溶剂萃取法从含钒石煤H2SO4-HF混合酸浸液中萃取分离钒的研究

i (2-ethylhexyl) phosphoric acid (P204) and tri-n-butyl phosphate (TBP) were used to extraction vanadium from a H2SO4-HF mixed acids leaching solution of stone coal in this paper. Effect of different operational factors such as equilibrium pH, extractant concentration, extraction stage, strip solution concentration, phase ratio were examined to optimize the condition for selective and quantitative extraction and stripping of vanadium. Based on the results of extraction as well as stripping isotherm, the extraction of vanadium was quantitative in six stages using 10% P204 and 5% TBP at A:O ratio of 1:1 and equilibrium pH of 2.4; 99.6% percentage stripping of vanadium from the loaded organic phase was obtained by five stage stripping using 1.5 mol/L H2SO4 at A:O ratio of 1:8. In the solvent extraction process, scrubbing is necessary for removing co-extracted and entrainment impurities by dilute sulfuric acid solution, more than 90% iron and arsenic can be scrubbed by 0.2 mol/L sulfuric acid.