The recovery of vanadium from a black shale from Guizhou Province of China was performed using a three-step process, which consists of a leaching step in the H2SO4-HF-NaClO system under atmospheric pressure,the vanadium separation from leachate by solvent extraction and stripping,followed by precipitation of ammonium vanadate and thermal decomposition.Under the optimum leaching conditions of 100 g/L sulfuric,15 g/L hydrofluoric acid,1.5 g/L NaClO,6 h leaching at 90℃and oxygen partial pressure of 1 200 kPa,and the liquid-to-solid ratio of 2,about 91%vanadium extraction is achieved.The vanadium extraction yields of solvent and stripping are 99.83%and 97.66%when using 10%(volume fraction)P204,5%TBP and 85%sulfonated berosene as organic phase and 15%(mass fraction)sulphuric acid as stripping agent.After thermal decomposition the purity of powder vanadium pentoxide products is 99.18%and the overall vanadium recovery is over 81%in the whole process.
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机译：用三步法从中国贵州省的一个黑色页岩中回收钒，该过程包括在大气压下在H2SO4-HF-NaClO系统中进行浸出步骤，通过溶剂萃取和汽提从浸出液中分离钒。在最佳浸出条件为：100 g / L硫酸，15 g / L氢氟酸，1.5 g / L NaClO，90℃浸出6 h和氧分压为1200 kPa的最佳浸出条件下固液比为2时，钒的萃取率约为91％。当使用10％（体积分数）的P204、5％TBP和85％时，溶剂和汽提的钒萃取率分别为99.83％和97.66％。磺化苯用作有机相，质量分数为15％的硫酸作为汽提剂。热分解后，五氧化二钒粉末的纯度为99.18％，整个过程中钒的总回收率超过81％。
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