Search Documents

By Akira Usui

Occurrence of hydrogenetic ferromanganese crusts has been well documented over inactive seamounts in the central and southern Pacific Ocean. It has been thus believed that the hydrogenetic crusts develop preferentially at water depths between about 800 to 2500 meters. In fact, according to the Manganese Crust Database (F. Manheim, 1988), only two occurrences are known at water depths below 5000 m out of 819 occurrences cited in the database. Unexpectedly, we found typical hydrogenetic ferromanganese crusts from deep-sea floors; 1) outcropping old volcanic basement over the Philippine Sea Plate (abandoned spreading centers and subducting old oceanic crusts) and 2) one from the slope of an abyssal hill in the Central Pacific Basin (Cretaceous deep-sea basin) at water depths ranging between 5200 to 6100 meters. We report their occurrences with submersible observations from Shinkai 6K, physical parameters (such as thickness of crusts about 2-4 cm in maximum), chemical composition, petrology of substrate, and results of Be-10 dating for some samples in comparison with typical Co-rich manganese crusts from the Central Pacific seamounts. The preliminary chemical and mineralogical analyses reveal that they are of typical hydrogenetic origin, and typical of iron-manganese oxide mineral, vernadite, slow and probably continuous growth, and lower content of Co than the Central Pacific seamount crusts. The occurrences and nature of the crusts indicate that deep-sea floors are also optimal for the growth of hydrogenetic crust even at 5000 m water depth or deeper, only if oxygenated deep waters are supplied and the sea-floor morphology keeps stable enough for significant geological time period. Additional details of chemical analyses will be prepared by November and to be shown in the conference.

Jan 1, 2001

By Kris De Bruyne

Since 2013, GSR has undertaken 4 exploration campaigns, which focused on environmental baseline monitoring (marine biology), resource definition and technological change. The seabed nodule collection vehicle has a significant influence on the achievable production rate and is for that reason thought to be a serious risk in developing an economical viable mining operation. GSR is currently working on a pre-prototype of a seabed nodule collection vehicle. The program, called ProCat, started in 2015 and will take up to end of 2019. ProCat can be split up in 2 phases: ‐ ProCat#1 [2015 – Q2 2017]: separate parallel testing of the nodule collection- and driving mechanism (Tracked Soil Testing Device Patania I – TSTD Patania I). The trafficability was tested in-situ; the collection mechanism was tested in a laboratory. Phase 1 has been completed successfully in September 2017. ‐ ProCat#2 [Q3 2017 – end of 2019]: the knowledge acquired during the first phase was used in this 2nd phase. Both collection mechanism and driving mechanism were integrated into the design of a pre-prototype seabed nodule collection vehicle (Pre-Prototype Vehicle Patania II – PPV Patania II). This pre-prototype vehicle will be used for a simulated mining test in Q2 of 2019 in the GSR- and BGR license area. The main objective of the ProCat research program, and especially the 2nd phase, is to integrate the nodule collector on the tracked chassis and develop an operating vehicle causing minimal environmental impact hereby validating the requirements for a full scale polymetallic nodule collection vehicle in the actual operational environment of the CCFZ. Following the ProCat project, GSR is working towards a system-integrated mining test once exploitation regulations have been agreed by the ISA and its member States.

Jan 1, 2018

By Akuila K. Tawake

The occurrences of polymetallic minerals within the Exclusive Economic Zones (EEZs) of many Pacific Island Countries (PICs) have been confirmed through marine scientific researches and seabed minerals exploration in the last forty years, and are increasingly being recognized by nations as a future potential source of revenue and economic development. For many of the smaller PICs, this may represent the only exploitable natural resource sector apart from fish. SOPAC (then under the CCOP/SOPAC) was actively involved with deep sea mineral exploration in many countries in the South Pacific between the 1970s and early 1980s that led to the discovery of a number of seabed mineral occurrences within the EEZs of these countries. In collaboration with SOPAC, a number of multinational consortia and national agencies were involved in this early stage of seabed mineral prospecting in the region. This was followed by a twenty-year (1985-2005) marine mineral prospecting in the Pacific through the collaborative effort of the Government of Japan and SOPAC as well as the Ridge 2000 program. Other mineral prospecting and marine scientific research initiatives have been conducted in recent years and the most notable one is the Nautilus Minerals advanced exploration in the Manus Basin in PNG. Based on the results of previous exploration, a number of countries in the region with moderate to high deep sea mineral resources potential are identified. Seafloor Massive Sulphide deposits have been confirmed in PNG, Tonga and Fiji while the Cook Islands and Kiribati have high manganese nodule resources potential in addition to significant occurrences of Cobalt-rich Crust within the EEZs of the Marshall Islands and the Federated States of Micronesia. Despite the recent surge in deep sea minerals interest and activity around the Pacific, specific policy, legislation and regulations necessary for the governance of deep sea mineral resources are lacking. Also lacking is the specific technical and human resources capacity essential to ensure that PICs are able to effectively manage these seabed resources. Consequently, SOPAC under the EU funded Deep-Sea Minerals (DSM) Project will work with Pacific ACP States to develop a regional regulatory framework from which they can develop their national frameworks for the sustainable management of their marine mineral resources. The work is of critical importance if PICs are to have effective environmental, fiscal and social management instruments in place for the exploration and exploitation of deep sea minerals that could support economic growth within the region as a whole.

