三聚氰胺沉钒试验研究

Experimental Study on Precipitation of Vanadium Using Melamine

以钒渣钠化焙烧工艺得到的碱性钒净化液为原料,分析了溶液中V、Na以及杂质Si、P的含量,研究了三聚氰胺代替常规铵盐作为沉淀剂的酸性铵盐沉钒新工艺,并探讨了溶液中Na含量对沉钒效果的影响。结果表明:采用三聚氰胺沉钒,在沉钒剂用量n(C_3H_6N_6)/n(TV)=0.3、pH=2.0、沉钒温度90℃及沉钒时间45 min的条件下,沉钒率大于98%,得到的钒沉淀物经500℃煅烧3 h,可以获得满足标准的粉状V_2O_5,且沉钒废水中V和NH_4^+含量极低,简化了后续的废水处理工序。该工艺适合于n[Na]/n[V]≤5.0的溶液体系,试验效果良好。

dium slag content of The purified alkaline vanadium solution obtained from the process of sodium roasting for vana- was used as the raw material in this experiment, and the content of V and Na, and impurities Si and P were analyzed. A new process of vanadium precipitation under acidic condition was in- vestigated using melamine as precipitant which substitutes for monium sulfate and ammonium carbonate, etc. ,and the effect the ordinary ammonium agents such as am- of Na content in the solution on vanadium precipitation was also studied. The results show that powdery V2O5 satisfying the standard requirements is obtained after 3 hours of calcination at 500 ℃ with the precipitate as raw material,which is prepared at 0.3 of mole ratio of melamine to vanadium, pH = 2.0,90 ℃ of precipitation temperature for 45 min. The precipitation rate of vanadium at the optimum conditions mentioned above is more than 98%, and the con- tent of remaining vanadium and NH4＋ in the wastewater keeps at an extremely low range, simplifying th subsequent treatment process for waste water. This method is suitable for the aqueous solution where [ Na]/n[ V] ≤5.0 （mole ratio） and has an excellent test result.