A New Era in Smelting Sustainability—Intensification …
71
Fig. 3 Typical flowsheet for
application of the
side-blowing process
has been applied at a number of lead smelting plants for molten slag reduction, as
part of a multi-furnace flowsheet operated in series (Fig. 3) [11].
The side-blowing process appears susceptible to suffer from a range of issues,
many of which are also inherent to the Vanyukov process, namely:
• Difficulties recovering from a partially or completely solidified bath, due to an
inability to provide significant heat input for bath remelting, other than through
the installation of roof-mounted burners.
• Low flowsheet availability due to the operation of multiple vessels in series, meaning a complete stop to production in the event of problems with one or more of
the processing units.
• Issues with independent regulation of the bath temperature and oxygen potential due to a reliance on efficient oxygen transfer through the bath between the
submerged injection points (tuyeres) and roof-fed coal used as both a fuel and
reductant.
• Difficulties accessing the injection tuyeres for inspections, maintenance and preventing molten material backflow in the event of a loss in process air/oxygen supply
due to the inability to rotate the furnace in the same manner as for PS converter
and SKS/QSL vessels.
There is currently limited publicly available literature and data covering application of the process for the treatment of purely solid, zinc-bearing feeds such as leach
residues, although a variant of the technology seems to have been used for the batch
fuming of zinc from molten slag in a similar manner to the box fuming process.
Comparison with Plasma Process
The plasma furnace has been developed over a number of years, and its potential in
zinc fuming applications was recognised, with the implementation of zinc fuming
plants at Hoyanger, Norway and Beerse, Belgium [12]. The main apparent advantage
of this process is use of a high-temperature plasma “burner” with relatively low gas
71
Fig. 3 Typical flowsheet for
application of the
side-blowing process
has been applied at a number of lead smelting plants for molten slag reduction, as
part of a multi-furnace flowsheet operated in series (Fig. 3) [11].
The side-blowing process appears susceptible to suffer from a range of issues,
many of which are also inherent to the Vanyukov process, namely:
• Difficulties recovering from a partially or completely solidified bath, due to an
inability to provide significant heat input for bath remelting, other than through
the installation of roof-mounted burners.
• Low flowsheet availability due to the operation of multiple vessels in series, meaning a complete stop to production in the event of problems with one or more of
the processing units.
• Issues with independent regulation of the bath temperature and oxygen potential due to a reliance on efficient oxygen transfer through the bath between the
submerged injection points (tuyeres) and roof-fed coal used as both a fuel and
reductant.
• Difficulties accessing the injection tuyeres for inspections, maintenance and preventing molten material backflow in the event of a loss in process air/oxygen supply
due to the inability to rotate the furnace in the same manner as for PS converter
and SKS/QSL vessels.
There is currently limited publicly available literature and data covering application of the process for the treatment of purely solid, zinc-bearing feeds such as leach
residues, although a variant of the technology seems to have been used for the batch
fuming of zinc from molten slag in a similar manner to the box fuming process.
Comparison with Plasma Process
The plasma furnace has been developed over a number of years, and its potential in
zinc fuming applications was recognised, with the implementation of zinc fuming
plants at Hoyanger, Norway and Beerse, Belgium [12]. The main apparent advantage
of this process is use of a high-temperature plasma “burner” with relatively low gas