BEGIN:VCALENDAR
VERSION:2.0
METHOD:PUBLISH
BEGIN:VEVENT
ORGANIZER;CN='8th ECIC & 9th ICSTI 2022':MAILTO:info@ecic-icsti.com
LOCATION:Room „Danzig“
SUMMARY:Isolating the influence of mineralogy and microstructure on iron-ore sinter reduction in the shaft and reserve zone of the blast furnace: lab experiments and thermodynamic modelling
DESCRIPTION:Here we discuss the influence of chemistry, mineralogy and microstructure of iron ore sinter on its reduction behavior under conditions relevant to the upper shaft and the reserve zone of the blast furnace process. Sinter material was produced in a sintering pot varying only limestone flux- and coke addition rate with an otherwise constant sinter mixture, to yield variation in basicity (CaO/SiO2: 1.7 – 4.1) and FeO (6 - 19 wt%). This material was coarsely ground and screened to 250-500 µm and used as starting material for isothermal reduction treatments in lab-experimental gas-mixing furnaces at the following conditions: (1) 750 °C with XCO (= CO/[CO+CO2]) of 0.55; and 950 °C with XCO of (2, 3 & 4 respectively) 0.65, 0.76, 0.90. The experimental starting materials thus retain the mineralogical and microstructural variations of quasi-industrial sinter, while excluding mesostructural variations (e.g. sinter size). Long duration experiments were performed to compare the resultant net reduction degree and mineralogy with (Factsage-)predicted thermodynamic equilibrium. Excellent agreement was found between the predicted and measured reduction degree of samples from long-duration experiments within the wustite stability field (conditions (1) & (2)), with broad agreement too in terms of mineralogical composition. Samples were consistently less reduced than predicted with conditions (3) & (4), reflecting kinetic limitations. For (4), these are the formation of dense metallic layers around wustite domains in the case of lower-basicity sinters, and the sluggish reduction of metastably formed brownmillerite (C2(A,F)) to metallic Fe, lime and Ca-aluminate in higher basicity sinters. Shorter duration time-series experiments performed at conditions (1) and (2) show clearly the passage of sequential concentric reaction(-zone) fronts through the particles. Categorical differences are seen in the initial reduction behavior of Si-Al-rich SFCA versus Fe-rich SFCA-I, while all SFCA types remain initially unreacted as the hematite-magnetite reaction front passes. 
CLASS:PUBLIC
DTSTART:20220631T104500
DTEND:20220631T111000
END:VEVENT
END:VCALENDAR