Journal of MMIJ

Special Edition for Progresses in Development of Deep-sea Mineral Resources

Published: January 01, 2016 Updated: January 01, 2016

Displaying 1-13 of 13 articles

Volume 131 (2015) Issue 12 Pages 581-587 Published: January 01, 2016
Current Trend of the Resource Supply Risk
Kohmei HALADA

Current trend of the resource supply risk is discussed from the viewpoint of MONOTSUKURI (Craftsmanship). What they call depletion of a resource is the incensement of excessive burden of acquisition of resource, not the exhaustion of the resource. The constrains of resource supply has several different types; that of mal-distribution, that from energy constrain, that from environmental constrain, that of discrepancy of supply speed. We need take care the different emergence of each individual metals such as common metals and rare metals. General trend which compromises all of them is that the resources are imported into financial commodity. The resource is no more the origin of value by being utilized, but by being fluctuated. We, MONOTSUKURI Japan have to get set for preparing technologies against this fluctuating supply risk.
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Volume 131 (2015) Issue 12 Pages 588-591 Published: January 01, 2016
Increasing Concerns On-Land Mining Faces
Masatsugu TANIGUCHIa

We are the first human generation to face the limit of natural capital,“ resources and environment”. We recognize that our economy and future are at great risk due to the degradation of global environment and the depletion of natural resources on land. At a time when on-land mining faces ever increasing environmental concerns and policy makers are confronted with increasing more difficult land-use priorities, it behooves us to develop prominently rich sub-sea resources in the EEZ of Japan, the world 6^th large area, because of concern over homeland security in terms of selfsufficiency in critical and strategic minerals demand.
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Volume 131 (2015) Issue 12 Pages 592-596 Published: January 01, 2016
Past, Present, and Future of Deep-Sea Mining
Tetsuo YAMAZAKI

Deep-sea mineral resources, such as manganese nodules, seafloor massive sulfides, cobalt-rich manganese crusts, and rare-earth element-rich deep-sea mud have been interested in as potential resources for metals near future because of their higher metal contents and no overburden removals. The R&D histories and current activities are introduced. In case of manganese nodules, three pilot mining tests at actual sites were taken place in the end of 1970s and the early 1980s. The time some pioneer environmental works were conducted simultaneously. These results still have important meanings in deep-sea mining. In the first decade of 21st century, seafloor massive sulfide mining has been focused as an immediate target for commercial mining. Currently all the deep-sea mining is considered to have higher possibilities for commercial mining because of the increasing world metal demands. Not only many states but also many venture companies are coming into the R&D arena. For the realization of deepsea mining, the durability of ore lift pipe has been the most critical technical and economic issue. On the basis of current technological progresses, the breakthrough is necessary. Japan's leadership is required for the sustainable mining good for the metal market and the environment.
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Volume 131 (2015) Issue 12 Pages 597-601 Published: January 01, 2016
Deep-Sea Mineral Potential in the South Pacific Region
Nobuyuki OKAMOTO

The Government of Japan and South Pacific Applied Geoscience Commission (SOPAC) have been conducting joint surveys of deep-sea mineral resources in the Exclusive Economy Zones (EEZs) of SOPAC member countries, since 1985. The various research and government institutions that have been closely involved in this long-standing program include: the Japan International Co-operation Agency (JICA) and Japan Oil, Gas and Metals National Corporation (JOGMEC) which is the former Metal Mining Agency of Japan (MMAJ) and relevant ministries of the participating Pacific Island government. The survey program is on-going using research vessel Hakurei-Maru No.2 which belongs to JOGMEC. This twenty year long, joint project initiative has been extremely successful in confirming the resource potential of the Pacific region through discovering valuable deep-sea mineral resources such as polymetallic nodules in the Cook Islands waters, cobalt-rich ferromanganese crusts in the Marshall Islands, Kiribati and Federated States of Micronesia, and polymetallic sulphides in the Fiji waters.
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Volume 131 (2015) Issue 12 Pages 602-609 Published: January 01, 2016
Current Situation of Manganese Nodule Exploration in Japanese License Area
Akira TSUNE, Masatsugu OKAZAKI

