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Tian Y, Xu Y, Guan W, Zheng Q, Dai Y, Ma S, Li Y. Decomposition Process of Nonoxidative Microwave Radiation Roasting of a Mixed Rare Earth Concentrate with Sodium Carbonate. ACS OMEGA 2021; 6:28119-28130. [PMID: 34723010 PMCID: PMC8552337 DOI: 10.1021/acsomega.1c04194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
This article introduces an efficient decomposition process that uses sodium carbonate (Na2CO3) and activated carbon (C) as additives to decompose Bayan Obo mixed rare earth concentrate (hereinafter to be referred to as RE concentrate) by nonoxidative microwave radiation roasting. The roasting temperature, holding time, and contents of Na2CO3 and activated carbon are investigated. The optimum process parameters for decomposition are 800 °C and 30 min. The ratio of m(Na2CO3)/m(RE concentrate) is 0.5, and the ratio of m(C)/m (ER concentrate and Na2CO3) is 0.2 based on experimental data. Under the above conditions, the decomposition rate (shortened to DR) of RE concentrate is 98.58%, and the removal rates (shortened to CRs) of fluorine (F) and phosphorus (P) reached 80.35 and 46.75%, respectively. These rates are higher than traditional oxidation roasting under the same conditions. The three reasons for the result are the unique microwave heating characteristics, the overall efficient reaction of the mixture (RE concentrate, Na2CO3, and activated carbon), and the high nonoxidation rate of cerium. For these reasons and large experimental data, the reaction rate of the mixture is improved, and the efficiency of dilute hydrochloric acid for leaching rare earth elements is enhanced. In this article, the valence of rare earth elements in the roasted ore is all in the form of trivalence. Importantly, this nonoxidative roasted product can avoid the generation of chlorine in hydrochloric acid leaching. Moreover, such a short holding time is scarce in traditional roasting. When the mixture was roasted by utilizing microwave heating, the sinter phenomenon of the roasted product was avoided at high-temperature roasting. Finally, the surface morphology of RE concentrate at different conditions was observed by scanning electron microscopy (SEM) analysis, which can be used to compare the specific differences of roasting methods. According to these results, this process is beneficial for the decomposition of RE concentrate in terms of Na2CO3 roasting and is helpful for improving the clean and green technology method of hydrometallurgy.
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Affiliation(s)
- Yu Tian
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
- College
of Chemistry and Chemical Engineering, Inner
Mongolia University, Hohhot 010021, China
| | - Yanhui Xu
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
- College
of Chemistry and Chemical Engineering, Inner
Mongolia University, Hohhot 010021, China
| | - Weihua Guan
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
| | - Qiyuan Zheng
- School
of Metallurgy and Environment, Central South
University, Changsha 410083, China
| | - Yufei Dai
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
- College
of Chemistry and Chemical Engineering, Inner
Mongolia University, Hohhot 010021, China
| | - Shengfeng Ma
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
| | - Yu Li
- State
Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive
Utilization, Baotou Research Institute of
Rare Earths, Inner Mongolia, Baotou 014030, China
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Thermodynamic and application study of complicated extraction system Ce(IV)–HF–H3BO3–H2SO4 using Cyanex 923. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2020.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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In-situ measurement of mineral phase transition and kinetics in roasting process of Bayan Obo mixed rare earth concentrate by sodium carbonate. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2021.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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