Experimental And Mechanism Study On The Extraction Of Vanadium From Acid Leaching Solution Of Stone Coal Vanadium Or

Vanadium is an important strategic metal,which is widely used in steel,aviation and chemical industries.Stone coal vanadium ore is one of the important vanadium resources in China.The composition of direct acid leaching solution is complex,and it is very difficult to purify and enrich.Therefore,the experiment and theoretical research of vanadium extraction were carried out.Based on the literature review,the bond length,bond angle,charge distribution and electrostatic potential of three organic amine extractant molecules TOA,N1923 and N263were analyzed by DFT（density functional theory）calculation method.The weak interaction between TOA and TBP was simulated at the atomic level.The conclusion that the structural characteristics of the dimer are better than that of the monomer molecule is obtained.The extraction system with TOA as the extractant and TBP as the synergistic extractant is theoretically screened.On the basis of DFT calculation,the extraction experiment of acid leaching solution of stone coal vanadium ore was carried out.The single factor experiment showed that the amount of extractant had the greatest influence on the extraction rate,followed by phase ratio,p H and extraction time.For the acid leaching solution containing 5.802 g/L vanadium and 3.35 g/L iron,the optimum conditions for extraction were determined as follow:10%TOA+5%TBP+85%sulfonated kerosene,p H=1.85,phase ratio O:A=1:3,extraction time 9 min.The optimum conditions for stripping were:0.8 mol/L Na₂CO₃solution,O:A=2.5:1,stripping time 15 min.The obtained stripping solution contained17.01 g/L vanadium,and 0.51 g/L iron was enriched by 3 times.The total recovery rate of vanadium was 96.54%.The separation effect of vanadium iron is good.The acid phosphorus extractant D2EHPA was further compared with the organic amine extractant TOA.The results showed that the extraction effect of organic amine extractant TOA from the acid leaching solution of stone coal vanadium ore was better than that of acid phosphorus extractant D2EHPA.The extraction kinetics of TOA+TBP system showed that the stirring intensity had little effect on the extraction rate,while the two-phase boundary area and temperature increased with the two conditions,and the vanadium concentration increased.The apparent activation energy was 72.48 KJ/mo L,which belonged to the chemical control type.By measuring the extraction rate of different reactants at different initial concentrations,the lg R-lg C relationship diagram of each reactant was drawn,the reaction order of the reactants was obtained,and the rate equation of the extraction reaction was obtained ln K=-3785.404061/T+9.10084.