Comparative Advantages of the Mineral Processing of Deep-Sea Polymetallic Nodules over Terrestrial Ores

2022 ◽  
pp. 199-217
Author(s):  
Chris Duhayon ◽  
Simon Boel
Keyword(s):  
Deep Sea ◽  
Mineral Processing ◽  
Polymetallic Nodules ◽  
Comparative Advantages

Polymetallic Nodules: Resource Potential and Mining Prospects

2021 ◽  
Vol 55 (6) ◽  
pp. 22-30
Author(s):  
Rahul Sharma
Keyword(s):  
Deep Sea ◽  
Environmental Issues ◽  
Industrial Applications ◽  
Green Energy ◽  
Steady Increase ◽  
Critical Metals ◽  
Alternative Source ◽  
Resource Potential ◽  
Polymetallic Nodules ◽  
International Seabed Authority

Abstract Deep-sea minerals such as polymetallic nodules have attracted significant interest among stakeholders not only for evaluating their potential as an alternative source of critical metals that are required for various industrial applications including green energy but also in developing technology for their exploitation. There has been a steady increase in the number of contractors having exploration rights over large tracts on the seafloor in the “Area,” and the International Seabed Authority that is mandated with the responsibility of regulating such activities is in the process of preparing a code for exploitation of these deep-sea minerals. This commentary takes a look at the resource potential and mining prospects of polymetallic nodules while addressing the economic and environmental issues associated with them.

scholarly journals Silurian metalliferous nodules from the region of Asaritsa peak, West Balkan mountain – preliminary results

2020 ◽  
Vol 81 (3) ◽  
pp. 75-77
Author(s):  
Atanas Hikov ◽  
Valeri Sachanski ◽  
Zlatka Milakovska ◽  
Elitsa Stefanova ◽  
Irena Peytcheva ◽  
...  
Keyword(s):  
Deep Sea ◽  
Nodule Formation ◽  
Deposition Mechanism ◽  
Preliminary Results ◽  
Polymetallic Nodule ◽  
Polymetallic Nodules

First data for polymetallic nodules and host sediments in Silurian sequence from the region of Asaritsa peak, West Balkan mountain are presented. The nodules are rich of Fe, Mn, Co and Ni. Both sediments and nodules have high content of REE. The described Silurian nodules and sediments show a number of similarities with modern deep-sea polymetallic nodule bearing sediments. Some differences such as probable depth of deposition, mechanism of nodule formation, degree of lithification are also established.

Impact of simulated deep-sea polymetallic nodule mining on sediment and pore-water geochemistry in prospective mining areas in the NE Pacific Ocean

2020 ◽  
Author(s):  
Jessica Volz ◽  
Laura Haffert ◽  
Matthias Haeckel ◽  
Andrea Koschinsky ◽  
Sabine Kasten
Keyword(s):  
Steady State ◽  
Pacific Ocean ◽  
Deep Sea ◽  
Surface Sediments ◽  
Small Scale ◽  
Mining Activities ◽  
Mining Equipment ◽  
Geochemical Conditions ◽  
Polymetallic Nodules ◽  
Ne Pacific

<p>Industrial-scale harvesting of deep-sea mineral resources, such as polymetallic nodules, is likely to have severe consequences for the natural environment. However, the effects of mining activities on deep‑sea ecosystems, sediment geochemistry and element fluxes are still poorly understood. Predicting the environmental impact is challenging due to the scarcity of environmental baseline studies and the lack of mining trials with industrial mining equipment in the deep sea. Thus, currently we have to rely on small-scale disturbances simulating deep-sea mining activities as a first-order approximation to study the expected impacts on the abyssal environment and ecosystem.</p><p>We have investigated surface sediments in disturbance tracks of seven small-scale benthic impact experiments, which have been performed in four European contract areas for the exploration of polymetallic nodules in the Clarion-Clipperton Zone (CCZ) in the NE Pacific Ocean. These small-scale disturbance experiments were performed 1 day to 37 years prior to our sampling program in the German, Polish, Belgian and French contract areas using different disturbance devices, such as dredges and epibenthic sledges. We show that the depth distribution of solid-phase Mn in the upper 20 cm of the sediments in the CCZ provides a reliable tool for the determination of the disturbance depth. We found that the upper 5–15 cm of the sediments were removed during various small‑scale disturbance experiments in the different contract areas. Transient transport‑reaction modelling for the Polish and German contract areas reveals that the removal of the surface sediments is associated with the loss of reactive labile organic carbon. As a result, oxygen consumption rates decrease significantly after the removal of the surface sediments, and consequently, oxygen penetrates up to tenfold deeper into the sediments inhibiting denitrification and Mn(IV) reduction. Our model results show that the return to steady state geochemical conditions after the disturbance is controlled by diffusion until the reactive labile TOC fraction in the surface sediments is partly re‑established and the biogeochemical processes commence. While the re-establishment of bioturbation is essential, steady state geochemical conditions are ultimately controlled by the burial rate of organic matter. Hence, under current depositional conditions, new steady state geochemical conditions in the sediments of the CCZ are reached only on a millennium-scale even for these small-scale disturbances simulating deep-sea mining activities.</p>

