Kinetics of reductive dephosphorization reaction for high-silicon Fe-Si-Ni melt
CHU Shao-jun1, CHEN Pei-xian2, HAN Pei-wei3, LU Ming-ying4
1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China; 2. Journal Publishing Center, University of Science and Technology Beijing, Beijing 100083, China; 3. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; 4. Party School of the CPC Bayannaoer City Committee, Bayannaoer 015000, Nei Mongol, China
Abstract：The behavior and kinetics of reductive dephosphorization (de-P) reaction for high-silicon Fe-Si-Ni melt was studied, which was one important part for developing a thermal-silicon reduction method to produce the nickel and chromium-iron based alloy for 300 series stainless steel production. The results showed that the de-P rate of Fe-Si-Ni melt mainly depends on the silicon content of the alloy melt, and the X-ray diffraction (XRD) analysis indicates that not only Ca3P2 but also Ca10+xSi12-2xP16 and Ca4SiP4 existed in the de-P slag. Besides, the mechanism of "rephosphorization" phenomenon in the de-P experiment for high-silicon Fe-Si-Ni melt was proposed. According to the experimental data, the kinetic formula of dephosphorization reaction in 10 kg induction furnace is given as dw([P])/dt = -Aw([P]) + Bt, (A and B were the empirical constants). For precipitation dephosphorization (SiCa alloy as dephosphorization agent, CaO-CaF2 as adsorption slag), the macro reaction kinetics formula was [%P] = 0.101e-0.101t+1.06×10-4t2-0.030 1 ([%P] was the mass fraction of phosphorus in the alloy w([P]) multiplied by 100, t was dephosphorization time). For interfacial dephosphorization (CaO(saturated)-CaF2 was dephosphorization slag), the macro reaction kinetic formula was [%P] = 0.113e-0.113t+ 7.76×10-5t2+0.001 43.
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