Environmental Engineering Reference
In-Depth Information
Table 7.3: Effect of H
2
O
2
on leaching of Ni [From ref.
475
. Reprinted with permission].
Amount of Ni leached out (wt.%)
Coked catalyst
Decoked catalyst
Oxalic acid
3
.
6
80
.
3
Oxalic acid
+
H
2
O
2
47
.
0
76
.
5
both additives had a similar effect
[485]
. However, as
Fig. 7.6
shows, for both V and Ni, the
most efficient system comprised the mixture of Fe(NO
3
)
3
+
oxalic acid. However, with this
system, the unwanted removal of Mo occurred as well. The Fe(NO
3
)
3
was more efficient than
Fe
3
(SO
4
)
2
presumably because of the higher oxidation strength of the nitrate group
[488]
.It
Figure 7.6: Effect of additives on leaching efficiency of oxalic acid [From ref.
488
. Reprinted
with permission].
