从含钒石煤燃烧灰渣浸出液中萃取钒的实验研究

Experimental Study on Extraction of Vanadium from Low Calorific Value Coal Ash Leaching Liquid

针对陕西某地低热值含钒石煤燃烧灰渣的硫酸浸出液,采用溶剂萃取法除杂并富集钒。结果表明:浸出液经中和还原处理后,采用12.5%P_(204)+5%TBP+82.5%磺化煤油进行4级逆流萃取,相比(O/A)为2,萃原液p H值为2,振荡时间为2 min,静置1 min,钒萃取率可达到99.31%。采用4级逆流反萃,反萃剂硫酸1.5 mol/L,相比(O/A)为4,振荡4 min,静置1 min,钒反萃率为96.94%。

Stone coal vanadium always exists in the complex form and there are regional differences in the process of extraction of vanadium. As for the sulfuric acid leaching liquid of low-calorific value vanadium-containing stone coal ash,the process of solvent extraction was adopted to enrich vanadium and remove the impurities from the leaching liquid. The leaching liquid was firstly subjected to a neutralizing reduction process,followed by 4-stage countercurrent extraction with 12.5% P_（204）＋5% TBP ＋82.5% sulfonated kerosene,with phase ratio（ O / A） at 2,initial p H value of extraction at 2,2-min mixing and 1-min settling,resulting in vanadium extraction rate at 99. 31%. While the subsequent 4-stage countercurrent stripping with 1.5 mol / L sulfuric acid,phase ratio（ O / A） at 4,4-min mixing and 1-min settling,can result in the stripping yield of vanadium up to 96.94%.