Development and Subsea Testing of Polymetallic Nodule Crusher for Underwater Mining Machine

Abstract Polymetallic nodules found in the deep oceans are viewed as potential resources for meeting the world's demand of many metals in the near future. Polymetallic nodule mining systems require subsea crushing systems for reducing the size of nodules to facilitate energy-efficient and safe pumping through risers of optimum size. Polymetallic nodules are friable, and deep-sea crushing has to be done with care to minimize the formation of fines, while obtaining the required size reduction. The crusher could also encounter objects with greater hardness during operation like small rocks, splinters, long fish bones, and shark teeth. All components in the crusher should be capable of operating in the deep ocean environment, which is hyperbaric and sediment laden. The equipment should be compact with minimum weight. Reversal of direction and dumping arrangements in the event of stalling are other essential design requirements. An underwater crusher capable of crushing mined nodules from a maximum size of 100 mm to a crushed size of 30 mm was developed using principles of design synthesis. The crusher was tested in land and integrated into a remotely operated crawler-based underwater mining machine that could mine and pump nodules through a flexible riser. The system was tested using artificial nodules at 512-m water depth off the Malvan coast in the Arabian Sea. This paper describes developmental methodology, land-based performance tests, and sea trials conducted on the developed crusher.

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Two new species of Sympagella (Porifera: Hexactinellida: Rossellidae) collected from the Clarion-Clipperton Zone, East Pacific

Zootaxa ◽

10.11646/zootaxa.4466.1.12 ◽

2018 ◽

Vol 4466 (1) ◽

pp. 152 ◽

Cited By ~ 1

Author(s):

SASCHA HERZOG ◽

DIVA J. AMON ◽

CRAIG R. SMITH ◽

DORTE JANUSSEN

Keyword(s):

New Species ◽

Pacific Ocean ◽

Polymetallic Nodule ◽

East Pacific ◽

Polymetallic Nodules ◽

Two New Species ◽

Nodule Mining ◽

Taxonomic Studies ◽

East Pacific Ocean

Two new Hexactinellida species from the Clarion-Clipperton Zone (CCZ) in the East Pacific Ocean are described. They are the first described representatives of the genus Sympagella in this region. The new sponges were collected in 2013 during the ABYSSLINE Project´s first cruise, AB01, on board the RV Melville. The CCZ is known for its polymetallic nodules but megafaunal biodiversity is still poorly understood. Our findings suggest that the poriferan fauna of the eastern CCZ is both species rich and inadequately known, and that substantially more sampling and taxonomic studies of the CCZ sponge fauna are required to establish a megafaunal biogeography and evaluate potential extinction risks resulting from polymetallic-nodule mining.

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From sea surface to seafloor: a benthic allochthonous eDNA survey for the abyssal ocean

10.1101/2020.05.07.082602 ◽

2020 ◽

Cited By ~ 1

Author(s):

Olivier Laroche ◽

Oliver Kersten ◽

Craig R. Smith ◽

Erica Goetze

Keyword(s):

Water Column ◽

Deep Sea ◽

Anthropogenic Impacts ◽

Spatial Scales ◽

Deep Ocean ◽

Environmental Dna ◽

Benthic Boundary Layer ◽

Large Sample Size ◽

Polymetallic Nodule ◽

Nodule Mining

AbstractDiverse and remote deep-sea communities are critically under-sampled and increasingly threatened by anthropogenic impacts. Environmental DNA (eDNA) metabarcoding could facilitate rapid and comprehensive biotic surveys in the deep ocean, yet many aspects of the sources and distribution of eDNA in the deep sea are still poorly understood. In order to examine the influence of the water column on benthic eDNA surveys in regions targeted for deep-sea polymetallic nodule mining, we investigated the occurrence of pelagic eDNA across: (1) two different deep-sea habitat types, abyssal plains and seamounts, (2) benthic sample types, including nodules, sediment, and seawater within the benthic boundary layer (BBL), and (3) sediment depth horizons (0-2 cm, 3-5 cm). Little difference was observed between seamounts and the adjacent abyssal plains in the proportion of legacy pelagic eDNA sampled in the benthos, despite an > 1000 m depth difference for these habitats. In terms of both reads and amplicon sequence variants (ASVs), pelagic eDNA was minimal within sediment and nodule samples (< 2%), and is unlikely to affect benthic surveys that monitor resident organisms at the deep seafloor. However, pelagic eDNA was substantial within the BBL (up to 13 % ASVs, 86% reads), deriving both from the high biomass upper ocean as well as deep pelagic residents. While most pelagic eDNA found in sediments and on nodules could be sourced from the epipelagic for metazoans, protist legacy eDNA sampled on these substrates appeared to originate across a range of depths in the water column. Some evidence of eDNA degradation across a vertical sediment profile was observed for protists, with higher diversity in the 0-2 cm layer and a significantly lower proportion of legacy pelagic eDNA in deeper sediments (3-5 cm). Study-wide, our estimated metazoan sampling coverage ranged from 40% to 74%, despite relatively large sample size. Future deep-sea eDNA surveys should examine oceanographic influences on eDNA transport and residence times, consider habitat heterogeneity at a range of spatial scales in the abyss, and aim to process large amounts of material per sample (with replication) in order to increase the sampling coverage in these diverse deep ocean communities.

