| Vanadium is an important strategic resource,has a broad application prospects.China is a big country vanadium resources,mainly vanadiumⅤ(Ⅲ)andⅤ(Ⅳ)occur in the form of stone coal,the traditional method of using sodium chloride roasting stone coal extracted from vanadium pentoxide,this process with a large quantity of emissions harmful gases Cl2 and HCl,serious pollution of the environment,while vanadium recovery rate of less than 50 percent,and the study of a new technology to replace the traditional process,reduce pollution and improve the utilization rate of resources is of great significance.In the literature available on the basis of this paper a stone coal mine in Shaanxi to the characteristics of oxidation roasting-acid leaching-extraction,direct acid leaching-extraction,sulfuric acid and roasting-immersion-extraction of vanadium three routes to more detailed the study,identified oxidation roasting-acid leaching process in the best conditions:roasting temperature of 850℃,roasting time 2h,two countercurrent extraction method for the extraction,leaching time(3+5)h, leaching temperature of 103℃,the amount of sulfate(5+30)mL/100g stone coal,liquid-solid ratio 1:1,vanadium leaching rate of 84 percent.The best direct acid leaching conditions:leaching temperature of 120℃, leaching time 8h,sulfuric acid consumption 40mL/100g stone coal, liquid-solid ratio 0.8:1,vanadium leaching rate of more than 80%. Sulfated roasting-immersion in the best conditions:roasting time 3h,the roasting temperature 200℃,sulfuric acid content of 38～40mL/100g stone coal,immersion for 3h,leaching temperature of 100℃,liquid-solid ratio 0.8:1,vanadium leaching rate to reach 90 percent.We can see that the oxidation roasting-acid leaching of acid consumption fewer,but more complex technology,direct acid leaching process is simple,but greater consumption of acid,vanadium leaching rate slightly lower,and sulfated roasting-immersion of vanadium recovery high rates,but higher roasting equipment.Leaching solution using 10%P204+5%TBP+85%kerosene as an extraction agent,the seven countercurrent extraction,extraction 7 minutes in each grade,0:A=1:2,vanadium extraction rate could reach more than 98%. Extract of the 0:A=1:2 conditions,the 1.5mol/LH2SO4 solution three stripping,each class 15 minutes,vanadium stripping rate of 98 percent. Stripping oxidation of the sodium chlorate,ammonia regulation pH to 2 around the 95℃for 3h,received more precipitation red vanadium ammonium, and more vanadium ammonium perchlorate at 550℃in muffle furnace under roasting 2h,can be obtained in line with the Chinese standards vanadium pentoxide.All three routes of the serious pollution of the environment omit the roasting sodium chloride,the first two in the total recovery of vanadium are close to 80 percent,and sulfate of roasting-immersion-extraction of vanadium recovery over 85%,products of V2O5 can reach Chinese standards, and process wastewater generated by the lime,can discharge by standards, the cost of materials through the preliminary estimates,three to vanadium process in industry are feasible.
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