Abstract
This paper brings an innovative processing route of manganese deep-sea nodules, which results in completely new grades of alloys. Deep-sea nodules were processed by aluminothermic method without the extraction of individual elements, producing complexly alloyed manganese-based “natural alloys”. Three levels of the amount of aluminum were used for the aluminothermic reduction, and hence the alloys differ strongly in the amount of aluminum, which has a significant effect on their phase composition. The alloys have very high wear resistance, comparable with tool steel. The disadvantage of low-aluminum alloy is the susceptibility to local thermal cracking during friction, which occurs especially in the case of a dry sliding wear against the static partner with low thermal conductivity.
Highlights
Polymetallic deep-sea nodules represent the untapped sources of valuable base metals such as Mn, Ni, Cu, and Co, as well as trace amounts of Zn, Mo, Ti, V, Zr, Si, and Al, and rare earth metals (REEs) [1,2,3]
Clarion–Clipperton Fracture Zones (CCZ) in the Pacific Ocean are the area of greatest economic interest with the total amount of manganese, nickel, and cobalt contained in the nodules exceed to that of terrestrial reserves [2,5]
The iron and silicon amount is decreasing with the increasing content of aluminum used for reduction, while the other elements do not exhibit systematic trends
Summary
Polymetallic deep-sea nodules represent the untapped sources of valuable base metals such as Mn, Ni, Cu, and Co, as well as trace amounts of Zn, Mo, Ti, V, Zr, Si, and Al, and rare earth metals (REEs) [1,2,3]. The. Clarion–Clipperton Fracture Zones (CCZ) in the Pacific Ocean are the area of greatest economic interest with the total amount of manganese, nickel, and cobalt contained in the nodules exceed to that of terrestrial reserves [2,5]. The nodules from CCZ contain 29.1% Mn, 5.4% Fe, 1.29% Ni, 1.19% Cu, and 0.23% Co [6]. Previous research has focused mainly on extraction of Cu, Ni, and Co from the polymetallic nodules; Mn extraction has gained more attention recently [6,8,9,10,11] The major crystalline phases in the nodules are Todorokite, (mixed oxides of Mn, Mg, Ca, Na, and K), Buserite (hydrated oxides of Mn and Na), Birnessite ((Na7 Ca3 )Mn70 O140 ·28H2 O) and Vernadite (δ-MnO2 ) or Manganosite (MnO) [1,2,3,7].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
