Pilot Programme on Deep Sea Mining - NTNU Oceans
Deep Sea Mining
NTNU Oceans pilot programme on deep-sea mining
New solutions for evaluation, exploration and extraction of sea-based minerals under societal responsibility for the environment and the international heritage of mankind
There are approximately ten known submerged massive sulphide (SMS) sites
along the Arctic Mid Ocean Ridge (AMOR). Additional sites has been identified as being favorable for new discoveries. The project will employ autonomous underwater vehicles (AUVs) to survey these areas for potential sites to take drill samples. While large-scale modeling and analysis can identify favorable locations, mapping them in detail is time-consuming and can benefit from improved autonomy in path planning.
This project will investigate the application of multivariate analysis to the combined sensor data from the AUV to identify favorable regions in-situ. Building on this interpretation and data fusion, the search pattern can be optimized online to maximize the information gain given constraints on time and energy. This not only involves the decision of which areas to cover, but also how to cover them. The underwater hyperspectral imager (UHI), for example, is a valuable new resource for data gathering, but also has different operating constraints than a side-scan sonar – as it needs to be closer to the seabed. This work is part of the Marmine project.
The mining systems project focuses on technological aspects related to the marine mineral extraction on the deep ocean floor. Given deposit descriptions in terms of size geometry, mechanical properties and mineralogy the following will be considered:
- review and assessment of existing and non-conventional extraction methods
- technical and economic feasibility of the above mentioned
Following a holistic approach to the mining system various technologies and mining equipment will be selected for the setup of a pilot-plan setup.This project will interface with the projects for Vertical transportation and Energy supply. Area of research include mechanical engineering, mechatronics and automation both for topside and subsea equipment. This work is part of the Marmine project.
This PhD project will investigate the electrical power system needed to supply deep sea mining applications.
The focus will be on the design of an optimized isolated power system, including power electronic converters, electrical drive systems and control strategy. Challenges regarding “deep subsea” working environment will be identified and addressed with a system level perspective. Numerical simulations will be carried out to study the proposed power system in order to ensure its efficient and stable operation in various conditions.
Deep-sea mining is an emerging human activity potentially having an impact on biogeochemical and ecological processes on the seafloor.
One project aims at developing a conceptual model on sediment-water interactions in SMS zones, as well as at improving and adapting existing biogeochemical models of benthic interactions under deep-sea mining conditions.
The other project focuses on another major environmental concern being the generation of plumes near the seabed and in the water column. Sediment from these plumes may accumulate on the seabed, choking suspension feeders and burying seabed animals. This project aims to estimate the impacts of such plumes on the benthos. The results may be used in future environmental impact assessments for deep-sea mining, and in the development of policy for environmental management.
Both studies will contribute to the establishment of guidelines for exploration and exploiting activities at deep-sea mineral deposits.
The focus of this study will be on normative questions involved in the development of new technology in general, and within deep sea mining in particular. Possible angles include:
- Corporate social responsibility in situations where companies are involved in the development of socially and environmentally controversial technology.
- Responsible research and innovation as a way to address social and environmental challenges in research initiatives.
- Research ethics in the broad sense, in other words the responsibility of researchers and research institutions for the social and environmental consequences of application of the research.
The oil industry has during the last decades developed sophisticated and successful methods and workflows for advanced geophysical exploration of oil and gas.
These methods can potentially give effective tools for marine mineral exploration through adjustments in acquisition, processing and interpretation techniques.In this project, the necessary adjustments will be studied and tested. In addition, new exploration methods and work flows will be developed.
The focus of this study will be on methods for direct resource detection and on technology with a minimum impact on the marine environment.
This PhD-project will be targeted on the development of the international laws, regulations and state of technologies that are relevant for subsea mining through the last 50-60 years. It will focus on selected critical issues and aim to understand the position of different groups of nations and how they develop and change over time. Of particularly importance will be the concept of Common heritage, the relation to environmental issues and how changes in subsea mining technology influence society.
