PRODUCTION METHOD OF VANADIUM OXIDE USING ION-EXCHANGE TO REALIZE WASTEWATER CIRCULATION

摘要

Disclosed is a product method of vanadium oxide, comprising the following steps: a. mixing vanadium-containing material with additive to give mixed material, wherein the additive is CaO or limestone, and the amount of the additive makes the CaO/V 205 weight ratio in the mixed material be 0.5-1.4 : 1; b. roasting the mixed material at 860"C-950 degrees celcius in oxidizing atmosphere for 60-240 min to give roasted material; c. adding water into the roasted material to give slurry, stirring, and slowly adding sulphuric acid solution to leach the slurry while controlling pH at 2.5-3.5; d. removing residue after leaching to give leachate, subjecting the leachate to P-removal treatment and Ca-removal treatment to make weight ratio of total V to P in the leachate 1000 and [Ca2+] in the leachate 0.05g/L, washing the residue with circulation water to give washing water useful for preparing slurry in next leaching; e. subjecting the P-removed and Ca-removed leachate to ion exchange with a strong acid cation resin which is previously transformed by ammonia or ammonium salt so as to obtain a exchanged solution in which the weight ratio ofNH3/Mn is 0.6-2000 : 1, the strong acid cation resin being the resin which can be used to exchange ion at pH of 2-5 to absorb Mn2+, Mg2+ and Fe3+; f. regulating pH of the exchanged solution with sulfuric acid to 1.5-2.5, heating to a temperature between 90 degrees celcius and boiling temperature, holding at the temperature for 30-120min, filtering, and washing and drying the precipitate to give ammonium polyvanadate, subjecting the ammonium polyvanadate to calcination to remove ammonia to give V2O5, or reducing the ammonium polyvanadate to give V2O3; and g. removing P, Mn, and Mg impurities in the wastewater generated in step f to make Mn2+ and Mg2+ concentrations lower than 5g/L respectively, and P concentration lower than 0.005g/L to give circulation water, and returning the circulation water to step c for preparing slurry and to step d for washing the residue, wherein the solid raw material used in the above steps has total alkali metal amount not more than 0.3 weight percentage, and total amount of Cl- and N03 - not more than 0.1 weight percentage; and the liquid raw material used in the above steps has total alkali metal amount not more than 0.1 g/L, and total amount of Cl and N03 not more than 0.1 g/L.