A process to upgrade heavy oil and convert the heavy oil into lower boiling hydrocarbon products is provided. The process employs a catalyst slurry comprising catalyst particles with an average particle size ranging from 1 to 20 microns. In the upgrade process, spent slurry catalyst in heavy oil is generated as an effluent stream, which is subsequently recovered/separated from the heavy oil via membrane filtration. Residual hydrocarbons, i.e., heavy oil and solvent employed in the filtration for the heavy oil extraction are removed from the catalyst particles in a drying zone which employs at least two drying apparatuses to volatize residual hydrocarbons in the catalyst. Valuable metals can be recovered from catalyst particles for subsequent re-use in a catalyst synthesis unit, generating a fresh slurry catalyst.