<Original Papers>Study on the High-Temperture Properties of Iron Ores, Sinters and Pellets. (I) : Study on the Microstructures and Physical Properties of Lime-Added Pellets

In the course of an investigation of the high temperature properties of iron ores, sinters and pellets in the reducing atmosphere, the microstructure and physical properties of lime-added pellets were first studied. The results obtained are summarized as follows : 1) The microstructure of the pellet was influenced by the amount of the lime added, that is, by basicity : the hematite bonding was found mainly in the structure of the pellets with basicity up to 0.6 : the amount of calcium-ferrite, such as mono-and di-calciumferrite, increases with increase of basicity above 0.6. 2) The compression strength of the pellets was shown to be related considerably with the micro structure of the pellets. 3) Macrocracks were shown to be generated more frequently in the pellets having unstable structures, of which the physical properties change largely with the alternation of reducing conditions and so considered to be related with the basicity in the frequency of generation