Method of metals recovery from refinery residues
AssigneeIntevep, S.A.
InventorMatthew Stephen Grimley
Life of this patent
Estimating the term…
Abstract
A method of recovering vanadium, nickel and molybdenum from heavy crude oil refinery residues comprises pyrolysis and combustion of the residues at temperatures up to 900° C. to produce an ash, converting the ash to an aqueous slurry comprising sodium hydroxide as leading agent and hydrogen peroxide as oxidizer, and extracting vanadium, nickel and molybdenum salts and oxides from the slurry. Extraction processes for the metals are disclosed.
Claims22
A method of recovering vanadium, nickel and molybdenum from heavy crude oil refinery residues, comprising pyrolysis and combustion of the residues at temperatures up to 900° C. to produce an ash, forming an aqueous slurry from the ash, and extracting vanadium, nickel and molybdenum compounds from the slurry, comprising recovering nickel in the form of nickel hydroxide by leaching and precipitation with magnesium oxide, and further comprising:
- (a) slurrying said ash with water and regenerated liquid from step (p);
- (b) treating said slurried ash with an aqueous solvent and an oxidizer in a leaching zone at leaching conditions;
- (c) passing the effluent of step (b), which comprises liquid and insoluble solids to a filtration zone, from which solid material is recovered as a filter cake;
- (d) passing the supernatant of step (c), which comprises an aqueous phase and an organic phase, to a mixer-settler zone, wherein the supernatant is adjusted for pH and ammonium metavanadate precipitated;
- (e) passing the effluent of step (d) to a filtration zone for the removal of ammonium metavanadate solid;
- (f) passing the supernatant of step (e) to a mixer-settler zone, wherein the supernatant is adjusted for pH and ammonium heptamolybdate tetrahydrate precipitated;
- (g) passing the effluent of step (f) to a filtration zone for the removal of ammonium heptamolybdate tetrahydrate solid;
- (h) passing the supernatant of step (g) to an effluent treatment system for removal of traces of metals and ammonium, all of which are recirculated to step (p), prior to disposal through a refinery effluent discharge;
- (i) slurrying the filter cake of step (c) with water;
- (j) treating said slurried insoluble solids of step (i) with an oxidizing agent in a leaching zone at leaching conditions;
- (k) passing the effluent of step (j) to a filtration zone for removal of solid coke contaminants;
- (l) passing the supernatant of step (k) to a mixer-settler zone, wherein the solution is neutralised and nickel hydroxide precipitated;
- (m) passing the effluent of step (1) to a filtration zone for separation of solid nickel hydroxide;
- (n) passing the insoluble solids of step (m), which comprises nickel hydroxide, to a dissolution zone, to which acetic acid is added under dissolution conditions to obtain nickel acetate tetrahydrate as product;
- (o) passing the supernatant of step (m) to the effluent treatment system for removal of traces of metals and ammonium, all of which are recirculated to step (p) prior to disposal through the refinery effluent discharge;
- (p) recirculating regenerated liquid from step (n) and step (h) to step (a).
Dependencies are inferred from the claim text.