stahl + eisen 03/2020 Leseprobe

■Economic return: potential for highly
rfitable reer aluable etal
(Cobalt, Nickel and Lithium)
Social ■ impact: closing the loop with
reuse of battery materials. Image promotion
of the EV industry and brand recognition
through engagement in battery
recycling
Supply ■ chain: without recycling, a shortage
of supply in several key raw materials
could be faced
■Regulatory: market players are assigned
or delegated with the responsibility of EV
battery recycling by government regulations
globally
Sustainable: ■ closed loop economy enabled
by innovative clean technology
There are currently two dominant process
routes for full processing / recycling
of LIBs: hydrometallurgical and pyrometallurgical
processes. The hydrometallurgical
process consumes acidic / basic /
industrial solvents, which are expensive
and require additional processing to treat
the toxic wastewater. It is also limited by
a low reaction speed and a complicated
process route. The pyrometallurgical
process involves melting at high temperatures,
which translates into high energy
consumption (and cost), and high environmental
emissions. The resulting
extracted metal requires subsequent
hydrometallurgical processing to further
separate the products. 4
The major drawbacks of current LIB
recycling technologies can be summarized
as a low product value from partial
processing (physical separation) and a
high operating cost for full processing
(physical + chemical separation), which
requires chemical conversion and metallurgical
separation.
The current high operating cost of
the chemical separation processes naturally
invites interest to develop a process
that can avoid both the high temperature
operations involving melting
of metals or oxides, as well as the operating
expenses associated with usage
of solvent extraction (and to a degree
hydrometallurgical altogether). 5 Given
Total number of EVs in circulation globally
(millions)
160
140
120
100
80
60
40
20
0
2018 2020 2025 2030
these unique design requirements, solid
state processes involving conversion of
elements of interest into desired forms
in a solid solid or solid gas reaction regime
become ideal candidates to achieve
the required chemical separation in the
EV LIB recycling exercise.
One of the most notable and well
developed solid state processes used in
modern metallurgical operations is the
production of Direct Reduced Iron (DRI)
for use in steelmaking, which can shed
much light on the design concept of a
solid state process for EV LIB recycling.
What can we learn from the
production of DRI?
DRI is produced from the direct reduction
of iron ore (in the form of lumps,
pellets, or fines into iron a reducing
gas or elemental carbon produced from
natural gas or coal. Many ores are suitable
for direct reduction. Direct reduction
processes can be broadly categorized
into two categories: gas-based and coalbased.
In both cases, the objective of the
process is to remove the oxygen contained
in various forms of ore, converting
it to metallic form in solid state.
The direct reduction process is comparativel
energ efficient as no melting
New EVs manufactured (millions)
50
45
40
35
30
25
20
15
10
5
0
2018 2020 2025 2030
RoW
China
is involved, with the reduction reactions
taking place below the melting point of
the metal in question (iron, in this case).
Today, direct reduction processes have
een developed to specificall overcome
the difficulties of conventional last
furnaces, the major production route
for primary steel production worldwide.
The initial capital investment and operating
costs of direct reduction plants
are generally lower than integrated steel
plants and are more suitable in locations
where supplies of high-grade coking
coal are limited but steel scrap is
generally available for recycling and
charging at an electric arc furnace. In
gas-based DRI processes, the charge
mix is introduced into a cylindrical
refractory-lined shaft furnace, where it
descends gravit ow and is contacted
upward owing reducing gas
(hydrogen and carbon monoxide),
which reacts with it to reduce the material
prior to producing DRI for discharge.
6
In various forms of coal based DRI
processes, the iron-bearing charge materials
to the DR reactor consist of a
miture of pellets andor lump ore, uxes
such as limestone and/or dolomite
and high volatile coal or lignite. There
Spent LIBs
Recycled
battery metals
~6 wt% Li
~18 wt% Ni
~18 wt% Co
Physical
Separation
Black
Mass
XProEM Process
~99,5 wt% Li
~99,9 wt% Ni
~99,9 wt% Co
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