Zinc Residue Fuming Process in Side-Submerged Combustion …
269
Fig. 1 Process flow of SSC and FF
cannot be effectively disposed of, and valuable metals such as lead and zinc have not
been recovered.
Based on the above reasons, Huize smelter intends to build a new SSC in the
existing plant, adjust the zinc residues treatment process to SSC + FF, and realize
the treatment of 150,000 t/a of zinc residues, while processing a small amount of
low-grade lead-zinc oxide ore. The SSC and DCS of the project were contracted by
ENFI and started design in January 2018 and completed by the end of July 2019. Up
to now, the project has been running continuously for more than two months, and
the service life of side lance has exceeded two months.
Process Flow
SSC is used to melt zinc residues. Natural gas is used as fuel, and crushed coal is
used to heat up the molten bath and maintain the weak reductive atmosphere in the
furnace. Because of the high iron content of zinc residues, quartz is added to reduce
the melting point of the slag and form a FeO–SiO 2 –CaO slag with low melting point.
SSC feeds continuously and discharges slag intermittently. Zinc residues, crushed
coal, and quartz are metered and added into the furnace by moving belt. Natural gas
and oxygen-enriched air are injected into the side lance to control the temperature
of the molten bath from 1200 to 1300 °C. Zinc residues melt in SSC, part of lead
and zinc volatilizes into the offgas, and sulfur enters the offgas in the form of SO 2 .
The offgas of SSC is cooled by the waste heat boiler and purified by the electrostatic
precipitator. The SO 2 content of the purified offgas is 3–4%, which is combined with
the offgas of the zinc roaster to produce acid. The collected dust is leached.
269
Fig. 1 Process flow of SSC and FF
cannot be effectively disposed of, and valuable metals such as lead and zinc have not
been recovered.
Based on the above reasons, Huize smelter intends to build a new SSC in the
existing plant, adjust the zinc residues treatment process to SSC + FF, and realize
the treatment of 150,000 t/a of zinc residues, while processing a small amount of
low-grade lead-zinc oxide ore. The SSC and DCS of the project were contracted by
ENFI and started design in January 2018 and completed by the end of July 2019. Up
to now, the project has been running continuously for more than two months, and
the service life of side lance has exceeded two months.
Process Flow
SSC is used to melt zinc residues. Natural gas is used as fuel, and crushed coal is
used to heat up the molten bath and maintain the weak reductive atmosphere in the
furnace. Because of the high iron content of zinc residues, quartz is added to reduce
the melting point of the slag and form a FeO–SiO 2 –CaO slag with low melting point.
SSC feeds continuously and discharges slag intermittently. Zinc residues, crushed
coal, and quartz are metered and added into the furnace by moving belt. Natural gas
and oxygen-enriched air are injected into the side lance to control the temperature
of the molten bath from 1200 to 1300 °C. Zinc residues melt in SSC, part of lead
and zinc volatilizes into the offgas, and sulfur enters the offgas in the form of SO 2 .
The offgas of SSC is cooled by the waste heat boiler and purified by the electrostatic
precipitator. The SO 2 content of the purified offgas is 3–4%, which is combined with
the offgas of the zinc roaster to produce acid. The collected dust is leached.