Hydroprocessing using regenerated spent heavy hydrocarbon catalyst

This patent describes a process for hydroprocessing a hydrocarbon feedstock. It comprises: contacting the feedstock with hydrogen under hydroprocessing conditions with a hydroprocessing catalyst wherein the hydroprocessing catalyst contains a total contaminant metals build-up of greater than about 4 wt. % nickel plus vanadium, a hydrogenation component selected from the group consisting of Group VIB metals and Group VIII metals and is regenerated spent hydroprocessing catalyst regenerated by a process comprising the steps: partially decoking the spent catalyst in an initial coke-burning step; impregnating the partially decoked catalyst with a Group IIA metal-containing impregnation solution; and decoking the impregnated catalyst in a final coke-burning step wherein the impregnated catalyst is contacted with an oxygen-containing gas at a temperature of about 600 degrees F to about 1400 degrees F