A Study On The New Production Process Of Extracted Vanadium From Stone Coal

Vanadium and their compounds, the important strategic resource, have a wideapplication prospects and demand. Mineral resources of vanadium are rich in ourcountry. Besides the vanadic titanomagnetite, Vanadium is also present in stone coal,so the extraction process of V₂O₅from the stone coal always attracts ever–increasingattention. Sodium chloride was used for roasting stone coal in traditional extractionprocess of V₂O₅. However, low recovery of V₂O₅and emitted a large quantity ofharmful gasses such as Cl2and HCl, exist in this traditional method, which lead to thewasting of resources and serious environmental problem. Therefore, it is greatsignificance for the study on a new extraction technology of V₂O₅to improve theutilization rate of resources and to reduce environmental pollution.According to the characteristics of the Guizhou stone coal mine，three productionprocess was adopted for the extraction of V₂O₅from stone coal by oxidationroasting–hydrous cycle soaking–adjusting pH to deposit V₂O₅, adding super acid andsuper alkali for roasting–acid leaching–extraction, are studied systematically.Through the study on the process of oxidation roasting–hydrous cyclesoaking–adjusting pH to deposit V₂O₅, The optimum process condition was selected inthis thesis: the original ore was fired for decarbonization, and is soaked in sulphuricacid （35％） at100℃for5h, the extraction ratio of V₂O₅is up to88.50％. In order torecycle the recovery the original ore, Sulphuric acid was added to adjust the pH ofinitial solution. After five circles, the average extraction ratio of V₂O₅is82.30％，and the concentration of V₂O₅solution is38.40g·L^–1. The pH of V₂O₅solution wasadjusted to deposit the Red vanadium and Fe（OH）3. NH₄VO₃is obtained by addingNH4Cl solution into soluble vanadium solution using the method of alkali fusion todissolve the V₂O₅. The residual solution can be adjusted pH continue to recycle theother metal ion.The optimum condition of adding super acid for roasting–acid leaching–extractionis that the original ore was grinded to80mesh, and added super acid in propotion of3％of stone coal weight, then the grinded stone coal being wetted by water wasdoughed into balls. The leaching rate of V₂O₅is up to86.14％by roasting thegrinded stone coal at700℃for4h, adding the roasted stone coal into sulfuric acid （5％） at90℃for4h, and keeping liquid–solid ratio for2:1. Calcium hydroxide was added into the above solution for adjusting the pH to2.0, then V₂O₅was extracted byusing the mix solution （O/A=2:1） which the oil phase contained P204（15％）, theTBP （5％）, sulphonated kerosene （80％） and limewater, and the extraction ratio ofV₂O₅is up to96.65%. Finally, the mix solution （O/A=2:1） was undergone a processof reversed phase extraction by adding the solution (60g·L^–1Na2CO3) into the reverseextractive solution, NH₄VO₃can be obtained by directly adding NH4Cl into the finalsolution containing V₂O₅(20.98g·L^–1). And the extraction ratio of V₂O₅is95.07%, inproportion.The best condition of adding super alkali for roasting–acid leaching: grinding thestone coal to80mesh, adding super alkali in propotion of5％of stone coal weight,and doughing into balls when adding water into stone coal, after roasting3h with700℃in muffle furnace, leaching the roasting of stone coal into4％sulfuric acid with90℃for4h, the liquid–solid ratio is2to1. The leaching rate of V₂O₅is87.10％. Afteradjust the limewater pH to4.0, V₂O₅was recycled by using RS–C214ion exchangeresin column. When the flow rate is0.5cm/min, the adsorption rate of V₂O₅is97.87％.The desorption ratio is98.60％when40g·L^–1Na2CO3was used for Elution solution,NH₄VO₃was obtained by directly adding NH4Cl in proportion.NH₄VO₃was prepared by the above three processes, V₂O₅was obtained byroasting NH₄VO₃with the purity of98.5％. Compared with the traditional process, thenew V₂O₅extraction technology can improve the utilization rate of resources andrecovery, and greatly reduce the pollution of environment.In conclusion, use NaVO3solution from extracted vanadium production process,the use of templates can step with the structure of micro–nano V₂O₅crystals, accordingthe low carbon environmental concept.