<i>In-situ</i> Phase Identification of Crystallized Compound from 2CaO·SiO₂–3CaO·P₂O₅ Liquid

Phase Identification of Crystal Precipitated from Molten CaO–SiO₂–FeO_x–P₂O₅ Slag by High Temperature <i>In-situ</i> X-ray Diffraction

“…The details of the calibration test are given in our previous paper. 29) We then confirmed that the observed phase transition temperatures of the P 2 O 5 -free CaO-SiO 2 -FeO x slag corresponded to the thermodynamic prediction by the FactSage 7.3 program with the use of the latest Fact Oxide database. 39) High-temperature in-situ X-ray diffraction was performed by transmitting a high-energy and high-intensity X-ray beam to the levitated molten slag through a transmissive Kapton polyimide film layer, and the diffracted light was collected by a two-dimensional amorphous Si flat panel detector at 1.5 s intervals.…”

“…However, the crystal structure of the α phase has not been confirmed. Because the crystal structure of the C2S compound with low phosphorus solubility rapidly transforms during cooling from high temperature, 29) it is almost impossible to verify the high-temperature phase in the solidified slag when it is analyzed at room temperature.…”

“…Recently, by a unique approach where high-temperature in-situ X-ray diffraction was performed by transmitting high-energy X-rays into the aerodynamically levitated C2S-C3P melt, we directly verified that crystallization of the liquid phase of the C2S-C3P system forms the α phase as the primary crystal. 29) In contrast, the molten slag made in the dephosphorization process is a multicomponent system consisting of not only CaO, SiO 2 , and P 2 O 5 , but also FeO x and other minor components. It should be noted that the C2S compound formed in cement clinker or liquid slag accepts to some extent various types of doping elements, including Fe 2 + and Fe 3 + , which affect the stable C2S polymorph.…”

Effect of the Fe2O3 Addition Amount on Dephosphorization of Hot Metal with Low Basicity Slag by High-Temperature Laboratorial Experiments

“…There are some studies on the micro-morphologies and main compositions in the different phases of dephosphorization slag at low temperature with low basicity [6,10,[14][15][16][17][18][19][20][21]. It was reported that the phase of dephosphorization slag is mainly composed of Fe (iron)-rich phase including metal oxide and Ca3Fe2O5, P-rich phase including 2CaO•SiO2 (C2S), Ca3(PO4)2 (C3P) and nCa2SiO4-Ca3(PO4)2 (nC2S-C3P), and matrix phase [6].…”

Effect of Temperature on Dephosphorization of Hot Metal in Double‐Slag Converter Steelmaking Process by High‐Temperature Laboratorial Experiments

“…In addition, the mineral structure and the composition of phosphorus‐rich phase in dephosphorization slag at low temperature and low basicity have been studied. [ 17–33 ] It was reported that the phosphorus is mainly enriched with the form of n Ca 2 SiO 4 ‐Ca 3 (PO 4 ) 2 (hereafter denoted as n C 2 S‐C 3 P) in the phosphorus‐rich phase whether the dephosphorization slag is cooled in the atmosphere of air or argon. [ 17 ] The crystal phase obtained in dephosphorization stage is stabler than that in desiliconization stage.…”