干湿法结合工艺回收废弃SCR脱硝催化剂中的钛、钒和钨

利用干湿法结合工艺实现废弃SCR脱硝催化剂中Ti、V和W元素的高效分离和浸出，提出成套废弃SCR脱硝催化剂中Ti、V和W的回收技术。以废弃SCR脱硝催化剂为研究对象，优选Ti、V和W元素最佳浸出工况，研究硫酸溶解法回收TiO₂和有机萃取法回收V₂O₅和WO₃的回收率与纯度。结果表明:酸浸还原浸钒最优工艺条件为温度140℃，液固比30∶1；钠化焙烧浸钨最优工艺条件为煅烧温度750℃，反应物与Na₂CO₃配比（质量比）为1∶1.5，在以上条件下V、W浸出率分别达到97.6%、93.6%。利用硫酸溶解法回收得到的TiO₂产物主要以锐钛矿晶型存在形式，在最佳焙烧温度750℃下，TiO₂回收率达到97.17%，纯度为95.35%。利用有机萃取法回收得到的V₂O₅和WO₃产物的回收率和纯度分别为72.47%、75.43%和93.25%、78.26%。

RECOVERY OF TITANIUM,VANADIUM AND TUNGSTEN FROM WASTE SCR DENITRATION CATALYST BY DRY-WET PROCESS

In this paper, the efficient separation and leaching of Ti, V and W elements in the waste SCR denitration catalyst were carried out by the dry-wet method, and the recovery technology of Ti, V and W in the waste SCR denitration catalyst was proposed. Taking waste SCR denitration catalyst as the research object, the leaching conditions of Ti, V and W elements were optimized, and the recovery rate and purity of TiO₂ recovered by sulfuric acid dissolution method and V₂O₅ and WO₃ recovered by organic extraction method were also researched. The results showed that the optimal process conditions for acid leaching and reduction of vanadium were temperature of 140 ℃, liquid-solid ratio of 30:1; and the optimal process conditions for sodium roasting and leaching of tungsten were roasting temperature of 750 ℃, reactants and Na₂CO₃ ratio of 1:1.5. Under the above reaction conditions, the leaching rates of V and W were 97.6% and 93.6%, respectively. The TiO₂ product recovered by the sulfuric acid dissolution method mainly existed in the form of anatase crystal. At the optimum roasting temperature of 750 ℃, the recovery rate of TiO₂ was 97.17% and the purity rate was 95.35%. The recovery and purity rate of the V₂O₅ and WO₃ products recovered by the organic extraction method were 72.47%, 75.43%, and 93.25%, 78.26%, respectively.