Change of coke properties during calcination.

In order to clarify the influence of carbonization temperature on coke qualities and oven operations, change of coke properties during calcination (500-1000°C) was investigated. The sample cokes were carbonized by a special electric test coke oven in which a heating wall is set on the upper side. Further coke productivity and coke qualities in the case of medium temperature carbonization were estimated by a mathematical model for carbonization.The following findings were obtained.(1) With the increase of carbonization temperature, microstrength of coke increases, while crystallite size of carbon does not increase untill 800°C. These phenomena are presumed to be attributed to the fact that three dimensional accumlation of crystallite precedes the growth of its size.(2) It is estimated by the model that the coke strength is sufficient in the medium temperature carbonization, although coke reactivity is slightly insufficient.