Search Results (5)

Cobalt-rich crust is a seabed metal mineral resource that is different from oceanic polymetallic nodules. Based on the higher Co content than polymetallic nodules, the commercial value of cobalt-rich crust may be better than that of polymetallic nodules. Due to the special distribution of valuable metals, commercial implementation is always limited. Herein, a novel process is proposed to efficiently and, in an eco-friendly way, recycle valuable metals from cobalt-rich crust. The results indicate that carbon could promote the decomposition of manganite in the cobalt-rich crust during the acid baking process, and the leaching ratio of Mn could increase by 50% when carbon is added during acid baking. In addition, it can be found that the promotion of carbon for Co is stronger at low sulfuric acid consumption than that at high sulfuric acid consumption; however, there is no promotion of carbon for leaching Ni and Cu during the acid baking process. The leaching ratio of Ni, Co, Cu, Mn, and Fe reached 98.59%, 91.62%, 93.81%, 41.27%, and 26.94%, respectively, when the mass ratio of the sulfuric acid and cobalt-rich crust was 0.567, the mass ratio of the carbon and cobalt-rich crust was 0.1, the temperature was 200 °C and the time was 240 min. This research could provide an alternative economic process for recycling valuable metals from cobalt-rich crusts. Full article

The quantitative evaluations of mineral resources and delineation of promising areas in survey regions for future mining have attracted many researchers’ interest. Cobalt-Rich manganese crusts (Mn-crusts), as one of the three significant strategic submarine mineral resources, lack effective and low-cost detection devices for surveying since the challenging distribution requires a high vertical and horizontal resolution. To solve this problem, we have built an engineering prototype parametric acoustic probe named PPPAAP19. With the echo data acquired by the probe, the interpretation of the accurate thickness information and the seabed classification using the deep learning network-based method are realized. We introduce the acoustic dataset of the minerals collected from two sea trials. Firstly, the preprocessing method and data augment strategy used to form the dataset are described. Afterward, the performances of several baseline approaches are assessed on the dataset, and the experimental results show that they all achieve high accuracy for binary classification. We find that the end-to-end approach for binary classification based on a 1D Convolution Neural Network has a comprehensive advantage. Such a demonstration validates the possibility of binary classification for recognizing the ferromanganese crust only in an acoustic manner, which may significantly contribute to the efficiency of the survey. Full article

It is now scientifically proven that specific categories of submarine raw materials, especially deep seas such as Mn and Fe oxides, polymetallic nodules, polymetallic sulfides (SMS) and some deep-sea sediment categories, can have significant potential for some critical metals for future use. One characteristic of these deposits is that although they often have lower Rare Earth Elements (REE) contents than the well-known land deposits, their sizes are very extensive, much higher than the land-based deposits. Therefore, the future use of these submarine formations as a source of REEs can be an important alternative to the exponentially growing demand for these strategic metals. These formations have significant potential to be a source of REEs in the markets when they are extracted as byproducts of the most critical metals such as copper, nickel, cobalt and manganese, from Mn nodules. To prove how realistic, the extraction of REE from those deposits is in market terms, we studied the economotechnical dimension and the potential or REEs compared to those of the well-known on-land REE deposits. Two studies are presented concerning the existing exploration pre-feasibility cases for REEs originated from two existing licences granted by the International Seabed Authority (ISA) in the Clarion Clipperton Zone (CCZ). The examination of these two cases has clearly shown that compared to the corresponding deposits of REE inland, the total basket prices of these submarine deposits are higher due to the higher contents of heavy REE such as Nd, Pr and Dy and Sm, Eu, Gd, Tb and Y in these marine deposits. Considering that the prices in the international markets for most of the REE oxides between 2019 and 2021 were very high, they gave these deposits even greater economic value. The significant advantage of the mining and metallurgical treatment of these manganese nodules and cobalt-rich manganese crusts is also related to the fact that REEs are not part of the crystal lattice of the minerals that host them, in contrast to what happens with land-based deposits. This makes their metallurgical processing more manageable and cheaper. This fact makes mining and metallurgical treatment economically favourable. On the other hand, the very low Th and U concentrations in these deep-sea deposits do not pose environmental risks in many well-known land-based REE deposits. Full article

Polymetallic manganese nodules (PMN), cobalt-rich manganese crusts (CRC) and seafloor massive sulfides (SMS) have been identified as important resources of economically valuable metals and critical raw materials. The currently proposed mineral processing operations are based on metallurgical approaches applied for land resources. Thus far, significant endeavors have been carried out to describe the extraction of metals from PMN; however, to the best of the authors’ knowledge, it lacks a thorough review on recent developments in processing of CRC and SMS. This paper begins with an overview of each marine mineral. It is followed by a systematic review of common methods used for extraction of metals from marine mineral deposits. In this review, we update the information published so far in peer-reviewed and technical literature, and briefly provide the future perspectives for processing of marine mineral deposits. Full article

Cobalt-rich manganese crusts (CRCs) are important as a potential mineral source that could occur throughout the Pacific on seamounts, ridges, and plateaus. We built a prototype parametric acoustic probe to complete the task of in-situ thickness measurements to estimate the volumetric distribution of deep-sea mineral. The prototype is designed with dual-channels for receiving the primary and secondary signal, which lays a foundation for improving the thickness extraction algorithm. Considering that the signal quality is degraded by the system interference and ambient noise, some improvements to the algorithm are proposed by including the wavelet-based envelope extraction method and the adaptive estimation strategy based on the dual-channel information. Additionally, wavelet regression is applied to reduce the measuring noise assuming that the CRCs have local thickness invariability. The algorithm is suitable for the CRCs with the structure of the multilayers at the top surface and one single layer at the bottom surface. A laboratory experiment is performed to validate the effectiveness of the algorithm. The experiments carried out on the China Ocean 51th voyage in the Western Pacific Ocean on Aug 30, 2018, are described and the data obtained by using the sit-on-bottom stationary measurement are processed to validate the design of the prototype. Full article