Phosphorus fixation capacity of CaO-SiO_(2)-Al_(2)O_(3)-MnO-Ce_(2)O_(3) slag based on structural considerations  

作　　者：Jiali Sun Chengjun Liu Maofa Jiang 

机构地区：[1]Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education),Northeastern University,Shenyang 110819,China [2]School of Metallurgy,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Rare Earths》2023年第3期446-453,I0005,共9页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(51874082);NSFC-Liaoning Joint Fund(U1908224)。

摘　　要：The phosphorus fixation capacity of some slag systems,such as Ce_(2)O_(3)-containing slag,has hardly been investigated from a thermodynamics view due to the lack of relevant thermodynamic data.Since the macroscopic properties are primarily determined by the microscopic structure,the correlation between phosphorus fixation capacity and slag structure was explored by spectroscopy(XPS),Raman spectroscopy,and ferromanganese dephosphorization experiments.The results show that the predominant species of P^(5+)are Q_(P)^(0)(PO_(4)^(3-))and Q_(P)^(1)(P_(2)O_(7)^(4-))units in the CaO^(-)SiO_(2)-Al_(2)O_(3)-MnO^(-)Ce_(2)O_(3)-P_(2)O_(5)quenched slag,and the phosphorus fixation capacity increases with the Q_(P)^(1)(P_(2)O_(7)^(4-))unit to Q_(P)^(0)(PO_(4)^(3-))unit transformation(the P-O^(0) bond to P-O^(-)bond transformation)since the electron cloud density between P and O atoms increases and the average radius of P-O bonds decreases.Especially,CaO or Ce_(2)O_(3) as a network modifier can release the O_(2)-and promote the P-O^(0) bond to P-O^(-)bond(connected to Ca^(2+),/Ce^(3+))transformation in the quenched slag.Furthermore,the phosphorus enrichment phases in the slow cooling slag are confirmed as nCa_(2)SiO_(3)-Ca_(3)P_(2)O_(8)(nC_(2)S-C3P)and CePO_(4) solid solutions by the scan electron microscopy(SEM),transmission electron microscopy(TEM),and energy-dispersive spectrometer(EDS)methods.The re sults show Ce_(2)O_(3) can depolymerize the polyphosphate structure partially replacing CaO after introducing Ce_(2)O_(3) into CaO based slag because of its strong ability to donate electrons.The above results not only help to understand the dependence of phosphorus fixation capacity on slag composition from a structural view,but also provide the theoretical guidance for optimizing the composition of Ce_(2)O_(3)-containing dephosphorization slag.

关 键 词：Phosphorus fixation capacity Slag structure X-ray photoelectron spectroscopy Raman spectroscopy Ce_(2)O_(3) CePO_(4) 

分 类 号：TF703[冶金工程—钢铁冶金]