Jan 1, 2010

By James R. Hein

Rodriguez Seamount, located 150 km off the central California coast at the base of the continental slope, was studied using the ROV Tiburon aboard MBARI?s R/V Western Flyer, October 13-16, 2003. Fe-Mn crust and rock samples were collected along the SW flank of the seamount at water depths from 700 to 2100 m; bottom-water dissolved oxygen content (O2) and temperature were determined at each sample site. Fifty-three samples of bulk crusts, crust layers, and surface scrapes (~0.5 mm) were analyzed for 59 elements. Data allow for the correlation of crust compositions with precisely known water depths and seawater O2 measured at the actual site of sample collection. This is the first detailed study of Fe-Mn crust compositions in a region of strong continental-margin upwelling. Compared to open-ocean seamount Fe-Mn crusts, Rodriguez crusts have significantly higher (2-6 fold) mean concentrations of Fe (26.9%), Al (1.65%), Si (13.0%), Cr (82 ppm), Th (64 ppm), and Ag (1.7 ppm); and significantly lower (2-8 fold) mean concentrations of Ca, P, Bi, Co, Cu, Ni, Tl, and especially Te (8.2 times lower). All but one Fe/Mn ratio are >1 compared to <1 ratios for open-ocean crusts. O2 contents (0.35-2.03 ml/L) are nearly perfectly corrected with water depth and elements correlated with one are correlated with the other. The Fe-Mn surface scrapes represent 60-450 ka (mean 150 ka) of growth, whereas the dissolved oxygen contents of seawater represent an instant in time. Assuming that the entire sample set was affected uniformly by oceanographic changes, we suggest that correlation of elements with O2 may reflect oceanographic processes. O2 has a negative correlation with P, V, As, Fe, U, Be, Pb, Cr, Mg, Y, Bi, Te, and REEs (except Ce) and a positive correlation with aluminosilicate-hosted elements (Al, K, Rb, Cs). This later relationship is related solely to water depth, indicating that detritus shed down the seamount slopes accumulates in greater abundances in deeper-water crusts. Si/Al ratios indicate that the detritus includes a large component of biosilica produced by upwelling-mediated high productivity. These observations are supported by positive correlations of aluminosilicate-hosted elements with crust growth rates (range 1.2-13.0 mm/Myr). In contrast, other elements (Sr, Co, Mn, Mg, Te, As, Mo, V, W, U, Ti, Ni, REEs, etc.) are negatively correlated with growth rates. Growth rate has a weak positive correlation with O2. These compositional characteristics indicate that even though low-O2 seawater acts as a reservoir for Mn and associated elements and produces slow growth rates, which would allow for the concentration of elements and surface oxidation processes to occur, the high rate of input of detritus and high bioproductivity ameliorate the strong concentration of most metals. This dilution is significantly enhanced by the doubling of FeOOH in the crusts--the main cause of the generally high growth rates compared to open-ocean crusts. The high growth rates limit the oxidation of Co, Tl, and especially Te on the crust surface, which is reflected by their relatively low concentrations. Within the range of oxygen contents measured, O2 has less of an influence on crust chemistry than does the availability and incorporation of FeOOH and detritus.

