Abstract

Waste selective catalytic reduction (SCR) catalysts are potential environmental hazards. In this study, the recovery of vanadium and tungsten from waste SCR catalysts by K₂CO₃ roasting and water leaching was investigated. The roasting and leaching conditions were optimized: the leaching efficiencies of vanadium and tungsten were 91.19% and 85.36%, respectively, when 18 equivalents of K₂CO₃ were added to perform the roasting at 900 °C for 2 h, followed by leaching at 90 °C for 1 h. Notably, in the described conditions, the leaching rate of silicon was only 28.55%. Titanates, including K₂Ti₆O₁₃ and KTi₈O₁₇, were also produced. Si removal was achieved in 85% efficiency adjusting the pH to 9.5, and the Si impurity thus isolated was composed of amorphous Si. Tungsten and vanadium were precipitated using CaCl₂. At pH 10 and following the addition of 0.10 mol of H₂O₂ and 16 equivalents of CaCl₂, the precipitating efficiencies of tungsten and vanadium were 96.89% and 99.65%, respectively. The overall yield of tungsten and vanadium was 82.71% and 90.87%, respectively.

Graphic abstract

中文翻译：

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通过K 2 CO 3焙烧和水浸，然后用CaCl 2沉淀从废物选择性催化还原催化剂中回收钒和钨。

摘要

废物选择性催化还原（SCR）催化剂具有潜在的环境危害。在这项研究中，研究了通过K ₂ CO ₃焙烧和水浸出从废SCR催化剂中回收钒和钨。优化了焙烧和浸出条件：当添加18当量的K ₂ CO ₃在900°C下焙烧2 h，然后在750℃下焙烧时，钒和钨的浸出效率分别为91.19％和85.36％。 90°C 1小时。值得注意的是，在所述条件下，硅的浸出率仅为28.55％。钛酸盐，包括K ₂ Ti ₆ O ₁₃和KTi ₈ O ₁₇，也产生了。通过将pH调节至9.5的85％的效率实现了Si的去除，并且由此分离出的Si杂质由非晶Si构成。用CaCl ₂沉淀钨和钒。在pH为10时，在加入0.10 mol H ₂ O ₂和16当量的CaCl _2之后，钨和钒的沉淀效率分别为96.89％和99.65％。钨和钒的总产率分别为82.71％和90.87％。

图形摘要