Reserch on the Manufacture of Metallurgical Formed Coke

Abstract

Manufacturing test of metallurgical formed coke were carried out using horizontal continuous fluidized sand bed carbonizer. In the horizontal fluidized bed given temperature distribution were set and the formed cokes were continuously made by allowing the briquets to flow through the fluidized bed.Prior to the pilot plant test, basic investigations to determine the fluidizing conditions of large particles such as briquets were carried out and the characteristics of a horizontal continuous fluidized bed were also studied using laboratory scale apparatus. As a results it was shown that even in the case of large particles such as briquets, fluidization of briquets is possible if an appropriate density of the fluidized particles is used as the medium. Further, the lateral thermal diffusivity of the fluidized bed is approximately 1/10 of that of the vertical direction, and by inserting suspended pack-ings into the bed, it was ascertained that the lateral thermal diffusivity could be still further minimized. Therefore, it was clearly shown that the horizontal continuous fluidized sand bed carbonizer is an advantageous apparatus for having a temperature distribution in a lateral direction.Based on the above preliminary findings a pilot plant scale pre-heater and car-bonizer were designed and built. Of these the Peclet number obtained from flow characteristics tests at room temperature using the carbonizer, within the range of the present experiments was 3-50, and if an appropriate selection of operational conditions are made, irregularities of the formed coke properties can be minimized.Owing to limitations of the carbonizer, carbonizing tests at over 900t were not conducted, but it was ascertained that continuous operations are possible and at the same time the weight loss of briquets during carbonization was investigated.