P507-N235无皂化体系负载钕有机相草酸直接沉淀工艺研究

Direct precipitation of neodymium with oxalic acid solution in P507-N235 non-saponifiable extraction system

  • 摘要: 对P507-N235双溶剂无皂化萃取体系的直接沉淀工艺进行研究,将传统先反萃后沉淀工艺合二为一,从酸度、流比、草酸用量及搅拌时间等方面,考察盐酸-草酸水溶液作为P507-N235-磺化煤油体系沉淀剂直接沉淀的效果.实验以稀土钕直收率来表征实验效果的差异性.研究结果表明:通过加入盐酸调节酸度并控制一定的流比、草酸用量和搅拌时间,可大大提高沉淀的效果.最优草酸沉淀条件为:酸度0.40 mol/L、流比1:1、草酸理论用量的120 %,搅拌时间5 min,其单级钕直收率可达97 %以上.反萃后有机相结构未发生改变,萃取能力可达到新有机相的90 %.

     

    Abstract: The direct precipitation of non-saponifiable extraction system using P507-N235 as solvents (plus sulfonated kerosene) was investigated. Stripping and precipitation are merged into one process. The effects of hydrochloric and oxalic acid on the strip-precipitation process were studied directly by changing the acidity, flow ratio, amount of oxalic acid and stirring time. The differences of experimental results were characterized by the direct recovery of Nd. The results show that the efficiency of strip-precipitation can be greatly improved by adjusting acidity with hydrochloric acid, controlling the flow ratio and the amount of oxalic acid. The strip-precipitation conditions were optimal when the acidity is 0.40 mol / L, flow ratio is 1:1, amount of oxalic acid is 1.2 times of theoretical value, stirring time is 5 min. The direct recovery of Nd is higher than 97 % by one-stage using this method. The structure of the organic phase kept unchanged after stripping, The extraction capability could reach 90 % of the new organic phase.

     

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