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利用钒渣钠化焙烧-水浸工艺得到的钒浸出液为原料,进行了酸性铵盐沉钒试验、多钒酸铵溶解度测定试验和X射线衍射表征,研究了温度为75~95℃和pH值为2.0~5.0范围内,温度和反应终点pH值对酸性铵盐沉钒沉钒的影响。研究结果表明:随着pH值的降低和沉淀温度的升高,沉淀产物晶体物相和杂质含量显著变化。pH值从5.0下降到2.0的过程中,沉淀产物中(NH4)4Na2V10O2.810H2O和(NH4)6V10O2.86H2O逐渐转化为NH4V3O8.0.5H2O,钒沉淀率显著上升,同时沉淀产物中钠、钾和硫含量显著降低;在pH值4.0~5.0范围内,随着温度的上升,沉淀产物由(NH4)4Na2V10O2.810H2O转化为(NH4)6V10O2.86H2O,钒沉淀率上升,同时沉淀物中钠和钾含量降低,所包裹的硫含量增加,沉淀温度为75℃时,沉淀产物主要为(NH4)4Na2V10O2.810H2O,沉淀物中钾含量处于0.140%~0.161%之间,硫含量处于0.010%~0.017%之间;在pH 2.0~3.0范围内,沉淀产物主要为NH4V3O8.0.5H2O,随着温度的上升,水解产生的多钒酸钠和多钒酸钾中的钠和钾被铵所取代生成NH4V3O8.0.5H2O,沉淀产物中钠和钾含量降低,沉淀的最佳工艺条件为pH 2.0~2.5,温度为95℃以上,反应2 h后,钒沉淀率达99.38%以上,沉淀物中钠,钾和硫含量分别降低至0.300%,0.090%和0.039%。
Vanadium leaching solution obtained by sodium vanadium slag roasting and water-immersing process was used as raw material. Acid ammonium salt vanadium precipitation test, multi-vanadate ammonium solubility test and X-ray diffraction characterization were carried out. The effects of pH value For the range of 2.0 ~ 5.0, the temperature and the end of the reaction pH value of the impact of acid ammonium salt precipitated vanadium precipitation. The results show that with the decrease of pH value and the increase of precipitation temperature, the crystal phase and impurity content of the precipitated product change significantly. During the process of pH value decreasing from 5.0 to 2.0, the precipitation products of (NH4) 4Na2V10O2.810H2O and (NH4) 6V10O2.86H2O were gradually converted into NH4V3O8.0.5H2O, the precipitation rate of vanadium increased significantly, while the precipitated products of sodium, potassium and sulfur (NH4) 4Na2V10O2.810H2O to (NH4) 6V10O2.86H2O, the precipitation rate of vanadium increased, while the contents of sodium and potassium in the precipitate increased with the increase of temperature in the range of pH 4.0-5.0. (NH4) 4Na2V10O2.810H2O, the content of potassium in the precipitate is between 0.140% and 0.161%, the content of sulfur is in the range of 0.010% to 0.017%, and the content of sulfur in the precipitate increases. When the precipitation temperature is 75 ℃, ; In the range of pH 2.0-3.0, the precipitated product is mainly NH4V3O8.0.5H2O. As the temperature rises, the sodium and potassium in the sodium polyvanadate and potassium vanadate produced by hydrolysis are replaced by ammonium to produce NH4V3O8.0.5 H2O, the content of sodium and potassium in the precipitated product decreased. The optimum conditions for the precipitation were pH 2.0-2.5 and the temperature was above 95 ℃. After 2 h of reaction, the precipitation rate of vanadium reached more than 99.38%. The contents of sodium, potassium and sulfur The content decreased to 0.300%, 0.090% and 0.039% respectively.