鉄塊成鉱および塊鉱石の品質評価に関する2, 3の考察

とくに3因子グラフの応用について

抄録

Operational results of blast furnaces have increasingly improved in conjunction with improvement of iron ore agglomerates such as sinter and pellets, and blast furnace operation technique.
And in order to maintain the quality of sinter and pellets, many properties, such as chemical compositions, size distribution, crushing strength, reducibility, high temp. reduction, softening and melting down temp., etc, are examined. However, it is not clear that which properties are regarded as significant for the blast furnace operation. Therefore, it is necessary to make clear the significant properties of the iron ore agglomerates.
For the purpose of the stable operation of the furnace and improvement of fuel rate, the authors proposed one method to regulate the heat balance in the blast furnace by three factors, i.e. oxygen volume in blast, ore to coke ratio, and JIS reduction rate of burden. It was proved from the examinations of operational results of many blast furnaces that the well stabilization of heat balance in the furnace was obtained in the range from 150° to 210° of the angle θ, which is made by plotting the data of the three factors on the diagram. It is possible to control the angle θ by adjusting both the mean JIS reduction rate of burden materials and ore to coke ratio as burden conditions.
Judging from these analyses, it is evident that the angle θ can be employed as an index which reflects the heat balance in a furnace and that the most important quality of burden for a blast furnace is the JIS reduction rate. However, high reducibility does not always mean a better results but it should be determined in relation with the heat balance.