Simultaneous Leaching of Seafloor Massive Sulfides and Polymetallic Nodules

Przemyslaw Kowalczuk,Kurt Aasly,Hassan Bouzahzah,Rolf Kleiv

doi:10.3390/min9080482

Przemyslaw Kowalczuk, Kurt Aasly + Show 2 more

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https://doi.org/10.3390/min9080482

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Abstract

Simultaneous leaching of seafloor massive sulfides (SMS) from Loki’s Castle on the Arctic Mid-Ocean Ridge (AMOR) and polymetallic nodules (PN) from Clarion Clipperton Zone (CCZ) of the Central Pacific Ocean was studied. Leaching tests were conducted using sulfuric acid and sodium chloride, at a temperature of 80 °C for 48 h under reflux. The effect of PN-to-SMS ratio was examined. It was shown that simultaneous leaching of two different types of marine resources was possible resulting in high dissolution rates of metals. The proposed process has many advantages as it does not require pyrometallurgical pretreatment, and yields solid products (i.e., silica, barite, elemental sulfur, albite, microcline, muscovite), which might be utilized for various industrial applications.

Highlights

Polymetallic nodules (PN), iron-manganese crusts (Fe-MnC) and seafloor massive sulfides (SMS)deposits, due to their high content of various economically important metals (i.e., Cu, Ag, Zn, Mn, REE, etc.), have been identified as important marine mineral resources for the future [1,2]
It was shown that simultaneous leaching of two different types of marine resources was possible resulting in high dissolution rates of metals
We suggested that polymetallic nodules might serve as a potential source of MnO2 acting as an oxidant for leaching of metals from SMS

Summary

Introduction

Polymetallic nodules (PN), iron-manganese crusts (Fe-MnC) and seafloor massive sulfides (SMS)deposits, due to their high content of various economically important metals (i.e., Cu, Ag, Zn, Mn, REE, etc.), have been identified as important marine mineral resources for the future [1,2]. Polymetallic nodules (PN), iron-manganese crusts (Fe-MnC) and seafloor massive sulfides (SMS). Each type of deposit presents individual challenges at every stage of exploration, exploitation, and metal extraction cycle [3]. SMS are metallic sulfide ores, while PN and Fe-MnC are metallic oxide ores, their processing requires different methodologies. Whereas sulfides are conventionally processed by flotation [4], leaching has become an efficient method for the extraction of metals from oxides [5]. The complex mineralogy and rapid oxidation of SMS provide challenges to conventional beneficiation by flotation [6,7,8], a new process to extract metals simultaneously by leaching of SMS and PN is proposed in this paper. The simultaneous leaching of manganese dioxide and sulfides such as chalcopyrite [9,10], sphalerite [11], and pyrite [12] in acid media has been investigated

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