Pb and Other Impurities Recovery …
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Pb Recovery in JX Nippon Mining & Metals
Pb Recovery in Saganoseki Copper Smelter
In the copper smelter, approximately 40% of Pb is distributed into the converter
dust from the raw material, and some Cu is contaminated in the dust. Therefore, a
two-stage Cu removal technology was installed at the Sagaseki Smelter [3, 4]. The
flowsheet for Pb recovery is shown in Fig. 5. Table 2 shows changes in the quality of
each intermediate. In the first stage, Cu is removed by specific gravity separation from
the slurry from the leaching of the converter dust with sulfuric acid. The removed
Cu is sent to the neutralization process and returned to the flash smelting furnace
with neutralized residue. The specific gravity separation of Cu reduces the Cu grade
in the Pb sulfate from 12–14 to 8.4%. In the second stage, the Cu is leached and
removed by ferric leaching from the converter dust to the leaching solution as shown
in Eq. (1).
Cu 2 S + 4Fe 2 (SO 4 ) 3 → CuSO 4 + 4FeSO 4 + S
( 1 )
Fig. 5 Flowsheet for Pb recovery in the Cu smelter
Table 2 Change in intermediate composition (%)
CF dust
Lead sulfate
Cu
Pb
Cu
Pb
Before the installations
16–22
5–10
12–14
16–20
After installation of Cu separation tank (2011/11~)
16–22
5–10
8.4
18–24
After installation of ferric leaching (2014/4~)
16–22
5–10
<1
20–30