Hot Transport of DRI
Midrex provides three methods of transporting hot DRI: HOTLINK®, hot transport conveyor or hot transport vessels. These provide a simple, reliable and economical means for retaining the sensible heat contained in HDRI. All three methods have been commercialized in recently built plants.
For any of the hot transport options, the MIDREX® Plant is designed to produce CDRI or HBI as a secondary product stream when the meltshop cannot accept HDRI. CDRI is produced using an external DRI cooler. For HBI, briquetting machines are located underneath the shaft furnace. Plants are designed to produce the two products simultaneously and to switch from one product to another instantaneously.
Melting Benefits
HOTLINK is based on proven technology and the design, using primarily gravity transport, will minimize HDRI metallization and temperature losses. The HOTLINK system delivers HDRI to the EAF between 600° C and 700° C .Midrex pioneered the hot discharge feature. This configuration of gravity-fed hot DRI has been used on all MIDREX HBI plants to produce more than 50 million tons since 1984.
HOTLINK places a MIDREX® Hot Discharge Furnace just outside and above the exterior wall of the meltshop. This allows hot DRI to be discharged from the shaft furnace to a surge bin and then directly to the EAF. HOTLINK Modules are equipped to handle any upset conditions via the hot DRI surge bin. The primary goal is to supply hot DRI to the EAF as demand requires.
Hot Transport Conveyor
In cases where the meltshop is not adjacent to the MIDREX® Shaft Furnace, an option is to use an insulated mechanical conveyor to transport hot DRI to the meltshop at a temperature of 500° C or higher. In this case, DRI is discharged hot from the furnace onto a fully enclosed and insulated conveyor, which is designed to minimize temperature loss and prevent oxidation.
The conveyors are specially designed for Midrex by Aumund Fördertechnik GmbH.
The DRI is fed to one of two hot DRI storage bins located above the EAF. As one bin is being filled, the other one is discharging HDRI to the EAF. It is critical that the transport method from the shaft furnace to the EAF be capable of delivering HDRI without adversely affecting product quality, while providing maximum operational flexibility. Additionally, the system must be reliable, maintenance friendly and easy to operate.
Module E at Hadeed in Saudi Arabia is the first MIDREX Plant to incorporate this option.
Hot Transport Vessels
Another means for transporting hot DRI to the meltshop is with the use of insulated vessels, normally with a capacity of 60-90 tons. The MIDREX Shaft Furnace is designed for hot discharge and the vessels are filled through a pipe with an air-tight seal. After one vessel is filled, the pipe is closed and another vessel begins to fill. The full vessels are transported by truck or rail to the meltshop.
The use of vessels is ideal for situations in which there is an existing meltshop and it is not possible to locate the shaft furnace close enough to utilize HOTLINK or a hot transport conveyor. Another application is the case of one MIDREX Plant feeding multiple meltshops.
Essar Steel pioneered the use of hot transport vessels in the 1990s and has charged several million tons of hot DRI to the EAFs by this method.
For any of the hot transport options, the MIDREX® Plant is designed to produce CDRI or HBI as a secondary product stream when the meltshop cannot accept HDRI. CDRI is produced using an external DRI cooler. For HBI, briquetting machines are located underneath the shaft furnace. Plants are designed to produce the two products simultaneously and to switch from one product to another instantaneously.
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
- 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
HOTLINK is based on proven technology and the design, using primarily gravity transport, will minimize HDRI metallization and temperature losses. The HOTLINK system delivers HDRI to the EAF between 600° C and 700° C .Midrex pioneered the hot discharge feature. This configuration of gravity-fed hot DRI has been used on all MIDREX HBI plants to produce more than 50 million tons since 1984.
HOTLINK places a MIDREX® Hot Discharge Furnace just outside and above the exterior wall of the meltshop. This allows hot DRI to be discharged from the shaft furnace to a surge bin and then directly to the EAF. HOTLINK Modules are equipped to handle any upset conditions via the hot DRI surge bin. The primary goal is to supply hot DRI to the EAF as demand requires.
Hot Transport Conveyor
In cases where the meltshop is not adjacent to the MIDREX® Shaft Furnace, an option is to use an insulated mechanical conveyor to transport hot DRI to the meltshop at a temperature of 500° C or higher. In this case, DRI is discharged hot from the furnace onto a fully enclosed and insulated conveyor, which is designed to minimize temperature loss and prevent oxidation.
The conveyors are specially designed for Midrex by Aumund Fördertechnik GmbH.
The DRI is fed to one of two hot DRI storage bins located above the EAF. As one bin is being filled, the other one is discharging HDRI to the EAF. It is critical that the transport method from the shaft furnace to the EAF be capable of delivering HDRI without adversely affecting product quality, while providing maximum operational flexibility. Additionally, the system must be reliable, maintenance friendly and easy to operate.
Module E at Hadeed in Saudi Arabia is the first MIDREX Plant to incorporate this option.
Hot Transport Vessels
Another means for transporting hot DRI to the meltshop is with the use of insulated vessels, normally with a capacity of 60-90 tons. The MIDREX Shaft Furnace is designed for hot discharge and the vessels are filled through a pipe with an air-tight seal. After one vessel is filled, the pipe is closed and another vessel begins to fill. The full vessels are transported by truck or rail to the meltshop.
The use of vessels is ideal for situations in which there is an existing meltshop and it is not possible to locate the shaft furnace close enough to utilize HOTLINK or a hot transport conveyor. Another application is the case of one MIDREX Plant feeding multiple meltshops.
Essar Steel pioneered the use of hot transport vessels in the 1990s and has charged several million tons of hot DRI to the EAFs by this method.
