Due to the increasing amount of CO2 in the atmosphere and the associated climate change new technologies for energy and CO2 intensive processes are inevitable. Therefore, the steel industry is pushed to take more actions towards higher energy and resource efficiency as well as environmental protection.
On this framework conditions the FluidRed technology is built up, which is a direct reduction process based on fluidized bed technology and hydrogen as reducing agent. Due to the usage of hydrogen and the fluidized bed technology a considerable reduction of the energy, resource consumption as well as the related CO2 emission should be accomplished.
Objectives and Motivation
- Use of hydrogen as reducing gas – generated from renewable energies (CO2-free ironmaking) or natural gas
- Direct use of any type of iron ore in form of pellet feed concentrate – no agglomeration step is required (enables low operation costs)
- High oxide yield due to dry dedusting and recycling of oxide dust
- High reduction rate at low temperatures and pressures owing to high particle surface
The FluidRed technology is developed based on prior research activities and experiences in the field of reduction metallurgy.
Within the scope of experimental campaigns with a lab scale fluidized bed reactor, the behavior of iron ore concentrate regarding the fluidization and reduction properties with hydrogen was investigated. The thereby gained know-how is used to generate a simulation model as well as to design a Hot Bench Scale.
This Hot Bench Scale should verify the FluidRed-process and should indicate the influencing parameters for the hydrogen reduction of iron ore concentrate based on the fluidized bed technology. In addition, further processing steps of the produced ultra-fine HDRI, Hot Direct Reduced Iron, are under investigation.
Therefore, the evaluation of a concept for hot briquetting and for melting in an EAF, Electric Arc Furnace, (inclusive a charging concept) of the ultra-fine HDRI is in progress. After the determination of an appropriate process for both further processing steps, these processes are going to be designed and with experimental campaigns verified. Furthermore, a concept for the connection of the FluidRed-process with the EAF and a charging system in the EAF gets engineered, for the melting of the ultra-fine HDRI in an EAF.
From the gained know-how of the experimental campaigns with the Hot Bench Scale, briquetting and melting test of the HDRI, an industrial-scale plant is planned. Besides the fluidized bed reactor all plant components, e.g. gas treatment or ore preheating system, are getting engineered and among each other coordinated.
Results and Application
The main objective of the project is the installation and the operation of the Hot Bench Scale, which processes iron ore concentrate directly to HDRI using hydrogen as reducing agent. Experimental campaigns with the Hot Bench Scale should verify the FluidRed technology as well as generate data for a technical layout of an industrial-scale plant. Moreover, the Hot Bench Scale will monitor the expectable process efficiency and quality of the produced HDRI.
Another outcome of the project are the two concepts for a further processing of the produced HDRI, briquetting in a hot compactor or melting in an EAF.