There is a certain number of the economical, political, and environmental reasons for the current delay with a fully operational seabed mineral mining. Both mining professionals and outside observers follow different opinions why minerals from the ocean floor still remain unreachable at industrial scale.
Some emphasize a hypothetical environmental impact of seabed mining on the ocean biodiversity. The others claims that seabed mining is less feasible than the onshore one. Still others see a conspiracy of the world mining corporations whose ongoing interests hinder seabed mining being at the same time focused on the occupied continental deposits.
All of the above is legitimate to some extent in the context of the discussion. However, all of the observers agree that the biggest hurdle staying in front of the industrial seabed mining is a technological complexity inherent in the creation of submersible mining vehicles. Such a consensus is based on the fundamental physical conditions at which the vehicles are to work.
One of the biggest challenges for the vehicles is a huge pressure at the depth where the richest seabed mineral deposits locate: 3–6 kilometers. It means that water will press a vehicle’s hull with a 30–60 MPa force. However, such pressure is hardly an unsolvable problem in the XXI century when the contemporary metallurgical engineering can offer titanium alloys allowing submersible apparatuses to dive even into Mariana Trench (about 11 km).
The other technological constraint refers to the type of operation of the industrial-scale submersible miners. Two basic types are usually considered: autonomous vehicles (both manned and unmanned) and remotely operated unmanned ones. Both concepts have their advocates being under development by different companies engaged in creation of seabed mining technologies.
True challenges of seabed miner designing
The main difference between two basic types of seabed miners comes to freedom of movement: autonomous vehicles can work independently on the ocean bottom while remotely operated ones are linked to a surface vessel with a vertical piping system through which the collected minerals should be delivered to the surface.
The freedom of movement entails a controversial choice between types of propulsion to be used in seabed miners. Some companies offer vehicles movable either on caterpillar or on wheels similar to the well-known onshore mining machinery. Such miners will move directly on the ocean bottom. The others, such as Krypton Ocean, develop zero-buoyancy floating vehicles similar to submarines that will levitate over the seabed moving with the help of propellers.
A significant divergence of opinion concerns the types of mining tools with which seabed minerals can be extracted. The issue is tightly linked to both a propulsion type of the vehicles and the effect with which the tools impact the ocean floor. In addition, the issue is determined by the type of seabed sediments: cobalt crusts are to be crushed before extraction while polymetallic nodules need to be just picked up from the bottom.
Hence, all available seabed miners can be roughly divided into two basic models: caterpillar-movable remotely operated vehicles and a zero-buoyancy floating vehicle both remotely operated and autonomous. To put the models in short, let’s call them a riding-type vehicle and a floating-type one respectively.
A few words about a riding-type model
Probably the main advantage of the riding-type design of submersible miners is the least extent of unfamiliarity for a conventional mining sector. Why reinvent the wheel if onshore caterpillar-driven mining vehicles are developed more than enough? Hence, the task comes to adaptation of a well-known onshore design to a deepwater operation. From a purely technical standpoint the task is less challenging than creation of some utterly different apparatuses having no analogs in the onshore mining.
When it is necessary to build a deepwater miner in a record time, nothing but an onshore caterpillar-driven vehicle fits prototyping best. Once such miners imply a remote operation only, many parts of submersible apparatuses become redundant. A crew cabin, bunkers for collected minerals, batteries (or a different type of fuel elements) for electric motors, ballast tanks for surfacing, sophisticated autonomous navigation equipment, and some other purely “maritime” parts all belongs to rather autonomous floating submarine-like vehicles than to a caterpillar-driven miners.
“The simpler the better” is perhaps a pragmatic motto for designing the seabed riding-type miners. In fact, such a design implies a mining working tool installed on a bearing frame with caterpillar drives and motors. The frame also carries a small transit bunker linked to a vertical piping system through which the collected minerals should be delivered to a surface. Power supply cables along with ones for remote telemetry are also integrated into the vertical delivery system.
Namely the relative engineering simplicity makes such a design very attractive for many companies in terms of both development costs and timing for the launch. And Krypton Group does not exclude such a type of vehicles if a certain mining mission requires designing it.
Pros and cons of a floating-type model
In contrast to a previously described type, the floating-type seabed miners imply a plethora of innovations applied to their designing. In most cases, a design has to be created from scratch since no analogs are available in the onshore mining. This feature can be accepted ambivalent. On the one hand, a technological uncertainty is a disadvantage in comparison with a well-developed caterpillar-driven design. On the other hand, engineers are untied from any available technological biases and patterns when the sky is the only limit for their creativity.