Jan 1, 2004

By Derek V. Ellis

This article is a summary, with documentation and references, of recent global developments in identifying environmental issues affecting the marine mining industry. It is recognised that marine mining for various products occurs at various depths from shallow water (e.g. aggregate and diamond mining) potentially to great depths (e.g. metalliferous muds, and manganese crusts and nodules). Nevertheless there are environmental issues in common, even though the options for resolutions will vary greatly. The point of this review is to identify the issues, so that where site-specific resolutions are considered, it is possible to draw on experience with the issues elsewhere. Related mining issues, e.g. tailings effluent quality, orebody geochemistry, are mentioned where relevant but are not detailed in this article, although obviously they are a part of there solutions to the environmental issues. The environmental issues and their resolutions are important - on the basis of the ethic of not creating more impact than is inevitable, and the long-term financial and social costs at a mine-site of not getting the resolutions right.

Jan 1, 2000

By S. Rajendran

Much advance has been made in offshore hydrocarbon exploration and exploitation in India. But the same amount of success could not be achieved in the case of other offshore minerals which are amenable for mining. However, employing present technology, there should not be any difficulty in successful exploitation with minimum environmental hazards. A demonstration is provided by considering the conditions prevailing in the Kerala offshore (southwest coast of India) scenario of monazite, ilmenite, phosphatic mud and calcareous deposits. Mud banks are unique phenomenon of the Kerala coast during monsoon season. Acting as barriers to waves, mud banks protect portions of the beaches from being eroded and trap sediments from either side facilitating growth of adjacent beach. The easy minable possibilities of the phosphatic mud during non-monsoon season with less pollution hazards and dumping back the waste material after processing for phosphate at the breaker zones to reduce the erosional effects on the coast make the exploitation economic and ecofriendly unlike the benefication of the lowgrade phosphate ores on land on a comparatively larger area and subsequent crushing, transport and resulting pollution.

Jan 1, 1993

By Yannick C. Beaudoin

Southern Explorer Ridge (SER) is an anomalously shallow, intermediate-rate spreading ridge located 200 kilometers off the west coast of Vancouver Island, Canada. It ranges in depth between 2600 m (deepest basins) and 1760 m (bathymetric minimum). At least 60 sulfide deposits are known to be associated with hydrothermal vent fields along the ridge. For the first time geological data, including deposit locations, collected from 15 marine expeditions to SER since 1983 have been assembled in a GIS format. GIS processing techniques were employed to plot the distribution of base metal concentrations for recovered sulfide samples. The highest base metal concentrations are found in the vicinity of the Magic Mountain site (main active vent field), and also proximal to a side scan sonar anomaly referred to as AGOR 171. Individual samples near these locations have yielded values as high as 29.3 wt\% Cu, 34.3 wt\% zinc, 0.97 wt\% Pb, 2.0 ppm gold, and 664 ppm silver. Sample paucity is the key limiting factor that prevents adequate assessment of the areas economic potential.

Jan 1, 2001

By Nobuyuki Okamoto

The present three-year long phase of the SOPAC/Japan Deep Sea Co-operative Mineral Resources Programme [Programme], commenced in 2000. The Programme has been funded by the Government of Japan through the Japan International Co-operation Agency (JICA) and the Metal Mining Agency of Japan (MMAJ), since 1985. Field survey activities and associated data analysis and interpretation, for the Programme, has largely been carried out by the Deep Ocean Resources Development Co., Ltd. (DORD). The Government of Japan has, since 1982, recognised DORD as one of its ? Pioneer Investigators? for manganese nodules in the Clarion Clipperton Fracture Zone . Although the objective of this paper is to present the results of the drilling cruise that was conducted from December 2001 to January 2002, within the North Fiji Basin, in Fiji?s EEZ, it will also seek to provide a broad overview of the results of the cruise conducted within the Cook Islands in May to June 2000, as well as present preliminary results of the cruise conducted in the Marshall Islands in June to July 2002.

Jan 1, 2002

By Alexander Malahoff

Field observations and sampling of land-based and submarine hydrothermal and geothermal sites show a definite link between the geological setting, fluid geochemistry and specialized assemblages of microorganisms found at these settings. Three initial sites have been chosen as a basis for these studies. The first site is located on hydrothermal vents in pit craters on the submarine volcano Lo?ihi (Hawai?i) at a water depth of 1,300 meters. The second site is within the geothermally active vents, ponds and lakes of the Taupo Volcanic Zone of New Zealand. The third site extends along the chain of volcanically and hydrothermally active volcanoes of the Kermadec-Tonga arc and back-arc system. To focus our work in New Zealand, a geomicrobiology field and experimental center has been established in Wairakei, New Zealand, with the relevant genomics, proteomic and bioinformatics work being conducted at the University of Hawaii. As part of a partnership between the University of Hawai?i, the Institute of Geological & Nuclear Sciences (GNS) and Victoria University of Wellington, a new interdisciplinary graduate course in geomicrobiology will be taught at Victoria University beginning next year. Since mineral-microbial interactions have been occurring for the past few billion years and these interactions have led to where one generates the other, a metal-bacteria research program has been initiated at GNS using arsenic-gold and other metal-bacterial interaction processes as a research objective. In this research program, we have completed the full genome of a new species of marine bacterium Idiomarina loihiensis from the Lo?ihi hydrothermal vents and identified specialized microorganisms living in pH 0.3 geothermal vent waters of White Island, New Zealand. The multidisciplinary approach to study the process of accumulation of metals in the hydrothermal systems clearly shows the path of how bacterial-mineral interaction can precipitate metal deposits. These studies will lead to new avenues for biomining, bioremediation and the understanding of the origins of life.

