THE DEVELOPMENT OF COBALT MINERALIZATION, BOU AZZER (MOROCCO)

Abstract

Cobalt, a magnetic transition metal, plays a pivotal role in various industrial sectors, including the production of alloys, batteries, and catalysts. Its economic significance is underscored by its increasing utilization in emerging technologies, particularly in electric vehicles and electronic devices. The formation of cobalt is intricately tied to complex geological processes, where, under specific conditions, it concentrates in minerals such as cobaltite and erythrite. Cobalt deposits often arise in conjunction with other metals like nickel and copper, necessitating specialized mining techniques for extraction. A notable illustration of cobalt mineralization is evident in the Bou Azzer region in Morocco. Renowned for its obducted ophiolitic complexes formed during the Pan-African collision in the Neoproterozoic (Cryogenian and Ediacaran), this area showcases the coexistence of Co-Ni-Fe arsenide and sulf-arsenide mineralization within a unique geological context. The hydrothermal phenomenon linked to the serpentinization of the ultrabasites in the Bou Azzer ophiolitic complex is accountable for these cobalt-rich mineralizations. The exploration of cobalt formation at Bou Azzer provides a captivating glimpse into the geological processes responsible for the concentration of this valuable metal. These findings not only elucidate the origins of cobalt but also enhance our comprehension of the geological evolution of the region, emphasizing the pivotal role of geology in the cobalt industry. This research is grounded in a comprehensive literature review of prior studies and the examination of a thin section prepared from a serpentinite sample sourced from the Bou Azzer mining area.

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2nd International Conference on Frontiers
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December 4-5, 2023 : Konya, Turkey
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© 2023 Published by AS-Proceedings
403
THE DEVELOPMENT OF COBALT MINERALIZATION, BOU
AZZER (MOROCCO)
Laadimi Yahia*, Tabit Abdelhalim1, Algouti Ahmed1, Aydda Ali2, Lakhlili Mohamed1, Majdouli
Kaouthar1, Lamrani Khadija1, Ramouch Khawla1, Toudamrini Hanane1
1 Laboratory: Geosciences, Geotourism, Natural Hazards and Remote Sensing/Faculty of Science Semlalia, University Cadi
Ayyad, Morocco
2Laboratory: Geosciences, Environment and Geomatic/ Faculty of Sciences Agadir Ibn Zohr, Morocco
*yahyalaadimii@gamil.com
Abstract – Cobalt, a magnetic transition metal, plays a pivotal role in various industrial sectors, including
the production of alloys, batteries, and catalysts. Its economic significance is underscored by its
increasing utilization in emerging technologies, particularly in electric vehicles and electronic devices.
The formation of cobalt is intricately tied to complex geological processes, where, under specific
conditions, it concentrates in minerals such as cobaltite and erythrite. Cobalt deposits often arise in
conjunction with other metals like nickel and copper, necessitating specialized mining techniques for
extraction.
A notable illustration of cobalt mineralization is evident in the Bou Azzer region in Morocco.
Renowned for its obducted ophiolitic complexes formed during the Pan-African collision in the
Neoproterozoic (Cryogenian and Ediacaran), this area showcases the coexistence of Co-Ni-Fe arsenide
and sulf-arsenide mineralization within a unique geological context. The hydrothermal phenomenon
linked to the serpentinization of the ultrabasites in the Bou Azzer ophiolitic complex is accountable for
these cobalt-rich mineralizations.
The exploration of cobalt formation at Bou Azzer provides a captivating glimpse into the geological
processes responsible for the concentration of this valuable metal. These findings not only elucidate the
origins of cobalt but also enhance our comprehension of the geological evolution of the region,
emphasizing the pivotal role of geology in the cobalt industry. This research is grounded in a
comprehensive literature review of prior studies and the examination of a thin section prepared from a
serpentinite sample sourced from the Bou Azzer mining area.
Keywords – Thin Section, Ophiolitic Complexes, Co-Ni-Fe Arsenide And Sulf-Arsenide Mineralization, Bou Azzer Buttonhole,
Hydrothermal Phenomena
I. INTRODUCTION
Cobalt as an element is essential in many
strategic domains, because of its particular
properties: its high melting point and the fact that it
retains its strength and magnetic properties even at
high temperatures. The aforementioned criteria
reinforce the world's demand for cobalt in various
industrial applications: the production of
rechargeable batteries, superalloys or magnets, as
well as a variety of chemicals with applications as
diverse as catalysts, adhesives, pigments and
pharmaceuticals. Co is dispersed in continental
crust in rocks ranging from Precambrian to recent
ages, with a Clarke of 25 g/t (Clarke = average Co
content in continental crust). Various processes
have led to the concentration of the metal in
potentially exploitable deposits magmatic

