BR-112025008516-B1 - All-in-one nickel recovery method for recovering nickel from nickel-containing raw materials.

Abstract

ALL-IN-ONE NICKEL RECOVERY METHOD FOR RECOVERING NICKEL FROM NICKEL-CONTAINING RAW MATERIALS. A nickel recovery method is provided herein, comprising: (A-i) a reduction heat treatment process for thermally treating a first feed material containing nickel and lithium; (B) a first leaching process for leaching the thermally treated product produced by the reduction heat treatment process; (A-ii) a roasting process for thermally treating a second feed material containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcination produced by the roasting process; (D) a neutralization process for neutralizing the second leachate produced by the second leaching process; and (E) a purification process for removing impurities contained in the neutralized solution produced by the neutralization process.

Inventors

• HEON SIK CHOI
• JE JOONG LEE

Assignees

• KOREA ZINC CO., LTD.
• KEMCO

Dates

Publication Date

20260317

Application Date

20240418

Priority Date

20230825

Claims (20)

1. 1. Nickel recovery method characterized by comprising: (A-i) a reduction heat treatment process for thermally treating a first feedstock containing nickel and lithium; (B) a first leaching process for leaching the thermally treated product produced by the reduction heat treatment process; (A-ii) a roasting process for thermally treating a second feedstock containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcined by the roasting process; (D) a neutralization process for neutralizing the second leachate produced by the second leaching process; (E) a purification process to remove impurities contained in the neutralized solution produced by the neutralization process; wherein the first raw material and the second raw material each independently comprise at least one selected from the group of an oxide, a hydroxide, a sulfide and a sulfur oxide, wherein the oxide, hydroxide, sulfide and sulfur oxide each independently contain ore, matte, black powder (BP), black powder (BP), mixed hydroxide precipitate (MHP), mixed carbonate precipitate (MCP), mixed sulfide precipitate (MSP) or a mixture thereof, wherein the first raw material comprises nickel in the form of nickel oxide or metallic nickel compound oxide, wherein the second raw material comprises nickel in the form of nickel sulfide, wherein the reduction heat treatment process is carried out from 650 to 950°C, wherein the roasting process is carried out from 650 to 950°C where the second leaching process is carried out at a temperature of 150 to 250°C under a pressure of 800 to 4300 kPa.
2. 2. Nickel recovery method according to claim 1, characterized in that the reduction heat treatment process is carried out by introducing the first raw material into a heat treatment equipment and injecting nitrogen gas.
3. 3. Nickel recovery method according to claim 1, characterized in that the first leaching process is carried out using a first leaching agent including an inorganic acid, water or a mixture thereof.
4. 4. Nickel recovery method according to claim 1, characterized in that the first leachate obtained from the first leaching process contains lithium and the first leaching residue contains nickel.
5. 5. Nickel recovery method according to claim 1, characterized in that the roasting process is carried out in such a way as to introduce the second raw material into a heat treatment equipment and inject oxygen gas.
6. 6. Nickel recovery method according to claim 1, characterized in that, in the second leaching process, the first leaching residue and calcine are leached in an atmospheric reactor and in a high-temperature, high-pressure reactor, respectively.
7. 7. Nickel recovery method according to claim 1, characterized in that the second leaching process is carried out using a second leaching agent including an inorganic acid or a mixture of an inorganic acid and water.
8. 8. Nickel recovery method according to claim 1, characterized in that the second leaching process is carried out in an environment with an acidity of 100 to 200 g/L.
9. 9. Nickel recovery method according to claim 1, characterized in that the neutralization process is carried out using a neutralizing agent including MHP, MCP, nickel hydroxide (Ni(OH)2), nickel carbonate (NiCO3), sodium hydroxide (NaOH), sodium carbonate (Na2CO3), calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2), calcium oxide (CaO), magnesium oxide (MgO) or a mixture thereof.
10. 10. Nickel recovery method according to claim 1, characterized in that the neutralization process is carried out at 80°C under pH conditions of 2 to 4.5.
11. 11. Nickel recovery method according to claim 1, characterized by the purification process comprising: (E-i) a first purification process to remove impurities contained in the neutralized solution produced by the neutralization process; (E-ii) a second purification process to remove impurities contained in a first purified solution produced by the first purification process; and (E-iii) a third purification process to remove impurities contained in a second purified solution produced by the second purification process.
12. 12. Nickel recovery method according to claim 11, characterized in that the first purification process removes impurities including copper, iron, aluminum, silicon, zinc, cobalt, magnesium or a combination thereof, using a precipitation method.
13. 13. Nickel recovery method according to claim 11, characterized in that the first purification process is carried out using (i) a sulfide precipitation process by adding a sulfide precipitating agent to the neutralized solution at a level of 1.0 to 2.5 equivalents of a copper content in the neutralized solution, (ii) a hydroxide precipitation process by adding a hydroxide precipitating agent to the neutralized solution at a level of 0.8 to 1.5 equivalents of an impurity content in the neutralized solution, or a combination of (i) and (ii).
14. 14. Nickel recovery method according to claim 11, characterized in that the second purification process removes impurities including zinc, magnesium, manganese or a combination thereof, using a solvent extraction method.
15. 15. Nickel recovery method according to claim 11, characterized in that the second purification process is carried out using (i) a loading process by adding a first extraction solvent to the first purified solution to extract impurities including zinc, magnesium, manganese or a combination thereof in an organic phase, and (ii) a desorption process by adding an inorganic acid to the organic phase to extract impurities including zinc, magnesium, manganese or a combination thereof, contained in the organic phase, in an aqueous phase.
