Corex gas , Corex process , Dome , DRI , export gas , Hot metal , Iron ore lump , Melter-Gasifier , non coking coal , pellets , Reduction furnace , Corex Process for Production of Iron During the late twentieth century, several new initiatives have been taken for the development of the smelting reduction technology which can become alternative route for the production of liquid iron hot metal since the conventional blast furnace BF ironmaking depends on metallurgical coal, which is required for producing BF coke needed for the production of hot metal in the blast furnace. Metallurgical coal is not only costly but is associated with environmental issues during its conversion to BF coke in the coke oven batteries. Smelting reduction process is that process which is based on smelting reduction technology and hence in this process the production of hot metal is carried out without the use of metallurgical coke. Corex process is one of these initiatives. It is the first and the only commercially established smelting-reduction process based on non-coking coal which is available as an alternative route to the blast furnace for the production of hot metal. Corex process was developed by the Austrian technology supplier VOEST in the late s, and its feasibility was confirmed during the s.
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Zolodal Corex Process for Production of Iron Advantages of the Corex process include i reduction in the specific investment cost compared with conventional blast furnace route of production, ii lower production cost, iii better environmental performance because of lower irpn and discharges, iv higher calorific value of export gas makes it suitable for use in a wide range of applications, v flexible with regards to the raw material uses since a wide variety of iron ores and coals can be used, vi good operational flexibility with respect to production capacity, production stops and raw material changes.
Retrieved October 27, Nevertheless, it helped to overcome the critical demonstration stage for this smelting reduction technology. Compared with the traditional iron making process via the blast furnace route, the COREX process differs since non coking coal can be directly used for ore reduction and melting work, eliminating the need for coking plants.
Views Read Edit View history. In the two-stage operation of the process DRI produced from prrocess shaft furnace is charged into a melter-gasifier for smelting. Because of many peripheral requirements, the total cost of a Corex project can be relatively high.
Iron ore lump ore, pellets, or a mixture thereof is charged into the reduction shaft, where it is reduced to direct reduced iron DRI by the reduction gas in counter flow. The emission levels with the Corex process are much lower than the BF route of production which consists of blast furnace, sinter plant and the coke ovens. The plant rated capacity is ranging fromtons per year totons per year.
The second stage of the process consists of melting and carburizing of hot DRI by the coal and oxygen which is added in the meter-gasifier. Sulphides discharge is around 0. The air emissions are also lower than the conventional BF units. The metallization degree of the DRI and the calcination of the additives are strongly dependent on four parameters namely i amount and quality of the reduction gas, ii temperature of the reduction gas, iii reducibility mqking the iron bearing burden, and iv average particle size and the distribution of the solids charged.
The commissioning was in This first generation reactor which is called melter-gasifier had a hearth diameter of 5. The gasified coal is then fed into a shaft furnace to remove oxygen from iron ore lumps, pellets or sinter and finally, this direct reduced iron DRI is fed to the smelting reactor. The most innovative pdocess of corrx Corex process is the separation of the iron reduction and smelting operations into two separate reactors, namely reduction shaft and melter-gasifier. Phenols discharge is around 0.
However, nearly all of the sulphur in the non-coking coal kaking the slag and hot metal. So, the phosphorous content of ore and coal should be as low as possible. Use of high purity oxygen in the Corex process generates of nitrogen free top gas.
Further due to the in-situ coking of the coal in the melter-gasifier, a large portion of sulphur is captured in the slag, dramatically decreasing emissions of gaseous SO2 or H2S. Typical analysis of hot metal from procfss Corex process consists of carbon — 4. Corex process captures most of the pollutants in an inert state in the slag and the released hydrocarbons are destroyed in the dome of the melter-gasifier.
Your email address will not be published. Reducing gas for the shaft furnace is produced by partial combustion of coal irn oxygen in the fluidized bed maknig the melter-gasifier. The outputs can be used either by integrated mills or EAF electric arc furnace mills. Smelting reduction processes come in two basic varieties, two-stage or single-stage.
The rest of the hot gas is then cooled and sent into the reduction shaft resulting in maing Corex export gas which is used to control pressure in the plant. Languages Deutsch Italiano Edit makign.
Due to this increased gas utilization which is based on gas recycling, gas production in the melter gasifier can be significantly lowered, which is directly reflected in lower fuel and oxygen consumption. However, this particular problem can be mitigated by using the export gas in electricity production.
Corex process distinguishes itself from the blast furnace route by i direct use of non-coking coal as reducing agent and energy source, ii Iron ore can be directly and feasibly charged to the process in form of lump ore, and pellets, and iii use of pure oxygen instead of nitrogen rich hot blast.
Furthermore, it has also been found that Corex plants require large amounts of oxygen which can be expensive. Related Articles
The reason for such interest stems from the fact that the conventional blast furnace ironmaking depends on metallurgical coal, which is required for producing BF grade coke. Continued supply of metallurgical coal at a competitive price is becoming increasingly difficult with the depletion of coking coal reserves. Besides, the coke oven batteries are among the most environmentally hazardous reactors so far. COREX is the first and the only commercially established smelting-reduction process, as an alternative route to blast furnace, based on non-coking coal. The COREX process offers high smelting intensity and hence higher productivity, ability to use various types of non-coking coals, use of iron ore fines to an extent, low net operating cost, possible generation of power or other alternative use of export gas generated from the ironmaking unit, besides being eco-friendly. The world class performance of COREX plant so far has justified the vision and concept of such large investment in a cluster of industries co-existing. This conglomerate concept is the most adaptable in developing countries where there exists significant growing market for steel, power, cement, industrial gases, mining and mineral processing.
The main reagents for the Corex process are iron ore , noncoking coal , and oxygen. The Melter gasifier has three main sections, the gaseous free board zone, the Char bed, and the hearth zone, and it has an effect on several stages in the process. First it serves to create the reduction gas by gasifying the coal with oxygen and then cooling it. After being reduced, the DRI is redirected to the char bed where the iron and slag are melted and then directed to the hearth zone. Meanwhile, carbon monoxide and hydrogen gas from the original gasification of the coal exit the gasifier while other byproducts are captured in the metallic slag. The rest of the hot gas is then cooled and sent into the reduction shaft resulting in the Corex export gas which is used to control pressure in the plant. Many of the gases resulting from this process can then be recycled or used to produce electricity.