CaO・2Fe2O3組成近辺の溶製物の還元に伴う膨張に及ぼすSiO2,Al2O3添加の影響
1987 年 73 巻 15 号 p. 1885-1892
詳細
1987 年 73 巻 15 号 p. 1885-1892
The reduction of CaO·2Fe2O3(CF2) in which SiO2, Al2O3 were added separately or simultaneously and resultant expansion have been studied in CO-N2 (4 : 6) mixed gas at 550 °C.
The main results obtained are as follows :
1) In melted material of CF2-SiO2 (SiO2 : 0.52.0 wt%) system, the addition of SiO2 into CF2 promotes the formation of 2CaO·SiO2(C2S), CaO·Fe2O3(CF) and Fe2O3. SiO2 is insoluble in CF2. The formed Fe2O3 increases the reduction and resultant expansion.
2) In melted material of CF2-CaO (1.87 wt%)-SiO2 (SiO2 : 0.52.0 wt%) system, the combined addition of SiO2 and CaO promotes the formation of CF2, CF and C2S. SiO2 is only slightly soluble in CF. Consequently, the formation of C2S and the disappearance of Fe2O3 restrains the reduction and resultant expansion.
3) In melted material of CF2-CaO (1.87 wt%)-SiO2 (1.0 wt%)-Al2O3 (Al2O3 : 0.58.0 wt%) system, the combined addition of SiO2, CaO and Al2O3 promotes the formation of CF2-α (SiO2 : 1.51.8 wt%, Al2O3 : ≤8.2 wt%) and CF2-β (SiO2 : 1.51.8 wt%, Al2O3 :>8.2 wt%).
Both CF2-α and CF2-β restrain the reduction, and the former promotes the resultant expansion, inversely, the latter restrains it.
