الفهرس | Only 14 pages are availabe for public view |
Abstract The demand for iron and reduced briquettes for the manufacture of different varieties of steel is continuously increasing and new solid reductant-based sponge iron plants are being constructed. In the existing blast furnace, an increase in pig iron 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 process of iron oxides by using hydrogen gas at different flow rate. In the present project work, an attempt has been made to study the reduction behavior and kinetics of indurated pellets of mixture of both mill scale and El-Dekhilla with iron ore. The effects 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 briquetting fine mill scale and El-Dekhilla fine pellets by hydrogen is carried out in the temperature range 700 to 1000 oC. 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 Ln k 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). |