Fusibilité et cristallisation des laitiers basiques peu phosphatés d’aciérie

Study of the State of Industrial P2O5‐Containing Slags Relevant to Steelmaking Processes Based on a New Thermodynamic Database Developed for CaO–FeOx–P2O5–SiO2–MnO–MgO–Al2O3 Slags − Part I: Ternary and Lower Order Systems

“…Cases where p(O 2 ) was set as 10 −5 atm will be further on designated as the “elevated p(O 2 ) case”. Riboud and co‐workers (within IRSID) justified this choice of p(O 2 ) by the fact that the ferric to ferrous ratio measured in some industrial samples was in the same range of that measured in corresponding laboratory slags when they were in equilibrium with a gas phase at a p(O 2 ) value of 10 −5 atm and a temperature of 1873 K (1600 °C) . Unfortunately, despite referring to those samples on several occasions, no details about the plant trials in terms of procedure and samples analysis were published, according to authors best knowledge.…”

“…The system CaO–FeO x –P 2 O 5 is a key‐system for modeling the behavior of phosphorous during refining of P‐containing hot metal. Also, this is the basic system of the so called “Thomas‐slags”, resulting from oxygen refining of high P hot metal (also labeled as Thomas‐Hot‐Metal) in the 1960s and 70s, for which the so called LD‐AC furnace was used . Since the initial phosphorous content of the hot metal in such processes was higher than 1 wt% at the time, the final P 2 O 5 contents in slags typically ranged between 10 and 20 wt %.…”

“…Experimental data on the behavior of this system in equilibrium with liquid Fe, i.e., at reduced p(O 2 ) (Table ), were provided by Görl et al Drewes and Olette provided experimental data on the system behavior at elevated p(O 2 ) . Muan et al as well as Margot‐Marette and Riboud studied the system behavior under air …”

“…The aforementioned experimental data on the system focused mainly on the determination of the position of the liquidus lines of the CaO‐rich part of the oxide system . The slag liquidus will be further divided in 2 parts: The “C2S_liquidus” denoting the boundary between (region 1) and (region 2) and the “CaO‐liquidus” denoting the boundary between (region 1) and (region 5).…”

“…At such conditions, the ferric (Fe 3+ ) to ferrous (Fe 2+ ) ratio in the system is very high (Figure ). Margot and Riboud provided experimental data at a temperature of 1873 K (1600 °C) while Phillips and Muan provided a hypothetical estimation of the slag liquidus, also at a temperature of 1873 K (1600 °C) . When including their results, the effect of p(O 2 ) on the system is expected to follow the scheme presented in Figure .…”