Waste Rejection on Seafloor by Hydrocyclone for Economic Seafloor Massive Sulfide Mining

2016 ◽  
Author(s):  
Yosuke Takeda ◽  
Tetsuo Yamazaki ◽  
Rei Arai ◽  
Naoki Nakatani
Keyword(s):  
Specific Gravity ◽  
Separation Efficiency ◽  
Massive Sulfide ◽  
Exclusive Economic Zones ◽  
Waste Separation ◽  
Economic Zones ◽  
Sea Area ◽  
Seafloor Massive Sulfide ◽  
High Possibility ◽  
Disposal Cost

Many seafloor massive sulfide (SMS) deposits have been discovered in Japan’s exclusive economic zones (EEZ). They have some useful metals and are expected to become future metal resources. In Japan, because of an expensive waste disposal cost, it seems to be difficult to realize the SMS mining. Adding a function of primary waste separation from metal-rich parts of SMS ore on seafloor by a hyrocyclone is proposed to overcome the problem. The water flow structure in a model hydrocyclone is observed in the study at first. Secondly, the performance of separation using differences in specific gravities of particles by the hydrocyclone is experimentally examined. Finally, the application of hydrocyclone in the actual sea area is examined. The result shows that 67% of larger specific gravity are collected and 67% of smaller one are rejected. From the separation efficiency, the hydrocyclone method is recognized to have a high possibility of application in the actual sea area.

CFD Analysis of Performance of Hydrocyclone for SMS Ore Separation on Seafloor

2017 ◽  
Author(s):  
Tetsuo Yamazaki ◽  
Yosuke Takeda ◽  
Rei Arai ◽  
Naoki Nakatani
Keyword(s):  
Massive Sulfide ◽  
Economic Problem ◽  
Scale Model ◽  
Small Scale ◽  
Cfd Analysis ◽  
Exclusive Economic Zones ◽  
Economic Zones ◽  
Seafloor Massive Sulfide ◽  
Analysis Of Performance ◽  
Small Scale Model

These days, many seafloor massive sulfide (SMS) deposits have been discovered in Japan’s exclusive economic zones. They have many kinds of useful metals, and are expected to be future metal resources. However, SMS mining faces an economic problem for the reason that disposal of unnecessary parts of SMS ores is very expensive in Japan. Adding a function of primary ore separation on seafloor is necessary for economical SMS mining. Some small scale model experiments were conducted by the authors. In this study, CFD analysis is applied for the results of the model hydrocyclone. From the analysis, the fundamental flow condition good for the ore separation in the cyclone is recognized.

Economic Seafloor Massive Sulfide Mining by Japan’s Model

2016 ◽  
Author(s):  
Tetsuo Yamazaki ◽  
Yosuke Takeda ◽  
Rei Arai ◽  
Naoki Nakatani
Keyword(s):  
Papua New Guinea ◽  
Waste Disposal ◽  
Mining Operation ◽  
Massive Sulfide ◽  
Sea Surface ◽  
Flexible Link ◽  
Private Companies ◽  
Mining Site ◽  
Seafloor Massive Sulfide ◽  
Disposal Cost

Because of the higher Au, Ag, and Cu contents, seafloor massive sulfides (SMS) have received much attention as future commercial mining targets by private companies and nations. One of them, Solwara 1 Project in Papua New Guinea (PNG), is scheduled to start the commercial mining operation from 2018. Because the mining site is inter-island area and almost no cost is necessary for the waste disposal in PNG, the economy of the mining is expected very well. In contrast with this, because all the SMS distribution sites in Japan locate outer ocean areas and the waste disposal cost on land in Japan is very expensive, the economy of SMS mining in Japan is quite negative. In order to overcome the problems, a self-standing riser with flexible link to the sea surface platform and a primary ore separation on the seafloor prior to the ore lift-up are proposed. The improved SMS mining concept named Japan’s model is examined.

Environmental Research for Assessing the Impacts of Mining Seafloor Massive Sulfides in Japan

2011 ◽  
Author(s):  
Tetsuhiko Toyohara ◽  
Nobuyuki Okamoto ◽  
Takahiro Kawai ◽  
Takayoshi Kodama ◽  
Hiroshi Shibasaki
Keyword(s):  
Massive Sulfide ◽  
Conservation Strategy ◽  
Environmental Research ◽  
Fiscal Year ◽  
National Corporation ◽  
Hydrothermal Ecosystems ◽  
Animal Communities ◽  
Sea Area ◽  
Seafloor Massive Sulfide ◽  
Oil Gas

In Japan, the Ministry of Economy, Trade and Industry (METI) commenced a research and development (R&D) project on seafloor massive sulfide (SMS) deposits in Japan’s exclusive economic zone (EEZ) in the 2008 fiscal year. The project defines the plan for the commercialization of SMS within 10 years. Japan Oil, Gas and Metals National Corporation (JOGMEC) conducted the research under contract to METI. SMS deposits are widely distributed in the sea area surrounding Japan and are expected to become domestic metal resources. Since the SMS fields include hydrothermal ecosystems, which often host dense endemic animal communities, an adequate environmental impact assessment (EIA) and a conservation strategy to protect biodiversity are required for sustainable development. We outline an environmental framework that is intended to contribute to a global standard for assessing the environmental impacts of SMS exploration and mining.

scholarly journals Flotation of Seafloor Massive Sulfide Ores: Combination of Surface Cleaning and Deactivation of Lead-Activated Sphalerite to Improve the Separation Efficiency of Chalcopyrite and Sphalerite

