Metallurgy and Processing of Marine Manganese Nodules

Abstract

This paper reviews the stale of the art in processing and extraction of ocean floor manganese nodules. It briefly reviews the mining sites where the abundant rich nodules occur and also discusses the metal distribution in nodules in view of economical processing and extraction of these metal values.The paper discloses in a detailed manner the physical and chemical characteristics of nodules. including porosity, surface area, water content and the effect of temperature on crystal structure of major constituents of nodules.In the extraction aspect of nodules, the paper reviews two different extraction schemes revealed in the literature, namely hydrometallurgical treatment and pyrometallurgical treatment. The hydrometallurgical treatments include acid leaching, ammonia leaching, leaching with reducing agents and leaching after high temperature pre-treatments such as in sulfating roasting, while the pyrometallurgical processes include smelting, chlorination-vaporization and segregation. The paper also covers metal recovery processes from leach liquor.An economic survey of processing nodules has been made in terms of problems associated with metal-marketing. and impact of metal production from nodules on mineral industries.

Simultaneous leaching of a deep-sea manganese nodule and chalcopyrite in hydrochloric acid

“…However, this ratio is less than 1 (between 0.49 and 0.60), indicating preferential dissolution pyrolusite ore, in an identical solution. The copper, manganese, and iron dissolution are shown, respectively, in Figures of iron from the chalcopyrite [27][28][29][30] as per reaction [7] or iron dissolution from pyrite present as an impurity in the 1(a) through (c), whereas Table I gives the dissolution of different metals such as Ni, Co, and Zn in the nodule at a chalcopyrite [21,22] via reactions [8] and [9]. …”

“…In all these cases, the extent of dissolution lurgical extraction of the same. [1][2][3][4][5][6][7][8][9] Various processing of MnO 2 and sulfide minerals individually was small or options have been examined, out of which about six routes negligible, whereas the same in combination was appreciable have been identified for future potential application. One of and also fast.…”

“…Aliquots (5 mL) were 5MnO 2 ϩ 2CuFeS 2 ϩ 20HCl ϭ 5MnCl 2 ϩ 2CuCl 2 [6] drawn at regular intervals, being replaced with an equal volume of the leachant, and were analyzed by atomic absorption ϩ 2FeCl 3 ϩ 10H 2 O ϩ 4SЊ spectrophotometry. The ferrous ion content was determined by standard classical methods (redox titration with K 2 Cr 2 O 7 Because Cl 2 is consumed quickly in the reaction system, solution using a barium diphenylamine sulphonate (BDAS)…”

Physicochemical and structural factors in the sulfuric acid leaching of nickel- and copper-bearing synthetic birnessites

“…According to Buser, these minerals are characterized by structurally conditioned imperfections, such as vacancies and interlayer regions, which impart to them reactivity even at room temperature. The leaching curves in Figure 7 for the doped Ni and Cu are characterized by an initial fast release of the elements followed by a very (1,2)] in terms of arrangement of MnO 6 octahedra. [39] slow dissolution.…”

“…Leaching was carried out with sulfuric acid. The leaching of sea nodules with sulfuric acid has been widely investigated [2,[35][36][37] and proposed to be a potential process, for example, via an H 2 SO 4 -H 2 SO 3 route, for metal extraction from sea nodules. [37,38] Cobalt-bearing birnessite samples are not included in this investigation, because of the difficulty of leaching trivalent cobalt with sulfuric acid.…”