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differentiation, chemical alteration or hydrothermal
activity. hydrothermal activity. Cobalt is almost
always extracted from copper (Cu) or nickel (Ni)
as a by-product. (Ni) as a by-product. The only
exceptions are the cobalt and nickel deposits at
Bou Azzer, the only mine in the world where Co is
extracted as a primary product.
The Bou Azzer buttonhole contains more than
100 cobalt arsenide mineralized bodies. They are
spatially and genetically associated with
serpentinites, formed by the transformation of
ophiolitic ultrabasites obducted during the Pan-
African collision in the Neoproterozoic
(Cryogenian and Ediacaran).
Fig.1: simplified geological map of the low Atlas[7]
II. MATERIALS AND METHOD
this work is the result of a literature review on
the formation of cobalt in the bou azzer buttonhole.
field visits were then made to collect samples for
the preparation of thin sections, with the aim of
comparing the results obtained with previous work.
the sample is taken from a serpentinite rock on
which a thin section is made and then studied using
a polarizing microscope and a reflection
microscope. the microscopic analysis of this slide
is used to determine the mineralogical composition
of the serpentinite rock and to detect clues to the
formation of cobalt mineralization.
III. RESULTS
The sample studied is taken from a band of
serpentinite trending NE-SW, which is strongly
brecciated and features hematite-filled fractures.
This serpentinite scale is influenced by NE-SW-
trending faults and also contains traces of cobalt
mineralization, identifiable by the presence of the
mineral erythrite.
Fig.2: A- traces of coblate as erythrite. B- hematite-filled
fractures
Analysis of the serpentinite sample under a
polarizing thin section microscope revealed the
presence of the following minerals:
▪ Antigorite: this is a form of serpentine
(polymorphic) that forms under high-
temperature, high-pressure (HT-HP)
conditions high temperature and high pressure
(HT-HP) conditions typical of subduction
zones. This mineral has an elongated fibrous
texture, mainly in an east-west direction. It
colorless under unanalyzed polarized light, and
polarizes into first-order grayish hues.
▪ Lizardite: this mineral occupies most of the
slide and has a mesh texture. It is also
colorless in unanalyzed polarized light and
polarizes in the first shades of gray.
▪ Chrysotile: fills the veins that run through all
the other minerals in the slide. These veins are
generally oriented north-south. In unanalyzed
polarized light, these mineral displays
characteristics similar to those of the mineral
above, and polarizes in first-order shades of
gray and yellow.
▪ Erythrite: is a mineral species composed of
hydrated cobalt arsenate. In natural light, it has
a pink prismatic appearance and third-order
polarization.

405
Fig. 3: Microscopic view of serpentinite sample (Liz:
Lizardite, Atg: antigorite, Ctl: chrysotile, Ery: erythrine).
Observation of the serpentinite section through a
metallographic microscope reveals the presence of
skutterudite in the erythrite prisms, which confirms
the link between serpentinization of ultrabasic
rocks and the generation of cobalt mineralization.
Fig. 4: Metallographic microscope view of serpentinite (Sku:
skutterudite, Ery: Erythrite).
The serpentinite section has a non-
pseudomorphic texture, in which the main mineral
has been completely transformed by the
serpentinization process and the formation of new
serpentinization process and the formation of new
minerals such as lizardite, antigorite antigorite,
chrysotile and erythrite
IV. DISCUSSION
The obtained results have revealed the existence
of a relationship between cobalt mineralization and
the process of serpentinization in ultrabasic rocks.
Serpentinization occurs through the alteration of
olivines containing nickel and cobalt at respective
concentrations of 3900 and 200 ppm [1].
Serpentinization is believed to have occurred in
an open system with the input of carbonic acid,
calcium, and water. In addition to serpentine and
magnetite, calcium and magnesium carbonates, as
well as nickel and cobalt carbonates, are formed.
The cobalt stock is ultimately re-concentrated in
easily leachable minerals such as magnetite and
carbonates.
The Bou Azzer ophiolitic complex is intimately
linked to the Pan-African orogeny, characterized
by a period of convergence leading to closure of
the ocean basin, northward subduction of the COA,
and genesis of a volcanic arc. Serpentinization of
ultrabasites began before the Pan-African B1 phase
and continued throughout this period [1].
Mineralization frequently occurs in fractures and
faults, either as amalgams between serpentinite,
quartz diorite and Ouarzazate Supergroup rocks, or
as cobalt-enriched mineralized cross-cutting faults
between quartz diorite and serpentinite [10]. Both
types of mineralization suggest the importance of a
circulating hydrothermal solution that concentrates
mineralization in fractures and faults.
V. CONCLUSION
In conclusion, the study focused on the formation
of cobalt mineralization in the Bou Azzer
buttonhole, which is associated with serpentinite
rocks resulting from the transformation of
ophiolitic ultrabasites during the Neoproterozoic
Pan-African collision. The research included a
literature review, field visits to collect samples and
microscopic analysis using polarizing and
reflection microscopes.
The study revealed a relationship between cobalt
mineralization and the serpentinization process in
ultrabasic rocks. Serpentinization, which occurs
under open-system conditions with the addition of
carbonic acid, calcium and water, led to the
formation of new minerals and the reconcentration
of cobalt in easily lixiviable minerals such as
magnetite and carbonates.
The Bou Azzer ophiolitic complex, influenced by
the Pan-African orogeny, played an important role
in the geological context of cobalt mineralization.
Mineralization was found in fractures and faults,
indicating the importance of circulating
hydrothermal solutions in the concentration of
cobalt-rich mineral deposits.
VI. REFERENCES
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Constantin, M, (2014), L‘impact de la Serpentinisation
sur les Gisements de Nickel, de Chromite et de Cobalt
du district Minier De Bou Azzer, (Anti-Atlas Central).

406
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