Exploration survey cruise of manganese nodule in the Clarion-Clipperton Zone (CCZ) has been conducted by DOMA (Deep Ocean Minerals Association) and DORD (Deep Ocean Resources Development Co., Ltd.) from 1975 to 1996 and 2011 to present. The manganese nodule survey of Japan in the CCZ during these periods is reviewed in this paper. From 1975 to 1987, the surveys were conducted in a wide area of the CCZ (3 million km²) in order to find and extract high potential areas of manganese nodules. After the registration of the Japanese license area (75,000km², consisting of West Area and East Area) in 1987, the aims of the surveys were shifted toward building up exploration techniques during 1987 to 1996, rather than extraction of high potential area. From 2011, exploration works were carried out in a selected area of the High Abundance Area (HAA), located in northwest of the West Area, for the purpose of increasing accuracy of manganese nodule resources by additional sampling, seafloor observation with taking photographs and acoustic sounding survey. Most of the area of the HAA, which is selected as a possible first target for commercial mining of Japan in future, is covered by the area of high nodule abundance of more than 10 kg/m². For the survey of 2012 in the HAA, AUV (Autonomous Underwater Vehicle) equipped with MBES, SBP, SSS and deep seas camera was used. Exploration equipment of modern technology such as AUV plays indispensable role in deep sea survey, and it is highly important to keep up with updated technologies for increasing quality of the surveys. Furthermore, the selection of model area(s) and the determination of the priority of survey contents are necessary for the preparation of the future survey plan.
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Volume 131 (2015) Issue 12 Pages 610-613 Published: January 01, 2016
The Overview of Project for Developing Seafloor Massive Sulfides in the EEZ of Japan
Satoshi UEDA, Nobuyuki OKAMOTO

For the future development of seafloor massive sulfides (SMS) in the EEZ of Japan, efforts to exploration and technological development have been enhanced. Ministry of Economy, Trade and Industry (METI) formulated "Plan for the development of ocean energy and mineral resources" in 2009, and it was amended in December 2013. In this plan, four technological fields of SMS have been carried out in parallel, respectively, Resource evaluation, Environmental impact assessment, Mining system techniques and Processing techniques. Toward the development and commercialization of SMS, We need many technical and social challenges. In order to achieve these challenges, we have to have a strategic vision. We must challenge to develop SMS through collaboration between industry, educational institutions and the administration of Japan. In this paper, current circumstances and issues of the development of SMS are presented.
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Volume 131 (2015) Issue 12 Pages 614-618 Published: January 01, 2016
Study on Mining System for Seafloor Massive Sulfide Mound and Results of On-Site Excavation Tests in Okinawa Trough
Seiya KAWANO, Takahiro KAWAI, Nobuyuki MASUDA, Jiro YAMATOMI, Nobuyuki OKAMOTO

Japan Oil, Gas and Metals National Corporation (JOGMEC) has started an exploration program for Seafloor Massive Sulfides (SMS) in the EEZ of Japan, and launched investigations on mining and processing technologies for SMS and studies for environmental impacts caused by SMS developments. With regard to the mining technologies, the studied mining system for SMS consists of three units: which are mining tools working on seafloor, riser and lifting systems, and production support vessels with unloading facilities onto shuttle ships. Physico-mechanical characteristics of the seafloor sulfides, which are key parameters for designing mining systems, have not fully clarified yet to apply for design purposes. Because exploration campaigns and geological characterizations are still undergoing. However, two types of mining tools for testing on seafloor were developed as the mining unit. Excavation tests on the actual SMS site with the depth of 1,600m in the Okinawa Trough, south-west of Japan, were conducted in 2012. Functions of the mining tools, such as cutting abilities for seafloor sulfides, moving and maneuvering performances, and climbing capabilities on slopes steeper than 25 degrees were examined in the tests. This paper describes the outline of the proposed mining system and mining tools for SMS, as well as the results of on-site subsea mining tests in the Okinawa Trough.
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Volume 131 (2015) Issue 12 Pages 619-626 Published: January 01, 2016
Characteristics of The Existing Mineral Phases of Japanese Submarine Hydrothermal Polymetallic Sulfides and Their Influence on Respective Mineral Processing Properties
Tatsuya OKI, Yoshihiro NISHISU, Mihoko HOSHINO

