摘要
研究了用 Tn OA n CH3(CH2 ) 6 CH3H2 SO4体系和 Tn OA CHCl3H2 SO4体系萃取 Cr( )的机理及萃合物组成。考察了水相酸度 ,Cr( )、萃取剂与 SO2 -4浓度 ,萃取时间及温度等因素对萃取的影响。用饱和法、摩尔比法、等摩尔系列法和 IR法确定了萃合物的组成和萃取平衡机理。结果表明 ,萃取过程属阴离子交换机理 ,萃合物的组成因 p H值和 c(Cr( ) )不同而异 ;p H值不同 ,Cr( )的型体也不一样 ;当 c(Tn OA)一定 ,p H =1 .0 ,c(Cr2 O2 -7) =0 .1 0 0 0 mol/ L时 ,形成的萃合物是 (R3NH ) 2 Cr2 O7(2∶ 1 ) ;当 p H =-1 .0 ,c(Cr2 O2 -7) =0 .0 1 945 mol·L-1时 ,形成的萃合物是 R3NHHCr O4(1∶ 1 ) ;SO2 -4不被萃取 ,c(Tn OA)及时间和温度对 Cr( )的萃取影响不大。试验结果与 Deptuta认为的 Cr( )的型体为 Cr2 O2 -7,Федоров和Жданов认为的 Cr( )的萃取型体为 Cr O2 -4的结论不同。
Solvent extraction of Cr(Ⅵ) with T n OA n octaneH 2SO 4 system and T n OAchloroformH 2SO 4 system have been investigated.The effects of aqueous phase acidity,total Cr(Ⅵ),SO 2- 4 and extractant concentration,extractive time and temperature on extraction of Cr(Ⅵ) are examined.Composition of extracted species and mechanism of extraction equilibrium are determined by saturation method,molar ratio method,equimolar series method and IR spectrum.The results show that extracted species is (R 3NH) 2Cr 2O 2- 7(2∶1) when pH=1.0,Cr 2O 2- 7 concentration is 0 100 0 mol/L,and R 3NHHCrO 4(1∶1) when pH=-1.0,Cr 2O 2- 7 concentration is 0.019 45 mol/L.SO 2- 4 is not extracted.Extraction mechanism belongs to anion exchange.The effects of T n OA concentration,extractive time and temperature on extraction of Cr(Ⅵ) are not notable.The experiment result differs from those of Deptuta and Federov and Zhdanov.Deptuta considers Cr(Ⅵ) species as Cr 2O 2- 7,Federov and Zhdanov consider Cr(Ⅵ) species as CrO 2- 4 when Cr(Ⅵ) is extracted from sulphate solution with T n OA.
出处
《湿法冶金》
CAS
2001年第3期141-148,155,共9页
Hydrometallurgy of China
关键词
三正辛胺
萃取
铬
萃取剂
chromium(Ⅵ)
tri n octylamine
extraction
mechanism