Some references have mentioned that the direct reduced iron temperature is between 800 and 1200 ° C. But I need accurate temperature for design and build a dust filter for the dust collector system.
Dear Muhammadreza Meleki,
Temperature is up to 1000 degree centigrade.
Direct reduced iron (DRI), also called sponge iron is produced from the direct reduction of iron ore (in the form of lumps, pellets, or fines) to iron by a reducing gas or elemental carbon produced from natural gas or coal. Many ores are suitable for direct reduction.
Temperature- Direct reduction refers to solid-state processes which reduce iron oxides to metallic iron at temperatures below the melting point of iron. Reduced iron derives its name from these processes, one example being heating iron ore in a furnace at a high temperature of 800 to 1,200 °C (1,470 to 2,190 °F) in the presence of the reducing gas syngas, a mixture of hydrogen and carbon monoxide.
In contrast to the blast furnace process, the direct-reduced iron process operates at temperatures of up to 1000 °C. The iron ores are therefore not melted. Direct reduction processes can be divided roughly into two categories: gas-based, and coal-based. In both cases, the objective of the process is to drive off the oxygen contained in various forms of iron ore (sized ore, concentrates, pellets, mill scale, furnace dust, etc.), in order to convert the ore to metallic iron, without melting it (below 1,200 °C (2,190 °F)).
The direct reduction process is comparatively energy efficient. Steel made using DRI requires significantly less fuel, in that a traditional blast furnace is not needed. DRI is most commonly made into steel using electric arc furnaces to take advantage of the heat produced by the DRI product.
Limitations and benefits
But limitations are there with Direct reduced iron is highly susceptible to oxidation and rusting if left unprotected, and is normally quickly processed further to steel. The bulk iron can also catch fire since it is pyrophoric. Unlike blast furnace pig iron, which is almost pure metal, DRI contains some siliceous gangue, which needs to be removed in the steel-making process.
Sponge iron is not useful by itself, but can be processed to create wrought iron or steel. The sponge is removed from the furnace, called a bloomery, and repeatedly beaten with heavy hammers and folded over to remove the slag, oxidise any carbon or carbide and weld the iron together. This treatment usually creates wrought iron with about three percent slag and a fraction of a percent of other impurities. Further treatment may add controlled amounts of carbon, allowing various kinds of heat treatment (e.g. "steeling").
Modern uses
In modern times, direct reduction processes have been developed to specifically overcome the difficulties of conventional blast furnaces. DRI is successfully manufactured in various parts of the world and enables production of specialised iron and steel based products in a decentralised manner (as distinct from the older, centralised Open Hearth Furnace based model of the so-called 'Integrated' Steel Plants). The initial capital investment (CAPEX) and operating costs (OPEX) of direct reduction plants are lower than integrated steel plants and are more suitable for developing countries where supplies of high grade coking coal are limited however steel scrap is generally available for recycling. Today, sponge iron is created by reducing iron ore without melting it. This makes for an energy-efficient feedstock for specialty steel manufacturers which used to rely upon scrap metal.
The DRI method produces 97% pure iron.
Hope it is helpful to you.
Ashish
Dear Ashish Thakur
Thanks a lot for your guidence. I need accurate temperature of DRI. Do you have any article or referencess about it?
Use exact 1000 degree centigrade. do not go beyond that. follow ASM heat treatment handbook.
Mohammadreza Maleki : Do you know the melting temperature of DRI pellet ( laboratory produced-without carbon and commercialized ones-with Carbon) ? Also, if you know the thermophysical properties of the DRI pellets, please share and their references.
- Badges
- Science topic
- Similar topics
- Engineering
- Materials Engineering
- Powders