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 for iron making Jun28

HIsarna process for iron making...

HIsarna process for ironmaking HIsarna process is a smelting reduction process for producing liquid iron directly from iron ore fines (IOF) and coal. It represents a new, potentially more efficient way of making iron and is being developed for substantial reduction of carbon emissions from the ironmaking process. It is an initiative of ULCOS (ultra low CO2 steelmaking) consortium of European steelmakers and is a combination of HIsmelt technology of Rio Tinto and Isarna technology developed at Tata Ijmuiden. It eliminates prior processing of raw materials as needed by the blast furnace process. The process consists of pre-reduction of IOF in cyclone converter furnace (CCF) of Isarna technology and bath smelting of iron in smelting reduction vessel (SRV) of HIsmelt process. The process name derives by combining the names of the two technologies (‘HI’ from HIsmelt and ‘sarna’ from Isarna, a celtic word for iron). First attempt of applying cyclone technology for the reduction of iron ore was attempted at Koninklijke, Hoogovens in 1960s but was abandoned. Another serious attempt was made in 1986 but because of economic crisis, the project was put on hold until 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 15-20 tons per hour (tph) of ore feed. The attempt was again halted in 1999 because of successful implementation of pulverized coal injections in the blast furnaces. HIsmelt was originally started by CRA (now Rio Tinto) in 1980s in a 2 tph pilot plant at Maxhutte, Germany followed by 8 tph pilot plant in Kwinana, Western Australia in the 1990s. Later in the first decade of present century, a commercial plant of 80 tph (60,000 tons per annum) was commissioned and operated at...