• Ocean and Polar Research
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• v.26 no.2
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• pp.187-197
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• 2004

The purpose of this paper is to investigate economic feasibility of manganese nodules in Korea area (Clarion-Clipperton Fracture Zone). We assumed that the production scale of manganese nodules were 3.0MT or 1.5MT and analyzed that the capital cost and operating cost were estimated in the four sectors, exploration, mining, transportation and metallurgical process. The capital cost and operating cost evaluation reflects the latest technical practices. First, for analyzing economic feasibility, the scenario suggests that the production of 4 metals can be made for 25 years. Assuming the discount rate at 8.0%, equity capital at 50% and tax at 27%. When manganese nodule were mininged 3.0 MT, economic feasibility analyses showed that IRR was 12.8 and pay-back period was 9.2 years, and when manganese nodules were mininged 1.5 MT, economic feasibility analyses showed that IRR was 4.0 and pay-back period was 11.8 years. This study indicated there is economic validity of at the product of manganese nodules 3.0 MT. In addition, we carried out a sensitivity analysis at the change of cobalt price on mining 1.5 MT. The result of sensitivity analysis clearly showed that economic validity is high at increasing of cobalt price 50% up.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.493-498
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• 1997

The purpose of this study is to develop geostatistical model for evaluating the abundance of deep-sea manganese nodule. The abundance data used in this study were obtained from the KODOS (Korea Deep Ocean Study) area. The variation of nodule abundance was very high within short distance, while sampling methods was very limited. As the distribution of nodule abundance showed non-gaussian, indicator simulation method was used instead of conditional simulation method and/or ordinary kriging. The abundance data were encoded into a series of indicators with 6 cutoff values. They were used to estimate the conditional probability distribution function (cpdf) of the nodule abundance at any unsampled location. The standardized indicator variogram models were obtained according to variogram analysis. This SIS method had the advantage over other traditional techniques such as the turning bands method and ordinary kriging. The estimating values by indicator conditional simulation near high abundance area were more detailed than by ordinary kriging and indicator kriging. They also showed better spatial characteristics of distribution of nodule abundance.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.280-285
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• 2008

Manganese nodule abundance estimated based on operation of a Free Fall Grab(FFG) needs to be corrected to make up for its incomplete recovery of nodule, because FFGs can not recover all the nodules distributed on seabed. The correction factor for nodule abundance was proposed as 1.29 and 1.13 in 1994 and 2002, respectively, mainly based on the analyses of seabed images. In this study we collected manganese nodules using both FFG and Box Corer(BC) at same stations to examine the accuracy of the previous correction factors. It was found that the nodule recovery of the BC was 1.4 times greater than that of the FFG at the same sampling station, suggesting the necessity of re-evaluation of the previously proposed correction factor for FFG. More extensive sampling and improvement of image analysis method are required to improve the precision of nodule abundance correction factor for FFG.

• Ocean and Polar Research
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• v.32 no.4
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• pp.463-473
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• 2010

Inshore tests were performed in order to verify the design concept of deep sea manganese nodule miner at a site near Hupo at East Sea of Korea in June of 2009. Total mining tests of the test miner, named 'Minero$^{(R)}$', together with flexible hose, lifting pump and lifting hose were accomplished. In this study, the performances of three subsystems of testminer (vehicle, pick-up device, and launch-and-recovery device) were analyzed for feasibility assessment of self-propelled remotely controlled miner, and also to compile basic data for designing a pilotminer. Performances of the test miner were defined based on the Functional Requirements of Axiomatic Design. The inshore tests revealed that the test miner generally satisfies the functional performances. Feasibility assessment and reflection on results are discussed within.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.160-163
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• 2001

In order to develop a nodule conveying system through a flexible pipe out of the deep-seabed manganese nodule miner, an experimental study of the solid-water slurry flow in vertical pipe is performed as the first stage of total experiments. Hydraulic characteristics of the pipe slurry flow such as slip velocity, transport concentration and pressure gradient are investigated for the size of particle, load ratio, and flow rate of water. The higher the load ratio is, the larger the transport concentration and pressure gradient become. The bigger the size of particles is, the larger the pressure gradient becomes. The effectiveness of the flow rate to hydraulic performance is also investigated. This results are to be used for designing crusher and pump, and operating the conveying device.

