Patent Application
20090249922
1. Field of the Invention
This invention relates to a new process for producing steel from iron ore using a locally produced hydrogen, produced by electrolysing water using electricity from a wind power generator on the mine site, as the reducing agent.
2. Brief Description of the Prior Art
The production of iron and steel, using carbon in the form of coal or coke as the reducing agent, has been known for some 2000 years. The invention of fluidized bed reactors and rotary ovens in the twentieth century it became possible to utilize natural gas and eventually hydrogen as the reducing agent. The use of hydrogen was always limited to locations where a source of inexpensive hydrogen all ready existed.
The steel making industries developed over time at places near the sources of reducing agent, or in other words, at or near the coal mines.
The production of steel using hydrogen produced from the electrolysis of water utilizing power from a wind power generator has not been known.
The herein presented process involves the reduction of iron ore concentrate, in a rotary oven, using heated hydrogen as the reducing agent, said hydrogen being produced either at the mine site or some other advantageous location and being produced through the electrolysis of water, using power generated by a wind power generator.
Depending on the location of the site and the availability of sufficient water and wind energy, this process could possibly produce the cheapest reducing agent and the cheapest steel product in the world. Most of the transportation used prior to end product would be eliminated.
The process first involves the mining and benification of the iron ore to a concentrate grade of from 69 to 73% iron (Fe). The iron ore concentrate is first stored in water proof silos and later fed to a rotary oven as needed.
Wind power generators are then used to produce the electric energy needed to electrolyze the water into oxygen and hydrogen. The hydrogen is first cooled and condensed into liquid hydrogen before it is placed into storage tanks.
The condensing of the hydrogen and storing it in tanks is a necessary step needed to give an even, constant and continuous process. Due to the inconsistency of wind energy, the steel making process would be uneven and inconsistent and hard to control due to the lack of a consistent supply of hydrogen. Another option would be the use of commercially available power during periods of low wind but this would undoubtedly be more expensive. Commercial power would however be kept available for emergencies.
The hydrogen is bled from the storage tanks, heated to about 1300 degrees C. and then fed into the rotary oven to reduce the iron ore concentrate.
After a processing time of about 2 hours the finished steel product, in the form of sponge iron is first cooled and then placed in water tight storage facilities for storage.
The effluents from the process, oxygen and water vapor, are released into the atmosphere after filtration to remove dust particles.
The application presents:
The Bristlecone process presents a new and very economic process for producing high quality steel from iron ore concentrate using hydrogen as the reducing agent, said hydrogen being produced on or near the mine site by using electric power produced from a wind power generator, to electrolyze water to hydrogen and oxygen.
Iron ore (magnetite or hematite or any other typical iron ore) is first mined (1,1) and then transported to the concentrator (1,2) where it is cleaned and concentrated to a grade of approximately 73% Fe (using magnetite). The concentrate is then fed into a rotary oven (1,3) or other applicable oven type, where it is reduced.
Wind power (1,4) is used to electrolyze water in an electrolysis unit (1,5) after which the hydrogen is moved to a cooling and condensing unit (1,6) where it is cooled and condensed for storage, after which it is moved to a storage tank (1,7).
Hydrogen is taken from the storage tank (1,7) as needed and moved to the heating unit (1,8) where it is heated to about 1300 degrees C., after which it is moved to the rotary oven (1,3) to be used as the reducing agent to produce high grade steel in a sponge iron (sponge steel) form.
The finished product is then cooled in the cooling unit (1,9) and then placed in a water proof storage unit (1,10) for storage.
The primary advantages of the Bristlecone Steel Process are:
