Process for Recovering Base Metals from Spent Hydroprocessing Catalyst

• US 20090136399A1
• Filed: 11/28/2007
• Published: 05/28/2009
• Est. Priority Date: 11/28/2007
• Status: Active Grant

• Current Assignee: Chevron USA Incorporated (Chevron Corp.)
• Original Assignee: Chevron USA Incorporated (Chevron Corp.)
• Inventors: Bhaduri, Rahul S.
• Granted Patent: US 7,658,895 B2
• Time in Patent Office: Days
• US Class Current: 423/56
• CPC Class Codes: C01B 17/20 Methods for preparing sulfides or polysulfides, in general ammonium sulfides or polysulfides C01C; sulfides or polysulfides of metals, other than alkali metals, magnesium, calcium, strontium and barium, see the relevant groups of subclasses C01F or C01G, according to the metal
• CPC Class Codes: C01C 1/242 Preparation from ammonia and sulfuric acid or sulfur trioxide
• CPC Class Codes: C01G 31/00 Compounds of vanadium
• CPC Class Codes: C01G 31/02 Oxides
• CPC Class Codes: C01G 39/00 Compounds of molybdenum
• CPC Class Codes: C01G 39/06 Sulfides
• CPC Class Codes: C01G 53/006 Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen nickelates C01G53/40
• CPC Class Codes: C01G 53/11 Sulfides
• CPC Class Codes: C22B 34/225 from spent catalysts
• CPC Class Codes: C22B 34/345 from spent catalysts
• CPC Class Codes: C22B 7/006 Wet processes
• CPC Class Codes: C22B 7/009 General processes for recovering metals or metallic compounds from spent catalysts for recovering specific metals C22B11/00 - C22B61/00
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

A method for recovering metals from a spent dispersed catalyst originating from a Group VIB metal sulfide catalyst containing at least a Group VB and Group VIII metal for hydrocarbon oil hydroprocessing is disclosed. In one embodiment, the method comprises the steps of: contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the group VIB metal and the Group VIII metal into the leaching solution at sufficient temperature and pressure; forming a slurry containing at least a group VIB metal complex and at least a group VIII metal complex, ammonium sulfate and solid residue containing at least a Group VB metal complex and coke; separating and removing the solid residue containing ammonium metavanadate and coke from the pressure leach solution (PLS); precipitating from the PLS at least a portion of the Group VIB metal and at least a portion of the Group VIII metal by controlling the pH at a pre-selected pH to selectively precipitate as metal complexes the Group VIB and Group VIII metals.

Claims

1. A method of recovering metals from a spent dispersed catalyst originating from a Group VIB metal sulfide catalyst and at least a Group VB metal promoted with a Group VIII metal for hydrocarbon oil hydroprocessing, the method comprising the steps of:

contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the Group VIB metal and the Group VIII metal into the leaching solution at a sufficient temperature and pressure to form a pressure leach slurry containing at least a Group VIB soluble metal complex and at least a Group VIII soluble metal complex and solid residue containing at least a Group VB metal complex and coke;

separating and removing the solid residue containing the Group VB metal complex and coke from the pressure leach slurry, forming a pressure leach solution;

precipitating from the pressure leach solution at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a first pre-selected pH to precipitate as metal complexes at least a portion of the Group VIB metal and at least a portion of the Group VIII metal.

2. The method of claim 1, wherein the Group VB metal is vanadium, and wherein the Group VB metal complex comprises ammonium metavanadate.

3. The method of claim 1, further comprising the step of:

recovering the precipitated metal complexes by at least a separation means selected from settling, filtration, decantation, centrifugation and combinations thereof, forming a first supernatant substantially free of at least a portion of the Group VIB metal and at least a portion of the Group VIII metal.

4. The method of claim 3, wherein the first supernatant contains 0.1 to 3% of the Group VIB metal in the spent dispersed catalyst for metal recovery, 1 to 20% of the Group VB metal in the spent dispersed catalyst for metal recovery, and 1 to 35% of the Group VIII metal in the spent dispersed catalyst for metal recovery.

