Spent catalyst used for denitration by selective catalytic reduction (spent SCR denitration catalysts) is one of the important urban mines due to the high content of TiO₂ (∼85 wt%) and the massive accumulation amount (over 100, 000 tons), therefore, value-added reutilization of titanium in spent SCR catalysts is considerably meaningful. In this paper, a novel method is proposed for converting the titanium oxide in spent SCR denitration catalysts to metallic titanium. Specifically, titanium dioxide (TiO₂) was firstly obtained from spent SCR denitration catalysts after removing the impurities by hydrometallurgy process. Then, TiO₂ is converted to Ti₂CO by carbothermic reduction method, and Ti₂CO was further purified by oleic acid capture. Finally, by utilizing the as-prepared Ti₂CO as the consumable anode in the NaCl-KCl molten salt, high-purity metallic titanium was deposited at cathode, all confirming the feasibility for the conversion of low–grade TiO₂ in the spent catalysts, from 60 wt% to high–purity metallic Ti (99.5 wt%), furthermore, the energy consumption of this process is 3950 kWh tonne⁻¹ Ti, which is lower than that of most traditional titanium metallurgy methods. The method herein can provide new insights for the value-added recycling of titanium resources in urban mines.

通过选择性催化还原脱硝的废催化剂（废SCR脱硝催化剂）由于TiO ₂含量高（约85 wt％）和大量堆积（超过100，000吨）而成为城市的重要矿山之一。因此，废SCR催化剂中钛的增值再利用意义重大。本文提出了一种将废SCR脱硝催化剂中的氧化钛转化为金属钛的新方法。具体地，在通过湿法冶金法去除杂质之后，首先从废SCR脱硝催化剂中获得二氧化钛（TiO ₂）。然后，通过碳热还原法将TiO ₂转化为Ti ₂ CO，并将Ti ₂通过油酸捕获进一步纯化CO。最后，通过将制得的Ti ₂ CO用作NaCl-KCl熔融盐中的消耗阳极，高纯度金属钛沉积在阴极上，所有这些都证实了在废催化剂中转化低级TiO ₂的可行性。从60 wt％到高纯度金属Ti（99.5 wt％），此外，此过程的能耗为3950 kWh吨^-1 Ti，低于大多数传统的钛冶金方法。本文的方法可以为城市矿山中钛资源的增值回收提供新的见解。