16. 16. Nickel recovery method according to claim 11, characterized by the third purification process removing impurities including cobalt, using a solvent extraction method.
17. 17. Nickel recovery method according to claim 11, characterized by the third purification process comprising (i) a loading process by adding a second extraction solvent to the second purified solution to extract impurities including cobalt in an organic phase, and (ii) a desorption process by adding an inorganic acid to the organic phase to extract impurities including cobalt, contained in the organic phase, in an aqueous phase.
18. 18. Method for manufacturing an aqueous nickel solution characterized by comprising: (F) a precipitation process carrying out a precipitation method for recovering nickel from a neutralized solution; and (G) a third leaching process of leaching the precipitate produced by the precipitation process, wherein the neutralized solution is produced by the nickel recovery method as defined in any one of claims 1 to 17.
19. 19. Method according to claim 18, characterized in that the precipitation process is carried out using a precipitating agent including sodium hydroxide (NaOH), sodium carbonate (Na2CO3), calcium hydroxide (Ca(OH)2), magnesium hydroxide (Mg(OH)2), calcium oxide (CaO), magnesium oxide (MgO) or a mixture thereof.
20. 20. Method according to claim 18, characterized in that the precipitation process is carried out at 85°C under pH conditions of 6.5 to 10.0.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for recovering nickel and a method for producing a nickel solution using the same. More specifically, the present invention relates to a method for refining nickel from feedstocks to recover high-purity nickel in various forms suitable for various uses and applications. FOUNDATION [0002] Nickel can be recovered from various raw materials, such as metallic nickel, matte nickel, nickel concentrate, and nickel-containing process by-products. It is known that among various forms of recovered nickel, nickel sulfate is preferably contained in an amount of 99% or more, with impurities reaching a few hundred ppm or less, for common cases. [0003] Conventionally, this nickel sulfate was produced by preparing a high-purity nickel sulfate solution by atmospheric pressure leaching with inorganic acids, neutralization with sodium hydroxide or sodium carbonate and removal of impurities, and then crystallization of the solution into nickel sulfate hexahydrate. [0004] However, such conventional methods are disadvantageous because there is a limited number of raw materials soluble in specific inorganic acids. In conventional methods, substances used as neutralizing agents (e.g., Na) are removed by washing with water after sludge filtration. This form of Na removal increases the volume of wastewater and requires significant processing time, resulting in reduced productivity and increased wastewater treatment costs. SUMMARY [0005] One embodiment of the present invention is to provide an all-in-one process for recovering highly pure nickel from complex nickel-containing feedstocks, which is a hybrid process combining pyrometallurgical and hydrometallurgical technologies, wherein even when various nickel-containing feedstocks are applied, appropriate responses can be made, followed by appropriate subsequent processes to acquire nickel in various forms as desired. [0006] Another embodiment of the present invention is to provide an environmentally friendly process that allows for the recycling of process by-products. [0007] Furthermore, the present invention aims to provide an economical and environmentally friendly nickel recovery process that allows for the selective isolation of lithium, the conversion of composite compounds into single compounds, and the recovery of inorganic acids from harmful gas through a pyrometallurgical type pretreatment and which is combined with a hydrometallurgical recycling process minimizing the influx of Na impurities, thus allowing application to complex raw materials, even in a single process. [0008] Several embodiments of the present invention relate to a nickel recovery method comprising: (A-i) a reduction heat treatment process for thermally treating a first feedstock containing nickel and lithium; (B) a first leaching process for leaching the thermally treated product produced by the reduction heat treatment process; (A-ii) a roasting process for thermally treating a second feedstock containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcined by the roasting process; (D) a neutralization process for neutralizing the second leachate (leached solution) produced by the second leaching process; and (E) a purification process for removing impurities contained in the neutralized solution produced by the neutralization process. [0009] In the nickel recovery method according to an embodiment of the present invention, the first and second raw materials may each independently include at least one selected from the group of an oxide, a hydroxide, a sulfide and a sulfur oxide, the oxide, hydroxide, sulfide and sulfur oxide, each independently containing ore, matte, black mass (BM), black powder (BP), mixed hydroxide precipitate (MHP), mixed carbonate precipitate (MCP), mixed sulfide precipitate (MSP) or a mixture thereof. [00010] In the nickel recovery method according to one embodiment of the present invention, the first feedstock may comprise nickel in the form of nickel oxide or nickel metallic oxide compound. [00011] In the nickel recovery method according to one embodiment of the present invention, the second feedstock may comprise nickel in the form of nickel sulfide. [00012] In the nickel recovery method according to one embodiment of the present invention, the reduction heat treatment process can be carried out at 650 to 950°C by introducing the first raw material into a heat treatment equipment and injecting nitrogen gas. [00013] In the nickel recovery method according to one embodiment of the present invention, the first leaching process can be carried out using a first leaching agent including an inorganic acid, water or a mixture thereof. [00014] In the nickel recovery method according to one embodiment of the present invention, the first leachate obtained by the first leaching process may contain lithium and the first leaching residue ma