5. The method of claim 4, further comprising the step of:

precipitating from the first supernatant at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a second pre-selected pH to precipitate as metal complexes at least 95% of the Group VIB metal and at least 95% of the Group VIII metal initially present in the first supernatant prior to the precipitation at the second pre-selected pH.

6. The method of claim 5, further comprising the step of:

recovering the Group VIB and group VIII metal sulfides by at least a separation means selected from settling, filtration, decantation, centrifugation and combinations thereof, forming a second supernatant containing less than 100 ppm of the group VIB metal, less than 20 ppm of the Group VIII metal, and less than 100 ppm of the Group VB metal.

7. The method of claim 1, wherein at least 90% of the Group VIB metal precipitates from the pressure leach solution as a metal complex.

8. The method of claim 1, wherein the Group VIB metal is molybdenum and wherein the first pre-selected pH is in the range of 2.5 to 3.3 to precipitate greater than 90% of the molybdenum as a molybdate complex.

9. The method of claim 8, wherein the pressure leach solution (PLS) is adjusted to the first pre-selected pH by adding to the PLS at least one of a mineral acid or a sulfur compound having a sulfhydryl group or an ionized sulfhydryl group, or mixtures thereof.

10. The method of claim 9, wherein the pH of the PLS is adjusted to a pH of 3.5 or less with an acid selected from the group of sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid.

11. The method of claim 10, wherein the PLS is adjusted to a pH of 3 or less with the addition of a sulfuric acid for at least 95% of the molybdenum to precipitate out as a molybdate complex.

12. The method of claim 9, wherein the pH of the pressure leach solution is adjusted to a pH of 3 or less with at least one of a water soluble sulfide, a water soluble poysulfide, or mixtures thereof.

13. The method of claim 1, wherein the Group VIB metal in the spent dispersed catalyst for metal recovery is molybdenum, the Group VIII metal in the spent dispersed catalyst for metal recovery is nickel, the Group VB metal in the spent dispersed catalyst for metal recovery is vanadium, and wherein the first supernatant contains 0.1 to 3% of the molybdenum present in the spent dispersed catalyst, 1 to 20% of the vanadium present in the spent dispersed catalyst, and 1 to 35% of the nickel present in the spent dispersed catalyst.

14. The method of claim 13, wherein at least one of a water soluble sulfide, a water soluble poysulfide, or mixtures thereof is added to the first supernatant for a pH level of between 5 and 7 to obtain a precipitate of Mo, Ni, and V sulfides.

15. The method of claim 14, wherein H₂S is added to the first supernatant at a pressure from atmospheric to 100 psig and at a temperature ranging from 50 to 95°

C.

16. The method of claim 6, wherein the Group VIB metal in the spent dispersed catalyst for metal recovery is molybdenum, the Group VIII metal in the spent dispersed catalyst for metal recovery is nickel, the Group VB metal in the spent dispersed catalyst for metal recovery is vanadium, the pressure leach solution is adjusted to a pH of 3 or less with the addition of a sulfuric acid for at least 95% of the molybdenum to precipitate out as a molybdate complex, the molybdate complex is separated from the first supernatant by filtration, H₂S is added to the first supernatant at a pressure from atmospheric to 100 psig and at a temperature ranging from 50-95°

C. to obtain a precipitate of Mo, Ni, and V sulfides, the Mo, Ni, and V sulfides are separated from the second supernatant by filtration, and wherein the second supernatant contains 100 to 1000 gpL ammonium sulfate, less than 100 ppm molybdenum, less than 20 ppm nickel, and less than 100 ppm vanadium.

17. A method of recovering metals from a spent dispersed catalyst originating from a hydroprocessing catalyst having a general formula (X)_a(M)_b[(CH₃CH₂)_cN(CH₃)₃]_dO_z and containing at least a group VB metal, wherein X is a Group VIII non-noble metal, M is a group VIB metal selected from Mo and W and combinations thereof, c is an integer from 10 to 40, the molar ratio of a:

b is from 0.5/1 to 3/1, the method comprising the steps of;

contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the Group VIB metal and the Group VIII metal into the leaching solution at a sufficient temperature and pressure to form a pressure leach slurry containing at least a Group VIB soluble metal complex and at least a Group VIII soluble metal complex, ammonium sulfate and solid residue containing at least a Group VB metal complex and coke;

separating and removing the solid residue containing the Group VB metal complex and coke from the pressure leach slurry;

precipitating from the pressure leach slurry at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a first pre-selected pH to precipitate as metal complexes at least a portion of the Group VIB metal and at least a portion of the Group VIII metal.

