本文選題：廢棄SCR催化劑　切入點：堿浸法　出處：《華北電力大學》2016年碩士論文　論文類型：學位論文

【摘要】：廢棄SCR催化劑中含有V、W和Ti等多種有價金屬,直接廢棄不僅會造成環(huán)境污染,且造成資源的浪費,因此回收其中的有價金屬具有重大意義。論文首先采用濕法冶金的方法,通過Na OH堿性浸出法浸出廢棄催化劑中的V和W,然后對浸出液進行鈣化沉淀,通過甲酸選擇性浸出混合沉淀物中的釩,經過除雜和加入氨水,釩將以偏釩酸銨的形式沉淀出來;甲酸浸出后沉淀物中的鎢,加入鹽酸轉化為鎢酸,經過灼燒,最終生成三氧化鎢。通過實驗確定了Na OH堿性浸出法最佳工藝條件和甲酸選擇性浸出最佳反應條件。結果表明:最佳條件為NaOH濃度為25%,固液比1:7,催化劑粒徑125~180μm,溫度60℃,浸出時間60min。隨后采用鈉化焙燒工藝從浸取后的濾渣中回收二氧化鈦。研究了碳酸鈉投加量、硫酸投加量、浸出熱水量、浸出時間、浸出溫度、焙燒時間、焙燒溫度對二氧化鈦回收率的影響。最佳條件:焙燒溫度700℃,Na2CO3與原料比為3.8,焙燒時間3.5h,80℃去離子水80mL,充分攪拌后靜置2h,5%的稀硫酸125mL。本文創(chuàng)新性的對廢棄SCR催化劑中的主要金屬元素Ti、V和W都提供了較好的回收途徑和較高的回收率,分別達到了92.15%、85.21%和75.42%。工藝過程更為清潔環(huán)保,對目前較為流行廢催化劑處理方法進行了總結和創(chuàng)新,最大程度的減少二次污染和二次排放。堿性浸取過程中的濾液和濾渣分別用來回來V、W和Ti,同時在工藝過程中所產生的堿液以及酸液均可以進行二次回收和處理。進行了經濟可行性分析,具有一定的經濟效益,為廢棄催化劑的回收處理及其工業(yè)化應用提供理論支持和工藝參考。
[Abstract]:There are many valuable metals in the waste SCR catalyst, such as VN W and Ti, which not only cause environmental pollution and waste of resources, but also cause waste of resources. Therefore, it is of great significance to recover the valuable metal from the catalyst. Firstly, hydrometallurgical method is adopted in this paper. The V and W in the waste catalyst were leached by NaOH alkaline leaching method, then the leaching solution was calcified and precipitated. The vanadium in the mixed precipitate was selectively leached by formic acid. After removing impurities and adding ammonia water, the vanadium would be precipitated in the form of ammonium metavanadate. After leaching with formic acid, the tungsten in the precipitate is converted into tungstic acid by adding hydrochloric acid. Finally, tungsten trioxide was formed. The optimum technological conditions of alkaline leaching of NaOH and selective leaching of formic acid were determined by experiments. The results showed that the optimum conditions were as follows: the concentration of NaOH was 25%, the ratio of solid to liquid was 1: 7, the particle size of catalyst was 125 ~ 180 渭 m, and the temperature was 60 鈩，

本文編號：1619836