Some may note that there are various deepwater vehicles and submarines which could serve as a prototyping basis. But even so, the applications of both scientifically oriented submersible apparatuses and military submarines are quite distinct from what seabed miners have to do at the ocean bottom. That’s why floating-type seabed miners should combine properties of both submersible apparatuses and onshore mining machinery.
The inherent surfacing mode along with a relative freedom of movement is what distinguishes the floating-type miners from riding-type ones most. The adjustable buoyancy provides the floating-type vehicles with a certain autonomy allowing them not to be firmly linked to the ocean bottom. They levitate over the ocean floor keeping their mining tools near the bottom to process and collect seabed minerals.
Ballast tanks, sophisticated navigation equipment, crew cabins (if vehicles are manned), cruise and maneuvering propellers, batteries and fuel elements, bunkers for the collected minerals all have to be available in the design of the floating-type miners making them more technologically challenging than riding-type ones are.
The question whether technological sophistication provides floating-type miners with certain advantages over riding-type ones requires careful consideration. Is it really worth complicating the structural design when the achievable performance won’t differ too much from what riding-type miners offer?
Leaving aside a possible mineral production output, it is necessary to admit that the very ability to move not only around the surface of the ocean floor but floating up and down in the water column makes the floating-type miners significantly more maneuverable in comparison with riding-type ones. Deep trenches, steep mountains, shipwrecks and the other deepwater obstacles that remain oftentimes impassible for riding-type miners can be easily overcome by the floating-type ones due to their adjustable buoyancy. This ability provides not less than an uninterrupted continuity of a mining process which provides feasibility of the whole project after all.
If water as a physical medium provides objects with buoyancy, why not create the bottom-topography agnostic apparatuses?
By the way, the booming drone-&-copter development reflects the desire to get the same maneuverability on land as submersible vehicles have under water. Disregard the medium (air or water), the three-dimension movement is more advanced than the two-dimension one.
The advanced 3D maneuverability provides another valuable property to the floating-type miners — the least possible effect on the ocean bottom.
Once the vehicles levitate over the ocean floor, they need to touch it for no purpose other than just picking up nodules from the bottom. In general, the very process of the polymetallic nodule mining differs from any kind of onshore mining very much. It implies collecting nodules while drilling, digging, excavation as well as any other ordinary mining processes are simply redundant. Hence, the engineering challenge comes to creation of such nodule-collecting tools that leave anything other than nodules untouched.
When it comes to mining of cobalt crusts, the situation does not differ too much. The process implies crushing a crust layer to the depth of 50–200mm. Some special crushing and grinding working elements of the mining tools should be applied. However, it does not mean that any additional impact on the ocean bottom such as caterpillar-made furrow is needed. And the vehicles with adjustable buoyancy can provide this.
The very approach to seabed mineral mining should imply the least possible impact on the ocean floor. Engineers must always keep this principle in mind when they develop seabed miners. That’s why Krypton Ocean is focused on the zero-buoyancy floating vehicles mostly.
When it comes to the vehicles’ operation issue, Krypton comes to a conclusion that both autonomous and remotely operated models can be equally viable.
Along with the development of a fully autonomous deepsea mining vehicle having adjustable buoyancy that provides delivering collected nodules from the ocean floor to an on-surface vessel batch by batch, another project is under development at Krypton Ocean now.
This is a different type of a remotely-operated seabed mining harvester that can collect nodules from the ocean floor and crush them right on board to prepare a concentrated suspension which can be pumped out subsequently to the surface via a special hydro-transport vertical delivery system.
The energy supply of the harvester is provided through deepwater cables integrated into the hydro-transport vertical delivery system. The full-control operation of the vehicles is conducted remotely by operators at a vessel on the surface. The vertical hydro-transport delivery and control system doesn’t change the general technological concept of the adjustable buoyancy, nevertheless. It means that an operator will be able to put the harvester into a surfacing mode whenever either repair or routine maintenance of the vehicle is needed.
Hence, Krypton Ocean provides a certain diversity of types of its seabed mining vehicles to better comply with every possible deepwater mining mission.
Since the concept of the least possible impact on the seabed is crucial for Krypton Ocean, the recent lab testing of its chain-like rotating tool for polymetallic nodules’ collection confirmed a principle possibility to take nothing but nodules from the ocean floor.
