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Reduction behaviour of powder mixtures of iron oxide and carbon in reactive atmospheres
Author(s) -
Singh Ajay,
Deo Kapil,
Ghosh Ahindra
Publication year - 2001
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200100097
Subject(s) - wüstite , char , chemistry , graphite , hydrogen , carbon dioxide , carbon fibers , oxide , argon , analytical chemistry (journal) , nuclear chemistry , pyrolysis , materials science , organic chemistry , composite number , composite material
Mixtures of fines of iron ore and carbon were kept in hot zone of furnace for various durations under flowing argon or mixture of hydrogen and carbon dioxide. Experiments were conducted at temperatures of 1150, 1250 and 1300 K. Other variables were inlet H 2 /CO 2 ratio both oxidising and reducing to wustite, Fe 2 O 3 /C ratio in sample and sample size. 2 types of carbon were selected, viz. graphite and activated char. The degree of reduction of oxide ( F ) was determined by subsequent hydrogen reduction of reaction products. F vs. time data did not follow any set pattern due to complex mechanism and kinetics. Equilibrium calculations predict that, inlet H 2 +CO 2 mixture which undergoes water gas shift reaction inside the furnace, reduces to wustite at a H 2 /CO 2 ratio of 3. As expected, generally it yielded highest value of F . However at 1300 K, even the gas with H 2 /CO 2 ratio of 1.5/1, although oxidising to wustite, gave comparably high value of F , presumably due to enhanced gasification rate at higher temperature. Although reactivity of graphite was much lower than that of activated char, they exhibited comparable extents of reduction.