A breakthrough ironmaking technology (1Tmk3) produces iron separated from slag by heating coal-iron ore composite pellets at temperatures as low as 1325C in about 10 minutes. Other researchers have studied the melting behavior, including the formation of a dense metallic shell separated from slag but the mechanism has not been yet fully understood. Exploring this knowledge gap was targeted in this study. The initial experiments included heating of composite samples at different temperatures and time intervals. Three coal types and two coal/ore ratios were investigated. By these experiments slag free iron production at low
temperature and short time was confirmed. Coal type and coal/ore ratio were found to have a
significant effect on melting behavior. The main series of experiments focused on the effect of slag composition mainly CaO and Si02, slag content and reaction time on the melting behavior. The main characterization methods included Optical Microscopy, Energy
Dispersed X-ray Analysis (EDX), and simultaneous Differential Thermal Analysis (DTA), and Thermo Gravimetric Analysis (TGA). Despite most of the obtained results being qualitative, this study was successful in exploring some of the most important reasons behind the melting behavior of coal ore composites. It was revealed that the formation of a low melting point slag containing FeO in the core of the pellet and its exudation to the iron shell is responsible for the formation of a dense metallic shell. Densification of iron occurs by reduction of FeO in slag. The rate and extent of reduction is related to the physical properties of slag that in turn is influenced by slag composition. More basic slags tend to have higher rate of FeO reduction in slag. By reduction of FeO in slag, the interfacial tension of the remaining slag with iron increases and slag is separated from iron. / Thesis / Master of Materials Science and Engineering (MMatSE)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/22302 |
| Date | 04 1900 |
| Creators | Roodsari, Mahshid Fathi |
| Contributors | Conochie, David, None |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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