Ferronickel alloy direct refining processes and processes for producing nickle sulfate or other nickel products

Patent metadata

Field	Value
Publication number	US-11873539-B2
Application number	US-202217977459-A
Country	US
Kind code	B2
Filing date	Oct 31, 2022
Priority date	Jan 4, 2021
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

Processes and methods for refining ferronickel alloy, and producing nickel sulfate or other nickel product, are provided, where the ferronickel alloy is treated with an oxidizing leach. The oxidizing leach may be, for example, a pressure oxidation (POX) leach or a leach with peroxide or copper (II) ions. The treatment may be in the presence of added copper, such as by providing a copper sulfate solution. Producing nickel sulfate may comprise removing copper and iron after the leach, removing impurities, and either crystallizing the nickel sulfate or precipitating/winning another nickel product.

First claim

What is claimed is:

1. A process for refining ferronickel alloy comprising treating the ferronickel alloy with an oxidizing leach,
wherein treating the ferronickel alloy comprises
adding a copper reagent, and
treating the ferronickel alloy in the presence of copper from the copper reagent.

2. The process of claim 1 , wherein treating the ferronickel alloy with the oxidizing leach further comprises:
treating the ferronickel alloy with a pressure oxidation (POX) leach,
treating the ferronickel alloy in the presence of peroxide, or
treating the ferronickel alloy in the presence of sulfuric acid.

3. The process of claim 2 , wherein treating the ferronickel alloy in the presence of peroxide comprises:
providing a peroxide treatment comprising treating the ferronickel alloy in the presence of peroxide and sulfuric acid to provide a discharge liquor, and
providing a POX treatment comprising treating the discharge liquor with the POX.

4. The process of claim 3 , wherein treating the ferronickel alloy in the presence of peroxide comprises:
providing the peroxide treatment comprising treating the ferronickel alloy in the presence of peroxide to provide a first discharge liquor,
providing the POX treatment comprising treating the ferronickel alloy with the POX to provide a second discharge liquor, and
returning at least a portion of the second discharge liquor to the peroxide treatment.

5. The process of claim 4 , wherein returning the second discharge liquor to the peroxide treatment increases the concentration of nickel in the peroxide treatment.

6. The process of claim 4 , wherein returning the second discharge liquor to the peroxide treatment adjusts the pH of the peroxide treatment.

7. The process of claim 1 , wherein treating the ferronickel alloy with the oxidizing leach comprises treating the ferronickel alloy at atmospheric pressure in a vessel.

8. The process of claim 1 , wherein the copper is provided as copper sulfide, copper oxide, or copper sulfate.

9. The process of claim 1 , further comprising producing an iron product of hematite, jarosite, or goethite.

10. The process of claim 9 , wherein producing the iron product comprises selectively removing iron in the form of hematite by pressure oxidation (POX) of the ferronickel alloy.

11. The process of claim 1 , further comprising a copper recovery step after the oxidizing leach, to recover at least a portion of the copper from the copper reagent when treating the ferronickel alloy in the presence of copper.

12. The process of claim 11 , wherein the copper recovery step comprises a solvent extraction step, an electrowinning step, a cementation step, a sulfidation step, a pH adjustment step, an ion exchange step, or a pressure oxidation step.

13. The process of claim 12 , wherein the copper recovery step comprises a cementation step wherein a portion of ferronickel alloy or nickel powder is provided to cement the copper from the copper reagent.

14. The process of claim 11 , wherein at least a portion of the recovered copper from the copper reagent is returned upstream to the step of treating the ferronickel alloy with the oxidizing leach or to a pre-leach step upstream of the oxidizing leach treatment step.

15. The process of claim 1 , wherein the copper reagent is added to the process during the oxidizing leach, a copper cementation step, or a pre-leach step upstream of the oxidizing leach.

