Hot Briquetted Iron (HBI)
Hot Briquetted Iron (HBI) is a premium form of DRI that has been compacted at a temperature greater than 650° C at time of compaction and has a density greater than 5,000 kilograms per cubic meter (5,000 kg/m3).
HBI was developed as a product in order to overcome the problems associated with shipping and handling of DRI – due to the process of compaction it is very much less porous and therefore very much less reactive than DRI and does not suffer from the risk of self-heating associated with DRI.
The principle market for HBI is electric arc furnace (EAF) steelmaking, but HBI also finds application as a trim coolant in basic oxygen furnace (BOF) steelmaking and as blast furnace feedstock.
HBI can be used as blast furnace burden material with the following environmental, productivity and cost benefits:
- Lower carbon dioxide emissions
- Increased blast furnace productivity (increase of about 8% for each 10% increase in burden metallisation)
- Reduced coke rate (decrease of about 7% for each 10% increase in burden metallisation)
Application
- Electric arc furnace (EAF) steelmaking
- Basic oxygen furnace (BOF) steelmaking (HBI is an excellent trim coolant)
- Blast furnace feedstock (BF)
Benefits of Using HBI in the EAF
- Very low residual element content enables production of high quality steel products or use of higher percentage of lower cost scrap in the charge mix
- Known and consistent chemistry, certified by analysis, assists melt consistency
- Consistent shape and form enable efficient material handling and storage
- High density can reduce the number of bucket charges, allows for increased use of lower cost, less dense feedstock and reduces storage space requirements
- Can be continuously charged to the furnace
- Acts as N scavenger = low N content in steel
The Benefits of HBI in the BOF
- HBI provides an optimal BOF charge due to:
- Low levels of residual elements
- Bulk density of ~2.8 t/m3 – higher than scrap
- Same metallic yield as hot metal
- More predictable mass and heat balances