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L. Xu and S. Ma
Table 1 Zinc residues
Element
Zn
Pb
Fe
S
SiO 2
CaO
Ag
Ge
wt%
17–19
5–7
18–22
7–9
3–4
5–7
0.014–0.018
0.016–0.022
Table 2 Production data
Item
Unit
Value
Zn residues
t/h (dry)
~22
Crushed coal
t/h
~2.5
Quartz
t/h
~2.0
Natural Gas
Nm 3 /h
~1700
O 2
Nm 3 /h, 85% O 2
~4300
Air
Nm 3 /h
~5000
SSC slag is discharged into the existing FF through chute and is reduced and
volatilized in FF to recover lead and zinc. The hot slag of SSC and reduction furnace
of lead system are treated by fuming furnace, and pulverized coal is injected as fuel
and reductant. The offgas of FF is cooled by the waste heat boiler, purified by the
tube cooler and bag filter, and the collected dust is leached. The purified offgas is
sent to the existing desulfurization system. The slag produced by FF contains zinc
< 2.0 and lead < 0.2%.
Production Indicators
SSC
(1) Raw materials
Up to now, the treatment of zinc residues by SSC can reach 22 t/h (dry). Due to the
large amount of zinc residues in the plant, lead-zinc oxide ore has not been treated.
The composition of zinc residues is shown in Table 1.
(2) Input
The production data of SSC are shown in Table 2.
Among them, the calorific value of crushed coal is 5000 kcal/kg and natural gas
is 8300 kcal/Nm
3 .
According to Table 2, the consumption of natural gas and crushed coal is converted
into standard coal, and the consumption of standard coal per ton of zinc residues is
~200 kgce/t.