Submarine hydrothermal polymetallic sulfides are present in the sea near Izu- Ogasawara and Okinawa in Japan. These sulfide deposits are primarily composed of iron, barium, zinc, and lead, and include copper, silver, and gold. Though clearly identifiable as polymetallic sulfides, their mineral processing behavior is known to be totally different from that of the Kuroko deposits extracted from land mines in Japan. In this report, a selection of ore samples of submarine hydrothermal polymetallic sulfides from around Japan were analyzed, and the typical characteristics influencing mineral processing were investigated. The characteristics of the existing mineral phases, such as the mineral components, mineral domain size, and element distribution on ground sample, were especially focused on and investigated in the study, with respect to the grinding size required to achieve sufficient mineral liberation to conduct effective mineral processing. The results suggest that many types of sulfide deposits are present even in highly limited deposit regions, so that the respective samples are difficult to treat as one group with respect to mineral processing, because the mineral components, domain size, and trace elements co-existing within the minerals differ among the samples.
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Volume 131 (2015) Issue 12 Pages 627-633 Published: January 01, 2016
Bioleaching of Deep-Sea Hydrothermal Ore Deposits by the Acidophilic and Thermophilic Archaeon Acidianus Brierleyi
Norizo SAITO, Ryoichi HARUKI, Toshiyuki NOMURA, Yasuhiro KONISHI

This article describes the bioleaching of deep-sea hydrothermal ore deposits by the acidophilic and thermophilic archaeon Acidianus brierleyi at 65℃. Bioleaching experiments with A. brierleyi were used to examine the dependence of leaching rates on three process parameters such as solution pH (pH 1.2–2.0), initial cell concentration (1×10¹³–1×10¹⁴ cells/m³), and initial ore-liquid loading ratio (5–40 kg/m³). The leaching of copper and zinc was markedly accelerated in the presence of A. brierleyi, and greater than 80 % extraction of copper and zinc in the ore sample (38–53 μm) was achieved at 65℃ within 10 days of batch operation. Nearly identical bioleaching rates of zinc and copper were obtained for the deep-sea hydrothermal sulfide (ore sample A) and terrestrial sulfide concentrates (sphalerite and chalcopyrite) by the thermophilic archaeon A. brierleyi. However, the bioleaching of lead was practically negligible because of precipitation of insoluble anglesite. The bioleaching of gallium tended to be suppressed as the initial ore-liquid loading ratio was increased from 5 to 40 kg/m³. The bioleaching of the ore sample (45.4 % SiO₂) yielded less than 5 % extraction of gallium in 10 days of batch operation at an initial ore-liquid loading ratio of 40 kg/m³, and gallium in the bioleaching residue was concentrated 1.8-fold of its initial content. Moreover, the concentration of gold in the bioleaching residue was increased by a factor of 1.9 after 10 days of batch operation. It can be concluded that bioleaching is an attractive processing route to recover valuable metals from deep-sea hydrothermal ore deposits.
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Volume 131 (2015) Issue 12 Pages 634-638 Published: January 01, 2016
The Environmental Impact Assessment for Mining Seafloor Massive Sulphides in Japan
Teruyoshi NARITA, Junya OSHIKA, Tetsuhiko TOYOHARA, Nobuyuki OKAMOTO, Yoshihisa SHIRAYAMA

Japan Oil, Gas and Metals National Corporation (JOGMEC) conducted the Environmental Impact Study research from 2008 fiscal year under contract to the Ministry of Economy, Trade and Industry (METI) for the commercialization of Seafloor Massive Sulphide (SMS). It is necessary to consider the potential impacts of mining on the surrounding environment and to promote the project for long-term perspective. Particularly, because the specific chemosynthetic ecosystem and the unique biological communities exist around the hydrothermal area, the quantitatively evaluations of the environmental impacts and the conservation measures of biodiversity to avoid or reduce the effects on them as much as possible is required. The environmental assessment programs consist of baseline survey, environmental impact modeling, and the methodological concepts that will be applied to conserve biodiversity. In this paper, we will introduce the review of the project during 2008-2012 and the future prospects of EIA project for SMS mining.
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Volume 131 (2015) Issue 12 Pages 639-642 Published: January 01, 2016
Recent Developments in Mineral Processing of Cobalt-Rich Ferromanganese Crust/Nodules
Mayumi ITO, Naoki HIROYOSHI

