Experimental study of coal based direct reduction in iron ore/coal composite pellets in a one layer bed under nonisothermal, asymmetric heating

Abstract

The reduction of hematite iron ore fines by different carbonaceous materials in composite pellets in a one-layer bed under nonisothermal asymmetric heating from above is studied. Temperature measurements at various points in the bed show that there are large gradients both inside and outside the pellets, with the reduction fastest at the top where the temperature is highest. The relative difference between the degree of metallisation between the top and the bottom of the pellet can be even greater during the reduction. The pellets undergo nonuniform swelling/shrinking towards the end of the reduction, and their height is less than their width. Reoxidation can start at the top of the pellet while the bottom has not yet been fully reduced. Those with a higher initial volatile content but with the same amount of fixed carbon as other pellets, gave a significantly higher degree of reduction without the involvement of fixed carbon gasification reactions.

Use of Iron Ore Fines in Cold-Bonded Self-Reducing Composite Pellets

“…Fruehan (46), Donskoi et al (47) and Sun and Lu (45) agreed that soft coal is a better reductant than coke, and that coals with higher volatiles showed higher reduction rates.…”

A study of direct reduction characteristics of Bayer process red mud-coal composite pellets

“…The direct reduced iron has excellent performance in reducing the use amount of coke, environmental protection, etc. The reduction process is a gas-solid reaction, which has been widely studied by a large number of scholars in the past few decades [2][3][4][5][6][7][8][9][10][11][12][13]. This work mainly focuses on the process condition experiments, saving energy and reducing material consumption.…”

Gasification and Migration of Phosphorus from High-phosphorus Iron Ore during Carbothermal Reduction

“…[1][2][3][4] Corresponding resources have also been reported in the United States and Egypt. 5) On account of the high content of phosphorus in the iron ore, which adversely affects the quality of pig iron and steel, phosphorus and iron combine to form Fe 3 P, thereby forming a binary eutectic Fe 3 P-Fe with iron and causing steel to exhibit a "cold and brittle" phenomenon; this phenomenon limits the use of the Highphosphorus iron ore in industry. [6][7][8][9] The development of this mine constitutes considerable economic importance.…”