文献类型：期刊文献

中文题名：磷酸三丁酯体系萃取分离磷酸中氟化物机理

英文题名：Mechanism of Extracting and Separating Fluoride in Phosphoric Acid by TBP System

作者：徐浩川[1];孙泽[1];于建国[1]

机构：[1]华东理工大学资源过程工程教育部工程研究中心,上海200237

年份：2020

卷号：46

期号：5

起止页码：589

中文期刊名：华东理工大学学报（自然科学版）

外文期刊名：Journal of East China University of Science and Technology

收录：CSTPCD;;Scopus;北大核心:【北大核心2017】；CSCD:【CSCD_E2019_2020】；

语种：中文

中文关键词：磷酸三丁酯;氟;氢键

外文关键词：tributylphosphate;fluorine;hydrogen bonding

摘要：湿法磷酸生产过程中,磷矿中伴生的氟杂质会进入浸取液,严重影响磷酸产品的质量。以磷酸三丁酯(TBP)作为脱氟的萃取剂,分别以磺化煤油(简称煤油)、异戊醇、二异丙醚作为稀释剂,依据量子化学计算、傅里叶变换红外光谱(FT-IR)、核磁共振氟谱(19F-NMR)、萃合物组成分析探讨了萃取机理,考察了氟元素不同赋存形态对萃取脱氟效果的影响。结果表明:TBP中P=O双键中的氧与HF发生氢键缔合作用实现萃取氟,异戊醇和二异丙醚中的氧与HF发生一般的氢键作用,实现协同萃氟的作用;有机相中氟化物存在形式主要为HF·TBP,在煤油、异戊醇和二异丙醚溶剂环境中的萃合物组成分别为:0.9HF·TBP、1.4HF·TBP和1.6HF·TBP;TBP可有效萃取磷酸中的F^?、CaF^+、MgF^+、FeFx^3-x(x为1~6),但不适用于脱除磷酸中的SiF6^2-、AlFx^3-x。
The associated fluorine impurities in phosphate ore seriously affect the quality of the phosphoric acid during the wet-process phosphoric acid production.Tributylphosphate(TBP)was used as an extractant,sulfonated kerosene(hereinafter referred to as kerosene),isoamylol,diisopropyl ether were used as the diluent,respectively.The extraction mechanism was investigated by quantum chemical calculation,Flourier transform infrared spectroscopy(FTIR),19F nuclear magnetic resonance(19F-NMR)and composition of extraction complexes.The binding energy of TBPkerosene with HF was calculated by implicit solvent model,while TBP-isoamylol and TBP-diisopropyl ether with HF were calculated by explicit solvent model.The results show that the binding energy of above three extraction systems are?13.399 kJ/mol,?19.199 kJ/mol,and?20.556 kJ/mol,respectively.Analyses of the FT-IR spectra of the loaded organic phases indicate the TBP extraction of HF is occurred by the association of hydrogen bonding,while the extraction of HF using isoamylol and dissopropyl ether is realized through hydrogen bonding.The main form of fluoride in organic solvent was HF·TBP according to the 19F-NMR spectra.The compositions of the extraction complexes in the solvent of kerosene,isoamylol,diisopropyl ether were determined to be 0.9HF·TBP,1.4HF·TBP and 1.6HF·TBP,respectively.The effects of different fluorine forms in wet-process phosphoric acid on defluorination rate were studied.It can be concluded that CaF+and FeFx^3-x(x=1-6)have a slight effect on the selectivity coefficient and defluorination rate.MgF+can be effectively extracted from the organic solvent by TBP,and the selectivity coefficient is increased with the increase of Mg2+concentration in the solution.The TBP extraction of SiF6^2- and AlFx^3-x were moderated,indicating that the defluorination of wet process phosphoric acid needs to be achieved by pretreatment or other methods when the contents of active silica and aluminum oxide in phosphate rock are high.