Jan 1, 2004

By Tap Pryor

A very small nation with large seabed resources requires a strategy. The simplest approach is to duplicate every step taken by the United Nations (UN), in its own leasing programme. In addition, the smaller nations must sell itself and its competitive offering. It is one thing just to await applicants and/ or tenders, another to work to make the leasing seem like a very good idea. This cap be achieved through publications, correspondence, meetings (such as the Underwater Mining Institute, but especially through pro-active planning, seeking the ideal technologies in both harvesting and processing. The ideal would be some combination that could begin quickly and on a small scale. It must be within the UN environmental guidelines. To meet the "quick and small criteria," simple harvesting and physical processing methods must be given the highest priority. Once these are satisfied, then marketing studies can be completed. There is, of course, a market for every element but only careful engineering and cost analysis will determine accessibility. What is required is a stepwise approach, gaining greater and greater credibility at each step. In fact, much planning can be done for very low cost. In the Cook Islands, the first crucial step was the East-West Center publication which pulled together all facts in one volume and which found the local resource to be richer in significant ways than Clarion-Clipperton. Most seem to believe that it could be many years before full production is possible, but this has been conventional wisdom for so long that it has taken on the suspicious aura of myth. Is it real? Have all possible recent technologies such as robotics and physical processing been taken into account? Either way, it is essential that a comprehensive approach be taken so that all factors from resource to market are considered as inter-related until a single business plan emerges. When that is in hand and when its profitability and risk levels are found to be credible, adequate investment funds are available.

Jan 1, 1994

By Peter B. Hale

Canada has a long history of marine-related industry and onshore mining. Even so, commercial interest in marine mining, excluding seawater mineral extraction and offshore extensions of hardrock deposits such as iron and coal, has been sporadic; despite the fact that shelf mineral deposits supply a significant proportion of the national market requirements for many countries. Several factors have accounted for this including: a relative abundance of onland mineral desposits; the fact that onland deposits can be mined using conventional technology; and, a general lack of knowledge and public awareness as to Canadian offshore non-fuel mineral resource potential. In the mid-1970s the Department of Energy, Mines & Resources formed the Departmental Coordinating Committee on Ocean Mining. The Committee addressed the question of shelf non-fuel mineral resource potential and concluded that, while several reports had raised the possibilty of this alternative source, there had not been a systematic evaluation of the resource base. This led to the formation of a Shelf Working Group, whose task it was to outline and implement a departmental program to advance our knowledge of shelf resource potential. A methodology was devised that utilized existing geoscientific and hydrographic

Jan 1, 1985

By Marlene Olivares Cruz

The particles that make up the deep-sea sediments have two main sources: 1) those that are created in situ from dissolved components and 2) those that are washed into the ocean in solid phases from the continents, atmosphere, space and interior of the Earth. Many particles as they sink through the water column reaches the seabed and are known as pelagic sediments with terrigenous, biogenic, authigenic, and cosmogenic components. Among the minerals found in the terrigenous fraction of pelagic sediments are quartz, clay minerals, feldspar, micas, ferromagnesians, and the biogenic fraction with remains of siliceous organisms, such as, radiolarian and diatoms. The chemical nature of marine sediments is controlled by the contribution of particulate matter derived from various sources with varying compositions for the fixing of elements during deposition and the compositional changes carried out within the sediments during diagenesis. In the last decade there have been several studies on the mineralogical composition of seabed sediments, suspended particulate materials and cores, together with paleontological and geochemical data are used for paleoclimatic and paleoenvironmental reconstructions, analyze changes in sea level, stratigraphic correlations and identify past and

