抄録
The crushing strength and reduction reactivity of a carbon-containing pellet prepared from a cold bonded pellet (CP) and COG tar have been examined with a tensile and compression machine and with a fixed-bed quartz reactor, respectively. The C-containing pellet is prepared by the chemical vapor infiltration (CVI) method under the conditions of tar pyrolysis temperature of 700℃ and CVI temperature of 350℃. When CP is heated up to 350℃, specific surface area (S_<BET>) and total pore volume (VEJB) increase from 20 to 60 m^2/g and from 0.06 to 0.075 cm^3/g, respectively, and the profile for pore size distribution gives a district peak around 2 nm. On the other hand, S_<BET> and V_<BJH> values of CVI sample are as low as < 1 m^2/g and < 0.01 cm^3/g, respectively, and the peak observed around 2 nm disappears completely. The crushing strength of the sample reaches 10 daN, and the value is comparable to those of typical metallurgical cokes. The evolution of CO, CO_2 or H_2O starts at 300-400℃, and the maximal rates of these gases evolved are observed around 700-800℃ during heat treatment of the sample in He. The extent of redaction after 60 min holding at 1000℃ reaches > 85%, and metallic-Fe is formed above 800℃.
