Changes of Mineral Phases during the Sintering of Fe2O3-CaO-SiO2 System

Mixtures oj fine powders with the basicities oj 0.6 to 5.0 consisting oj 80% hematite, slaked lime, alld quartz were heated rapid£l' to 900° -1 400 0 e and cooled in air.The process oj the Jormatioll oj minerals during rapid heating was examined.At a temperature oj about 950° to 1 ooooe, calciumJerrite was Jormed and caustic lime originatedJrom slaked lime was consumed completely.At temperatures lower than 1 150 0 e, quart z hardly reacted with other minerals such as hematite, caustic lime, and calciumJerrite.Thus, the microstructures changed, rega rdless oj the basicities, into those consisting if primary hematite, calciumJerrite, and quartz.At temperatures higher than about J J 60° to 1 J 80 0 e, calcium Jerrite melted and reacted wilh quartz.By this reaction, characteristic microstuctures were Jormed according to the basicities.The microstructure if mixture with the basiciry lower than 1.6 consisted aJ glassy silicate and secandary hematite originatedJram calciumJerrite .The micrastructure aJ mixture with the basiciry higher than 2.0 cansisted aJ calcium Jerrite and dicalcium silicate.On the basis aJ the abave results, the micrastructures and the Jormation pracesses aJ self-fluxing sinters with va rious basicities were discussed.