Hydrogenetic, Diagenetic and Hydrothermal Processes Forming Ferromanganese Crusts in the Canary Island Seamounts and Their Influence in the Metal Recovery Rate with Hydrometallurgical Methods

Abstract

Four pure hydrogenetic, mixed hydrogenetic-diagenetic and hydrogenetic-hydrothermal Fe-Mn Crusts from the Canary Islands Seamount Province have been studied by Micro X-Ray Diffraction, Raman and Fourier-transform infrared spectroscopy together with high resolution Electron Probe Micro Analyzer and Laser Ablation Inductively Coupled Plasma Mass Spectrometry in order to find the correlation of mineralogy and geochemistry with the three genetic processes and their influence in the metal recovery rate using an hydrometallurgical method. The main mineralogy and geochemistry affect the contents of the different critical metals, diagenetic influenced crusts show high Ni and Cu (up to 6 and 2 wt. %, respectively) (and less Co and REY) enriched in very bright laminae. Hydrogenetic crusts on the contrary show High Co and REY (up to 1 and 0.5 wt. %) with also high contents of Ni, Mo and V (average 2500, 600 and 1300 μg/g). Finally, the hydrothermal microlayers from crust 107-11H show their enrichment in Fe (up to 50 wt. %) and depletion in almost all the critical elements. One hydrometallurgical method has been used in Canary Islands Seamount Province crusts in order to quantify the recovery rate of valuable elements in all the studied crusts except the 107-11H, whose hydrothermal critical metals’ poor lamina were too thin to separate from the whole crust. Digestion treatment with hydrochloric acid and ethanol show a high recovery rate for Mn (between 75% and 81%) with respect to Fe (49% to 58%). The total recovery rate on valuable elements (Co, Ni, Cu, V, Mo and rare earth elements plus yttrium (REY)) for the studied crusts range between 67 and 92% with the best results for Co, Ni and V (up to 80%). The genetic process and the associated mineralogy seem to influence the recovery rate. Mixed diagenetic/hydrogenetic crust show the lower recovery rate for Mn (75%) and Ni (52.5%) both enriched in diagenetic minerals (respectively up to 40 wt. % and up to 6 wt. %). On the other hand, the presence of high contents of undigested Fe minerals (i.e., Mn-feroxyhyte) in hydrogenetic crusts give back low recovery rate for Co (63%) and Mo (42%). Finally, REY as by-product elements, are enriched in the hydrometallurgical solution with a recovery rate of 70–90% for all the studied crusts.

Petrographic and geochemical characterization of the Middle‒Upper Jurassic Fe–Mn crusts and mineralizations from Monte Inici (north-western Sicily): genetic implications

“…3 and 7). These mineral phases are commonly related to oxy-hydroxides colloids involved in the first stage of hydrogenetic precipitation (Marino et al 2019). Finally, sulfides, authigenic mixedlayer clays, or opaline silica, generally associated to hydrothermal deposits (e.g., Jach and Dudek 2005;Marino et al 2018), are not documented in the Fornazzo samples.…”

“…The Fe-Mn crusts, nodules and mineralizations, associated to rockground or hardground (sensu Clari et al 1995) formed in ancient carbonate rocks or in present marine sediments, represent a significant lithofacies indicating peculiar geological and biogeochemical environments (Ehrlich 1975; Valeria Russo is currently an independent researcher. * Giovanna Scopelliti giovanna.scopelliti@unipa.it Palmer and Wilson 1990;Fürsich et al 1992;García-Ruiz et al 1994;Clari et al 1995;Gupta 1995;Bayon et al 2004;Reolid 2011;Föllmi 2016;Jiang et al 2020) and sometimes significant potential metal source (Ehrlich 1975;Rona 2003;Polgári et al 2004;Hein et al 2013;Kuhn et al 2017;Marino et al 2019). These deposits are characterized by a complex mineralogical and chemical composition, with prevalence of iron and manganese but also showing relatively high concentration of trace elements as Co, Cu, Ni, Cr, V (e.g.,Nicholson et al 1997;Rona 2008;Hein et al 2010).…”

“…Diagenetic deposits result from direct precipitation of Fe-Mn oxy-hydroxides during early diagenesis at or below the seafloor, usually in response of changing redox conditions (Force and Cannon 1988;Hein and Koski 1987;Okita et al 1988;Jach and Dudek 2005;Guido et al 2016). Finally, Fe-Mn nodules and/or crusts related to submarine hydrothermal systems precipitate directly from hydrothermal solutions associated to submarine volcanism (Manheim and Lane-Bostwick 1988;Fleet 1993;Abad et al 2010;Marino et al 2019). In addition to these three main typologies, or rather, interplaying with them in particular conditions, processes of biomineralization have been added (Lin et al 1996;Han et al 1997;Wang et al 2009;Polgári et al 2012;Lozano and Rossi 2012;Rajabzadeh et al 2017).…”

Mineralogy and geochemistry of ferromanganese oxide deposits from the Chukchi Sea in the Arctic Ocean

“…Such deposits are formed through three end-member processes: hydrothermalism, diagenesis, and hydrogenesis (Hein et al 1997). Hydrogenetic deposits mainly consist of Fe vernadite and birnessite and are enriched in critical elements like Co, Te, and Mo, whereas hydrothermal and diagenetic deposits often contain todorokite, asbolane, and buserite and are concentrated in Ni, Cu, Zn, and Li (Marino et al [2019] and references therein). The ferromanganese oxide deposits in the Pacific, Indian, and Atlantic oceans have been extensively explored (Hein et al 1997;Hein and Koschinsky 2014), but ferromanganese oxide deposits in the Arctic Ocean still remain largely unexplored because of the remote location.…”

Minerals of Rare Earth Elements in High-Phosphorus Ooidal Ironstones of the Western Siberia and Turgai Depression

“…Phosphorus occurs in ooidal ironstones as a mechanical admixture, adsorbed form [14,[21][22][23][24][25], or an individual authigenic mineral [8,[26][27][28] formed by diagenesis. Among the phosphorus minerals in ooidal iron ore, francolite (Ca 5 (PO 4 , CO 3 , OH) 3 F) [29,30], apatite (Ca 5 (PO 4 ) 3 )(OH, F, Cl), fluroapatite (Ca 5 (PO 4 ) 3 F), hydroxyapatite (Ca 5 (PO 4 ) 3 (OH)), chlorapatite (Ca 5 (PO 4 ) 3 Cl), vivianite (Fe 2+ 3 ( [40,41], and synchysite (CaREE(CO 3 ) 2 F) [42], are found in sedimentary deposits, whose presence should be confirmed or disproved in sedimentary iron ores. If we consider the increasing importance of REE for global industry [43], it becomes clear that we must evaluate the new industrial and genetic types of their deposits.…”