Spectral Analysis of Trace Fluorine Phase in Phosphogypsum
ZHAO Hong-tao1, 2, 3, LI Hui-quan1*, BAO Wei-jun1, WANG Chen-ye1, LI Song-geng3*, LIN Wei-gang3
1. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 2. University of Chinese Academy of Sciences, Beijing 100049, China 3. State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
Abstract:Phosphogypsum, which contains more than 90% of the calcium sulfate dihydrate(CaSO4·2H2O), is a kind of important renewable gypsum resources. Unlike the natural gypsum, however, phosphorus, fluorine, organic matter and other harmful impurities in phosphogypsum limit its practical use. To ascertain the existence form, content and phase distribution of trace fluoride in phosphogypsum has important theoretical values in removing trace fluoride effectively. In this present paper, the main existence form and phase distribution of trace fluoride in phosphogypsum was investigated by the combination of X-ray photoelectron spectroscopy (XPS) and Electron microprobe analysis (EMPA). The results show that trace fluoride phase mainly includes NaF, KF, CaF2, K2SiF6, Na2SiF6, Na3AlF6, K3AlF6, AlF3·3H2O, AlF2.3(OH)0.7·H2O, Ca5(PO4)3F, Ca10(PO4)6F2. Among them, 4.83% of fluorine exists in the form of fluoride (NaF, KF, CaF2); Accordingly, 8.43% in the form of fluoride phosphate(Ca5(PO4)3F, Ca10(PO4)6F2); 12.21% in the form of fluorine aluminate(Na3AlF6, K3AlF6); 41.52% in the form of fluorosilicate(K2SiF6, Na2SiF6); 33.02% in the form of aluminum fluoride with crystal water(AlF3·3H2O, AlF2.3(OH)0.7·H2O). In the analysis of phase constitution for trace elements in solid samples, the method of combining XPS and EMPA has more advantages. This study also provides theoretical basis for the removal of trace fluorine impurity and the effective recovery of fluorine resources.
[1] LI Fei(李 飞). Phosphate & Compound Fertilizer (磷肥与复肥), 2012, 27(6): 69. [2] TIAN Yao-peng, XIE Ji-you, SUN Zhi(田耀鹏,谢吉优,孙 志). Inorganic Chemicals Industry(无机盐工业), 2014, 46(1): 8. [3] Rentería-Villalobos M, Vioque I, Mantero J, et al. Journal of Hazardous Materials, 2010, 181: 193. [4] Cárdenas-Escudero. C, Morales-Flórez. V, Pérez-López. R, et al. Journal of Hazardous Materials, 2011, 196: 433. [5] DING Guang-yue, LI Yue, FAN Cai-mei, et al(丁光月,李 岳,樊彩梅,等). Journal of Taiyuan University of Technology(太原理工大学学报), 2011, 42(6): 593. [6] JIA Xing-wen, WU Zhou, MA Ying(贾兴文,吴 洲,马 英). Materials Review(材料导报), 2013, 27(12): 141. [7] Lee M G, Jang Y N, Ryu K W, et al. Energy, 2012, 47(1): 370. [8] Song K, Jang Y N, Kim W, et al. Chemical Engineering Journal, 2012, 213(1): 251. [9] XU Ai-ye, LI Hu-ping, LUO Kang-bi(徐爱叶,李沪萍,罗康碧). Science & Technology in Chemical Industry(化工科技), 2010, 18(6): 59. [10] ZHAO Jian-guo, ZHANG Ying-hu, ZHANG Zong-fan, et al(赵建国,张应虎,张宗凡,等). Inorganic Chemicals Industry(无机盐工业), 2013, 45(7): 1. [11] KONG Xia, LUO Kang-bi, LI Hu-ping, et al(孔 霞,罗康碧,李沪萍,等). Chemical Engineering(China)(化学工程), 2012, 40(8): 65. [12] QIN Zong-hui, XIE Bing, LIU Yan(秦宗会,谢 兵,刘 艳). Science and Technology of West China(中国西部科技), 2010, 9(21): 1. [13] XU Song-ning, WANG Sheng-gang, HAN Hai-bao, et al(徐送宁,王胜刚,韩海豹,等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2013, 33(3): 834. [14] WU Yuan-yuan, LI Ling-xia, HU Xian-jun(吴园园,李玲霞,胡显军). Journal of Chinese Electron Microscopy Society(电子显微学报), 2010, 29(6): 574.