2006 Volume 92 Issue 12 Pages 802-808
Carbon composite iron oxide pellets intentionally including residual volatile matter (V.M.) were proposed to decrease the initial temperature for reduction reaction of carbon composite iron ore agglomerate under a rising temperature condition, such as in a blast furnace shaft. The carbonization of coal (Newcastle blend coal) under a rising temperature condition was interrupted at a certain temperature, TC, max =823, 873, 973, 1073 and 1273K, to obtain semi-coal-char containing some residual V.M. Furthermore, to investigate the behavior of gas evolution from the coal char, the semi-coal-char obtained at TC, max(1)=873K was heated from room temperature up to TC, max(2)=1273K at 200Kh-1 in nitrogen atmosphere. In carbonizing at TC, max(1)=1273K, V.M. was almost emitted from TC, max(1)=873K. Total gas volume of two step carbonization (TC, max(1)=873K and TC, max(2)=1273K) almost agreed with that of one step carbonization (TC, max= 873K).
The semi-coal-char including residual V.M. was mixed with reagent grade hematite in the mass ratio of one to four. Then, Bentonite was added to the mixture as a binder, and the carbon composite iron oxide pellets including residual V.M. were prepared and reduced under rising temperature conditions in nitrogen atmosphere. It was confirmed by the XRD analysis of the reduced pellets that the carbon composite iron oxide pellets using the semi-coal-char at TC, max=823K have the fastest reducibility of the iron oxide.