking at where the most common deposits are found, it is fairly clear that deep sea mining will be quite challenging and nearly impossible for humans to do, themselves.
The likely intersection of technologies will be robotics, mapping, navigation, and electromechanical equipment that can sustain depth, high pressure, and high acidity.
It is approximated that only 5% of the total ocean floor has been mapped. Considering Earth is covered 70% by water, this means that more than half of our planet is unmapped.
The Schmidt Ocean Institute is using what they call the R/V Falkor multibeam sonar systems to create high-resolution bathymetric maps ("topography" of the ocean floor). The EM302 (30KHz) multibeam sonar system is used for deep water mapping, capable of imaging 8,000 m depths. For more shallow waters of less than 2,000 m, the EM710 (70-100KHz) multibeam echo sounder is the tool of choice.
Both of these systems expand mapping range and speed. Mapping typically occurs at 9mph, with the sonar systems mounted on a gondola that prevents bubbles from interfering with sonar readings. Everything from ship speed, water temperature, and salinity need to be taken into account when processing sonar data.
Image courtesy of the Schmidt Ocean Institute.
Ocean floor mapping is big enough of a deal to warrant its own Shell Ocean Discovery XPrize. From 2015 to just May 2019, teams from around the world competed for a prize purse of $7 million in developing high-resolution, fast, and autonomous ocean floor mapping technology.
Mapping and prospecting are often among the first steps necessary before actual sea mining can occur.
After mapping has been conducted, areas of interest need to be identified and investigated further. This is where remotely-operated vehicles (ROV) and associated technologies come into play.
ROVs for mineral prospecting typically host a suite of sensors and manipulators. Visual and sonar sensors help provide feedback for operators that are usually onboard a tethered vessel or on land. Chemical sensors can indicate change in the pH of water, which can help locate hydrothermal vents. Drills and manipulators allow operators to check for mineral deposits and identify areas of interest. Depending on the objective, they may be specifically designed for high pressure or high heat environments.
Nautilus Minerals, an underwater mining company, plans to use a few different ROVs: ones for prospecting and inspecting potential sites, more heavy duty ROVs for more involved sampling or worksite preparation, and then much larger and heavier duty ones for full-blown mining operations.
Image courtesy of AUVAC.
For prospecting and inspection, the Abyss AUV manufactured and designed by IFM-GEOMAR can sustain depths of up to 6,000 m, and can carry payload equipment for seafloor mapping, magnetic/gravitational measurements, conductivity/temperature/chemical composition measurements, as well as photography. It uses 2x 5.6 kWh 29V lithium-ion batteries, capable of operating for up to 24 hours.
In China, the RainbowFish ROV has been under development since 2015 and is expected to be able to reach depths of up to 11,000 m. The company behind the RainbowFish plans to rent a fleet of vehicles to the Chinese government, which has taken an interest in deep-sea resource utilization.
Who Owns the Seabed? (AKA The Regulatory Environment)
Seabed mining and developing the regulatory framework to ensure it is done in a responsible and sustainable way is no easy feat. Permission to mine the seabed is granted by the International Seabed Authority, headquartered in Jamaica. Some of the regulatory considerations that must be taken include environmental impact and international laws of the sea.
Mining the seabed has the potential to cause significant harm to the ecosystem. Just a few of the considerations at play regarding sea life and biodiversity are:
- Polymetallic nodules often host sea sponges and octopi
- Seamounts are biologically diverse
- Hydrothermal vents have unique biological communities
- Underwater mining can increase the temperature of the waters it is occurring in
- There is always the risk of mismanagement of byproducts and waste
- An increase in oceanic noise has already had demonstrable impacts on whale populations
Overall, there is concern regarding the general fragility of the ocean environment, which is already facing a great number of challenges.
Combine these concerns with territorial and international laws and you have a messy affair. The ocean outside of national waters is considered the "heritage of mankind" and, just like space mining, the rights and ownership to deposits can get murky and must be managed in a way that is globally agreed upon.
However, despite these challenges, the United Nations considers underwater mineral resources to be essential to its "Sustainable Development Goals" for economic and social global benefit. In part, this is because these metals are necessary for the technologies that can help us solve other global issues such as access to clean water and renewable energy.
In essence, these reserves of minerals are crucial to the development of the very technologies that could make them obsolete in the future.
Deep-sea mining isn't a new concept, nor is it beyond the realm of possibility for many large-scale mining companies. It is, however, a deeply complicated task that will benefit from new sensor technologies, more ruggedized components, and the influx of autonomous and remotely-operated vehicles.
If you have experience in mining applications, working minerals crucial for electronics, or creating equipment for deep-sea environments, please share your stories in the comments below.