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Furnace is a kind of equipment that is used in process of smelting.
It is basically used for smelting process. Smelting is a process
which involves the reduction of Lead-bearing scrap into metallic
Lead in a furnace. The melting furnace has been designed for
smelting small size lump scrap of iron, steel, aluminum, any
nonferrous metals and waste metal shavings covered with oil or
grinding slurry without preliminary cleaning and briquetting. The
product of smelting, depending on initial raw material, can be
either a branded metal, or an ingot for a further processing.
Lead Scrap Furnace:
Each furnace is designed and operated to produce a certain Lead
product. The following furnaces are the most common types of
smelting furnaces used in the industry:
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Blast Furnace
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Reverberatory Furnace
Blast
furnaces are designed and operated to produce a hard (high alloy
content) Lead product. Blast furnaces emit high levels of Lead fume
during the the following processes:
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Charging
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Tapping
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Tuyere Punching
Charging: Emissions may occur at blast furnace feed conveyor
transfer points and charging points.Spillage of Lead-containing dust
may occur if bucket elevators, conveyors, or skip hoists are
overfilled. Lead fume and dust may be emitted from the blast furnace
if the charge level is too low.
Blast
furnace tapping operations involve removing the slag and then
tapping molten Lead from the furnace into molds or ladles. Some
smelters tap metal directly into a holding kettle which keeps the
metal molten for refining. The other smelters cast the furnace metal
into blocks and allow the blocks to solidify.
Blast air for the combustion process enters the blast furnace
through "tuyeres." The tuyeres occasionally begin to fill
with accretions and must be physically punched, usually with a steel
rod, to keep them unobstructed. The conventional method used for
this task is to remove the cover of the tuyeres and insert the steel
rod. After the accretions have been "punched," the cover is
replaced. Recently smelters have been able to adapt an
"off-the-shelf" automatic tuyere puncher that has greatly reduced
employee Lead exposure. However, even with the automatic system
there are occasions when the tuyere pipe has to be cleared by using
a jackhammer or rod.
Reverberatory furnaces are designed and operated to produce a
soft, nearly pure Lead product. Reverberatory furnaces emit high
levels of Lead fume during the following processes:
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Charging
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Tapping Lead and Slag

Charging
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Spillage or emissions may occur at feed conveyor transfer and
charging points of the reverberatory furnace.
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Emissions may occur through leaks in refractory material, which
allow Lead dust and fumes to escape.
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Lead fume and dust may be emitted from the reverberatory furnace if
the furnace is run at positive pressure or if bridging occurs during
charging wet materials.
Reverberatory furnace tapping operations involve pouring the
molten Lead and slag from the furnace into molds or ladles. Some
smelters tap metal directly into a holding kettle, which keeps the
metal molten for refining. Other smelters cast the furnace metal
into blocks and allow the blocks to solidify.
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