Sep 14, 2011

By Nobuyuki Okamoto

Ferromanganese crusts on the seamounts in the Pacific Ocean are potential resources of cobalt, nickel, platinum and REEs. Particularly, those of the Republic of Marshall Islands and the Federated States of Micronesia (FSM) waters are believed to be of the highest resources potential area in the Pacific Ocean. The total six cruises using the Japanese Research Vessel Hakurei Maru No. 2 were carried out in the seamounts of the Marshall Islands in 1996, 1998 and 2002, and of the FSM in the 1997, 1998 and 2005 for evaluation of economic potential for cobalt-rich ferromanganese crusts as part of the Japan-SOPAC joint project. During these cruises numerous data such as bathymetric, geological, geophysical and environmental data were obtained. Geophysical exploration with backscatter mapping and side scan sonar, visual imaging using towed TV camera and geological sampling using dredge bucket and/or benthic multi-coring system (BMS) were conducted on these seamounts. In this presentation, we will report the mode of distribution of the crusts and calculated resource estimation based on the results of these geological and geophysical shipboard survey and land-based analyses. Keywords: ferromanganese crusts, Marshall Islands, Micronesia, resource potential

Jan 1, 2011

By Jan Stenlokk

The Norwegian Petroleum Directorate, which is the Government agency for the management of offshore geo-resources including seabed minerals, is about to finish this year’s marine data acquisition cruise in the Norwegian Sea. We would very much like to present the preliminary results of that cruise, including the discovery of a new black smoker and surrounding sulphide deposits.

Jan 1, 2018

By James R. Hein

Ferromanganese oxyhydroxide crusts (Fe-Mn crusts) precipitate out of cold ambient seawater onto hard-rock surfaces at water depths of about 600-4000 m throughout the ocean basins. Fe-Mn crusts concentrate most elements in the Periodic Table above their mean concentration in the earth&apos;s crust (continental plus oceanic crust), except for the major rock-forming oxides and also notably gold and palladium. Tellurium is concentrated greater than any other element relative to its earth&apos;s crust mean (about 1 ppb). For example, mean contents of the elements heretofore known to be most enriched in crusts, Mo, Tl, Sb, Co, Mn, Bi, As, Se, and Pb are enriched 100 to 1000 times over their earth&apos;s crust mean, whereas the mean Te content in Fe-Mn crusts is enriched about 50,000 times. However, the distribution of Te in the earth is poorly known. Estimates of the mean Te content of the earth&apos;s crust range from 0.36 to 10 ppb, with 1 ppb being the most commonly cited mean content (compilations in Levinson, 1974 and Govett, 1983). If we took the highest estimate of 10 ppb, then Te would be enriched in Fe-Mn crusts five times more than the next most enriched element, or 5000 times the estimated maximum mean earth&apos;s crust.

Jan 1, 2000

By S. Kim Juniper

The discovery of chemosynthetic-based ecosystems at hydrothermal vents in the deep ocean was arguably one of the most important findings in biological science in the latter half of the 20th century. More than 100 vent fields have been documented along the 60,000 km global mid-ocean ridge system. Over 500 new animal species, over 80% of which are endemic to the vents, have been described from this environment. Unusual, highly evolved symbioses between invertebrates and chemolithautotrophic bacteria are common at vents, producing concentrations of biomass that rival the most productive ecosystems on Earth. Hydrothermal vents ecosystems, because of their very limited area and the presence of endemic species, are highly vulnerable to human disturbance. Mining for polymetallic sulphide deposits poses the greatest future physical threat to hydrothermal vents and their biological communities. However, there is more immediate concern about the impact of concentrated scientific research activities. Some sites have been revisited by several research expeditions per year for more than a decade. As vent sites become the focus of intensive, long-term research, oversight organizations are discussing mitigative measures to avoid significant loss of habitat or oversampling of populations. Canada recently became the first national jurisdiction to set aside a hydrothermal vent site as a Marine Protected Area.

Jan 1, 2001

By Richard Harrison, Frank Lim

"Lifting of slurry from the seabed mining machine to the surface production vessel is a critical element of any deepwater seabed mining system. A Vertical Transport System (VTS) comprises pump(s), riser string, connectors and hang-off assembly as its main components, but it is the pipe material, riser configuration and installation method that often attract the most discussions.This presentation will feature important VTS design work 2H has done over the years for different stakeholders, and highlight the work carried out as a partner to the EU funded Blue Mining Joint Industry Project.The key challenges faced by a deepwater VTS are:??High riser payload??Large deck space for storing riser joints??Long time to deploy and retrieve riser??Uncertain metocean conditions??Vortex induced vibrations??Weld and connector fatigueIncreasing the water depth further sees the longer and increasingly ‘springy’ riser experiencing axial resonance caused by wave induced vessel heave motions being close to the riser resonant period. This can lead to snatch loading and fatigue failure in the riser.The presentation will discuss the above design issues, analysis requirements and provide guidance on pump/riser selection. Solutions to mitigate the resonant response issues will also be proposed.."