Polymetallic nodules are essential for food-web integrity of Pacific abyssal plains

2020 ◽  
Author(s):  
Tanja Stratmann ◽  
David Amptmeijer ◽  
Daniel Kersken ◽  
Karline Soetaert ◽  
Dick van Oevelen
Keyword(s):  
Food Web ◽  
Deep Sea ◽  
Mitigation Strategy ◽  
Extensive Literature ◽  
Literature Research ◽  
Polymetallic Nodules ◽  
Link Density ◽  
Sessile Organisms ◽  
High Diversity ◽  
Interaction Webs

<p>The abyssal seafloor is at some locations covered with polymetallic nodules that provide hard substrate for sessile organisms. Extraction of these mineral-rich nodules will likely severely modify the trophic and non-trophic interactions within the abyssal food web, but the importance of nodules and their associated sessile fauna in supporting this food web remains unclear. Here, we present highly resolved interaction webs with ~200 (Peru Basin) and ~450 (Clarion-Clipperton Zone, CCZ) food-web compartments based on an extensive literature research. Compartments were connected with ~3,100 (Peru Basin) and ~8,500 (CCZ) trophic and non-trophic (e.g. substrate-providing nodules) links. The webs were used to assess how nodule extraction would modify the number of network compartments, number of links, link density and web connectance. We showed that nodule removal would reduce the number of food-web compartments and links by ~25% and ~35%, respectively, in the Peru Basin and by 21% and 20%, respectively, in the CCZ. Subsequent analysis identified stalked sponges, living attached to the nodules, as key structural species that support a high diversity of commensal and mutualistic fauna. We conclude that nodules are critical for food-web integrity and suggest the deployment of artificial sponge stalks as a potential mitigation strategy for deep-sea mining.</p>

scholarly journals Microbial communities associated with sediments and polymetallic nodules of the Peru Basin

2020 ◽  
Author(s):  
Massimiliano Molari ◽  
Felix Janssen ◽  
Tobias Vonnahme ◽  
Frank Wenzhöfer ◽  
Antje Boetius
Keyword(s):  
Community Composition ◽  
Deep Sea ◽  
Microbial Community Composition ◽  
Rrna Gene ◽  
Operational Taxonomic Units ◽  
Polymetallic Nodules ◽  
Relevant Role ◽  
Bacterial And Archaeal Communities ◽  
Clarion Clipperton Fracture Zone ◽  
And Function

Abstract. Industrial-scale mining of deep-sea polymetallic nodules will need to remove nodules in large areas of the seafloor. The regrowth of the nodules by metal precipitation is estimated to take millions of years. Thus for future mining impact studies, it is crucial to understand the role of nodules in shaping microbial diversity and function in deep-sea environments. Here we investigated microbial community composition based on 16S rRNA gene sequences retrieved from sediments and nodules of the Peru Basin (> 4100 m water depth). The nodule field of the Peru Basin showed a typical deep-sea microbiome, with dominance of the classes Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, and Acidimicrobiia. Nodules and sediments host distinct bacterial and archaeal communities, with nodules showing lower diversity and a higher proportion of sequences related to potential metal-cycling bacteria (i.e. Magnetospiraceae, Hyphomicrobiaceae), bacterial and archaeal nitrifiers (i.e. AqS1, unclassified Nitrosomonadaceae, Nitrosopumilus, Nitrospina, Nitrospira), and bacterial sequences found in ocean crust, nodules, hydrothermal deposits and sessile fauna. Sediment and nodule communities overall shared a low proportion of Operational Taxonomic Units (OTU; 21 % for Bacteria and 19 % for Archaea). Our results show that nodules represent a specific ecological niche (i.e. hard substrate, high metal concentrations and sessile fauna), with a potentially relevant role in organic carbon degradation. Differences in nodule community composition (e.g. Mn-cycling bacteria, nitrifiers) between the Clarion-Clipperton Fracture Zone (CCZ) and the Peru Basin suggest that changes in environmental setting (i.e. sedimentation rates) play also a significant role in structuring the nodule microbiome.

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