Ye-hui-zi WU, Kang-gen ZHOU, Chang-hong PENG, Kui YI, Jing-kun DENG, Zai-rong QIU, Wei CHEN, Ke-jing ZHANG
A sustainable approach for recovering battery
grade FePO4 and Li2CO3 from Al/F-bearing spent
LiFePO4/C powder was proposed, including acid leaching, fluorinated
coordination precipitation, homogeneous precipitation, and high-temperature
precipitation. Under the optimal conditions, the leaching efficiencies of Li,
Fe, P, Al, and F were 97.6%, 97.1%, 97.1%, 72.5%, and 63.3%, respectively. The
effects of different parameters on the removal of Al/F impurities were
systematically evaluated, indicating about 99.4% Al and 96.4% F in the leachate
were precipitated in the form of Na3Li3Al2F12,
and their residual concentrations were only 0.0124 and 0.328 g/L, respectively,
which could be directly used to prepare battery grade FePO4 (99.68% in
purity). Lithium in the Al/F-bearing residue could be extracted through CaCO3−CaSO4 roasting followed by acid leaching, ultimately obtaining 99.87% purity of Li2CO3.
The recovery rates of Li and Fe were 96.88% and 92.85%, respectively. An
economic evaluation demonstrated that the process was profitable.
and Cu 
evolve into S 
, and the Bs 
rotates into
the orientations near R-Bs and S. With increasing deformation, the S, Bs, and
R-Bs orientations further rotate around the TD axis and disperse into new
orientations, forming recrystallized grains. The shearing bands with different
initial orientations exhibit similar orientation evolution patterns, all of
which evolve from the initial orientation to a series of recrystallization
orientations.
tensile twins
during the tensile deformation, resulting in a reduction in plasticity.
. The growth of D019-χ phase depends on the diffusions of Ti
and Mo, and consumes a large number of elements. This progress leads to the
appearance of γ′ precipitation
depletion zone (PDZ) around D019-χ phase. The addition of Ni improves the stability of L12-γ′ phase and the mechanical properties
of Co-based superalloys.
