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Effect of the Initial P Content on Dephosphorization of Hot Metal with Low Basicity Slag at 1623 K
Author(s) -
Yang Wenkui,
Yang Jian,
Zhang Runhao,
Sun Han
Publication year - 2021
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.202100066
Subject(s) - metal , slag (welding) , activation energy , oxygen , analytical chemistry (journal) , oxide , silicon , materials science , chemistry , oxygen atom , metallurgy , nuclear chemistry , molecule , organic chemistry
The effect of the initial P content ranging from 0.057% to 0.292% in hot metal on dephosphorization with low basicity (CaO/SiO 2 ) slag at 1623 K is investigated using high‐temperature laboratorial experiments. With increasing initial P content in the hot metal, the dephosphorization ratio increases first and then decreases, with the highest dephosphorization ratio of 83.2% at the initial P content in the hot metal of 0.173%. The phases in dephosphorization slags are basically consistent, which are mainly composed of n Ca 2 SiO 4 ‐Ca 3 (PO 4 ) 2 , Ca 2 SiO 4 , metal oxide, Ca 3 (PO 4 ) 2 , Ca 3 Mg(SiO 4 ) 2 , Ca 2 Fe 2 O 5 , and MgAl 2 O 4 . The compositions of all the P‐rich phases are close to the connection line between Ca 2 SiO 4 and Ca 3 (PO 4 ) 2 in the phase diagram. In addition, with increasing the initial P content in hot metal, the viscosity and activation energy values of the dephosphorization slag increases at the present dephosphorization temperature of 1623 K and the values of the activation energy of the dephosphorization slags increase gradually. The area fractions of Q 0 + Q 1 ( Q i , i is the number of bridging oxygen per silicon atom) units decrease, whereas those of the Q 2 + Q 3 units increase. The average number of nonbridging oxygen per silicon atom (NBO/Si) value decreases, indicating that the degree of the polymerization (DOP) of the corresponding dephosphorization slag increases resulting in the increased viscosity.