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 253 ◽  
Author(s):  
Kosei Aikawa ◽  
Mayumi Ito ◽  
Atsuhiro Kusano ◽  
Ilhwan Park ◽  
Tatsuya Oki ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Zinc Sulfate ◽  
Separation Efficiency ◽  
Massive Sulfide ◽  
Surface Cleaning ◽  
Water Soluble ◽  
Ethylene Diamine ◽  
Sulfide Ores ◽  
Seafloor Massive Sulfide

The purpose of this study is to propose the flotation procedure of seafloor massive sulfide (SMS) ores to separate chalcopyrite and galena as froth and sphalerite, pyrite, and other gangue minerals as tailings, which is currently facing difficulties due to the presence of water-soluble compounds. The obtained SMS ore sample contains CuFeS2, ZnS, FeS2, SiO2, and BaSO4 in addition to PbS and PbSO4 as Pb minerals. Soluble compounds releasing Pb, Zn2+, Pb2+, and Fe2+/3+ are also contained. When anglesite co-exists, lead activation of sphalerite occurred, and thus sphalerite was recovered together with chalcopyrite as froth. To remove soluble compounds (e.g., anglesite) that have detrimental effects on the separation efficiency of chalcopyrite and sphalerite, surface cleaning pretreatment using ethylene diamine tetra acetic acid (EDTA) was applied before flotation. Although most of anglesite were removed and the recovery of chalcopyrite was improved from 19% to 81% at 20 g/t potassium amyl xanthate (KAX) after EDTA washing, the floatability of sphalerite was not suppressed. When zinc sulfate was used as a depressant for sphalerite after EDTA washing, the separation efficiency of chalcopyrite and sphalerite was improved due to deactivation of lead-activated sphalerite by zinc sulfate. The proposed flotation procedure of SMS ores—a combination of surface cleaning with EDTA to remove anglesite and the depression of lead-activated sphalerite by using zinc sulfate—could achieve the highest separation efficiency of chalcopyrite and sphalerite; that is, at 200 g/t KAX, the recoveries of chalcopyrite and sphalerite were 86% and 17%, respectively.

scholarly journals Tracking the global reduction of marine traffic during the COVID-19 pandemic

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David March ◽  
Kristian Metcalfe ◽  
Joaquin Tintoré ◽  
Brendan J. Godley
Keyword(s):  
Large Scale ◽  
Human Mobility ◽  
Western Mediterranean ◽  
Western Mediterranean Sea ◽  
Marine Traffic ◽  
Human Movements ◽  
Exclusive Economic Zones ◽  
Global Impacts ◽  
Economic Zones

AbstractThe COVID-19 pandemic has resulted in unparalleled global impacts on human mobility. In the ocean, ship-based activities are thought to have been impacted due to severe restrictions on human movements and changes in consumption. Here, we quantify and map global change in marine traffic during the first half of 2020. There were decreases in 70.2% of Exclusive Economic Zones but changes varied spatially and temporally in alignment with confinement measures. Global declines peaked in April, with a reduction in traffic occupancy of 1.4% and decreases found across 54.8% of the sampling units. Passenger vessels presented more marked and longer lasting decreases. A regional assessment in the Western Mediterranean Sea gave further insights regarding the pace of recovery and long-term changes. Our approach provides guidance for large-scale monitoring of the progress and potential effects of COVID-19 on vessel traffic that may subsequently influence the blue economy and ocean health.

Autonomous Technology and Dynamic Obligations: Uncrewed Maritime Vehicles and the Regulation of Maritime Military Surveillance in the Exclusive Economic Zone

2021 ◽  
pp. 1-30
Author(s):  
Simon MCKENZIE
Keyword(s):  
Legal Regime ◽  
Coastal State ◽  
Maritime Surveillance ◽  
Legal Obligations ◽  
Legal Implications ◽  
Exclusive Economic Zones ◽  
Dynamic Quality ◽  
Economic Zones ◽  
Environmental Interests ◽  
Autonomous Technology

Abstract The development of uncrewed maritime vehicles [UMVs] has the potential to increase the scale of military maritime surveillance in the exclusive economic zones of foreign coastal states. This paper considers the legal implications of the expanded use of UMVs for this purpose. It shows how features of the legal regime—namely how its application depends on determining the intent of a vessel's operation (to distinguish marine scientific research from military surveillance), as well the obligation to have due regard—have a “dynamic” quality that will pose a challenge to UMVs operated by autonomous technology. The legal obligations will require equipping UMVs with the capacity to communicate something about their identity, the purpose of their mission, and to be able to have some capacity to be responsive to the economic and environmental interests of the coastal state.

Military Activities in the Exclusive Economic Zones of Foreign Coastal States

2012 ◽  
Vol 27 (4) ◽  
pp. 795-803 ◽  
Author(s):  
Moritaka Hayashi
Keyword(s):  
United States ◽  
Exclusive Economic Zone ◽  
Law Of The Sea ◽  
United States Military ◽  
Opposing View ◽  
Coastal State ◽  
Stable Order ◽  
Exclusive Economic Zones ◽  
Economic Zones ◽  
Common Understanding

Abstract One disturbing element in an overall stable order built on the Law of the Sea Convention is the disagreement between some States over the use of the exclusive economic zone (EEZ) of a coastal State by another State for military purposes. While it appears to be generally accepted that military activities in the EEZ of another State are part of “the freedoms . . . of navigation and overflight and other internationally lawful uses of the sea related to these freedoms . . .” under Article 58(1), some States, notably China, hold an opposing view. The disagreement has led to several incidents involving forceful disturbance of activities of United States military vessels and aircraft in and above the EEZ of China. There is an urgent need for the States concerned and the international community to find a common understanding on the issue or some kind of practical arrangement for avoiding further serious incidents.

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