Effect of Change the Percentage of Mill Scale on the Reduction of Briquettes Made from El-Baharia Iron Ore by Hydrogen

The demand of iron for the manufacture of different types of steel is increasing continuously and new solid reductant-based sponge iron plants are being commissioned. In the existing blast furnace, an increase in production by at least 25% to 35% can be achieved by using reduced iron ore. Also, the majority of fines which are generated during the course of handling, mining and transportation are exported at a through away price which needs to be utilized by making iron ore briquettes for sponge iron making. A lot of investigations have been carried out on direct reduction of iron oxides by using hydrogen gas. In the present work, an attempt has been made to study the reduction behavior and kinetics of fired mill scale added to iron ore pellets. The effect of different reduction parameters such as temperature and hydrogen flow rate also, the effect of drop damage resistance, applied pressure and compressive strength was studied. Reduction of briquetted fine mill scale added to iron ore by hydrogen is carried out in the temperature range 700 to 1000oC. In the reduction kinetic study, the most satisfactory model is to take the slope of the initial linear region of fractional reduction vs. time curve as a measure of rate constant (k) and lnk vs. 1/T plots are straight line from which activation energy was calculated. In kinetic studies relating to reduction of ores, a mechanism is assumed that correlates time (t) to conversion (R): R=F (t) The most satisfactory model is that which gives the higher R2 coefficient on plotting F (R) against (t).