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过程工程学报 ›› 2022, Vol. 22 ›› Issue (11): 1521-1527.DOI: 10.12034/j.issn.1009-606X.221347CSTR: 32067.14.jproeng.221347

• 研究论文 • 上一篇    下一篇

高炉烟尘真空还原过程中铅锌钾氯的挥发特性

王耀宁1,2， 马红周1,2*， 王子钰1,2， 王碧侠1,2， 施瑞盟1,2   

  1. 西安建筑科技大学
  • 收稿日期:2021-11-03 修回日期:2022-01-20 出版日期:2022-11-28 发布日期:2022-11-28
  • 通讯作者: 马红周 mhzwyn@126.com
  • 作者简介:王耀宁(1975-)，女，陕西省宝鸡市人，硕士，讲师，金属材料加工专业，E-mail: yaoningwang@126.com；通讯联系人，马红周，E-mail: mhzwyn@126.com.
  • 基金资助:
    陕西省自然科学基础研究基金项目

Volatilization characteristics of lead, zinc, potassium and chlorine in blast furnace dust by vacuum reduction

Yaoning WANG1,2,  Hongzhou MA1,2*,  Ziyu WANG1,2,  Bixia WANG1,2,  Ruimeng SHI1,2   

  1. 1. School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi 710055, China 2. Key Laboratory of Gold and Resources of Shaanxi Province, Xi'an, Shaanxi 710055, China
  • Received:2021-11-03 Revised:2022-01-20 Online:2022-11-28 Published:2022-11-28

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摘要： 炼铁过程中会产出大量富集铅、锌、氯、钾等元素的烟尘，这些元素的存在对烟尘中铁的循环利用有不利影响，对其分离是实现高炉烟尘高效循环利用的首要条件。本工作对高炉烟尘进行了TG-DSC综合热分析，对铅、锌、氯、钾元素的水溶特性及其在真空还原过程中的挥发特性以及还原渣中铁的物相进行了研究。结果表明，烟尘在744及963℃有明显的吸热峰，说明在此温度下有较强烈的反应发生。根据烟尘中铅、锌、氯、钾的水溶特性，定性判断四种元素在烟尘中的主要存在形式为ZnCl2, KCl, ZnO, ZnFe2O4, PbO。真空还原可有效提取高炉烟尘中的铅、锌、钾、氯等元素，在炉内压力10 Pa、1100℃保温30 min条件下，烟尘中的铅、锌、钾、氯的挥发率分别为99.90%, 99.76%, 98.31%, 99.70%；烟尘中氯的存在形式主要为ZnCl2和KCl，氯在400~600℃时主要以ZnCl2形式挥发，600℃以上以KCl形式挥发；烟尘中锌除了以ZnCl2挥发以外，在高温阶段为ZnO和ZnO?Fe2O3被还原为金属锌而挥发；钾的挥发以KCl为主，铅的挥发是PbO被烟尘中的碳还原为金属铅蒸气而挥发。高炉烟尘中铁主要为Fe2O3，通过真空还原在895℃保温30 min，Fe2O3被还原为Fe3O4, FeO和Fe，在1075℃保温30 min时Fe2O3基本转变为结晶度较好的Fe。

关键词: 高炉烟尘, 真空还原, 铅, 锌, 氯, 钾

Abstract: In the iron smelting process, a large amount of blast furnace (BF) dust enriched with lead, zinc, chlorine, potassium and other elements will be produced. The existence of these elements has a negative impact on the recycling of iron in the BF dust. Therefore, the separation of these elements is the primary condition for realizing the efficient recycling of the BF dust. In this work, TG-DSC comprehensive thermal analysis was carried out for BF dust, and the water-soluble characteristics of lead, zinc, chlorine, potassium and their volatilization characteristics in the vacuum reduction process as well as the phase of iron in the reduction slag were studied. The results showed that the smoke had obvious endothermic peaks at 744 and 963℃, which indicated that there was a strong reaction at this temperature. According to the water-soluble characteristics of lead, zinc, chlorine and potassium in the smoke, it was qualitatively judged that the main forms of the four elements in the smoke were ZnCl2, KCl, ZnO, ZnFe2O4 and PbO. The vacuum reduction can effectively extract lead, zinc, potassium, chlorine and other elements from the blast furnace dust. Under the furnace pressure of 10 Pa and the temperature of 1100℃ for 30 min, the volatilization rates of lead, zinc, potassium and chlorine in the dust were 99.90%, 99.76%, 98.31%, and 99.70% respectively. The existing forms of chlorine in smoke were mainly ZnCl2 and KCl. Chlorine volatilized mainly in the form of ZnCl2 at 400~600℃ and KCl above 600℃. In addition to the volatilization of zinc in smoke by ZnCl2, zinc in smoke was volatilized by the reduction of ZnO and ZnO?Fe2O3 to metal zinc at high temperature stage. The volatilization of potassium was mainly KCl, and the volatilization of lead was caused by the reduction of PbO by carbon in smoke to metal lead vapor. The iron in the blast furnace dust was mainly Fe2O3. Fe2O3 was reduced to Fe3O4, FeO and Fe by vacuum reduction at 895℃ for 30 min, and Fe2O3 was basically transformed into Fe with good crystallinity at 1075℃ for 30 min.

Key words: blast furnace dust, vacuum reduction, lead, zinc, chlorine, potassium