Search results
Results from the WOW.Com Content Network
Direct-reduced iron has about the same iron content as pig iron, typically 90–94% total iron (depending on the quality of the raw ore) so it is an excellent feedstock for the electric furnaces used by mini mills, allowing them to use lower grades of scrap for the rest of the charge or to produce higher grades of steel.
In the iron and steel industry, direct reduction is a set of processes for obtaining iron from iron ore, by reducing iron oxides without melting the metal. The resulting product is pre-reduced iron ore. Historically, direct reduction was used to obtain a mix of iron and slag called a bloom in a bloomery.
The iron ore is introduced into the furnace upstream and mixed with a small amount of fuel, typically hard coal. [21] After 6 to 8 hours, [22] it exits the furnace as pre-reduced iron ore at 1,000 °C. The amount of iron recovered ranges from 94% to 97.5% of the initial iron in the ore. [21]
The HIsarna ironmaking process is a direct reduced iron process for iron making in which iron ore is processed almost directly into liquid iron ().The process combines two process units, the Cyclone Converter Furnace (CCF) for ore melting and pre-reduction and a Smelting Reduction Vessel (SRV) where the final reduction stage to liquid iron takes place.
Direct reduction is the fraction of iron oxide reduction that occurs in a blast furnace due to the presence of coke carbon, while the remainder - indirect reduction - consists mainly of carbon monoxide from coke combustion. It should also be noted that many non-ferrous oxides are reduced by this type of reaction in a blast furnace.
The Corex Process is a smelting reduction process created by Primetals Technologies as a more environmentally friendly alternative to the blast furnace. [1] Presently, the majority of steel production is through the blast furnace which has to rely on coking coal [2] and requires a sinter plant in order to prepare the iron ore for reduction. [3]
Using a specially constructed electric arc furnace, a mixture of hematite with +0.2% carbon content and coal (or charcoal) is smelted in a continuous process, with the reduced metal accumulating at the bottom of the furnace, where it can be tapped off. Carbon content in the product can be controlled by changing the quantity of coal in the furnace.
The feedstocks are partially oxidized to generate syngas using metal oxide oxygen carriers as the oxidant. The reduced metal oxide is then oxidized in the regeneration step using air. The syngas is an important intermediate for generation of such diverse products as electricity, chemicals, hydrogen, and liquid fuels.