Wet Metallurgical Extraction Of Vanadium Pentoxide And Zirconium Oxychloride

Part One: preparation of Vanadium Pentoxide from weatheringcoal mine by roasting with CaOV₂O₅ is extracted from weathering coal mine by the process of roasting with CaO, leaching by acid, precipitating Ca(VO₃)₂ by Ca(OH)₂ and carbonate dissolving of ammonium vanadate by (NH₄)₂CO₃, followed vanadium precipitate. The kinetics process of carbonate dissolving of ammonium vanadate by (NH₄)₂CO₃ is inquired. The results show:(1) The optimum conditions for roasting are as follows: mine:CaO: MnO₂=25:l :0.4, roasting temperature 1050°C, reaction time 3.5 hour. Under these conditions the rate of vanadium conversion can reach the value of over 64%.(2) The optimum conditions for leaching by acid are as follows: the mass ratio of charge ratio is 2:1, the acidity is3.2%, reaction time is 1 hour.(3) The conditions for carbonate dissolving of ammonium vanadate by (NH₄)₂CO₃ are as follows: n (the molar ratio of (NH₄)₂CO₃ to V₂O₅) =6, room temperature and reaction time is 2 hour at the condition of normal pressure. The rate of vanadium conversion can reach the value of over 83%. The conditions for carbonate dissolving of ammonium vanadate are as follows: n=3, temperature is 50°Cand reaction time is 2 hour at the condition of high pressure. The rate of vanadium conversion can reach the value of over 92%.(4)The relation of R (the rate of vanadium conversion) and t(reaction time) fits 1 — (1— R)^1/3=kt, k(the rate constant)=0.3554.The process of carbonate dissolving of ammonium vanadate by (NH₄)₂CO₃ is controlled by chemical reaction kinetics (5) The purity of V2O5 can reach 98.4% by this technique.