An efficient method for recycling spent residue cat-cracking catalysts (SRC) to prepare broadly-applicable mullite-based wear-resistant ceramics

摘要

Spent residue catalysts (SRC) of fluid cat-cracking were used as raw materials for the preparation of wear-resistant ceramics. The starting material was wet-milled and then dried to obtain semi-dried powders. The resultant powder was pressed into various shapes and sintered at various temperatures (1300 to 1450 degrees C). The bulk density and linear shrinkage of the samples increased as the temperatures rose, while the apparent porosity and water absorption behaved in a reverse manner. Based on the results, the specimens sintered at 1450 degrees C appeared to be the best alternatives for the preparation of the wear-resistant ceramics. The results also revealed that pre-calcination has no significant effect on the final properties of the ceramic products. The XRD results approved that mullite is the only crystallized phase in the specimens sintered at 1450 degrees C. Moreover, the absence of vanadium and nickel-based phases in the XRD pattern indicated that these elements had been stabilized in the glassy phase. SEM images displayed the presence of needle-like mullite grains, in agreement with the XRD results. Additionally, SEM images illustrated that the fractures, appeared after the wear test, were inter-granular and may have been resulted from the well-controlled sintering conditions. Generally, the results of this study suggest a cleaner method for converting the SRCs to wear-resistant mullite-based ceramics with a wide range of industrial applications.