Abstract: The alkaline solution containing vanadium was used as the raw material,which was from the process of sodium roasting for vanadium slag.After the removal of silicon and phosphorus from the solution,sodium sulfate and chromic anhydride were added into the solution to prepare vanadium and chromium containing solution with a fixed composition.Then,the representative process for acidic precipitation of vanadium with ammonium salt was adopted to investigate the impacts of sodium,chromium and vanadium contents in the vanadium and chromium containing solution as well as the ammonium addition coefficient on the precipitation rate of vanadium and Na₂O content in the obtained V₂O₅.The results show that it is feasible to apply the acidic precipitation of vanadium with ammonium salt to the solution containing vanadium and chromium in a certain concentration range,which can achieve desirable effects.On the precondition of satisfying the high vanadium deposition rate and qualified products,the maximum permissible concentration of sodium in the solution is determined at c(Na)/c(V)=2.4(the content ratio of sodium to vanadium).As the concentration of vanadium increases,the maximum permissible concentration of chromium in the solution changes with c(Cr)/c(V)(content ratio of chromium to vanadium) gradually decreasing at c(Na)/c(V)=1.8.The solution containing 25 g/L of vanadium,24 g/L of chromium and 45 g/L of sodium was concentrated for vanadium precipitation,and the results indicate that a maximum 26 g/L of vanadium can be permitted for the increase of vanadium concentration via reducing the liquid to solid ratio in the leaching process.The obtained V₂O₅ meets the relevant quality requirements with ammonium addition coefficient of 1.5.Few influences of ions concentration and ammonium addition coefficient were found on the vanadium precipitation rate.This study can provide the guidance for vanadium precipitation in the solution containing vanadium and chromium.