Study On Extraction And Reuse Of Effective Metals From Deactivated Hydrogenation Catalyst

The rapid development of world economy makes the demand of oil products moreand more big, which comes from all walks of life. But the pressure also increases day byday brought by shortage of resource and environmental problem. This is a inevitablerequirement that every country must improve oil processing depth and products quality,therefore, it cause the rapid development of catalytic hydrogenation technology.Meanwhile, the number of hydrogenation catalyst used in hydrogenation process increasesrapidly, the catalysts lose activity permanently due to the deposition of metals on thesurface of catalyst and the damage of structure. A large quantity of deactivated catalystwas discharged as spent catalyst. This isn’t conducive to environmental protection, andlead to a large number of useful metals loss. The study of recovery and reuse of effectivemetals from deactivated hydrogenation catalyst has better economical and environmentalbenefit.The technique of extraction of effective metals such as W, MOfrom deactivatedhydrogenation catalyst by the method of air roasting and then leaching in aqueousammonia was studied in this paper. The effects of roasting temperature and time,liquid-solid ratio, leaching temperature and time on the W and MOextraction wereanalyzed. The method of recovering nickel as nickel nitrate from catalyst residue wasstudied. The influence of concentration of sodium hydroxide, added amount of nitric acidand reaction time was investigated. Then made by the impregnation method reclaimedmetals loaded to γ-Al2O3.The influence of impregnation time on load and loadingreclaimed metals on SSA, bulk density, pore volume and pore diameter distribution ofsupporter.The experimental results showed that the extraction rates of W, MOcould arrive to95.03%,92.56%, respectively, when roasting temperature was600℃, roasting time was3h,liquid–solid was3:1, leaching temperature was65℃, leaching time was5h. The recoveryof nickel could reach63%when concentration of sodium hydroxide was30%, added amount of nitric acid was50ml, leaching time was1.5h. The purity of reclaimed nickelnitrate could reach to98%.The load of W, MO, Ni could arrive to14.01%,6.48%,3.80%respectively. And loading reclaimed metals had no influence on the structure of supporter.SEM and XRD measurements showed that W, MO, Ni with their oxide crystalline formdispersed evenly to the carrier.