The strength of an historical study will be to study the changes that have taken place during the last half century with regard to values, interests and possibilities, how they came about and how they influenced the law of the sea. The policies and strategies of the different states and NGOs during the negotiations will be of interest. Of particular importance will be to study the Norwegian government and Parliament strategies and decisions compared to other states.
Detailed and accurate ore characterisation is necessary to maximise the efficiency of deposit identification, resource extraction, mineral processing and waste management. Through various petrographical methods, identification and description of deposit lithologies will provide information for compositional, textural, mineral liberation and processing considerations.
This work is part of the Marmine project, and the data generated will directly feed in to other work packages, such as the Deep sea mining systems, and Mineral processing options. Contrasting pre- and post-processing material will track the effectiveness of utilised mineral refinement techniques, improving process methodology, whilst rock mass characterisation will inform extraction and pit design considerations.
Mineral chemistry and textures may serve as fingerprints for the ore-forming processes. Detailed investigation of ore minerals and cogenetic, non-economic minerals can provide insights into the fundamental processes governing the formation of seafloor massive sulfide deposits in slow spreading ridges, including metal source(s) and fluid evolution. This may provide additional information to the search for onshore analogues. Also, the concentration and distribution of low grade precious and critical elements is important for identifying potential byproducts
The assessment of undiscovered mineral resource potential in the mid-Atlantic ridge (MAR) area which falls within Norwegian jurisdiction, using play analysis. The candidate will contribute in a further development of the assessment methodology and is also expected to apply this to selected commodities and ore deposit types on the Norwegian mainland.
The goal is to increase the level of understanding on how the play analysis and quantitative techniques can be used to assess the mineral potential of marine and onshore mineral deposits.
The study of inactive as well as active ridge segments that are formed at slow and fast spreading rates and the estimation of consequences these have had on the grade, tonnages and ore-metal distribution of marine Cu-Zn-Cu-Au-PGE deposits.
Offshore mining will include mining equipment deployed on the seafloor and may be connected to a flexible hose and a rigid riser for vertical transport. Alternative vertical transport systems include mechanical, airlift and hydraulic systems.
One project focuses on the dynamic behaviour of the vertical riser as a critical element that will govern the weather limitations and costs of such operations. At large water depths vertical instabilities may occur as a result of the flow conditions in combination with other loads from ship motions, ocean waves and vortex induced shedding.This PhD project focuses on how the flow conditions can be modelled in sufficient detail to enable time domain simulations where all these effects can be captured. PhD candidate Tor Huse Knudsen
A second project focuses on the development of numerical tools for simulating deep sea mining riser operations. This includes finite element (FEM) modeling of the structure, an empirical model for the external hydrodynamic loads, and a 1D multiphase flow model for the internal flow.
Such a simulation tool can be used to predict the dynamic behavior of the riser, including time varying stresses and fatigue damage, and may therefore be used to design safe structures for deep sea mining. Part of the MOVE Center for Research-based Innovation. Post-doc Mats Jørgen Thorsen.
Dynamic pipe flow modelling for Ocean Mining Lift System is a third vertical transport project. This research work aims to develop the 1D dynamic pipe flow model for the transport of minerals from sea bed to the sea surface.
The developed model can be used to predict the pressure drop, local particle concentration and bed layer formation along the mining riser. Flow model will be extended to study the feasibility of the gas lift system for deep sea mining application. These models will be improved by using lab scale experiment al data.
Post-doc Niranjan Reddy Challabotla
Contact: Professor Svein Sævik
Underwater Hyperspectral Imaging (UHI) will be tested for its application in seafloor mineral mapping. Through their spectral signatures, this technology allows to identify and classify different types of minerals.
NTNU’s contribution to the Horizon2020 Blue Mining project involves the development of an automated image analysis system for seafloor manganese nodules and massive sulfides. Data are acquired with the first deep-sea UHI sensor and used to develop a classification method optimized for seafloor minerals.
Contact: Post-doc Ines Dumke (finished)