北海道炭コークスによる高爐操業
1951 年 37 巻 2 号 p. 71-77
詳細
1951 年 37 巻 2 号 p. 71-77
In view of utilizing domestic resources for the iron manufacturing at Wanishi Iron Works, its blast furnace operation has desisted from the use of strong caking foreign coal and is now carried on with coke made entirely from Hokkaido coal. The operating blast furnaces at present are two sets, namely the Nakamachi No. 3 B.F. (nominal capacity 700ton/day output) and the Wanishimachi No. 3 B.F. (nom. cap. 225ton/day). The Nakamachi B.F. is operated with the coalite coke, while the Wanishimachi B.F. mainly with coke made from Hokkaido coal without blending of coalite.
As the Hokkaido coal is highly volatile, the ordinary coke made therefrom is weak and brittle. The coalite coke, made from the same coal blended with 25% of pulverized coalite, has 16% ash and Strength by Drum Test as much as 80%, which, however, is not yet strong enough for the large 700ton furnace. Our effort in devising better ore preparation and appropriate operation methods to supplement the deficient coke strength has thus far made it possible to produce about 600tons of pig iron per day.
The Hokkaido coal-made coke not through blending of coalite has 17% ash and Strength 50-60%. The Wanishimachi B.F, capable of effectively using such less strong coke or under-size coke, is qualified to produce pig for outside sale. In the present situation, when obtaining of strong caking coal is difficult and the production capacity of coalite still insufficient, the small blast furnace is doing an important part in this industry.
