China 
Africa 
Explore chapters and articles related to this topic
International law and policy related to offshore energy and mining
Published in Mark Zacharias, Jeff Ardron, Marine Policy, 2019
In 1967, when Ambassador Arvid Pardo of Malta addressed the UN General Assembly, it was from the chapter on polymetallic nodules from The Mineral Resources of the Sea (Mero, 1965) that he quoted and which galvanized the General Assembly into action. The historical (over-) estimates of the perceived riches of DSM were mainly about polymetallic nodules, and hence this resource has the longest history of commercial exploration and research. Unlike SMS and land-based mining, the resource is only on the surface. Therefore, the footprint of polymetallic nodule DSM is expected to be the largest of any kind of DSM (and larger than terrestrial mining) on the scale of several hundred square kilometres of seafloor each year per operation. Additionally, it is thought that the effects of sediment plumes arising from the collection of nodules and wastewater return could considerably amplify the footprint of affected biology beyond that of the immediate mined area. The extent and nature of sediment plume impacts, long suspected to be a major environmental stressor (Burns, 1980), has been a topic of recent and ongoing research projects.
Digging plasticity water-saturated soils
Published in Genadiy Pivnyak, Volodymyr Bondarenko, Iryna Kovalevska, Theoretical and Practical Solutions of Mineral Resources Mining, 2015
In shallow water there might be used hydraulic excavators, draglines, underwater scrapers, bucket dredgers and submersible earthmoving machines (amphibians). Nowadays several types of seabed mineral deposits are of some economical interest. Among them are deposits of polymetallic nodules in the Pacific and Indian Ocean, metal-rich silts in the Red Sea, and organic-mineral sediments in the Black Sea. The depth of their stratification varies from 0.5 to 6 thousand meters. To extract minerals at the great depth such mining equipment with bucket work tools as continuous line bucket system, dragline dredgers, and seabed excavating machines were developed. Although only a few of them were tested in the field operating conditions.
Leaching with Acids
Published in C. K. Gupta, T. K. Mukherjee, Hydrometallurgy in Extraction Processes, 2019
It has been emphasized in literature and in the first chapter of this book that for assuring the supply of metals and materials for the future, we cannot continue to depend on land-based resources. The ocean beds have shown enough indication of the possibility of vast reservoirs of metals and materials. A great deal of attention has been focused the world over on using manganese nodules from the ocean bed as potentially important and huge mineral resources. Extensive research efforts are being conducted to evolve an economical method of processing the manganese nodules. Among the acid-leaching techniques evaluated so far for the treatment of manganese nodules is the work of a Belgium Company,100 Metallurgie Hoboken-Overpelt (MHO). The process involving leaching with hydrochloric acid has come to be known as the MHO process. The nodules are crushed and leached with concentrated hydrochloric acid to dissolve manganese and other valuable metal oxides. The basic principle and flowsheet of the process have already been described in Chapter 1 with the help of Figures 4 and 5. The dissolution of nodules was claimed to be more or less complete, and the leach liquor contained 110 to 120 Mn, 25 Fe, 5 Cu, 1 Co, 0.6 Zn, 0.3 V, and 0.2 Mo in g/l. The total chloride concentration of the liquor was about 200 g/l. The acid leach liquor was subjected to a series of solvent extraction and precipitation steps to recover pure salts of copper, aluminum, nickel, manganese, zinc, molybdenum, and vanadium. The final solution contained only magnesium chloride and was pyrohydrolyzed in a spray roaster to recover HCl for leaching and magnesia for various neutralization steps.
Alternative Resources for Producing Nickel Matte - Laterite Ores and Polymetallic Nodules
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Kun Su, Feng Wang, John Parianos, Zhixiang Cui, Baojun Zhao, Xiaodong Ma
Polymetallic nodules were found first in the Pacific Ocean at a depth between 4000 and 6000 m during the scientific expeditions of the HMS Challenger between 1872 and 1876 (Das and Anand 2017; Hein and Koschinsky 2014; Monhemius 1980). The nodules have drawn significant attention since 1970s as they contain high amounts of valuable metals that are essential for the green-technology and high-technology industries (Hein and Koschinsky 2014). The CCZ in the East Pacific Ocean is of particular interest for mining because it hosts enormous quantities of nodules (minimum 21 Gt with an areal density up to 10–15 kg/m2). The nodules have a high metal grade and local abundance, making their use economical for metal production (ISA 2010). The CCZ nodules contain high contents of various metals, such as manganese (typically 26–30 wt%), nickel (1.2–1.4 wt%), copper (0.9–1.3 wt%), and cobalt (0.15–0.25 wt%) (ISA 2010; Sen 1999). They are therefore triggering a high interest for deep-ocean mining operations. National agencies and private companies have carried out numerous research activities over the past four decades (Van Nijen, Van Passel and Squires 2018). Although no commercial mining has been reported yet, it was estimated that polymetallic-nodule mining is likely to begin in earnest in the mid to late 2020s (Hein, Koschinsky and Kuhn 2020).