OPTIMIZATION OF SMELTING PROCESS BY SURFACE RESPONSE MODELING FOR PIG IRON PRODUCTION

Gopal Ghosh Roy, Chanchal Biswas, Arnab Swarnakar, Rajib Dey, Manoj Kumar Mitra

Abstract: The pre reduced iron-carbon composite products have found usages in electric smelting process as well as in BF/BOF industry for producing pig iron. The aim of this study is to utilize the iron ore fines of different fraction; boiler grade coal and plant waste coke dust for reduction and assess the feasibility of smelting in closed Raising Hearth Furnace for lab scale pig iron production. The statistical model of Box Behnken Design (BBD) method is successfully utilized to optimize the process parameter for smelting experiments. The reduced nuggets are charged in the standard raising hearth furnace for smelting at three different temperatures, time and lime percentage. The raw materials and reduced specimens are characterized using X-ray Diffractometers (XRD) Scanning Electron Microscope, (SEM) Energy Dispersive X-ray spectrometer (EDX), and Chemical Analysis method. The smelted samples are characterized by using XRD, SEM-EDX, and OES analysis. The microstructure analysis is carried out by an optical microscope for the metallic part of the samples after smelting. It is observed that better slag metal separation is achieved when higher smelting temperature, time and higher percentage of calcined lime are used.

Keywords: Nugget Making, Solid State Reduction, Direct Reduced Iron, Box Behnken Design (BBD), Smelting

DOI: https://doi.org/10.15623/ijret.2016.0507037