【作者】 陈晨；

【导师】 李文艳； 董长青； 陆强；

【作者基本信息】 华北电力大学(北京) ， 热能工程， 2016， 硕士

【摘要】 选择性催化还原(SCR)烟气脱硝技术,是目前国内主流脱硝技术,而催化剂又是SCR脱硝技术的核心。SCR脱硝催化剂的工作环境十分恶劣,多种因素会导致催化剂活性逐渐下降,并最终成为废弃催化剂。随着SCR脱硝技术在国内的普及以及SCR脱硝工程的大量实施,废弃SCR脱硝催化剂的高效处置是未来将要面对的一个严峻的环保问题,已经引起了广泛关注。废弃SCR脱硝催化剂处理不当不仅会对环境造成严重的危害,同时废催化剂中V2O5、WO3和TiO2等高附加值的金属氧化物也会因无法被再次利用而浪费。然而,国内目前还没有针对废弃SCR脱硝催化剂成分回收工作的相关企业,也没有成熟完善的回收技术工艺。本文首先以自制V-W/Ti系SCR脱硝催化剂为原料,结合V2O5、WO3和TiO2成分的化学特征,探索钒、钨和钛元素的分离方案；将可行方案尝试用于实际废弃SCR脱硝催化剂,并进行优化和改进,实现钒、钨和钛元素的高效分离；在此基础上,对钒、钨元素的提纯进行了研究,通过萃取除去杂质元素,并将钒、钨元素转移至较易处理的溶液中；最终,回收得到高品质钒、钨和钛产品。研究主要结论如下：(1)依次通过还原酸浸法和钠化焙烧法,可实现钒、钨和钛元素的高效分离,其中钒、钨元素的分离效率分别达到了96.40%和96.65%,而钛元素在分离钒、钨元素的过程中几乎无损失；(2)萃取提纯钒元素,钒元素的损失率为2.14%,而硅、铝杂质元素的去除率分别为97.96%和93.13%；调节含钨溶液pH值除硅、铝杂质元素,去除率分别达到了81.53%和97.14%,而钨元素的损失率为2.18%；进一步萃取提纯钨元素,钨元素损失率为1.09%,硅、铝去除率分别为94.36%和95.55%；(3)分别通过水解法、煮沸结晶法和硫酸溶解法回收得到V2O5、钨酸的铵盐和TiO2,三者纯度可分别达到99.731%、99.563%和98.930%；钒、钨和钛元素回收率则分别约为95.0%、93.5%和80.0%。更多还原

【Abstract】 The selective catalytic reduction (SCR) flue gas denitrification technology is currently the mainstream denitration technology in our country, and the catalyst is the core of SCR technology. The working environment of SCR denitration catalyst is very bad, a variety of factors will lead catalyst activity decreased gradually and eventually become waste catalyst. With the large scale application of the SCR De-NOx technique and the construction of the SCR systems, how to treat the waste SCR catalysts has gained increased attention in recent years. Misconducting the waste SCR catalyst not only cause serious harm to the environment, but also the valuable V2O5, WO3 and TiO2 components can’t be recovered any more. But there are no related units who can recovere waste De-NOx SCR catalyst or mature recovery techniques at present.Firstly, the paper used the self-made V-W/Ti SCR denitration catalyst as raw materials to explore the separation technique of the three major elements (V, W and Ti) which based on the chemical characteristics of V2O5, WO3 and TiO2. Improving the technique which is suitable for the actual waste De-NOx SCR catalyst and achieve the efficient separation of the three elements. Based on that, purify the elements (V, W) to remove the impurity elements and obtain high-quality products. The results show as following:(1) Acid leach reduction method and sodium roasting method can achieve the efficient separation of the three elements. The separation efficiency of V and W elements is 96.40% and 96.65%.(2) Extraction purification V:the loss rate of V is 2.14%, the removal efficiency of Si and Al is 97.96% and 93.13%; Regulated pH to Purification W:the loss rate of W is 2.18%, the removal efficiency of Si and Al is 81.53% and 97.14%; Extraction purification W:the loss rate of V is 1.09%, the removal efficiency of Si and Al is 94.36% and 95.55%.(3) Respectively through hydrolysis method, crystallized method and sulfuric acid method, the purity of V2O5, tungstate and TiO2 recovered is 99.731%,99.563% and 98.930%; The recovery rate of V, W, Ti is 95.0%,93.5% and 80.0%.更多还原