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Cyanex 272 and subsequently stripped from the extract with the aqueous solution of ammonia.
However, if present, Fe would interfere with the V separation. After the separation of Mo and
V, the efficient separation of Ni and Co from Al could be achieved using the mixture of LIX 63
and SYNEX DN-052 in the EXXSOL D 80 ( Fig. 11.21a ).
In another study, Zhang et al. [677] evaluated commercial reagents, such as TR-83, PC-88A,
and PIA-8, under similar conditions. Among these reagents, PIA-8 exhibited a similar
performance as CYANEX-272. Thus, Mo could be nearly completely extracted from the
solution at a pH approaching zero together with V, Fe and small amounts of Al. These
co-extracted metals could be scrubbed from the solvent phase using H 2 SO 4 before Mo was
recovered by stripping using 5 to 7% ammonia. Vanadium could be further recovered from the
scrub solution still containing Fe and Al after adjusting pH to about 1.5 using Ca(OH) 2 .
Subsequently, V could be recovered by stripping with 6% ammonia. Figure 11.22 [622] shows
that for the 20 vol.% TR-83 in EXXSOL D80 and PC-88A in EXXSOL D80, the separation of
Mo was interfered with Fe.
Figure 11.21 [622] shows that the separation of Ni and Co from Al is possible, but it may
require large adjustment of pH. This problem was elevated using LIX 63 and/or the mixture of
Figure 11.22: Extraction of metals (A) with TR-85 in EXXSOL D80 and (B) with PC-88A in
EXXSOL D80 [From ref. 622 . Reprinted with permission].
 
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