废SCR催化剂中TiO_(2)载体的深度净化研究

Study on Deep Purification of TiO_(2) Carrier in Waste SCR Catalyst

湿法化学法是从废脱硝催化剂中回收高纯度TiO_(2)载体的有效方法。为进一步提高回收TiO_(2)纯度,同时探究湿法化学过程对TiO_(2)表面物化性质的影响,采用草酸浸出+混碱热压浸出的方法从废脱硝催化剂中回收TiO_(2),其纯度可达97.37%。采用XRD、TEM、BET、TGA等表征手段对废催化剂、回收TiO_(2)载体以及高纯商业TiO_(2)载体的表面性质进行了研究。结果表明,回收TiO_(2)载体物相结构、表面形貌、比表面积和孔结构、颗粒粒径和表面羟基均得到有效恢复,满足商业TiO_(2)载体的要求。但氧化还原性和表面酸性与高纯商业TiO_(2)载体存在一定差异。该研究为从废脱硝催化剂中回收TiO_(2)的进一步利用和改性提供了基础和参考。

The wet chemical method is an effective method for recovering high-purity TiO_(2) carriers from waste denitrification catalysts.In order to further improve the purity of recovered TiO_(2) and explore the impact of wet chemical processes on the surface physicochemical properties of TiO_(2),TiO_(2) is recovered from waste denitrification catalysts by oxalic acid leaching and mixed alkali hot press leaching method.Its purity can reach 97.37%.The surface properties of waste catalysts,recovered TiO_(2) carriers,and high-purity commercial TiO_(2) carriers are studied using characterization methods such as XRD,TEM,BET,and TGA.The results show that the phase structure,surface morphology,specific surface area and pore structure,particle size,and surface hydroxyl groups of the recovered TiO_(2) carrier are effectively restored,meeting the requirements of commercial TiO_(2) carriers.However,there are certain differences in redox and surface acidity between high-purity commercial TiO_(2) carriers.This study provides a foundation and reference for the further utilization and modification of TiO_(2) recovered from waste denitrification catalysts.