On the Mineral Composition and the Formation of the Scaffold at the Shaft of Higashida No 4 BF

Abstract

The mineral composition and texture of the scaffold sample, taken from the shaft of Higashida No 4 BF were examined and the formation mechanism of the scaffold was discussed. Determined minerals were wüstite, a'-dicalcium silicate, periclase, merwinite, sulfide, carbon, potassium magnesium aluminium silicate and alkali aluminium silicate. The latter two were regarded to be new species. In the loose part of the scaffold considerable amounts of dicalcium silicate and potassium magnesium aluminium silicate and in the dense part large quantities of merwinite and alkali aluminium silicate were found. The formation process of this scaffold is discussed as follows: The particles of dicalcium silicate, potassium magnesium aluminium silicate, periclase and some sorts of minerals in the system of Na₂O-Al₂0₃-Si0₂, which are not directly originated from the charged materials, are deposited on the wall of the furnace together with iron oxide particles. After the temperature is elevated, the accumulated mass of the mineral particles changes to a dense body by sintering with the generated liquid of the system of Na₂0-Al20₃-Si0₂, and at the final stage of sintering merwinite and alkali aluminium silicate come to compose mainly of the scaffold.