18. The method of claim 17, further comprising the steps of:

recovering the precipitated metal complexes by filtration, forming a first supernatant containing 0.1 to 3% of the Group VIB metal in the spent dispersed catalyst for metal recovery, 1 to 20% of the Group VB metal in the spent dispersed catalyst for metal recovery, and 1 to 35% of the Group VIII metal in the spent dispersed catalyst for metal recovery;

precipitating from the first supernatant at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a second pre-selected pH to precipitate as metal sulfides at least 95% of the Group VIB metal and at least 95% of the Group VIII metal initially present in the first supernatant prior to the precipitation at the second pre-selected pH;

recovering the Group VIB and Group VIII metal sulfides by filtration, forming a second supernatant containing less than 100 ppm of the Group VIB metal, less than 20 ppm of the Group VIII metal, and less than 100 ppm of the Group VB metal.

19. The method of claim 18, wherein the Group VIB metal is molybdenum and wherein the pre-selected pH is in the range of 2.5 to 3.3 to precipitate greater than 90% of the molybdenum.

20. The method of claim 18, wherein the spent dispersed catalyst originating from a hydroprocessing catalyst having a median particle size of 0.01 to 200 microns.

21. The method of claim 18, wherein the spent dispersed catalyst has a pore volume of 0.05-5 ml/g as determined by nitrogen adsorption.

22. A method of recovering metals including vanadium from a spent dispersed catalyst having a general formula (M^t)_a(X^u)_b(S^v)_d(C^w)_e(H^x)_f(O^y)_g(N^z)_h containing at least a Group VB metal, wherein M is at least one group VIB metal, X is at least one of a non-noble Group VIII metal, a Group VIIIB metal, a Group VIB metal, a Group IVB metal, and a Group IIB metal, 0=<

b/a=<

5, (a+0.5b)<

=d<

=(5a+2b), 0<

=e<

=11(a+b), 0<

=f<

=7(a+b), 0<

=g<

=5(a+b), 0<

=h<

=0.5(a+b);

t, u, v w, x, y, z, each representing total charge for each of;

M, X, S, C, H, O and N, respectively;

ta+ub+vd+we+xf+yg+zh=0;

the method comprising the steps of;

contacting the spent dispersed catalyst with a leaching solution containing ammonia and air to dissolve the Group VIB metal and the Group VIII metal into the leaching solution at a sufficient temperature and pressure to form a pressure leach slurry containing at least a group VIB soluble metal complex and at least a group VIII soluble metal complex, ammonium sulfate and solid residue containing at least a Group VB metal complex and coke;

separating and removing the solid residue containing ammonium metavanadate and coke from the pressure leach slurry;

precipitating from the pressure leach slurry at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a first pre-selected pH to precipitate as metal complexes at least a portion of the Group VIB metal and at least a portion of the Group VIII metal;

recovering the metal complexes by filtration, forming a first supernatant containing 0.1 to 3% of the Group VIB metal in the spent dispersed catalyst for metal recovery, 1 to 20% of the Group VB metal in the spent dispersed catalyst for metal recovery, and 1 to 35% of the Group VIII metal in the spent dispersed catalyst for metal recovery;

precipitating from the first supernatant at least a portion of the Group VIB metal and at least a portion of the Group VIII metal, wherein the precipitation being carried out at a second pre-selected pH to precipitate as metal complexes at least 95% of the Group VIB metal and at least 95% of the Group VIII metal initially present in the first supernatant prior to the precipitation at the second pre-selected pH; and

recovering the Group VIB and group VIII metal sulfides by filtration, forming a second supernatant containing less than 100 ppm of the group VIB metal, less than 20 ppm of the Group VIII metal, and less than 100 ppm of the group VB metal.