To produce the high quality coke from a coal, it is generally said that the coal must contain a proper amount of swelling-, coking-, and caking-component.
Depletion of reserves of coal seams considered as the best coking coals and continuous requirements of modern blast furnace practice make improvement, on this account, not only on the blending techniques to make raw material having suitable component for good coke, but also on the techniques of coking procedure.
Based on our recent microscopic investigation with regard to the thermal behaviours of coal during carbonization, it has been clarified that one of the most important character of coke, the strength, is greatly influenced by the thickness of walls and the size and distribution of pores, which are mostly completed by the temperature of 600°C, and not always by chemical compositions of coal.
Accordingly, if the suitable assemblage of pore and wall during the process of carbonization is realized by any proper method, the coke of good nature may be obtained.
As one of these possible ways, an specially constructed oven is used, in which coal is heated by high frequency electric wave.
As well known, the coal of plastic state is given a sort of sound wave by this electric wave though it is very slight. Therefore, we have tried to accelerate the sound motion in the coal using ultrasonic wave, which is introduced through graphite conical horn.
In this paper the procedure and the results obtained under the microscope are commented in detail.
However, since the experiment has not been finished with a satisfactory result, further studies are needed using several kinds of coal until more sufficient results are obtained.