欢迎访问过程工程学报, 今天是

过程工程学报 ›› 2020, Vol. 20 ›› Issue (2): 182-188.DOI: 10.12034/j.issn.1009-606X.219187

• 反应与分离 • 上一篇    下一篇

碳酸钠对镍渣碳热还原的催化作用

李小明， 闻震宇， 李 怡， 王伟安， 邢相栋*   

  1. 西安建筑科技大学冶金工程学院，陕西 西安 710055
  • 收稿日期:2019-04-25 修回日期:2019-06-18 出版日期:2020-02-22 发布日期:2020-02-19
  • 通讯作者: 邢相栋 xaxingxiangdong@163.com
  • 基金资助:
    中国国家自然科学基金;中国国家自然科学基金

Catalytic effect of sodium carbonate on the carbothermic reduction of nickel slag

Xiaoming LI, Zhenyu WEN, Yi LI, Weian WANG, Xiangdong XING*   

  1. School of Metallurgical Engineering, Xi?an University of Architecture and Technology, Xi?an, Shaanxi 710055, China
  • Received:2019-04-25 Revised:2019-06-18 Online:2020-02-22 Published:2020-02-19

PDF

摘要： 以全铁含量39.40wt%和SiO2含量32.50wt%的镍渣为原料，针对其中的铁以铁橄榄石形式存在难以直接还原磁选提铁的问题，在镍渣中添加不同质量比的碳酸钠促进镍渣碳热还原，进行了热力学计算和实验验证。结果表明，碳酸钠添加量由0增加至6wt%时，还原产物中铁的金属化率和回收率不断增大，继续增大碳酸钠添加量至8wt%时，铁的金属化率和回收率略有减小。不添加碳酸钠的还原产物中铁粒径很小，平均粒径为6 ?m，难还原的铁橄榄石大量存在，而加入6wt%碳酸钠的还原产物中铁粒径粗大，平均粒径增大至17 ?m，铁橄榄石含量明显降低，金属铁的XRD衍射峰强度明显增加。

关键词: 镍渣, 铁橄榄石, 碳酸钠, 碳热还原

Abstract: Nickel slag, a byproduct come from the nickel flash smelting process, contains a high content of iron and different quantities of valuable metals, such as nickel, copper, cobalt, etc. It is a potential metal resource for the iron and steel industry. The reasonable development and utilization of nickel slag meets the requirements of comprehensive utilization of secondary resources, with environmental, economic, and social benefits. However, nickel slag is difficult to reduce because of its complex mineral composition and containing a lot of fayalite, so catalyzing the reduction of nickel slag to extract valuable metal has become an urgent issue. This work took the nickel slag with total iron content of 39.40wt% and SiO2 content of 32.50wt% as raw materials, the thermodynamic calculation and experimental were carried out with different proportions of sodium carbonate added. The results showed that with the increase of the proportion of sodium carbonate from 0 to 6wt%, the degree of metallization and iron recovery rate of the reduced products increased. The content of sodium carbonate increased to 8wt%, the degree of metallization and recovery rate of iron in the reduced products remained the same or even slightly decreased. The results of SEM showed that the particle size of iron in the reduction product without sodium carbonate added was only 6 μm, and EDS analysis showed that fayalite was abundant. However, the particle size of iron in the reduction product for nickel slag added with 6wt% sodium carbonate was 17 μm, and the content of fayalite was significantly decreased. The diffraction intensity of metallic iron was significantly increased in the XRD pattern. These results indicated that sodium carbonate can promote the reduction of nickel slag and the obtained large size of iron was helpful for subsequent magnetic separation.

Key words: nickel slag, fayalite, Na2CO3, carbothermic reduction