Summary Analyses on a used Unocal experimental demetallation catalyst after extended testing showed that the carbon level increased, and the metals and sulfur levels decreased, from top to bottom in the bed. The level of deposited metals (V+Ni+Fe) ranged from about 110% of the fresh catalyst at the top of the bed to about 15% at the bottom in fairly linear fashion. The average deposited metals level was 52 wt% of the fresh catalyst. The apparent stoichiometric molar ratio of metals to sulfur ranged from 1:1 at the top of the bed to 1:2 at the bottom. At least some of the deposited metals occurred as [V, (Fe, Ni)]3-xS4, where x represents a small deviation from ideality resulting from structural defects.