Mathematical model and reaction mechanism of molybdenum and tungsten extraction with TRPO from peroxide solution  

采用TRPO从过氧化氢溶液中萃取钼和钨的数学模型和反应机理

作　　者：Xin-bing XIA Gui-qing ZHANG Wen-juan GUAN Li ZENG Sheng-xi WU Qing-gang LI Zuo-ying CAO 夏新兵;张贵清;关文娟;曾理;巫圣喜;李青刚;曹佐英(中南大学冶金与环境学院,长沙410083;中南大学有色行业冶金分离科学与工程重点实验室,长沙410083;稀有金属冶金与材料制备湖南省重点实验室,长沙410083)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]Key Laboratory of Metallurgical Separation Science and Engineering in Nonferrous Industry,Central South University,Changsha 410083,China [3]Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第9期3123-3135,共13页中国有色金属学报（英文版）

基　　金：support from the National Natural Science Foundation of China(No.51604304)。

摘　　要：To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.为了解利用三烷基氧化膦(TRPO)从过氧化氢溶液中萃取钼和钨的化学行为,采用斜率法、拉曼和红外光谱研究钼和钨的萃取反应机理。通过建立数学模型,获得钼或钨的萃取分配比(D_(Mo)或D_(W))关于平衡pH值、TRPO浓度和温度等变量的经验公式,并进一步在H^(+)-W-Mo-H_(2)O_(2)溶液中验证经验公式的可靠性。结果表明:经验公式计算的D_(Mo)或D_(W)和实验值吻合度良好。实验条件下,20°C时钼和钨的萃取平衡常数分别为K_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.70)、K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)和K_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)。钼和钨的主要萃合物结构为[H_(2)Me_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO(Me=Mo或W)。获得的经验公式可以用于估算和分析低浓度钼和钨混合溶液中钼和钨的萃取和分离。

关 键 词：tungsten MOLYBDENUM solvent extraction tri-alkyl phosphine oxide(TRPO) hydrogen peroxide(H_(2)O_(2)) 

分 类 号：TF841.2[冶金工程—有色金属冶金] TF841.1