• Ocean Science Journal
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• v.41 no.3
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• pp.149-161
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• 2006

The aims of this study are 1) to construct a database using geostatistics and Geographic Information System (GIS), and 2) to derive the spatial relationships between manganese nodule abundance and other geological factors such as metal grade, slope, water depth, topography, and acoustic characteristics of the sub-bottom. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses. The greater the copper and nickel grade, the higher the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than $3^{\circ}$ except for seamounts and cliff areas. The rating shows no correlation with slope. The rating is highest for slopes between 2.5 and $3.5^{\circ}$ in block N1 and between 4.0 and $4.5^{\circ}$ in block N3. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The rating proves lowest for seamount and hill crest. Our results show that the rating increases with the water depth in the study area. Nodule abundance dose not show any significant relationship with the thickness of the upper transparent layer in the study area.

• Ocean and Polar Research
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• v.36 no.4
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• pp.373-381
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• 2014

Korea contract Mn-nodule field in the NE equatorial Pacific is composed of seven sectors with average water depths of 4,513-5,025 m. Of the various factors controlling the properties of Mn-nodule, it seems that water depth is likely connected to the chemical composition and occurrence of nodules. To test whether such an assumption held in each sector, we reviewed previous research data accumulated since 1994 for one of the northern sectors (hereafter KR1) where there are stark contrasts in water depth. High-resolution seabed mapping clearly separates a northern part (KR1N) from a deeper southern part (KR1S), cutting across in the middle of the KR1. In addition, significant volcanic activities forming numerous seamounts are distinctive especially in KR1N. In terms of nodule occurrence, manganese nodules in KR1S are comparatively larger (2-4 cm) with a discoidal shape, while those in KR1N are generally small (<2 cm) with poly-lobate and irregular shapes. Nodules in KR1N also have lower Co, Cu, Mn and Ni, and higher Fe contents. The spatial separation in nodule characteristics might be caused by volcanic activities in KR1N rather than water depth contrast. During the formation of the seamounts in KR1N, rock fragments and volcanic ashes as new nuclei of the nodules would have been continuously generated. As a result, the nodules could not grow larger than 2 cm and display the shapes of a newbie (i.e., irregular and poly-lobate shapes). Moreover, significant Fe supply from volcanic activities probably decreases the Mn/Fe ratio, which may lead to the KR1 nodules being misinterpreted as a hydrogenic in origin compared to other sectors where a high Mn/Fe ratio is present.

• 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.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.10a
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• pp.26-31
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• 2001

In order to measure the distance from the bottom in the ocean we use ultrasound altitude sonars. The manganese nodule pick-up device developed by KRISO is also using an altitude sonar to control the gap between the pick-up head and sea bottom. This paper describes the performance of the altitude sonar by an experimental method. The experiment was performed with four ground models in a small basin, Manganese nodule models and water-bentonite mixture was used for setting up the ground models. Buttorworth filter was applied to remove the noise caused by a servo motor and its controller. The results show that the altitude sonar gives a good estimation of the types and slopes of the bottom as well as the distance.

• Journal of Industrial Technology
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• v.19
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• pp.189-195
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• 1999

A study on the separation Cu, Ni, and Co was carried out using LIX 84 leachate, chelate extractant. For this test, artificial test solution was prepared by varing concentrations of Cu, Ni, Co, $(NH_4)_2CO_3$ and $(NH_4)_2SO_4$. It found that pH of the solution was very important factor for the separation of nickel from copper. The results showed that nickel was effectively extracted from copper by using LIX 84 at pH 1.0 to 1.2. The volume ration or organic to aqueous phases was 1.0. According to the McCabe-Thiele diagram, the extraction rate of copper was 99 percents at the equal ratio of organic to aqueous phase in three stages.