Process for the production of a PGM-enriched alloy

Patent metadata

Field	Value
Publication number	US-10202669-B2
Application number	US-201615197102-A
Country	US
Kind code	B2
Filing date	Jun 29, 2016
Priority date	Jun 30, 2015
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

A process for production of a PGM (platinum group metal)-enriched alloy containing iron and PGM(s) (platinum, palladium and/or rhodium) includes steps of: (1) providing a sulfur-free PGM collector alloy, (2) providing a copper- and sulfur-free material capable of forming a molten slag-type composition including silicon dioxide and magnesium and/or calcium oxide, (3) melting the PGM collector alloy and slag-forming material within a converter until a multi-phase system of a lower high-density molten mass of PGM collector alloy and an upper low-density molten mass of slag-type composition has formed, (4) contacting an oxidizing gas with the lower high-density molten mass of step (3) until conversion of the PGM collector alloy into a PGM-enriched alloy, (5) separating an upper molten slag formed in step (4) from the PGM-enriched alloy by difference in density, (6) allowing the separated molten masses to cool down and solidify, and (7) collecting the solidified PGM-enriched alloy.

First claim

We claim:

1. A process for production of a platinum group metal (PGM)-enriched alloy comprising 0 to 60 wt. % of iron and 20 to 99 wt. % of at least one PGM selected from the group consisting of platinum, palladium and rhodium, the process comprising steps of:
(1) providing a sulfur-free PGM collector alloy comprising 30 to 95 wt. % of iron and 2 to 15 wt. % of the at least one PGM;
(2) providing a copper- and sulfur-free material capable of forming a slag-type composition when molten, wherein the molten slag-type composition comprises 10 to 30 wt. % of magnesium oxide and/or calcium oxide and 70 to 90 wt. % of silicon dioxide;
(3) melting the PGM collector alloy and the material capable of forming a slag-type composition when molten in a weight ratio of 1:0.75 to 5 within a converter until a multi-phase system of a lower high-density molten mass comprising the molten PGM collector alloy and at least one upper low-density molten mass comprising the molten slag-type composition has formed;
(4) contacting an oxidizing gas comprising 0 to 80 vol. % of inert gas and 20 to 100 vol. % of oxygen with the lower high-density molten mass obtained in step (3) until it has been converted into a lower high-density molten mass of the PGM-enriched alloy;
(5) separating an upper low-density molten slag mass formed during step (4) from the lower high-density molten mass of the PGM-enriched alloy by difference in density;
(6) allowing the molten masses separated from one another in step (5) to cool down and solidify; and
(7) collecting the solidified PGM-enriched alloy.

2. The process of claim 1 , wherein the PGM-enriched alloy comprises:
0 to 45 wt. % of iron,
30 to 99 wt. % of the at least one PGM,
0 to 60 wt. % of nickel,
0 to 5 wt. % of copper, and
0 to 10 wt. % at least one other element.

3. The process of claim 2 , wherein the at least one other element is selected from the group consisting of silver, gold, aluminum, calcium, and silicon.

4. The process of claim 1 , wherein the PGM-enriched alloy comprises:
0 to 20 wt. % of iron,
40 to 90 wt. % of the at least one PGM,
0 to 60 wt. % of nickel,
0 to 5 wt. % of copper, and
0 to 3 wt. % of at least one other element.

5. The process of claim 4 , wherein the at least one other element is selected from the group consisting of silver, gold, aluminum, calcium, and silicon.

6. The process of claim 1 , wherein the PGM collector alloy provided in step (1) comprises 40 to 70 wt. % of iron, 0 to 20 wt. % of nickel, and 5 to 15 wt. % of the at least one PGM.

7. The process of claim 1 , wherein the PGM collector alloy comprises no more than 4 wt. % of copper.

8. The process of claim 1 , wherein the PGM collector alloy comprises:
30 to 95 wt. % of iron,
0 to 20 wt. % of nickel,
2 to 15 wt. % of the at least one PGM,
0 to 4 wt. % of copper, and
0 to 30 wt. % at least one other element.

9. The process of claim 8 , wherein the at least one other element is selected from the group consisting of silver, gold, aluminum, calcium, silicon, phosphorus, titanium, chromium, manganese, molybdenum, and vanadium.

10. The process of claim 9 , wherein the PGM collector alloy comprises:
40 to 70 wt. % of iron,
0 to 15 wt. % of nickel,
5 to 15 wt. % of the at least one PGM
0 to 1 wt. % copper, and
0 to 20 wt. % of the at least one other element.

11. The process of claim 10 , wherein the at least one other element is selected from the group consisting of silver, gold, aluminum, calcium, silicon, phosphorus, titanium, chromium, manganese, molybdenum, and vanadium.

12. The process of claim 1 , wherein the molten slag-type composition comprises:
10 to 30 wt. % of magnesium oxide and/or calcium oxide,
70 to 90 wt. % of silicon dioxide,
0 to 20 wt. % of iron oxide,
0 to 20 wt. % of sodium oxide,
0 to 20 wt. % of boron oxide, and
0 to 2 wt. % of aluminum oxide.

13. The process of claim 1 , wherein the molten slag-type composition comprises:
20 to 25 wt. % of magnesium oxide and/or calcium oxide,
75 to 80 wt. % of silicon dioxide,
0 wt. % of iron oxide,
0 to 10 wt. % of sodium oxide,
0 to 10 wt. % of boron oxide, and
0 wt. % of aluminum oxide.

14. The process of claim 1 , wherein the PGM collector alloy and the material capable of forming a slag-type composition when molten are melted in a weight ratio of 1:0.75 to 3.

15. The process of claim 1 , wherein the converter is heated to raise its contents to a temperature of 1200 to 1850 ° C.

16. The process of claim 1 , wherein the oxidizing gas is oxygen.

17. The process of claim 1 , wherein the contact between the oxidizing gas and the lower high-density molten mass is made by passing or bubbling the gas through the lower high-density molten mass from the bottom of the converter and/or by a gas lance whose exhaust is immersed into the lower high-density molten mass.

18. The process of claim 1 , wherein the contacting with the oxidizing gas takes 1 to 5 hours.

Assignees

• Heraeus Deutschland Gmbh & Co Kg
• Heraeus Precious Metals North America LLC

Inventors

• Ritschel Norbert
• Taylor Jimmy
• England Todd
• Peters Brian
• Stoffner Felix
• Röhlich Christoph
• Voss Steffen
• Winkler Holger

Classifications

• C22B9/00 Primary

  General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals · CPC title

• Y02P10/214

  Cross-Sectional Technologies · mapped topic

• C22B23/06 Primary

  Refining · CPC title

• C22B11/02

  by dry processes · CPC title

• C22B11/026

  from spent catalysts · CPC title