Zinc Residue Fuming Process in Side-Submerged Combustion …
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Table 3 Slag
Element Zn
Pb
Fe
S
SiO 2
CaO
Ag
Ge
wt%
16–20 0.5–2 24–26 0.1–0.3 18–21 11–13 0.002–0.003 0.004–0.007
Table 4 Dust
Element
Zn
Pb
S
Ag
Ge
wt%
35–45
25–35
4–6
0.06–0.1
0.05–0.09
Table 5 Volatilization rates
Element
Zn
Pb
Ag
Ge
%
25–30
70–80
75–85
70–80
(3) Output
The composition of slag and dust produced by SSC is shown in Tables 3 and 4.
The volatilization rates of Zn, Pb, Ag, and Ge in SSC are shown in Table 5.
The SO 2 content in the offgas of SSC is 3–4% after being treated by waste heat
boiler and electrostatic precipitator and mixed with the offgas of zinc roaster to
produce acid. The SO 2 content in the offgas after mixing is 5–6%.
FF
(1) Raw materials
FF is used to deal with SSC slag while dealing with some zinc residues. The
composition of SSC slag is shown in Table 3.
(2) Input
According to the calculation of treating only SSC slag, the consumption of pulverized
coal per ton of SSC slag is about 220 kg, and the calorific value of pulverized coal
is 5200 kcal/kg. According to the calculation of 0.65 t SSC slag per ton of zinc
residues, the consumption of converted standard coal per ton of zinc residues in FF
is ~110 kgce/t.
(3) Output
The composition of slag and dust produced by FF is shown in Tables 6 and 7.
The volatilization rates of Zn, Pb, Ag, and Ge in FF are shown in Table 8.
The SO 2 content in the offgas is less than 0.2% after being treated by waste heat
boiler, tube cooler, and bag filter, which is sent to the existing desulfurization system
for treatment.