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The Development History and Latest Progress of Deep-Sea Polymetallic Nodule Mining Technology

Minerals ◽

10.3390/min11101132 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1132

Author(s):

Yajuan Kang ◽

Shaojun Liu

Keyword(s):

Deep Sea ◽

High Efficiency ◽

High Reliability ◽

Commercial Development ◽

Mining System ◽

Mining Technology ◽

Polymetallic Nodule ◽

Systems Research ◽

Polymetallic Nodules ◽

Nodule Mining

Deep-sea polymetallic nodules are a mineral resource with potential for commercial development. Due to the unique deep-sea environment in which they are found, specialized technology and equipment are required for their extraction. In this paper, firstly, the development of deep-sea polymetallic nodule mining technology is classified into three stages, and its characteristics are summarized. Moreover, the results from research into deep-sea polymetallic nodule mining technology are analyzed, including proposals for mining systems, research into key technologies, basic scientific problems, and proof of technical feasibility from sea tests. Secondly, the testing of the collector prototype and the environmental impact assessment study of Global Sea Mineral Resources NV, as well as the progress of the deep-sea polymetallic nodule mining test project in China, are introduced. On this basis, the opportunities and challenges brought by the fast-growing demand for electric vehicles to the development of deep-sea polymetallic mining technology is analyzed, and a possible technical scheme for a mining system and the trends in its development towards high reliability and high standards of environmental protection according to the requirements of commercial exploitation are explored. This provides a reference for the research and development of high-efficiency technology and equipment for the mining of deep-sea polymetallic nodules.

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Estimation of Reliability of Underwater Polymetallic Nodule Mining Machine

Marine Technology Society Journal ◽

10.4031/mtsj.49.1.4 ◽

2015 ◽

Vol 49 (1) ◽

pp. 131-147 ◽

Cited By ~ 5

Author(s):

Nidhi Varshney ◽

Siva Rajesh ◽

Anantha Padmanabhan Aarthi ◽

Narayanmurthy Renganayahi Ramesh ◽

Narayanswamy Vedachalam ◽

...

Keyword(s):

Water Depth ◽

Ocean Basin ◽

Mining Machine ◽

Hydraulic Systems ◽

Term Operation ◽

Control Power ◽

Polymetallic Nodule ◽

Central Indian Ocean ◽

Key Factor ◽

Nodule Mining

AbstractThis paper presents the reliability analysis carried out on the subsystems of the underwater polymetallic nodule mining machine developed by National Institute of Ocean Technology, India, which is being enhanced for polymetallic nodule mining technology demonstration at 6,000-m water depth in the Central Indian Ocean Basin, where manganese nodules are available in abundance. The mining machine, which is a tracked vehicle, was successfully demonstrated at a water depth of 512 m, wherein the nodules are collected, crushed, and pumped to the mother vessel. Reliable long-term operation at 6,000 m is the key factor, as retrieval of the system to the top side for rectification is costly and time-consuming. It is identified that the reliability of the 6,000-m-rated mining machine subsystems could be improved by the use of localized control power, redundant electronics, and hydraulic systems. It is estimated that, with the suggested improvements, the probability of failure of the systems involved in vehicle maneuvering, mineral crushing, and pumping could be reduced from 91%, 88.8%, and 84.59% to 68%, 57%, and 39%, respectively, when the systems are operated for a period of 1,460 h in a year. The results serve as a guideline for 6,000-m-depth-rated mining machine system design with a trade-off on size, weight, and required level of reliability.

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Characterization and Transcriptome Analysis of a Long-Chain n-Alkane-Degrading Strain Acinetobacter Pittii SW-1

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18126365 ◽

2021 ◽

Vol 18 (12) ◽

pp. 6365

Author(s):

Weina Kong ◽

Cheng Zhao ◽

Xingwang Gao ◽

Liping Wang ◽

Qianqian Tian ◽

...

Keyword(s):

Unsaturated Fatty Acids ◽

Sulfur Metabolism ◽

Quantitative Polymerase Chain Reaction ◽

Deep Ocean ◽

Rrna Gene ◽

Alkane Hydroxylase ◽

Degradation Rates ◽

Acinetobacter Pittii ◽

Ocean Environment ◽

Long Chain

Strain sw-1, isolated from 7619-m seawater of the Mariana Trench, was identified as Acinetobacter pittii by 16S rRNA gene and whole-genome sequencing. A. pittii sw-1 was able to efficiently utilize long-chain n-alkanes (C18–C36), but not short- and medium-chain n-alkanes (C8–C16). The degradation rate of C20 was 91.25%, followed by C18, C22, C24, C32, and C36 with the degradation rates of 89.30%, 84.03%, 80.29%, 30.29%, and 13.37%, respectively. To investigate the degradation mechanisms of n-alkanes for this strain, the genome and the transcriptome analyses were performed. Four key alkane hydroxylase genes (alkB, almA, ladA1, and ladA2) were identified in the genome. Transcriptomes of strain sw-1 grown in C20 or CH3COONa (NaAc) as the sole carbon source were compared. The transcriptional levels of alkB and almA, respectively, increased 78.28- and 3.51-fold in C20 compared with NaAc, while ladA1 and ladA2 did not show obvious change. The expression levels of other genes involved in the synthesis of unsaturated fatty acids, permeases, membrane proteins, and sulfur metabolism were also upregulated, and they might be involved in n-alkane uptake. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) confirmed that alkB expression was significantly induced by C20, C24, and C32, and almA induction extent by C24 and C32 was higher than that with C20. Furthermore, ladA2 expression was only induced by C32, and ladA1 expression was not induced by any of n-alkanes. In addition, A. pittii sw-1 could grow with 0%–3% NaCl or 8 out of 10 kinds of the tested heavy metals and degrade n-alkanes at 15 °C. Taken together, these results provide comprehensive insights into the degradation of long-chain n-alkanes by Acinetobacter isolated from the deep ocean environment.

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