Jan 1, 2017

By Ian Selby

Recent offshore diamond exploration has been concentrated in the SW Joseph Bonaparte Gulf. I`IW Australia. Extensive high resolution seismic and sampling surveys have been carried out in Cambridge Gulf, offshore of the mouth of the OR River and other rivers of the region. Surface-tow boomer surveys have been correlated with sampling data from vibracores and a wide diameter (1m) airlift system, providing a geological framework for the area. Although large-scale bulk sampling has not been undertaken, there has been no reported recovery of diamonds since 1993. The geology and prospectivity of a range of potential diamond traps in high energy, fluvial and transgressive depositional settings has been assessed. Potentially diamondiferous targets include (i) a shoreline apron. (ii) fluvial/estuarine channel infills and terraces and (iii) ravinement surfaces.. Although there is evidence for a long history of fluvial development and sea level changes, the majority of the investigated traps represent the result of erosion and sedimentation during and following the last interglacial. Significant volumes of unconsolidated gravels and coarse-grained sands with occasional indurated layers are present, and are locally exposed at sea beet In place s thick successions (>5m) of fine-grained overburden overlie the coarse-grained sediments.

Jan 1, 1998

By Tobias Hens, Andrew Frierdich, Barbara Etschmann, Joël Brugger, Barrie Bolton

"Advancing our knowledge about trace metal distribution and abundance provides insight into formation, alteration, and trace element enrichment processes of ferromanganese nodules and crusts. A fundamental understanding of these mechanisms, in turn, has implications for the selective recovery of critical metals and the development of sustainable hydrometallurgical techniques. Synchrotron-based X-ray Fluorescence (SXRF) is a powerful, state-of-the-art analytical tool that can examine geochemical features of Fe-Mn nodules and crusts, such as abundance and distribution of trace elements, in an integrated and efficient manner. By correlating trace element composition and Mn oxidation states in these highly complex samples, it can be determined whether these parameters are related to the Mn oxide mineralogy (vacancy content of crystal lattice) and chemistry.In this study, eleven Fe-Mn nodule and crust samples from three circum-Australian locations – the South Tasman Rise, Lord Howe Rise, and Coral Sea – were analyzed at the Australian Synchrotron, Victoria, Australia. Micrometer-scale spatial resolution of geochemical features, such as concentric growth structures and element distribution, was achieved with high sensitivity (Fig. 1). For instance, Ni could be detected at 10's of ppm to 1 wt% levels. Information on other redox-sensitive trace elements, which are present at 10-1000 ppm levels (e.g., Cu, Co, Ti), were gained by means of fully quantitative elemental composition maps."

Jan 1, 2017

By Tobias Hens, Andrew Frierdich, Joël Brugger

The rapid advancement of green technologies in recent years is closely tied to an ever- increasing demand for raw materials. Innovative forms of zero-emission transportation and sustainable power generation will require a variety of traditional metals such as Ni and Co, but also many non-traditional metals (e.g., REY). Many of these elements are known to be highly enriched in deep-sea ferromanganese (Fe-Mn) nodules and crusts. However, unlocking these metals from their deposits through metal processing is – aside from deposit exploration and production – expected to be a critical component that will affect the overall economics of the marine mining value chain. Hence, research and development of tailored metal processing solutions which can target specific metals of interest in Fe-Mn nodules and crusts, is required. Dynamic mineral recrystallization (DMR) of Fe-Mn oxide phases is a geochemical process that may have notable potential for hydrometallurgical applications. We have recently demonstrated that Ni can effectively be cycled between deep-sea Fe-Mn nodules and crusts and solutions through dynamic mineral recrystallization. DMR occurs in nature as abiotic background process during biogeochemical Mn cycling when dissolved Mn(II) is in direct contact with Mn oxides. Trace metals which are incorporated in the Mn host phases, are cycled between solid phase and solution via coupled dissolution (trace metal release) – reprecipitation (trace metal incorporation) mechanisms.

Jan 1, 2018