The ocean floor presents one of the last great unexplored territories for mining. Despite the world’s deepest seabeds thus far remaining largely unexplored, National Geographic estimated in 2016 that subsea reserves could contain up to $150tn worth of gold alone. Such riches are hard to ignore and, with no sign of exploration interests slowing either above or below the waves, may soon be the next major area for mining projects. For while there are significant challenges to overcome, deep sea mining also promises not just material wealth but the possibility of lessened impact.
Among the interested parties is DeepGreen, which has taken concerns around ocean mining head on by producing a paper outlining the difference in impact of mines on the seafloor compared to those on land. If the technical challenges can be overcome, and deep sea mining can prove to be environmentally kinder as DeepGreen believes, it could prove to be a revolutionary step-change for the mining sector.
Scarlett Evans (SE): Tell me about your company – what do you do and what is your mission?
Gerard Barron (GB): DeepGreen is in business to change the metals game, with the end point being a circular metal economy powered by renewable energy.
Today we don’t have enough metal in the system to be able to live off its recycled form—we would need to inject hundreds of millions of tonnes of metal from mining virgin ores. Unfortunately, the way we produce metal today comes with planetary scale environmental and social costs.
At DeepGreen, our current hypothesis is that producing virgin metals from a unique, abundant and high-grade deep-sea resource called polymetallic nodules is probably our best chance of compressing the environmental and social burdens of metal production. Our vision is to enable the circular supply chain for metals, speeding the transition to EVs and renewable energy storage. If we are successful, we will help to inject enough critical base metals into the system so that we can stop collecting and processing virgin minerals and effectively become a recycling company, selling metals as a service to our customers.
Right now we are developing a project in the Clarion Clipperton Zone (CCZ) in the Pacific Ocean which holds a very large concentration of polymetallic nodules – containing enough metal to electrify the entire global car fleet of 1.3 billion cars several times over.
SE: What benefits do you believe ocean mining holds over sourcing minerals on land?
GB: Polymetallic nodules contain high concentrations of nickel, cobalt and manganese—the same metals that make up most EV batteries—as well as copper needed for electric wiring. It is like having several mining projects in one, except the nodules are sitting unattached on top of the deep seabed and therefore don’t require the removal of millions of tonnes of overburden and waste rock, or human settlements or tropical rainforests to get at the ore.
In addition, the nodules don’t contain toxic levels of heavy elements and this makes it possible to process them with zero solid waste and no toxic tailings. This means no tailing dam collapses, eco- and human toxicity and very low eutrophication potential. We see this as a step change for the metals industry.
SE: What does the process of ocean mining actually involve?
GB: Compared to the alternative of sourcing from the land, it’s a pretty straightforward process, starting with exploration. Because the nodules are on the surface of the seabed you can actually see them, and with underwater drones and box core sampling we can generate a resource estimate without having to dig or drill.
As for getting the nodules, we will deploy a tracked vehicle to depths between 4,000 and 4,500 metres that will be connected to a surface vessel by a long riser and an umbilical to provide power and comms to the vehicle. The front of the collector has a nozzle that blows seawater over the nodules to dislodge them from the sediment, and then the nodules are lifted up the riser pipe up to the surface vessel where they will be transported by another vessel to the shore for near-zero-waste processing.
Since this method of collecting nodules was successfully executed back in the 1970s, we are not reinventing the wheel on any of the major components of the system. What we will have that they didn’t back then, however, is a global regulatory regime and much higher rates of efficiency.
SE: Your white paper looked at the impacts of mining different materials from cradle to gate – how did you go about selecting and predicting these impacts?
GB: We essentially built on existing work for land ores (as well as other indicators that are critical for mining) and created an apples-to-apples comparison for battery material production from nodules.
Our white paper team created high-fidelity models to quantify the global warming potential and several other important indicators in the study. For land ores, results were derived from models documented in existing literature. For nodules, results were derived from a new life-cycle assessment model developed for the purpose of enabling like-for-like comparisons. Data for the nodules model was sourced from detailed operating concepts, engineering models, survey data for the CCZ, preliminary economic assessments, comparables from literature and industry benchmarks, to name a few.
SE: What were some of the conclusions you drew from the paper?
GB: Some of the high-level findings are that when it comes to building one billion EV batteries, sourcing the minerals from polymetallic nodules leads to: 70% less CO2 emissions, 100% less solid waste, 47% lower production cost, 97% fewer human/worker impacts and 93% less wildlife at risk – and this is just the beginning.
Saying this, while producing metals from nodules leads to significant reduction of major impacts, there are things with nodule collection that we need to pay close attention to. For instance, it’s important to understand that their collection will disturb the top 5-15 cm of mud on the seabed and partially remove nodules in collection areas that certain deepsea wildlife need for their life functions. As a precaution, more seabed areas are set aside by the ISA into preservation zones than are currently under contract for exploration—and we plan to add to these zones with more no-take zones ourselves.
SE: What are some of the other concerns people raise about sourcing materials from the ocean?
GB: People are concerned about impacts to biodiversity on the abyssal seabed, which is a worry that we share. Generating sediment plumes at the seabed, as well as the impacts of noise and light on deep-sea ecosystems are also topics of concern.
As with any new industry, people have a lot of questions and it’s our job to provide answers. For those things we don’t yet have answers to, we are working to get them and we are investing in a three-year environmental and social impact assessment program, as well as ongoing monitoring and adaptive environmental management thereafter. Our commitment is to travel in the open as we work to understand and minimize the environmental and social impacts of sourcing these critical minerals, and we will continue to work with the global community to ensure that we do this right.
SE: Would we need to introduce significant technological or infrastructure changes to our current systems to allow for ocean mining?
GB: We can actually leverage capital and technology from industries like oil and gas, as these industries have immense deep-sea experience and assets that we can use.
There are also a lot of talented young engineers that are starting out their careers in oil and gas — and even mining — that don’t necessarily see those as industries of the future. We are seeing a lot of interest from engineers and others in offshore work that are excited about what we are doing and want to play a role in the green transition.
SE: What’s next for the company?
GB: While DeepGreen is in full-on engineering mode with our offshore technology partners, our environmental team is designing some particularly exciting technology that will result in a virtual replica of the entire project environment in the deep ocean. This will result in a cloud-based software system that will allow us to adjust operations in real time to minimize environmental impact, as well as give various stakeholders and the ISA real-time visibility and monitoring capabilities.
We’re also continuing to build strategic partnerships with EV manufacturers and owners of onshore mineral processing facilities, and we look forward to announcing soon an exciting project to create the world’s greenest EV with metals derived from the recent bulk sample of nodules we brought to shore just this month.