Abstract

Thermodynamic modeling results of lanthanum equilibrium content in metal under the slag of CaO–SiO₂–La₂О₃–Al₂O₃–MgO system corresponding to the chemical composition of 16 points of local simplex plan are presented using the HSC 8.03 Chemistry (Outokumpu) software package in combination with the simplex planning lattice method. In the work, slag is represented by CaO–SiO₂–La₂O₃–15% Al₂O₃–8% MgO oxide system in a wide range of chemical composition for temperatures of 1550 and 1650°C, and metal contains 0.06% C, 0.25% Si, 0.05% Al (in this expression and hereinafter in mas. %). The mathematical modeling results are shown graphically in the form of composition–equilibrium content diagrams of lanthanum. There is a significant effect of slag basicity on the lanthanum equilibrium content in metal. An increase in slag basicity from 2 to 5 at a temperature of 1550°C leads to an increase in the lanthanum equilibrium content from 0.2 ppm in the region of lanthanum oxide concentration of 1–5% to 7 ppm in the region of increased concentration of lanthanum oxide to 4–7%. Hence, the increase in slag basicity favorably affects the development of lanthanum reduction. Increase in metal temperature also has positive effect on lanthanum reduction process. As temperature rises to 1650°C, the lanthanum equilibrium content in metal increases from 0.2 ppm in the region of lanthanum oxide concentration of 1–3% to 12 ppm in the region of increased concentration of lanthanum oxide to 4–7%. In diagrams of chemical composition of slag containing 56–61% CaO, 12–14% SiO² and 4–7% La₂O₃ the lanthanum content in metal at level of 7–12 ppm is ensured in temperature range from 1550 to 1650°C. Therefore, a decisive role of slag basicity is confirmed, as well as the concentration of lanthanum oxide and temperature factor into the development of lanthanum reduction from slags of the studied oxide system by aluminum dissolved in metal.

中文翻译：

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CaO–SiO 2 –La 2 O 3 –15％Al 2 O 3 –8％MgO系炉渣下金属中镧的平衡含量

摘要

在金属的镧含量平衡热力学模拟结果的CaO-的SiO的炉渣下₂ -La ₂ О ₃ -Al ₂ ö ₃ -MgO对应的本地单工计划16分的化学组成系统所使用的HSC 8.03化学（呈现（Outokumpu）软件包结合单纯形规划格方法。在工作中，炉渣由CaO–SiO ₂ –La ₂ O ₃ –15％Al ₂ O _3表示在1550和1650°C的温度下，具有广泛化学组成的–8％MgO氧化物体系，金属含有0.06％C，0.25％Si，0.05％Al（在此表示，以下表示质量％）。数学建模结果以镧的组成-平衡含量图的形式以图形方式显示。炉渣碱度对金属中镧平衡含量有显着影响。在1550°C的温度下，炉渣碱度从2增加到5，导致镧平衡含量从1–5％的氧化镧浓度范围内的0.2 ppm增加到75％的氧化镧浓度范围内的7 ppm。氧化镧达到4–7％。因此，炉渣碱度的增加有利地影响了镧还原的发展。金属温度的升高对镧还原过程也有积极作用。当温度升至1650°C时，金属中的镧平衡含量从氧化镧浓度1–3％的区域的0.2 ppm增加到氧化镧浓度增加至4–7％的区域的12 ppm。在含56–61％CaO，12–14％SiO的炉渣的化学成分图中²和4-7％的La ₂ ö ₃在金属镧含量在7-12 ppm的水平，确保在温度范围1550年至1650年℃。因此，证实了炉渣碱度的决定性作用，以及氧化镧的浓度和温度因数对溶解于金属中的铝从研究的氧化物体系的炉渣还原镧的发展起了决定性作用。