The use of Hot Briquetted Iron (HBI) in the Electric Arc Furnace (EAF)
Hot Briquetted Iron (HBI) is a manufactured product with guaranteed specifications, which allows steelmakers to produce grades of steel not possible with scrap charges alone.
Benefits from the Using HBI in the Electric Arc Furnace Are:
- Chemical composition is well defined
- Physical properties are known
- Can be used in either long or short arc operation
- Can be used in both AC and DC Electric Arc Furnace’s (EAF)
- Lower residual content than scrap
- High apparent density of > 5000 kg/m3 (>312 lb/ft3)
- Higher bulk density than scrap (average: 2800 kg/m3 or 175 lb/ft 3)
- Rapidly sinks through the slag for rapid melting on the liquid steel
- Can be used in scrap preheating processes
- Can be stored outdoors in bulk
- Can be moved easily on conveyor belts
- Free-flowing from bins
- Can be charged in scrap buckets
- Can be continuously charged
- Controlled carbon content
- Useful in slag foaming
- Controlled boil rinses nitrogen from steel bath
- Charge Hot Briquetted Iron (HBI) on top of heavy scrap/bundles to maximize bucket charge density
- Fill the rest of bucket according to local practices
- Use Hot Briquetted Iron (HBI) in the last bucket when several buckets are used to improve refining of the melt
Typical Operating Results
Hot Briquetted Iron (HBI) Preheating
- Industrial experiences under certain operating conditions and equipment have demonstrated that Hot Briquetted Iron (HBI) can be preheated to temperatures greater than 750°C in gases containing less than 5% oxygen either as part of the scrap mix or when using 100% Hot Briquetted Iron (HBI).
- By preheating the Hot Briquetted Iron (HBI), the metallization ratio is increased by about 2% when reaching temperatures greater than 550°C. However, the carbon content will be decreased.
- During preheating, some re-oxidation occurs. However, the grain in metallization offsets the effect.