Redsmelt process for ironmaking Apr19

Redsmelt process for ironmaking...

Redsmelt process for ironmaking Redsmelt is a new ironmaking process based a two reduction steps. These are (i) pre-reduction of iron bearing materials in a rotary hearth furnace (RHF), and (ii) smelting of the hot pre-reduced iron (DRI, direct reduced iron). Originally a submerged arc furnace (SAF) has been used for the second step. SAF has now been replaced by a coal and oxygen blown converter (oxy-coal reactor) known as ‘New Smelting Technology’ (NST). The RHF reduces green pellets made out of iron ore, reductant fines and binders to produce hot, metallized DRI which is charged to the NST for its smelting to hot metal. Redsmelt process has been conceived to be consisting of a cost-effective and environmental-friendly technology. The important highlights of the process are as follows. The process does not need any prepared charge materials The process does not need electrical energy, since the DRI smelting is carried out using chemical energy The smelter is having high productivity resulting into limited investment cost The process can use practically all the residues generated during various processes of the steel plant (including sludges and oily mill scales), thus it solves the increasing issue of steel wastes treatment The off-gas coming from the smelting reactor is used as a fuel in the RHF, with optimization of the overall energy utilization. This results into effective reduction in energy consumption A Redsmelt demonstration plant with two step smelting reduction process was built and tested in Piombino works (Italy) for the production of hot metal. The demonstration plant was commissioned in the year 2003. The two production steps in the demonstration plant have been based upon pre-reduction of iron-bearing materials in a RHF and smelting of the hot DRI in an oxy-coal converter. The plant has been designed...

Iron Ore Pellets and Pelletization Process Nov26

Iron Ore Pellets and Pelletization Process...

Iron Ore Pellets and Pelletization Process Pelletizing of iron ore was started in the 1950s to facilitate the utilization of finely ground iron ore concentrates in steel production. For the pelletizing of iron ore there are two main types of processes namely, the straight travelling grate (STG) process and the grate kiln (GK) process. In the STG process, a stationary bed of pellets is transported on an endless travelling grate through the drying, oxidation, sintering and cooling zones. In the GK process, drying and most of the oxidation is accomplished in a stationary pellet bed transported on a travelling grate. Thereafter, the pellets are loaded in a rotary kiln for sintering and then on a circular cooler for cooling. The pelletizing processes are discussed in the article under the link http://ispatguru.com/iron-ore-pellets-and-pelletizing-processes/. The pellets may be acid or fluxed pellets. Acid pellets – Basicity of acid pellets is usually less than 0.1. The fired pellet strength is, to a certain degree, due to hematite bridges of polycrystalline structure. These pellets normally have large volume of open pores. The reduction gas quickly penetrates through these pores into the pellet core and simultaneously attacks the structure in many places. This results into an early structural change which begins at low temperatures over the entire pellet volume. Fluxed pellets – These are also known as basic pellets. Basicity of fluxed pellets is greater than 0.1 and can vary. Basicity of normal basic pellets range from 0.1 to 0.6 and have low CaO percentage. During the firing of these pellets, a glassy slag phase consisting of SiO2, CaO, and Fe2O3 of varying percentage is formed. Due to increased flux addition, there is formation of some slag and due to it, there is to a certain extent slag bonding with...