Zheng Qiyuan, Xu Yanhui, Ma Shengfeng, Tian Yu, Guan Weihua, Li Yu
State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization, Baotou Research Institute of Rare Earths, Baotou 014030, Inner Mongolia, China.
College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, China.
ACS Omega. 2021 Apr 9;6(15):10486-10496. doi: 10.1021/acsomega.1c01218. eCollection 2021 Apr 20.
The investigation of the dielectric properties of bastnasite concentrate has critical directing centrality for the microwave roasting process of bastnasite concentrate. The dielectric properties are correlated with information such as thermogravimetry-differential scanning calorimetry and temperature rise curves. This combination permits a targeted study of the mechanism of the microwave roasting process, providing new evidence about the unique conditions of this microwave roasting process. This work also explores the response surface methodology based on a central composite design to optimize the microwave non-oxidative roasting process. Single-factor tests were conducted to determine the suitable range of factors such as the content of activated carbon, holding time, and roasting temperature. The interactions between parameters were investigated through the analysis of variance method. It was indicated that the models are available to navigate the design space. Also, the optimal roasting temperature, content of activated carbon, and holding time were 1100 °C, 20%, and 21.5 min, respectively. Under these conditions, the decomposition rate of bastnasite concentrate (hereinafter to be referred as DRBC) and the oxidation rate of cerium (hereinafter to be referred as ORC) was 99.8% and less than 0.3%, respectively. The new non-oxidizing roasting method significantly shortens the roasting time, reduces the energy consumption, and has great significance for industrial applications.
氟碳铈矿精矿介电性能的研究对氟碳铈矿精矿的微波焙烧过程具有关键的指导意义。介电性能与热重-差示扫描量热法和升温曲线等信息相关。这种结合使得对微波焙烧过程的机理进行有针对性的研究成为可能，为该微波焙烧过程的独特条件提供了新的证据。这项工作还基于中心复合设计探索响应面法以优化微波非氧化焙烧过程。进行了单因素试验以确定诸如活性炭含量、保温时间和焙烧温度等因素的合适范围。通过方差分析法研究了参数之间的相互作用。结果表明这些模型可用于指导设计空间。此外，最佳焙烧温度、活性炭含量和保温时间分别为1100℃、20%和21.5分钟。在这些条件下，氟碳铈矿精矿的分解率（以下简称DRBC）和铈的氧化率（以下简称ORC）分别为99.8%和小于0.3%。这种新的非氧化焙烧方法显著缩短了焙烧时间，降低了能耗，对工业应用具有重要意义。