Cobalt-rich ferromanganese crust/nodules, manganese nodules are underwater minerals and they are unused resources where the commercial potential will depend on trends in mining and treatment costs of onshore mines. Manganese nodules were discovered in 1870 and the ore contains Mn, Ni, Cu, and Co as valuable metals and hydrometallurgical and pyrometallurgical treatment has been investigated. Cobalt-rich ferromanganese crust/nodules were discovered in 1980 and they have attracted attention since the cobalt content exceeded 1 percent. During the mining operation, unfavorable waste rock may be dredged with the ferromanganese oxide components and the ores require mineral processing to remove the substrate/nuclei rock before the metallurgical treatment. This paper reviews the mineral processing methods and further metallurgical treatments of cobalt-rich ferromanganese crust/nodules.
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Volume 131 (2015) Issue 12 Pages 643-647 Published: January 01, 2016
The Present Conditions and Problem for Recovering Metals from Cobalt Rich Manganese Crust
Hiroshi SHIBASAKI, Mikio KOBAYASHI, Yasuhiro KONISHI, Tomoyuki YOSHIDA, Satoshi SHIOKAWA

The cobalt rich manganese crusts are distributed on the flat top or the slope of seamounts in the economic zone and the open sea around Minami Torishima Island. Cobalt rich manganese crust and manganese nodule are iron manganese oxide mainly composed of oxide of Mn and Fe. However, their distribution condition and composition are different. Manganese nodule contains some 2.0% of copper and nickel together. On the other hand, the cobalt rich manganese crust includes less copper and nickel than manganese nodule does, but contains a higher level of cobalt and platinum. Metal Mining Agency of Japan (MMAJ), which is current Japan Oil, Gas and Metals National Corporation (JOGMEC), has selected“ Smelting and Chlorine Leaching” as the most suitable technique from the viewpoint of nickel, cobalt and copper's recovery from the manganese nodule. (Kojima, in 1996) For the treatment of cobalt rich crust, JOGMEC has established an improved metal recovery technology, which is called the“ Improved Smelting and Chlorine Leaching”, after the investigation from 2003 through 2008. . In the“ Improved Smelting and Chlorine Leaching”, JOGMEC has introduced“ slag cleaning” process for cobalt and another process for platinum in order to enhance the recovery level. Also JOGMEC found technique to recover metal using bioleaching effectively.
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Volume 131 (2015) Issue 12 Pages 648-655 Published: January 01, 2016
Exploration and Development of “REY-Rich Mud”: A New Deep-Sea Mineral Resource
Koichiro FUJINAGA, Kazutaka YASUKAWAb, Yutaro TAKAYA, Junichiro OHTA, Kentaro NAKAMURA, Yasuhiro KATO

Deep-sea mineral resources have attracted considerable attention in the last few decades as a new source of base metals and rare metals. Recently, we discovered that mud with high rare-earth elements and yttrium (REY) concentrations (termed“ REY-rich mud”) is widely distributed on the deep-sea floor of the Pacific Ocean. REYrich mud has the following great advantages as a mineral resource: (1) high concentrations of REY, (2) remarkable abundance, (3) high exploration efficiency due to homogeneous stratiform distribution, (4) very low concentrations of radioactive elements (e.g., Th and U), and (5) ease of REY extraction and recovery. During the R/V Kairei cruise KR13-02, we discovered extremely high-grade REY-rich mud (the maximum REY content exceeds 6,500 ppm) in the Japanese Exclusive Economic Zone (EEZ) around Minamitorishima. We also found that the distribution of the REY-rich mud can be explored by a shipboard sub-bottom profiler. The REYrich mud within the Japanese EEZ has enormous significance in terms of securing the strategic mineral resource, because REY are critical in the advancement and development of high-tech manufacturing and green technology. Currently, we are continuing to explore the distribution of REY-rich mud in the Minamitorishima EEZ. In addition, together with private-sector corporations, we are also starting to address the challenges for developing the new deep-sea mineral resource, including various technical issues (e.g., how to lift the mud from the seabed deeper than 5000 m of water depth), environmental impact assessments, and economic evaluations. The collaborative efforts of industry, academia, and the government are the key to success of deep-sea mining of REY-rich mud.
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