稀土顺丁橡胶中试生产废水钕含量测定方法研究

Study on Determination of Neodymium Content in the Wastewater From Production of RE Cis-1,4-Polybutadiene Rubber in Pilot-scale

采用吸光光度法测定钕,其测定条件:最大吸收波长λ=674 nm,加入顺序为Nd3+标液→CPAⅢ→缓冲溶液,ρ(Nd3+)测量上限=2.0 mg/L,0.500 g/L CPAⅢ无水乙醇溶液加入量=3.0 mL,pH=2.0盐酸-甘氨酸缓冲溶液加入量=9.0 mL。标准曲线的斜率=0.428 2,回收率介于97.50%～102.4%,满足回收率≤±5%要求。中试水样常规分析表明ρ(Ca2+)=10.85 mg/L。使用Origin拟合,得到Ca2+存在时测定钕的修正方程。此式适用于ρ(Ca2+)为0～20 mg/L。经测定,水样中含钕=3.35 mg/L,属于微量级。

The determination of neodymium content in the wastewater from production of RE cis-1,4-polybutadiene rubber in pilot-scale by absorption spectrometry was studied.The determination conditions were as follows：the maximum absorption wavelength was 674 nm;Nd3＋ standard solution,CPAⅢ and buffer solution were added in turn,upper limit ofρ（Nd3＋） was 2.0 mg/L,dosage of 0.500 g/L CPAⅢ anhydrous ethanol solution was 3.0 mL and pH was 2.0,dosage of hydrochloric acid-glycin buffer solution was 9.0 mL.The slope of standard curve was 0.428 2,the recovery of standard curve was in the range of 97.5%～102.4%,which can meet the requirement that measurement error was not more than ±5%.The metal element analysis was carried out by ICP-AES,concentration of calcium was 10.85 mg/L.The correction equation of determining neodymium was regressed by Origin under 0～20 mg/L calcium co-exist.Then,the determined concentration of neodymium in the waste water was 3.35 mg/L,whose concentration was in the micro-level.