Structure of Sinters Formed from Complex Chinese Iron Ores
Domestic iron ores and sinters from six mills in PRC have been evaluated. A large number of the ores consist of dense magnetite and hematite, and complex iron ores containing minerals including pyrite, pyrrhotite, biotite and siderite. One particular ore was extremely complex containing a high level of fluorite. Based on the sinter samples received, one sinter was obviously produced from predominantly magnetite blends as silicate glass and SFCA of high temperature morphology were the major bonding phases present and the major iron oxide mineral was magnetite. For the plants using predominantly hematite ore in their blends, SFCA is relatively well developed and the sinters also have a very high level of relict hematite. Sinters with this are characterised by high reducibility and a good strength. However, such a sinter structure is not formed automatically when a high level of hematite is present in the blend. The structure of three sinters indicated that when coke rate is high such a structure is not achievable although high temperature morphology SFCA is developed. The sinter produced from ore containing high fluorite is the most reducible but is also extremely weak. The strength of the different mineral phases in the sinters were characterised using indentation techniques. Good correlations were obtained between tumble indices of the sinters and a composite fracture toughness of the major phases. The study also showed that some of the more typical structures found in these plant sinters could be reproduced using a bench-scale furnace under controlled conditions.
- ISIJ international
ISIJ international 37(5), 449-457, 1997-05-15
The Iron and Steel Institute of Japan