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过程工程学报 ›› 2022, Vol. 22 ›› Issue (10): 1429-1437.DOI: 10.12034/j.issn.1009-606X.222303

• 研究论文 • 上一篇    下一篇

白云鄂博稀土共生矿超重力梯级分离稀土元素的工艺研究

兰茜, 高金涛, 郭占成*
  

  1. 北京科技大学钢铁冶金新技术国家重点实验室,北京 100083
  • 收稿日期:2022-08-22 修回日期:2022-09-05 出版日期:2022-10-28 发布日期:2022-10-26
  • 通讯作者: 郭占成 cguo@ustb.edu.cn
  • 作者简介:兰茜(1993-),女,河北省石家庄市人,博士研究生,冶金工程专业;通讯联系人,郭占成,E-mail: zcguo@ustb.edu.cn.

Study on technology of super gravity step separation of rare earth elements in Bayan Obo rare earth ore

Xi LAN,  Jintao GAO,  Zhancheng GUO*   

  1. State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2022-08-22 Revised:2022-09-05 Online:2022-10-28 Published:2022-10-26
  • Contact: Zhancheng Guo cguo@ustb.edu.cn

摘要: 我国白云鄂博矿稀土储量居世界首位,其稀土矿物以轻稀土为主,Ce, La, Pr, Nd占稀土氧化物总量的97%以上,具有重要的工业价值。由于四种稀土元素具有极其相似的物化性质,因此在目前的处理工艺中很难实现不同稀土元素的彼此分离。本工作基于稀土精矿的矿相演变及元素迁移规律,在降温熔析过程中不同温度区间内会析出不同稀土相:在1400~1500℃的温度区间只有氧化稀土相析出,随着温度降至1200~1400℃,铁酸稀土相开始析出,当温度降至1100~1200℃时铈磷灰石相析出。利用超重力技术进行氧化稀土相、铁酸稀土相、铈磷灰石相的梯级分离实验,结果表明,98.38%的Ce元素优先以氧化稀土相形式析出并实现分离,97.70%的La元素进入铁酸稀土相作为第二相被分离,而Pr和Nd元素最终以铈磷灰石相的形式分离,以此实现了稀土精矿中Ce, La, Pr, Nd的梯级分离。

关键词: 白云鄂博, 稀土精矿, 稀土元素, 超重力冶金, 梯级分离

Abstract: The rare earth reserves of Bayan Obo mine in China rank first in the world, and its rare earth minerals are mainly light rare earth, of which cerium, lanthanum, praseodymium and neodymium account for more than 97% of the total rare earth oxides, which has important industrial value. Since the rare earth elements have extremely similar physical and chemical properties, it is difficult to realize the separation of different rare earth elements from each other in the current treatment process. In this work, a green and efficient method was proposed for respectively recovering rare earth elements under supergravity from rare earth concentrate. Based on the evolution of mineral phases and elemental migration laws of the rare earth concentrate, it was found that different rare earth phases would be precipitated in different temperature intervals during the melting and cooling precipitation process. It could be concluded that the rare earth elements (REEs: Ce, La, Pr, Nd) were discovered to be precipitated as the rare earth oxide, rare earth ferrate and britholite phases respectively at various temperature ranges of 1400~1500, 1200~1400, and 1100~1200℃, respectively. However, the rare earth phases were intimately intertwined with each other in the normal gravity. Consequently, the respective separation of REEs (Ce, La, Pr, Nd) at their corresponding precipitation temperatures was conducted under the supergravity. 98.38% of Ce was firstly enriched into the rare earth oxide and separated from the concentrate as driven by the supergravity, 97.70% of La was enriched into the rare earth ferrate and separated subsequently, and the Pr and Nd were precipitated further into britholite and separated from the system. Accordingly, the high purity of rare earth oxide, rare earth ferrate, and britholite phases were attained respectively, and the stepwise separation of Ce, La, Pr and Nd in the rare earth concentrate were achieved, achieving the green and efficient recovery of REEs (Ce, La, Pr, Nd) from the Bayan Obo rare earth concentrate with no additives, no hazardous waste, and no secondary pollution.

Key words: Bayan Obo, rare earth concentrate, rare earth element, supergravity metallurgy, stepwise separation