Lead Scrap Melting Furnace
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:
• Blast Furnace
• 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:
• Charging
• Tapping
• 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: In tapping process the slag is removed then tapping molten lead is also removed from the furnace into ladles or molds. To keep the metal molten, some smelters tap metal directly into a holding kettle. Then comes the task of solidification of molten lead. The smelter casts the molten lead into blocks so that it can be used for the further treatments or operations in various purposes.
It is important to understand the process called Tuyeres Punching. In this process, air is forced into a blast furnace to help or facilitate the process of combustion through Tuyeres. During this process, the Tuyeres (nozzle) begin to fill with accretions and must be punched manually so that it can remain unblocked. By using a steel rod the obstruction of tuyere is done. The cover of tuyere is removed and then the rod is inserted. Once having the accretions done, the cover is replaced. By adapting "off-the-shelf" automatic system tuyere puncher, the exposure of lead has been reduced. But sometimes this automatic system requires cleaning using a rod or jackhammer physically.
Reverberatory Furnaces are those furnaces which is designed and operated in the production of a nearly pure and soft Lead. During charging and tapping Reverberatory Furnace emit high level of Lead Fume.
Charging
- Feed conveyor transfer point and charging point are the areas where emissions or spillage may occur.
- Leaks in refractory material causes emissions which allow the Lead dust and fumes to escape.
- If bridging occurs during charging wet materials or furnace runs at a positive pressure Lead Fume and dust may be emitted from the Reverberatory Furnace
In Reverberatory Furnace Tapping process the molten Lead and slag is poured from the furnace into Ladles or Molds. Like Blast Furnace, to keep the metal molten, some smelters tap metal directly into a holding kettle. Then comes the task of solidification of molten lead. The smelter casts the molten lead into blocks so that it can be used for the further treatments or operations in various purposes.
