Cupola用 然料로서의 國産 無煙炭의 特性 = The properties of domestic Anthracite Coal as a Fuel for the Cupola

다국어 초록 (Multilingual Abstract)

Since Korea does not produce mineral fuels for the coke, the coke for the cupola operation must have been imported. This coke, however, has been limited not only in suppling but also in costing. Moreover, though anthracite and the domestic coke which is made with this fully crushed anthracite mixed with proper binder are much used for the cupola, the character of these fuels are not prevailing, so there are so many difficulties in cupola operation.
The purpose of this study is to find the character of anthracite and domestic coke, by comparing tapping temperature, chemical composition, and mechanical property of cast iron resulted from the domestic coke and anthracite with those from the coke through the experiment of melting in the cupola as well as in the high frequency induction furnace charged with these fuels and coke.
The character of anthracite for the cupola usage gained from this investigation are following:
1. Anthracite
(1) As reaction of combustion is not active, it is difficult to raise tapping temperature more than 1400℃.
(2) Carburization is very active, consequently, carbon content of cast iron is around the eutectic compostion, and sulphur content reaches abhut 0.1%, for sulphur pick-up is more active.
(3) Tensile strenght of cast iron is about 13∼15kg/㎟. Relative hardness increased and that causes mechanical property worse.
2. Domestic Coke
(1) Because this in more active in combustion reaction, the tapping temperature is to be gained up to 1500℃.
(2) Carburization of this is less active than that of anthracite, but it is similar to carburization of anthracite. Consequently, carbon content of cast iron is apporximately near to eutectic composition. Quantity of sulphur pick-up of this is less than that of anthracite but more than that of coke.
(3) Tensile strenght of cast iron resulted from domestic coke is stronger than that of cast iron resulted from anthracite, but it shows about 70% of tensile strenght of cast iron resulted from the coke. Moreover hardness decreases. This causes the property of cast iron better than that of anthracite.
3. The mixed usage of Anthracite and Domestic coke
(1) Tapping temperature becomes higher according to the mixed rate of domestic coke.
(2) Without considering the tapping temperature, composition and mechanical property of cast iron makes little differences. Consequently, these are similar to those of cast iron resulted from anthracite.