竖罐炼镁过程中镁蒸气流动相变规律-《郑州大学学报(工学版)》

文章信息/Info

Title:: Flow and Phase Change Characteristics of Magnesium Vapor in Vertical Retort During Silicothermic Process

作者:: 陈毛¹; 张少军¹; 李荣斌²; 南俊杰²; 刘金辉¹; 杨沛胥¹; 1.郑州大学材料科学与工程学院,河南郑州 450001, 2.北京科技大学冶金与生态工程学院,北京 100083

Author(s):: CHEN Mao; ZHANG Shaojun; LI Rongbin; NAN Junjie; LIU Jinhui; YANG Peixu; School of Materials Science and Engineering, Zhengzhou University, 450001, Zhengzhou, Henan, School of Metallurgy and Ecological Engineering, Beijing University of Science and Technology, Beijing 100083

Keywords:: magnesium smelting; magnesium vapor; vertical retort; silicothermic process; flow resistance

摘要:: 皮江法炼镁工艺中,掌握镁蒸气流动和结晶规律是获得高质量结晶镁的关键。针对这一问题,研究了复式竖罐内镁蒸气从还原反应区流动到结晶区过程中的流动规律,并通过引入高温稀薄气体中流导的概念给出了镁蒸气流动过程阻力计算方法,推导出镁蒸气流动阻力与还原罐内径、运动距离以及压强之间的关系式。结果表明:镁蒸气的结晶过程不仅受温度和压强影响,还与结晶器的内径相关,适当减小结晶器内径可获得致密度较高的结晶镁;镁蒸气从复式竖罐中的反应区流动到结晶区,镁蒸气的总压降约为 150 Pa,还原反应区平均压强数量级在百帕以上;镁冶炼初期,部分料球温度低于 600 ℃ 时,镁蒸气以“ 凝华-升华” 的方式在反应区层移,随着料球整体温度升高到 600 ℃ 以上,镁蒸气流动阻力减小,能够顺利进入结晶器结晶。

Abstract:: In the Pidgeon magnesium smelting process, mastering the laws of magnesium vapor flow and crystallization is the key to obtaining high-quality crystalline magnesium. In this paper, the flow characteristic of magnesium vapor in the compound vertical retort from the reduction reaction zone to the crystallization zone was studied. The calculation method of flow resistance was given by introducing the concept of conductance in hightemperature rarefied gas. The relationship between flow resistance and the retort inner diameter, retort size, vapor pressure was deduced. It is shown that the crystallization process of magnesium vapor is not only affected by temperature and pressure, but also related to the diameter of the crystallizer. Appropriately reducing the inner diameter of the crystallizer can obtain crystalline magnesium with higher density. The total pressure loss of magnesium vapor in the compound vertical retort from the reaction zone to crystallization zone is about 150 Pa, and the average working pressure in the reaction zone is higher than two order of magnitude. In the early stage of magnesium smelting, when the temperature of part of the pellets is lower than 600 ℃ , the magnesium vapor moves in the reaction zone in a “condensation-sublimation” manner. As the temperature of the overall pellet rises above 600 ℃ , the flow resistance of magnesium vapor decreases, and it can smoothly enter the crystallizer for crystallization