Mechanism of Phosphorus Enrichment in Dephosphorization Slag Produced Using the Technology of Integrating Dephosphorization and Decarburization
Mechanism of Phosphorus Enrichment in Dephosphorization Slag Produced Using the Technology of Integrating Dephosphorization and Decarburization
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DOI：
10.3390/met11020216
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发表时间：
2021-01
期刊：
影响因子：
2.9
通讯作者：
Haimeng Xue;Jie Li;Yunjin Xia;Yongjian Wan;Liangjun Chen;Changji Lv
中科院分区：
文献类型：
--
作者：
Haimeng Xue;Jie Li;Yunjin Xia;Yongjian Wan;Liangjun Chen;Changji Lv
为了更好地理解和发展单转炉脱磷脱碳一体化技术（简称IDDSC），通过计算对相关热力学问题进行了讨论。根据热力学计算，建立了磷分布比、温度和渣组成之间的桥梁。此外，利用IDDSC技术对铁水熔炼的4个热段进行了研究，建立了脱磷行为与炉渣组织之间的联系。研究结果揭示了脱磷渣中磷富集的机理。结果表明，随着矿渣碱度的增加，脱磷效率逐渐提高。随着渣中FeO含量的增加，脱磷效率先升高后降低。P2O5和FeO在与CaO和SiO2反应时存在竞争关系。当CaO/FeO较高时，FeO供给不足。因此P2O5优先与CaO和SiO2通过[3n + 2](CaO) + 2SiO2 + n(P2O5) = n(3CaO·P2O5)-2CaO·SiO2(s)反应生成富P2O5的nC2S-C3P固溶体，促进了[P]从铁水中脱除。当CaO/FeO较低时，FeO通过a(CaO) + b(SiO2) + c(FeO) = aCaO·bSiO2·cFeO(s)与CaO和SiO2发生反应，生成CaFeSiO4，而不是富P2O5固溶体。因此，CaO/FeO较低的炉渣脱磷能力较差。
In order to better understand and develop the technology of integrating dephosphorization and decarburization in a single converter (abbreviated as IDDSC), the relevant thermodynamic issues were discussed by calculation. Based on the thermodynamic calculation, the bridges between the phosphorus distribution ratio, temperature, and slag composition were constructed. Besides, the connections between the dephosphorization behavior and the microstructure of slag were also established by investigating four heats of hot metal smelt using IDDSC technology. As a result, the mechanism of phosphorus enrichment in the dephosphorization slag was revealed. Also, the results show that the dephosphorization efficiency increases gradually with increasing slag basicity. While the dephosphorization efficiency increases first and then decreases with the increase of FeO content in slag. There is a competition relationship between P2O5 and FeO in reacting with CaO and SiO2. When CaO/FeO is relatively high, not enough FeO is provided. Thus P2O5 is in priority to react with CaO and SiO2 through [3n + 2](CaO) + 2SiO2 + n(P2O5) = n(3CaO·P2O5)-2CaO·SiO2(s), generating P2O5-rich nC2S-C3P solid solution which promotes the removal of [P] from the hot metal. When CaO/FeO is relatively low, FeO competes over P2O5 in reacting with CaO and SiO2 through a(CaO) + b(SiO2) + c(FeO) = aCaO·bSiO2·cFeO(s), generating CaFeSiO4 instead of P2O5-rich solid solution. As a consequence, the slag with low CaO/FeO shows a poor dephosphorization ability.