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.