Activity of Chromium Oxide in CaO‐SiO2 based Slags at 1873 K
Activity of Chromium Oxide in CaO‐SiO2 based Slags at 1873 K
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DOI：
10.1002/srin.200506009
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发表时间：
2005-04
影响因子：
2.2
通讯作者：
Kazuki Morita;K. Tsukiashi;Munekazu Kimura;N. Sano
中科院分区：
文献类型：
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作者：
Kazuki Morita;K. Tsukiashi;Munekazu Kimura;N. Sano
熔渣中铬氧化物的热力学性质对于优化不锈钢精炼工艺和铬矿还原工艺具有重要意义。作者在前人的研究中发现，铬铁矿在熔渣中的溶解度随氧分压和炉渣组成的变化而变化很大。本文总结了1873K时，在中等还原条件下测得的氧化铬的活度数据和氧化还原平衡，Po2=6.95×10−11atm。对于CaO-SiO_2-CROX系统，氧化铬的活度系数随碱度的增加而增大，根据所确定的相关系，确定了精炼不锈钢的最佳炉渣组成为CaCr2O4和Cr2O3饱和的炉渣。另一方面，氧化镁和氧化铝的存在导致氧化铬的活性和氧化还原平衡的不同行为，建议在1873K的实际不锈钢精炼过程中采用44质量%的CaO-39质量%的SiO_2-11质量%的Al_2O_3-6质量%的氧化镁渣。
Thermodynamic properties of chromium oxides in molten slags are very important for optimization of stainless steel refining processes as well as reduction processes of chromium ores. The solubility of chromite into molten slags has been found to vary drastically with oxygen partial pressure and slag composition in the former studies by the authors. In the present study, activity data and redox equilibria of chromium oxides measured under moderately reducing conditions, PO2= 6.95×10−11 atm, at 1873 K are summarized. For the CaO‐SiO2‐CrOx system, the activity coefficient of chromium oxide increased with increasing basicity and the optimized slag composition for stainless steel refining is assessed as that saturated with CaCr2O4 and Cr2O3 using the phase relations determined. On the other hand, the presence of MgO and Al2O3 brings about different behaviour of chromium oxide activity and redox equilibria and the 44 mass per cent CaO ‐ 39 mass per cent SiO2 ‐11 mass per cent Al2O3 ‐ 6 mass per cent MgO slag is recommended to reduce the chromium oxidation loss in the practical stainless steel refining process at 1873 K.