EXTRACTION AND PURIFICATION OF MOLYBDENUM FROM DEACTIVATED HYDRODESULFURIZATION CATALYSTS BY RADIATION-THERMAL TREATMENT

The radiation-thermal processes induced by intense fast electron beams of up to 2.0 MeV energy in deactivated Ni(Co)-Mo/Al2O3 catalysts in t he 670 - 1370 K temperature interval are studied by fluorescence X-ray radiometric element analysis, UV-Vis diffuse reflectance spectroscopy , and X-ray diffraction analysis. It is shown that electron-beam irrad iation results in crystallization of a number of Mo-containing phases, which are readily destroyed during high-temperature radiolysis. In ad dition to the production of aluminonickel spinel and corundum phases f ree of C and S, Mo(VI) oxide sublimation characterized by the low-temp erature threshold (similar to 770 K) is found to occur during radiatio n-thermal treatment. The lowering of the temperature threshold is expl ained by radiolysis of Mo-containing compounds.