A system of grippers was equipped with a specially designed clamping mesh to improve functionality of the nodule-collecting tool. The mesh reliably fixes nodules in the tool after grippers take nodules from the ocean floor without any significant re-suspension of the seabed ooze.
Thereby, the seabed landscape remains untouched at the areas of contact between the ocean floor and a nodule-collecting tool of Krypton’s deepsea mining vehicles. The recently tested design showed almost zero seabed ooze appearing in bunkers of the mining vehicles.
It should be reminded that in addition to the present gripper-type design another chain-like version with buckets is also available.
Krypton Ocean raises the bar in seabed mining technologies being fully aware that the process of collection of nodules alone is only half the battle. The true challenge comes to making the entire seabed mining activity as eco-friendly as possible. Besides, the mining process efficiency must meet feasibility expectations.
This is all about turnover after all
Seabed mining feasibility is one of the least recognizable issues for potential investors. Nothing weird is in such doubts in fact — the absence of an industrial-scale practice of seabed mining can hardly add confidence to the issue. Oftentimes, pragmatic investors cannot distinguish the experimental prototyping having dubious curiosity-induced prospects from commercial engineering aimed at gaining actual profits.
It is not enough to represent a prototype of a seabed miner to attract funds for serial production. Many companies represent prototypes created as a “thing-in-itself” since the task comes to just implementing grants from some international organizations. Such prototypes were created with a purely scientific interest having no commercial background.
To state that the majority of seabed miners belong to that category can be a truth only in part. There are few companies who consider seabed mining as a practicable business. They represent series of conceptual seabed vehicles having different working specializations instead of showing a single “general” design. Besides, such activity as mineral mining is hardly imaginable without a full-cycle processing facilities: separation & enrichment factories, metallurgical and refinery plants (if metals are to be extracted from the seabed sediments), advanced logistics etc.
Hence, the holistic approach to seabed mineral mining is the indicative feature which helps distinguish those technology providers who are going to develop seabed mining as an actual commercial activity from those who see designing of seabed miners as an interesting technological challenge when the development is funded by some non-commercial international entities.
The final objective is profit
From the day one, Krypton Group is a purely commercial enterprise whose activities are entirely dedicated to establishing an actually working seabed mining business. Everything Krypton does is about turnover after all, even though the stage of gaining profits has not come yet. All experiments, tests, and the development process as a whole constitute an intellectual investment of Krypton in an emerging seabed mining sector. Since we all are living in the days of a transition to the so-called knowledge economy, what other than unique know-hows can be the most valuable investment in the future?
The true intentions of Krypton can be easily detected through its website content. In addition to technological and scientific sections, the commerce-oriented ones are available as well. The very structure of Krypton Ocean Group reveals its desire to handle a practical seabed mining business: a full-cycle process of mining and processing of ocean minerals as well as production of refined metallic alloys are distributed among Krypton’s divisions.
Making great efforts in developing deepwater vehicles of various types Krypton, nevertheless, does not take this activity as an end in itself. The designing of its own seabed miners is just one of the methods for providing Krypton’s business model with maximum efficiency.
Unlike many who still hesitate, Krypton clearly sees the great commercial opportunities in mining minerals from the ocean bottom. Especially it concerns the so-called “battery metals”.
The final objective of Krypton Group comes to supplying zinc, cobalt, nickel, copper, and manganese as finished products to a global metal market. Needless to say that such a task requires all necessary stages of the fully operational metal production business where building seabed miners is just an important initial step. Hence, in order to assess seabed miners developed by Krypton, it is recommended to consider the entire business model of Krypton Ocean Group. In brief, the conclusion to which the very logic of this model leads is that seabed miners constitute the final objective of Krypton under no circumstances. They are just a means leading to the final objective — selling ocean-originated battery metals to the world market.
Summarizing the issue regarding two basic models of the deepwater miners we have to admit that the choice between them belongs to each organization that sooner or later will start an industrial-scale seabed mineral mining. We believe that a clear public awareness regarding some crucial distinctive features of both concepts is what would help make the right choice.
Since the seabed mining technology is still at the stage of conceptual prototyping, we all have time to evaluate all pros and cons of every available model of seabed miners. We should remember that the future of a seabed mining sector depends on our environmental responsibility in addition to proper feasibility calculations. This is about the so-desired sustainable development in the days when a transition to a post-carbon economy is emerging. And an integral part of the transition is the battery minerals from the ocean floor.
When the seabed mining rush is coming, it is important not to confuse the vehicles, right?