Spent petroleum refining catalyst is regarded as the important secondary resource for valuable metals. However, common recycling strategies, including soda roasting, acid and alkaline solutions leaching and chemically precipitation, produced large quantities of high salinity wastewater. This study proposed an efficient method to recovery of Mo and Ni from the spent hydrodesulfurization (HDS) catalyst via O₂-rich roasting and organic acid leaching with the advantage of less salinity wastewater production. The transformation of Mo(IV) into soluble Mo(VI) was enhanced by O₂-rich atmosphere roasting, and 98.64% of Mo(IV) was oxidized at 650 ℃ for 2 h in atmosphere containing 30% of O₂. The oxidation process of Mo(IV) was agreed with the shrinkage pore model, and regulated by surface reaction and internal diffusion. 97.97% of Mo(VI) was leached from roasted product by oxalic acid, separated with complexation extraction agent of Ala-TBP and recovered as (NH₄)₈Mo₁₀O₃₄ and (NH₄)₂Mo₃O₁₀ by evaporative crystallization. Ni was leached out from spent catalyst with 1 mol/L acetic acid, and precipitated as NiC₂O₄ with oxalic acid. 95.92% of Mo and 96.77% of Ni were recovered from spent HDS catalyst with this recycling route. This study provided a high-efficient and eco-friendly method to recovery of valuable metals from spent catalyst.

废石油炼制催化剂被视为重要的有价金属二次资源。然而，常见的回收策略，包括苏打焙烧、酸碱溶液浸出和化学沉淀，会产生大量高盐废水。本研究提出了一种通过富O ₂焙烧和有机酸浸出从废加氢脱硫(HDS)催化剂中回收Mo和Ni的有效方法，具有减少含盐废水产生的优点。富O ₂气氛焙烧促进了Mo(IV)向可溶性Mo(VI)的转化，在含30% O ₂的气氛中，650 ℃ 2 h，98.64%的Mo(IV)被氧化。 Mo(IV)的氧化过程符合缩孔模型，并受到表面反应和内部扩散的调控。焙烧品经草酸浸出97.97%的Mo(VI)，用Ala-TBP络合萃取剂分离，蒸发结晶回收为(NH ₄ ) ₈ Mo ₁₀ O ₃₄和(NH ₄ ) ₂ Mo ₃ O ₁₀ 。用1 mol/L乙酸从废催化剂中浸出Ni，并用草酸以NiC ₂ O ₄形式沉淀。通过该回收路线，从废HDS催化剂中回收了95.92%的Mo和96.77%的Ni。该研究为从废催化剂中回收有价金属提供了一种高效、环保的方法。