Intevep, S.a.

Roberto Schemel

Domingo P Rodriguez

Ramon Salazar

A process for the regeneration of a spent catalyst used in the upgrading of heavy hydrocarbon feedstocks comprises roasting a spent natural iron base catalyst contaminated with carbon, sulfur and vanadium at a temperature of not more than 400.degree. C. in the presence of a carbonate selected from the group consisting of sodium, potassium, and mixtures thereof so as to eliminate carbon from the catalyst and obtain a roasted product containing iron oxide and water soluble salts of sulfur and vanadium. The roasted product is thereafter water leached so as to dissolve the soluble salts of sulfur and vanadium. The regenerated catalyst is thereafter separated from the leaching liquor so as to obtain a catalyst substantially free of carbon and sulfur.

Process for the regeneration of spent catalyst used in the upgrading of

A method for precipitating vanadium from vanadium bearing liquors comprises adjusting the pH of the vanadium bearing liquor with a precipitating agent selected from the hydroxides of Na, K and Ca to a range of about 5.5 to 6.5, preferably 6.0 to 6.2 so as to precipitate vanadium in the trivalent and tetravalent states. Remaining traces of vanadium are then cemented by additions of calcium hydroxide, calcium oxide or mixtures thereof. The dried precipitate is then heated in the presence of air and Na and/or K so as to form a reaction product in the form of a water soluble salt which, when dissolved in water, results in vanadium in its pentavalent state.

Method for precipitating vanadium from vanadium bearing liquors and

A method for the removal and recovery of vanadium from a vanadium bearing material by leaching the vanadium bearing material in the presence of a leach promoter and removing the vanadium so leached from the leaching solution by precipitation. The leaching promoter forces the vanadium present in the vanadium bearing material into solution.

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San Antonio de Los Altos, Venezuela

Roberto Schemel