Akademik Veri Yönetim Sistemi
Journal of Sustainable Metallurgy, cilt.9, sa.4, ss.1-15, 2023 (SCI-Expanded)
A significant amount of spent Ni-Mo HDS catalyst hazardous waste is generated during the petroleum refining processes. This waste contains valuable metals such as Mo, Ni, and Al. The most interesting route for a sustainable waste management is the recovery of valuable metals from the environmental and economic point of view. In this work, hydrometallurgical method was used to investigate the recovery of valuable metals from roasted Ni-Mo HDS catalyst and determine the effect of particle size, stirring speed, acid concentration, and temperature on the leaching rate of MoO3, NiMoO4, Al2O3, and AlPO4. Optimum leaching conditions, in which 92% of MoO3, 93% of NiMoO4, 55% of Al2O3, and 71% of AlPO4 leached, were determined as 180 min of reaction time, unground catalyst, stirring speed of 300 min−1, 2 M HCl solution, and 328 K. Avrami Kinetic Model was found to be the most suitable kinetic model for the experimental data obtained from the leaching experiments. Kinetic parameters used in Avrami Kinetic Model were calculated for the leaching reactions of MoO3, NiMoO4, Al2O3, and AlPO4. Apparent activation energy values were calculated for the leaching reaction of MoO3, NiMoO4, Al2O3, and AlPO4 in HCl solutions as 31.43, 45.42, 42.37, and 51.07 kJ mol−1, respectively. Experimental results and kinetic calculations showed that leaching rates of NiMoO4, Al2O3, and AlPO4 are more temperature dependent than that of MoO3 due to having higher apparent activation energy values. Model kinetic equation, which gives fraction of compound extracted values as a function of time, was derived as