The basic steel production process based on three steps which are raw material preparation, ironmaking then steelmaking. All this processes can be ended with many different type of steels for specific needs. Methods for fabrication steel have advanced essentially since industrial production began in the late 19th century. Current techniques are as yet dependent on a similar fundamental ground as the first Bessemer Process, which uses oxygen to bring down the carbon content in iron.
Ironmaking step, includes the crude feeds of iron metal, coke, and lime being melted in a blast furnace. Additionally, the final liquid iron still contains 4-4.5 percent carbon and different pollutions that make it fragile.
Steelmaking has two essential techniques: BOF (Basic Oxygen Furnace) and the more present day EAF (Electric Arc Furnace). Essential shaping, for example, hot rolled and cold rolled strips, rods, tube rounds, structural shapes, rails. Afterwards, secondary procedures that are coating, heat treatment, surface treatment, metal cutting give the steel its last shape and properties
Despite all challenges like evolving customer demands, geopolitical uncertainty, impact of e-mobility, the effect of digitalization, some technologies provide more efficient processes, higher quality steels, environmental-friendly production, quality consistency etc. Here are four technological developments in steelmaking industry:
1. The ORC Technology
Thermodynamically heat changes to work in a cycle called Rankine Cycle and this system dependent on water gives around 85% of overall power generation.
The Organic Rankine Cycle has same working principal of the Rankine Cycle but ORC depends on a turbo generator running. It transforms heat energy into mechanical energy and electrical energy at last. The difference is rather than creating steam from water, the ORC technology vaporizes a natural liquid. Therefore it provides slower turn of the turbine, reduces pressure and no abrasion of the metal parts and sharp edges. This system can produce enough power from waste up to 700 house around. Also industrial facility’s carbon footprint decrease about 10.000 tons of CO2 while removing the water need for cooling systems.
2. Hybrit Process
The collaborative task of three Swedish organizations, SSAB, LKAB and Vattenfall started the project called ‘Hybrit’ (‘Hydrogen Breakthrough Ironmaking Technology’). The goal is creating zero carbon in steel production beginning from 2020.
Conventional production of pig iron includes coke and iron ore to remove oxygen on the other hand this process releases the atmosphere hazardous gas carbon dioxide. The mentioned new generation procedure utilizes hydrogen, which besides can remove the oxygen in the iron ore, yet the outcome is water vapor instead of carbon dioxide. Change existing procedures to remove characteristic conditions on petroleum products. In this way the Hybrit process idea is totally becoming green steel.
The Hybrit process falls within several advancements that are the utilization of hydrogen as a decrease agent, with the hydrogen being generated through electrolysis dependent on sustainable power. From a natural point of view, the most significant benefit of this is the fumes from this procedure is water rather than carbon dioxide. The products coming HDR (Hot Direct Reduction) process out is named DRI (Direct Reduced Iron) or “sponge iron) which is fed into BOF or EAF mixed with appropriate amount of scrap, and further prepared into steel. In spite of the fact that this particular blend of procedures has not been executed at the business scale. A few of the individual segments are as of now broadly utilized in the worldwide steel industry. Numerous parts of the HDR/EAF arrangement have been tried and sent in modern settings but key difficulties still remain.
3. Jet Process
Particularly equipment and robotization have been improved and optimized within the most recent years to completely consent to real standards. One of latest advancement for exceptional converters is the Jet Process. General proficiency of over half is come to and a wide scope of scrap rates can be handled in exceedingly profitable way. An innovative way to amplify scrap and HBI (Hot Briquetted Direct Reduced Iron) rates in converter steelmaking.
The internal energy of the hot metal is discharged during the oxygen-blowing step make it conceivable to feed around 20% scrap converters. Providing external power allows to make the rate up to around 30%. This additional power usually can be given by electricity or coal. The Jet Process is designed to take advantage of chemical energy of coal more efficiently and cost effectively in converter. Scrap metal additions can be higher without external energy by this way. Also high adaptability of system make easier to implementation. Hypothetically, scrap charge rates from 0 to 100% are conceivable with this adaptable procedure. No coal addition is neccessary up to 30% scrap charges. To increase the adaptability it is designed a modular converter which enables the fast installation of a conventional BOF converter base and an oxygen blowpipe, thereby enabling the converter to be quickly installed to operate as a typical BOF converter.
4. Molten Oxide Electrolysis
Molten Oxide Electrolysis is an unconventional electrometallurgical system that allows quickly production of metal in the liquid state from oxide raw material. It promises considerable simplification of the whole process and essential energy need minimization. Molten Oxide Electrolysis has been proved utilizing anode materials which are graphite for use with ferro-alloys and titanium and iridium for use with iron. It is needed to overcome several challenges to produce metal without process carbon such as process temperature, corrosion of metals considering electrolysis conditions and abrasion of refractory materials.
Still it offers exceptional properties in terms of applicability to multiple metals as well as high temperature operation to produce liquid metal. A review of the transport properties of molten oxides shows that an unprecedented yield can be predicted as a promising feature for tonnage production.
Molten Oxide Electrolysis advancements created in Massachusetts Institute of Technology. Professor Donald R. Sadoway’s lab proved that it could be possible to produce emission free steel by producing low cost inert anode at the lab scale with help from NASA, the American Iron and Steel Institute, and the Deshpande Center at MIT. Looking at the state of the technology in electrode materials, it appears that quantitative design criteria for both cathode and anode continue to be developed.
Molten Oxide Electrolysis
https://www.primetals.com/portfolio/steelmaking/converter-carbon-steelmaking/ Hybrit Process