• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.222-228
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• 2008

We conducted a dynamic analysis of an underwater test collector, which operates on extremely soft soil of deep-seafloor. The underwater test collector consists of nodule pick-up device, vehicle tracks, nodule crusher, loading frame and electric-electronic system. The weight of underwater test collector is about 8600 kg. The average normal pressure, that the underwater test collector supports, is about 6.0 kPa. The dynamic analysis model of underwater test collector is developed using commercial software RecurDyn-LM and Visual Fortran 90. A terramechanics model of extremely soft soil is implemented to the software based on user-written subroutine and applied to the dynamic analysis of the underwater test collector model. The dynamic responses of test collector are studied with respect to track velocities, terrain conditions, and coefficients of added mass and drag.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.411-415
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• 2009

Some microorganisms are capable of leaching Mn(II) from nonsulfidic manganese ores indirectly via nonenzymatic processes. Such reductive dissolution requires organic substrates, such as glucose, sucrose, or galactose, as a source of carbon and energy for microbial growth. This study investigated characteristics of Mn(II) leaching from manganese nodules by using heterotrophic Bacillus sp. strain MR2 provided with corn starch as a less-expensive substrate. Leaching of Mn(II) at 25.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$ was accompanied with cell growth, but part of the produced Mn(II) re-adsorbed onto residual $MnO_2$ particles after 24 h. Direct contact of cells to manganese nodule was not necessary as a separation between them with a dialysis tube produced similar amount [24.6 g Mn(II) $kg^{-1}$ nodule $day^{-1}$]. These results indicated an involvement of extracellular diffusible compound(s) during Mn(II) leaching by strain MR2. In order to optimize a leaching process we tested factors that influence the reaction, and the most efficient conditions were $25\sim35^{\circ}C$, pH 5~7, inoculum density of 1.5~2.5% (v/v), pulp density of 2~3 g/L, and particle size <75 ${\mu}m$. Although Mn(II) leaching was enhanced as particle size decrease, we suggest <212 ${\mu}m$ as a proper size range since more grinding means more energy consumption The results would help for the improvement of bioleaching of manganese nodule as a less expensive, energy-efficient, and environment-friendly technology as compared to the existing physicochemical metal recovery technologies.

• Economic and Environmental Geology
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• v.28 no.2
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• pp.155-164
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• 1995

The kriging model, one of the geostatistical models, has been used to evaluate the deep-sea manganese nodule deposits until now. The distribution of the manganese nodule deposits estimated by the model shows the smooth surface as well as much difference from the actual distribution. Subsequently, it estimates the deposit distribution roughly in terms of the limited data of surveyed zone. Therefore, this paper presents the interpretation methodology of the deep-sea manganese nodule deposit distribution by using the fractal model to overcome the problems caused by the geostatistical model. Also, the manganese nodule distributions are interpreted by using the manganese nodule data sampled in the GH82-4 zone, west longitude $165^{\circ}40^{\prime}-169^{\circ}00^{\prime}$, and south latitude $0^{\circ}00^{\prime}-2^{\circ}40^{\prime}$ neighboring Nova-Canton Trough in the Pacific Ocean which was surveyed by the Geological Survey of Japan in 1982.

• Ocean and Polar Research
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• v.36 no.4
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• pp.505-514
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• 2014

The development of deep seabed manganese nodules has been carried out with the aim of commercial development in 2023. It is important to forecast the price of the four metals (copper, nickel, cobalt, and manganese) extracted from manganese nodules because price change is a criterion for investment decision. The main purpose of the study is to forecast the price of four metals using the ARIMA model and VAR model, and calculate the MAPE to compare a goodness-of-fit between the two models. The estimated results of the two models reveal statistical significance and are in keeping with economic theory. The results of MAPE for goodness-of-fit show that the VAR model is between 0.1 and 0.2, and the ARIMA model is between 0.4 and 0.6. That is, the VAR model is better than the ARIMA model in forecasting changes in the price of metals.

• Ocean and Polar Research
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• v.25 no.3
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• pp.257-267
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• 2003

Deep-sea bottom photographs acquired in the Clarion-Clipperton fracture zone of the northeast equatorial Pacific were analyzed to reveal the controlling processes for the spatial variation of manganese nodule. The results show that regional-scale occurrence variations of manganese nodule are mainly controlled by primary productivity of surface water, sedimentation rate, and water depth (or carbonate compensation depth). As a result, the diagenetic accretion on nodules increases toward southwest while hydrogenetic accretion increases toward northeast. Considering the northwestward movement of Pacific Plate, this regional-scale variation of manganese nodule occurrence seems to be affected by oceanic environment during the active growth period (Oligocene-Miocene) of Pacific Plate.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.45-50
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• 2002

This study presents a modeling method to predict fate of resuspended sediment in the development of deep-sea mineral resources. Resuspended deep-sea sediment during the development is considered a major environmental problem. In order to quantitatively analyze the resuspended sediment in the water column, particle size distribution (PSD) is considered an important factor. The model developed here includes PSD and coagulation process, as well as sedimentation process. Using the model, basic simulation was performed under representative environmental setting. The simulation showed the dynamics of change of particle size distribution for 50 m depth of water column up to 10 days of simulation time. Coagulation seemed an important factor in the fate of resuspended deep-sea sediment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.323-337
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• 1999

Seafloor morphology and manganese nodule occurrence were studied in the Korea Deep-sea Environmental Study (KODES) area, northeast equatorial Pacific, to understand their relationship. Study area is composed of three elongated valleys and hills with about 100~200 m height along NNE-SSW direction. Valley region is generally flat. However, hill region is very rugged with big cliffs of about 100m height and small depressions of several tens of meters depth. Tectonic movement along the Clarion-Clipperton fracture zone, consequent formation of elongated abyssal hills and Valleys, erosion of siliceous bottom sediments by bottom currents, and dissolution of carbonate sediments on the abyssal hills below CCD result in the rugged morphology. Manganese nodule occurrence is closely related to the morphology of the study area; mostly rounded-shaped manganese nodules with about 5 cm diameter are abundant on the flat valley region, whereas irregular shaped nodules (or manganese crust) with less than 5 cm to about 1 m diameter occur on the hill. These results supports the previous reports that nodule abundance, composition, and morphology are variable both on regional and local small scales on the seafloor even within some abundant nodule provinces depending on oceanographic characteristics such as bathymetric features, surface sediment type, sediment thickness, and so on. We suggest that such oceanographic characteristics affect interrelatedly on the formation of manganese nodules, and tectonic movement of the Pacific plate ultimately constrain the nodule occurrence. A potential mining place in the KODES area seems to be the valley region, which is elongated to the NNW-SSE direction with 3-4 km width.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.455-466
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• 2010

Seabed mineral resources explored by Korea are categorized into major three types of deposit; manganese nodule, manganese crust and polymetallic sulfides. Pt displays high enrichment factors (400, ore/crust ratios) in manganese nodule. Rare earth oxide content in manganese nodule ranges from 0.037 to 0.302 REO % with mean value of 0.12 REO %. Both of Te and Pt are enriched elements in manganese crust, displaying enrichment factors of 10800 and 150, respectively. Rare earth oxide's contents of manganese crust are slightly higher than manganese nodule's (0.013~0.387 REO %, average = 0.18 REO %). Se and In are outstanding rare metals from seabed polymetallic sulfides, showing enrichment factors of 1300 and 110, respectively. Au (0.8~26.3 g/t) and Ag (0.9~348.0 g/t) are another enriched elements in polymetallic sulfides. The main concern at exploiting seabed mineral resource will be a securing rare metals for high-technology industries and rare metals from subsea mineral deposits will add economic values to commodity candidates such like Co, Ni and Cu.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.229-236
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• 2008

The deep-sea miner is the tracked vehicle system which drives on the deep-seabed and gathers a manganese nodules. The miner is operated by remote control in real-time by the station of surface vessel. So operating S/W is a important part of miner remote operating. At present, the test miner has been designed and manufactured for near-shore sea-test. The test miner consists of mechanical parts, and electric-electronic parts. Because those parts should be controled and monitored remotely, operating S/W for control and monitoring is necessary by all means. In this paper, real-time operating S/W for a control and monitoring of the test miner was designed and developed using PXI, embedded controller and LabVIEW. This real-time operating S/W was developed for an efficient test of test miner in a near seabed area. Moreover, database management system(DBMS) was developed too for the data management of test miner monitoring using MS SQL and LabVIEW.

• Economic and Environmental Geology
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• v.24 no.4
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• pp.335-346
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• 1991

It is observed that calcareous nodules of the Hwajeol Formation are locally skarnized in the Sangdong district, in which the skarn mineralization extends 5 Km westward from the Sangdong mine area to the Hwajeolchi area. After a hidden granite beneath the Sangdong mine was discovered by exploration drillings, the exploration teams of the Sangdong mine and the Korean Mining Promotion Corporation have assumed that the skarn nodule of the Hwajeol Formation was derived from emplacement of a granite in deep place and the occurrence of hidden ore bodies below the skarn, and they have discovered high grades of tungsten orebody in the same horizon of the Sangdong ore body. Mutual genetic relatioships between epidote and garnet may be explained by following chemical reactions $Ca_2FeA_{12}$ $Si_3O_{12}(OH)+CaCO_3=Ca_3(Fe,\;Al)_2$ $SiO_{12}+1/2CO_2+1/2H^+Ca_3FeSi_3O_{12}+SiO_2+CO_2=2CaFeSi_{12}O_6+CaCO_3+1/2O_3$. It is concluded that epidote and garnet are useful as target minerals indicating a potential occurrence of deep seated hidden ore body. Since the epidote may inform the emplacement of the granite, while the garnet in the skarn nodule of the Hwajeol Formation may reflect a strong hydrothermal mineralization taking place from the depth.