16. The process of claim 1 , wherein the oxidizing leach provides a discharge liquor comprising uncrystallised metal sulfate, and further comprising producing a nickel product by crystallizing the uncrystallised metal sulfate to form a crystallized nickel sulfate or a co-crystallized nickel and cobalt sulfate in a mother liquor.

17. The process of claim 16 , further comprising separating the crystallized nickel sulfate or co-crystallized nickel and cobalt sulfate from the mother liquor, wherein the mother liquor comprises a remaining uncrystallised metal sulfate, and the process further comprises basifying a portion of the mother liquor to convert the remaining uncrystallised metal sulfate to a basic metal salt, and using the basic metal salt upstream of crystallizing the metal sulfate.

18. The process of claim 17 , wherein using the basic metal salt upstream comprises converting the basic metal salt back to the uncrystallised metal sulfate.

19. The process of claim 1 , further comprising:
treating the ferronickel alloy with a pressure oxidation (POX) leach;
providing a discharge liquor from the oxidizing leach, the liquor comprising uncrystallised metal sulfate;
producing a nickel product by crystallizing the uncrystallised metal sulfate to form a crystallized nickel sulfate or a co-crystallized nickel and cobalt sulfate in a mother liquor;
separating the crystallized nickel sulfate or co-crystallized nickel and cobalt sulfate from the mother liquor, the mother liquor comprising a remaining uncrystallised metal sulfate;
basifying a portion of the mother liquor to convert the remaining uncrystallised metal sulfate to a basic metal salt, and
using the basic metal salt upstream of crystallizing the metal sulfate.

20. An improved method for direct refining ferronickel alloy, the improvement comprising providing a copper reagent during leaching of the ferronickel alloy.

21. The method of claim 20 , wherein the leaching of the ferronickel alloy comprises an oxidizing leach.

22. A process for producing a nickel product, the process comprising:
treating a ferronickel alloy feedstock with an oxidizing leach to form a leached material, the leached material comprising nickel, and iron;
removing at least a portion of the iron from the leached material and recovering the nickel product,
wherein treating the ferronickel alloy feedstock comprises adding a copper reagent and treating the ferronickel alloy feedstock in the presence of copper from the copper reagent.

23. The process of claim 22 , wherein treating the ferronickel alloy feedstock with the oxidizing leach further comprises:
treating the ferronickel alloy feedstock with a pressure oxidation (POX) leach,
treating the ferronickel alloy feedstock in the presence of peroxide, or
treating the ferronickel alloy feedstock in the presence of sulfuric acid.

24. The process of claim 23 , wherein treating the ferronickel alloy feedstock in the presence of peroxide comprises:
providing a peroxide treatment comprising treating the ferronickel alloy feedstock in the presence of the peroxide; and
providing a POX treatment comprising treating the ferronickel alloy feedstock with the POX.

25. The process of claim 22 , wherein recovering the nickel product comprises crystallizing an uncrystallized nickel sulfate from the leached material to form a crystallized nickel sulfate in a mother liquor, separating the crystallized nickel sulfate from the mother liquor, wherein the mother liquor comprises a remaining uncrystallised nickel sulfate, and basifying a portion of the mother liquor to convert the uncrystallised nickel sulfate to a basic nickel salt.

26. The process of claim 25 , further comprising using the basic nickel salt upstream of crystallizing the nickel salt.

27. The process of claim 26 , wherein using the basic nickel salt upstream comprises converting the basic nickel salt back to the uncrystallised nickel sulfate.

Assignees

• Hatch Ltd

Inventors

• Fraser Robert John
• Fossenier Jacqueline
• Neisani Maryam
• Harkouk Louiza Kahina
• Nazari Amir Mohammad
• Liu Fangyu

Classifications

• C01G53/10

  Sulfates · CPC title

• C22B23/06 Primary

  Refining · CPC title

• C22B23/043 Primary

  Sulfurated acids or salts thereof · CPC title

• C22B23/0461

  by chemical methods · CPC title

• C22B3/08 Primary

  Sulfuric acid {, other sulfurated acids or salts thereof} · CPC title