Details

Autor(en) / Beteiligte

• Nicol, S.
• Jak, E.
• Hayes, P. C.

Titel

Controlled Solidification of Liquids Within the SFC Primary Phase Field of the “Fe2O3”-CaO-SiO2 System in Air

Ist Teil von

• Metallurgical and materials transactions. B, Process metallurgy and materials processing science, 2019-12, Vol.50 (6), p.3027-3038

Ort / Verlag

New York: Springer US

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• To provide fundamental information on the phases and microstructures formed during sintering, a liquid with a bulk composition within the silico ferrite of calcium (SFC) primary phase field in the ternary “Fe 2 O 3 ”-CaO-SiO 2 system in air was solidified at a controlled rate. Samples of a bulk composition with a CaO/SiO 2 ratio of 4.00 and 69.24 wt pct Fe 2 O 3 , were cooled from 1623 K (1350 °C) at 2 K/s, with samples quenched at temperatures between 1513 K (1240 °C) to 1453 K (1180 °C). The silico ferrite of calcium and aluminium I (SFCA-I) and Ca 7.2 Fe 0.8 2+ Fe 30 3+ O 53 phases were observed to form an intergrowth (‘SFC-I’) rather than the anticipated SFC phase. Solidification was found to occur in three stages, Liquid + ‘SFC-I’, Liquid + ‘SFC-I’ + C 2 S + CF 2 , and C 2 S + CF 2  + CF, where C 2 S denotes dicalcium silicate, CF denotes calcium ferrite and CF 2 denotes calcium diferrite. The phases formed and the solidification sequence differ from those predicted under equilibrium and Scheil–Gulliver Cooling. Although not directly applicable to industrial operations, this research clearly shows that the formation of both the SFCA and SFCA-I phase in iron ore sinters is controlled by kinetic processes rather than equilibrium conditions.