Pyrometallurgical Recovery of Valuable Metals …
543
FY183a
FY183b
FY186a
FY186b
melilite
liquid
melilite
liquid
Fig. 1 Typical microstructures of the reduction slags
slag FY183 and only 2.7 wt% PbO was present in the liquid of slag FY186. Higher
As 2 O 3 (9.1 wt%), Cu 2 O (0.7 wt%), and Sb 2 O 3 (1.7 wt%) were also present in slag
FY183. It is clear that the reductant was not enough to reduce the oxides during
the smelting reduction of slag FY183. It is noticed that the “FeO” concentration in
FY183 (9.6 wt%) is lower than that in FY186 (14 wt%) which might be responsible
for different reduction degree. The plant trials were not stable to achieve high lead
recovery and low PbO in the slag. The processing parameters need to be optimized
to obtain acceptable and stable operations.
Thermodynamic Considerations for New Process to Treat
Copper Smelter Dust
It can be seen from Table 1 that PbSO 4 is the major component in the copper smelter
dust which is also the major component in lead batteries. If PbSO 4 is used for reduction directly, a large amount of PbS will be formed under reducing conditions and
vaporized to form dust again. In the lead battery recycling process, a number of