对比盐酸、硫酸、硝酸和草酸等几种常规酸对废弃脱硝催化剂活性组分五氧化二钒(V2O5)的提取效果,并考察酸的种类、浓度以及提钒温度对提钒效果的影响。结果表明:盐酸的提钒效果最佳,可将V2O5含量降至0.191%(质量分数),几种酸的提钒效果由大到小的顺序依次为盐酸、草酸、硫酸、硝酸。其次,硫酸的浓度对其提钒量影响最大,浓硫酸的效果是稀硫酸的2.8倍;而处理温度则对草酸的提钒效果影响最为显著,室温下草酸较高温少提取58.4%的V2O5。Uv-vis结果显示:V2O5经盐酸、硫酸以及草酸提取后,在浸渍液中出现(VO)^2+的低价钒离子,这有利于提升酸的提钒效果。此外,酸处理对样品的比表面积影响较为显著,经浓草酸处理比表面积可恢复至60.8 m^2/g,相比原有废弃催化剂的提升39.6%。
The effects of HCl, H2SO4, HNO3 and oxalic acid (H2C2O4) on the V2O5 extraction of waste deNOx catalyst were studied. The type of acid, acid concentration and treat temperature also have remarkable impacts on the effect reduce from high to low of reactant. The results show that V2O5 content can be reduced to 0.191% (mass fraction) with HCl treated. The order is HCl, H2C2O4, H2SO4 and HNO3. In addition, the V2O5 extraction performance of catalyst is susceptible to the concentration and temperature changes. The concentrated H2SO4 has 2.8 times V2O5 extraction performance than diluted one. Furthermore, the V2O5 extraction capability of H2C2O4 is decreased by 58.4% as temperature drops. Uv-vis results show that, V2O5 can be transformed into (VO)^2+ ions by impregnating samples with HCl, H2SO4 and H2C2O4. The specific surface area can also be recovered to 60.8 m^2/g after H2C2O4 extraction, with 39.6% increase compared with waste deNOx catalyst.