Glossary
Steel and refining
Direct reduced iron
Also known as DRI, sponge iron, HBI, hot-briquetted iron.
Direct reduced iron (DRI) is iron produced from iron-ore pellets by reducing the ore in the solid state, using natural gas, hydrogen or coal as the reducing agent. DRI feeds electric arc furnaces and is the leading candidate for low-carbon iron-making, particularly with hydrogen as the reducer.
DRI dust-handling issues
DRI processes generate fine iron-bearing dust at multiple points:
- DRI plant baghouse hoppers
- DRI cooler dust extraction
- HBI (hot-briquetted iron) hot screening dust
- Storage-silo discharge points
The dust is fine, dense, and prone to bridging under self-weight in tall silos. Sonic horns on DRI dust hoppers prevent the discharge interruptions that would otherwise force operator intervention.
Related terms
Related terms
- Electric arc furnaceAn EAF melts steel scrap and DRI in a refractory-lined vessel using an electric arc. Dust collection is via a roof-evacuation duct to a large baghouse, prone to compartment fouling.
- HopperA hopper is an inverted-pyramid or conical vessel for storing and discharging bulk solids. Bridging and rat-holing are the universal failure modes; sonic horns are a clean, low-maintenance remedy.
- Bridging (bulk-solids)Bridging (also arching) is the formation of a stable arch of bulk solids above the discharge outlet of a hopper or silo, stopping material flow. The universal failure mode of bulk-solids storage.