DRI Products
The MIDREX® Process can produce three different product forms, depending on the application: cold DRI (CDRI), hot briquetted iron (HBI) and hot DRI (HDRI).
CDRI is generally stored for later use in a nearby electric arc furnace (EAF). HBI is a briquetted product that is ideal for storage and for shipping to distant consumers. HDRI is discharged hot from the shaft furnace and transported to an EAF for melting.
CDRI is generally stored for later use in a nearby electric arc furnace (EAF). HBI is a briquetted product that is ideal for storage and for shipping to distant consumers. HDRI is discharged hot from the shaft furnace and transported to an EAF for melting.
| CDRI | HBI | HDRI |
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CDRI
Most MIDREX® Plants built to-date produce CDRI. After reduction, the pellets and lump are cooled in the lower part of the MIDREX® Shaft Furnace to about 50° C. This material is temporarily stored in silos to passivate it before transportation to an adjacent EAF or another site. CDRI is ideal for continuous charging to the EAF.
Most MIDREX® Plants built to-date produce CDRI. After reduction, the pellets and lump are cooled in the lower part of the MIDREX® Shaft Furnace to about 50° C. This material is temporarily stored in silos to passivate it before transportation to an adjacent EAF or another site. CDRI is ideal for continuous charging to the EAF.
HBI and Hot Briquetting
Hot briquetting of DRI has been practiced on an industrial scale for more than three decades and is now the preferred method of preparing DRI for storage and transport internationally. To make HBI, hot DRI is discharged from the MIDREX® Shaft Furnace at about 700° C and compressed into pillow-shaped briquettes with a typical size of 30 x 50 x 110 mm. HBI is 50 percent denser than DRI pellets and lump, which reduces the tendency for reoxidation.
Hot briquetting of DRI has been practiced on an industrial scale for more than three decades and is now the preferred method of preparing DRI for storage and transport internationally. To make HBI, hot DRI is discharged from the MIDREX® Shaft Furnace at about 700° C and compressed into pillow-shaped briquettes with a typical size of 30 x 50 x 110 mm. HBI is 50 percent denser than DRI pellets and lump, which reduces the tendency for reoxidation.
This enables HBI to be stored and handled without special precautions as recognized by the International Maritime Organization (IMO). HBI can be moved using typical scrap handling equipment and easily batch charged to the EAF, thus requiring no capital investment by the steel mill. HBI can be continuously charged with specially-designed systems.
HDRI
Charging of HDRI to an adjacent EAF at 600° C or higher provides the optimum way for DRI users to increase productivity and reduce cost. Midrex offers three methods for hot transport: HOTLINK®, hot transport conveyor and hot transport vessels.
Melting Benefits
HDRI
Charging of HDRI to an adjacent EAF at 600° C or higher provides the optimum way for DRI users to increase productivity and reduce cost. Midrex offers three methods for hot transport: HOTLINK®, hot transport conveyor and hot transport vessels.
Melting Benefits
- Increases EAF productivity by 15-20%
- Decreases EAF electricity requirements by 120-140 kWh/t liquid steel
- Decreases EAF electrode consumption by 0.5-0.6 kg/t liquid steel
- Decreases EAF refractory consumption by 1.8-2 kg/t liquid steel
Flexibility
- Combination plants allow for simultaneous discharge of HDRI and CDRI or HBI as determined by EAF operation and market conditions
- MIDREX Plant can continue operation when EAF is off-line
- EAF can continue operation using stored CDRI/HBI when MIDREX® Plant is off-line
- Use of proprietary SIMPAX® Software for process automation and HDRI quality prediction enables plant operators to optimize plant availability, efficiency and productivity
