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Current and future supply of minerals
Published in Natalia Yakovleva, Edmund Nickless, Routledge Handbook of the Extractive Industries and Sustainable Development, 2022
Karin E. Olson Hoal, Eric Pirard, Alan R. Butcher
Deep-sea mining refers to the extraction of resources from the seabed and the ocean floor. It does not refer explicitly to the mining of mineral concentrations from beaches and dune strands (placers and heavy mineral sand deposits) which is a major activity for commodities such as zirconium, titanium, and diamonds. Geologists make a distinction between the seabed, which is a submerged area of continental crust at reasonably shallow depths (a few hundred metres), and the ocean floor, which is made of oceanic crust and found on average at 4,500 m below sea level. The continental crust and the oceanic crust have strongly contrasting compositions. Whereas chromium, nickel and cobalt are expected to occur in higher amounts in the oceanic crust, which is fed from the more geochemically primitive and ultramafic Earth’s mantle, other elements such as lithium, tin and tungsten are expected to occur more abundantly in the more geochemically evolved continental crust. The main challenge of seabed mining is to develop underwater exploration and efficient underwater mining technologies with limited impact on the environment. Given the very high biodiversity found in those shallow waters, the risk of technical failure and its dissemination through oceanic circulation is not to be underestimated. A few projects have been developed with Neptune Minerals focusing on seabed massive sulphides in the Western Pacific at depths of 500 m–1,000 m being among the most emblematic.
Global Status
Published in Ranadhir Mukhopadhyay, Victor J. Loveson, Sridhar D. Iyer, P.K. Sudarsan, Blue Economy of the Indian Ocean, 2020
Ranadhir Mukhopadhyay, Victor J. Loveson, Sridhar D. Iyer, P.K. Sudarsan
The UK has a large potential to extract renewable energy from offshore. The UK has the largest installed offshore wind capacity in the world to generate electricity and it occupies around 36% of the global size. The industry is witnessing rapid growth due to technological innovations in the field. Wind energy is environmentally friendly and cost effective and is well-supported by the government. Deep-sea mining, considered as an alternative to terrestrial mining, is seen as a great potential for the blue economy, as significant amounts of deposits of cobalt, nickel, and manganese exist on the seafloor in the form of manganese nodules. The UK’s industry is exploring the possibility of mining deep-sea resources.
Sea: Pollution
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Water Resources and Hydrological Systems, 2020
Deep sea mining is a relatively new mineral retrieval process that takes place on the ocean floor; however, the complete consequences of full-scale mining operations are still unknown. Ocean mining sites are located usually around large areas of polymetallic nodules or active and extinct hydrothermal vents at about 1400–3700 m below the ocean’s surface.[30] The vents create sulfide deposits, which contain precious metals such as silver, gold, copper, manganese, cobalt, and zinc.[31,32] The deposits are mined using either hydraulic pumps or bucket systems that take ore to the surface to be processed. As with all mining operations, deep sea mining raises questions about environmental damage to the surrounding areas. The removal of parts of the seafloor will result in disturbances to the benthic layer, increased toxicity of the water column, and sediment plumes from tailings. Removing parts of the seafloor disturbs the habitat of benthic organisms, possibly depending on the type of mining and location, causing permanent disturbances.[33] Among the deep sea mining products, sediment plumes could have the greatest impact. Plumes are caused when the tailings from mining (usually fine particles) are dumped back into the ocean, creating a cloud of particles floating in the water. Two types of plumes occur: near-bottom plumes and surface plumes.[30] Near-bottom plumes occur when the tailings are pumped back down to the mining site. The floating particles increase the turbidity, or cloudiness, of the water, clogging filter-feeding apparatuses used by benthic organisms. Surface plumes cause a more serious problem. Depending on the size of the particles and water currents, the plumes could spread over vast areas. The plumes could affect zooplankton and light penetration, in turn affecting the food web of the area.[30,34]
Optimization of impeller of deep-sea mining pump for erosive wear reduction based on response surface methodology
Published in Marine Georesources & Geotechnology, 2023
As one of the core pieces of equipment in a deep-sea mining transportation system, a deep-sea mining pump transports mineral particles such as polymetallic nodules, cobalt-rich crusts, and polymetallic sulfides. These coarse-grained minerals influence the hydraulic performance and wear characteristics of a mining pump. As such, a mining pump is required to possess many advantages, such as high performance, wear resistance, wide flow passage, and no blockage (Yang et al. 2021). Under normal circumstances, the hydraulic performance and wear characteristics of a theoretically designed mining pump are first analyzed, a suitable method for optimizing the design of the main flow passage components (such as the impeller) is then adopted, and finally the performance of the optimized mining pump is analyzed to improve the overall performance of the mining pump.
Recognition of cobalt-rich crusts based on multi-classifier fusion in seafloor mining environments
Published in Marine Georesources & Geotechnology, 2021
Gang Hu, Haiming Zhao, Fenglin Han, Yanli Wang
In this paper, an ultrasonic method is used to identify cobalt-rich crust in deep-sea mining. Three basic classifiers, including the PNN, SVDD and PNN, are designed by the KFDA feature dimension reduction method. The superior recognition characteristics of each classifier are screened by a GA. A MCF recognition method based on D-S theory is proposed. By extracting the credibility of the classifier and recalculating the BPA function, the conflict evidence is measured and synthesized, and the D-S fusion method is improved, thereby improving the MCF recognition rate. The experimental results show that the fusion recognition method proposed in this paper is better than the single classifier identification method in terms of the recognition accuracy of a strong reverberation environment and has a good recognition rate.
The economics of mining seabed manganese nodules: A case study of the Indian Ocean nodule field
Published in Marine Georesources & Geotechnology, 2019
Ranadhir Mukhopadhyay, Sankalp Naik, Shawn De Souza, Ozinta Dias, Sridhar D Iyer, Anil K Ghosh
India does not have any primary resources of Co. The secondary sources, however, are Ni-bearing laterite deposits in Odisha (formerly Orissa) and declining Cu slag produced by Hindustan Copper Limited, Rajasthan. Due to the specialized nature of its applications (jet engines, paint and petrochemical industries, carbides, synthetic liquid fuels, rechargeable batteries, cellular telephones, etc.) and difficulty in substitution, the future demand for Co is likely to follow an increasing trend. India imported 1193 tons of cobalt in 2012 and 443 tons in 2013 (IBM 2016). The deep sea mining venture is capable of producing over 3000 tons of cobalt annually for the worth of almost US $200 Million (Glasby 2000; ISA 2010).