HIsmelt process of Ironmaking Jul02

HIsmelt process of Ironmaking...

HIsmelt process of Ironmaking  HIsmelt is short for high intensity smelting. It is a direct smelting process for making liquid iron straight from the iron ore.  The process has been developed to treat iron ore fines with minimum pretreatment, making the process more flexible in terms of the quality of iron ore it can treat.  The process allows the use of non coking coal and iron ore fines with significant impurities. The core of the HIsmelt process is the smelt reduction vessel (SRV) which has a refractory lined hearth and water cooled upper shell. The process is carried out in this vessel. The refractory hearth contains the molten iron bath and liquid slag. The main product of the process is liquid iron or hot metal which can be used in steel melting shop or cast in pig casting machine to produce pig iron. The byproduct of the process is slag and the off gas. Main features of the process HIsmelt process has the following unique features. The method of solid injections using high speed lances ensure that the capture efficiency in the melt is high and even ultra fines can be used directly. The ‘natural’ 5 % to 6 % FeO level in the slag in conjunction with the metal carbon at 4 % creates conditions for strong partition of phosphorus from metal to slag. Typically around 80 % to 90 % of phosphorus goes to slag. Coal performance has virtually no dependence on particle morphology, since the coal is ground fine for injection. Historical process development  The origin of the HIsmelt process is traced back to the bottom blown oxygen converter process (OBM) and the evolution of the combined blowing steel making process developed by Klöckner Werke at their Maxhütte steel works.  CRA (now Rio...

HIsarna process of iron making Jun28

HIsarna process of iron making...

HIsarna process of iron making HIsarna process is an ironmaking smelting reduction process where liquid iron is produced directly from iron ore fines and coal. This process eliminates prior processing of raw materials as needed by the blast furnace process. This process is an initiative of the ULCOS (ultra low CO2 steelmaking) consortium of European steelmakers. HIsarna is a combination of HIsmelt technology of Rio Tinto and the Isarna technology developed at Tata Ijmuiden. The process consists of pre-reduction of ore fines in cyclone converter furnace (CCF) of Isarna technology and bath smelting of iron in smelt reduction vessel (SRV) 0f HIsmelt process. The name of the process has been given by combining the names of the two technologies (‘HI’ from HIsmelt and ‘sarna’ from Isarna, a celtic word for iron). The process represents a new, potentially more efficient way of making iron. The technology is being developed in order to substantially reduce carbon emissions from the iron making process. Initial developmental work The very first attempt of applying cyclone technology in the reduction of the iron ore was attempted at Koninklijke Hoogovens in 1960s but the attempt was abandoned. Another serious attempt was made in 1986 but because economic crisis the project was put on the back burner until the early 1990s. The project was revived when coke supply became scarce during mid 1990s. CCF technology was then developed at a pilot scale with capacities of 15 to 20 tons per hour of ore feed. The attempt was again halted in 1999 due to successful implementation high pulverized coal injections in the blast furnaces. HIsmelt originally started By CRA (now Rio Tinto) in 1980s a 2 tons per hour HIsmelt pilot plant at Maxhutte, Germany followed by 8 tons per hour pilot plant in...