含钪黑钨渣酸浸液中锆的N235+TBP预萃取

湖南某黑钨渣硫酸浸出液(硫酸的浓度为1.8 mol/L)的钪、锆元素含量分别为48.18、138.00 mg/L,为消除锆对萃取钪的影响,在萃取钪前以N235和TBP为复合萃取剂进行了除锆预萃取试验。结果表明:1在复合萃取剂N235、TBP与磺化煤油的体积比为15∶15∶70,有机相与水相相比为1.5∶1,萃取时间为5 min,萃取温度为25℃,萃取振荡频率为120 r/min情况下进行单级萃取,对应的锆、钪萃取率分别为92.03%和0.96%;在硫酸溶液浓度为5mol/L、反萃相比为3∶1、反萃时间为30 min、反萃温度为25℃、振荡频率为180 r/min情况下进行3级反萃,对应的锆、钪反萃率分别为99.23%和98.22%。因此,该工艺可高效地分离锆、钪。2再生有机相对萃原液中锆的萃取率可达91.97%,与新配制萃取剂效果接近,说明再生萃取剂可以循环利用。

N235+TBP Preextraction of Zr from Wolframine Residue Containing Sc

The content of Sc and Zr is 48. 18 mg/L and 138. 00 mg /L respectively in sulfuric acid leaching solution(sulfu-ric acid concentration 1. 8 mol/L) of some wolframine slag from Hunan. To eliminate the effect of Zr on Sc extraction,zirconium pre removal experiment using N235 and TBP as composite extracting agent was conducted before scandium extraction. Results show that:①Under the condition of volume ratio of N235,TBP and sulfonated kerosene is 15 ∶ 15 ∶ 70 in the composite extrac-ting agent,ratio of organic phase to water phase 1. 5 ∶ 1,extraction time 5 min,extraction temperature 25℃,extraction oscillation frequency 120 r/min,single stage extraction was conducted and extraction rates of Zr and Sc were 92. 03% and 0. 96% respec-tively. Under the condition of sulfuric acid solution concentration 5 mol/L,the ratio of organic phase to water phase of extraction 3 ∶ 1,reverse extraction time 30 min,reverse extraction temperature 25 ℃,oscillation frequency 180 r/min,three-levels reverse extraction was conducted and extraction rates of Zr and Sc were 99. 23% and 98. 22% respectively. Therefore,the process can ef-ficiently separate zirconium and scandium.②Extraction rate of Zr can reach to 91. 97% by regenerative extractant whose effect is close to the new extractant,which illustrates regenerative extractant can be recycled.