Reducing Dephosphorization of SiMn Alloy by Molten CaO-CaF2 Flux and Thermodynamic Stability of Ca3P2 under Atmospheric Cooling Conditions
作者单位：School of Materials Science and Engineering University of Ulsan Ulsan 680-749 Korea
会议名称：《Ninth International Conference on Molten Slags,Fluxes and Salts(MOLTEN12)》
会议日期：2012年
学科分类：08[工学] 0806[工学-冶金工程] 080601[工学-冶金物理化学]
关 键 词：Phosphide capacity CaO-CaF 2 slag Reducing dephosphorization Phosphine(PH3) gas
摘 要：This study consists of experimental measurement of the phosphide capacity of the CaO-CaF 2 flux in equilibrium with SiMn alloy at 1823 K,and includes the thermodynamic analysis of the stability of reducing refining slags under wet atmospheric cooling *** phosphide capacity increased with increasing CaO concentration in the flux,followed by a constant *** composition for the saturating capacity is in good accordance to the saturation content of CaO in the CaO-CaF 2 flux at 1823 *** the Vee ratio（=CaO/SiO 2） of the reducing dephosphorization slag is greater than about 1.35,CaO（lime） and Ca 2 SiO 4（dicalcium silicate） phases appeared during cooling cycle based on the CaO-SiO 2-CaF 2 phase diagram,resulting in an increase of the evolution rate of PH 3 gas due to an increase in the reaction ***,when the Vee ratio of the slag is lower than about 1.35,CaF 2,Ca 4 Si 2 F 2 O 7（cuspidine）,and CaSiO 3（wollastonite） phases appeared from the phase diagram,resulting in negligible amount of PH 3 evolution during cooling because the reaction between Ca 3 P 2 and H 2 O was restricted to the surface of bulk slag.