All-in-one nickel recovering method for nickel hydroxide recovery from raw materials containing nickel
Provided herein is a nickel recovering method, comprising: (A-i) a reduction heat treatment process for thermally treating a first raw material containing nickel and lithium; (B) a first leaching process for leaching the heat-treated product produced by the reduction heat treatment process; (A-ii) a roasting process for thermally treating a second raw material containing nickel and sulfur; (C) a second leaching process for leaching the first leaching residue produced by the first leaching process and calcine produced by the roasting process; (D) a neutralization process for neutralizing the second leachate produced by the second leaching process; (E) a purification process for removing impurities contained in the neutralized solution produced by the neutralization process; and (F) a precipitation process of performing a precipitation method to recover nickel from the purified solution produced by the purification process, and a nickel hydroxide is recovered by the precipitation process.
1. A nickel recovering method, comprising:
(A-i) a reduction heat treatment process for thermally treating a first raw material containing nickel and lithium;
(B) a first leaching process for leaching a heat-treated product produced by the reduction heat treatment process;
(A-ii) a roasting process for thermally treating a second raw material containing nickel and sulfur;
(C) a second leaching process for leaching a first leaching residue produced by the first leaching process and a calcine produced by the roasting process;
(D) a neutralization process for neutralizing a second leached solution produced by the second leaching process;
(E) a purification process for removing impurities contained in a neutralized solution produced by the neutralization process; and
(F) a precipitation process of performing a precipitation method to recover nickel from a purified solution produced by the purification process, and a nickel hydroxide is recovered by the precipitation process.
2. The nickel recovering method of claim 1 , wherein the first raw material and the second raw material each independently comprises 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.
3. The nickel recovering method of claim 1 , wherein the first raw material comprises nickel in a form of nickel oxide or nickel metal composite oxide.
4. The nickel recovering method of claim 1 , wherein the second raw material comprises nickel in a form of nickel sulfide.
5. The nickel recovering method of claim 1 , wherein the reduction heat treatment process is carried out at 650 to 950° C. in a manner of introducing the first raw material into a thermal treatment equipment and injecting nitrogen gas.
6. The nickel recovering method of claim 1 , wherein the first leaching process is carried out using a first leaching agent including an inorganic acid, water, or a mixture thereof.
7. The nickel recovering method of claim 1 , wherein a first leachate obtained by the first leaching process contains lithium and the first leaching residue contains nickel.
8. The nickel recovering method of claim 1 , wherein the roasting process is carried out at 650 to 950° C. in a manner of introducing the second raw material into a thermal treatment equipment and injecting oxygen gas.
9. The nickel recovering method of claim 1 , wherein, in the second leaching process, the first leaching residue and the calcine are leached in an atmospheric reactor and a high-temperature, high-pressure reactor, respectively.
10. The nickel recovering method of claim 1 , wherein the second leaching process is carried out using a second leaching agent including an inorganic acid, water, or a mixture thereof.
11. The nickel recovering method of claim 1 , wherein the second leaching process is carried out at a temperature of 150 to 250° C. under a pressure of 800 to 4300 kPa.
12. The nickel recovering method of claim 1 , wherein the second leaching process is carried out in a liquid environment with an acidity of 100 to 200 g/L.
13. The nickel recovering method of claim 1 , wherein the neutralizing process is carried out using a neutralizing agent including MHP, MCP, nickel hydroxide (Ni(OH) 2 ), nickel carbonate (NiCO 3 ), sodium hydroxide (NaOH), sodium carbonate (Na 2 CO 3 ), calcium hydroxide (Ca(OH) 2 ), magnesium hydroxide (Mg(OH) 2 ), calcium oxide (CaO), magnesium oxide (MgO), or a mixture thereof.
14. The nickel recovering method of claim 1 , wherein the neutralizing process is carried out at 80° C. under conditions of a pH of 2 to 4.5.
15. The nickel recovering method of claim 1 , wherein the purification process comprises:
(E-i) a first purification process for removing impurities contained in the neutralized solution produced by the neutralization process;
(E-ii) a second purification process for removing impurities contained in a first purified solution produced by the first purification process; and
(E-iii) a third purification process for removing impurities contained in a second purified solution produced by the second purification process.
16. The nickel recovering method of claim 15 , wherein the first purification process removes impurities including copper, iron, aluminum, silicon, zinc, cobalt, magnesium, or a combination thereof, using a precipitation method.
17. The nickel recovering method of claim 15 , wherein the first purification process is carried out using (i) a sulfide precipitation process of adding a sulfide precipitating agent to the neutralized solution at a content of 1.0 to 2.5 equivalents of a copper content in the neutralized solution, (ii) a hydroxide precipitation process of adding a hydroxide precipitating agent to the neutralized solution at a content of 0.8 to 1.5 equivalents of an impurity content in the neutralized solution, or a combination of (i) and (ii).
18. The nickel recovering method of claim 15 , wherein the second purification process removes impurities including zinc, magnesium, manganese, or a combination thereof, using a solvent extraction method.
19. The nickel recovering method of claim 15 , wherein the second purification process is carried out using (i) a loading process of adding a first solvent extractant to the first purified solution to extract impurities including zinc, magnesium, manganese, or a combination thereof into an organic phase, and (ii) a stripping process of adding an inorganic acid to the organic phase to extract impurities including zinc, magnesium, manganese, or a combination thereof, contained in the organic phase, into an aqueous phase.
20. The nickel recovering method of claim 15 , wherein the third purification process removes impurities including cobalt, using a solvent extraction method.
21. The nickel recovering method of claim 15 , wherein the third purification process comprises (i) a loading process of adding a second solvent extractant to the second purified solution to extract impurities including cobalt into an organic phase, and (ii) a stripping process of adding an inorganic acid to the organic phase to extract impurities including cobalt, contained in the organic phase, into an aqueous phase.
22. The nickel recovering method of claim 1 , wherein the precipitation process is carried out by a precipitant including sodium hydroxide (NaOH), calcium hydroxide (Ca(OH) 2 , magnesium hydroxide (Mg(OH) 2 ), calcium oxide (CaO), magnesium oxide (MgO), or a mixture thereof.
23. The nickel recovering method of claim 1 , wherein the precipitation process is carried out at 85° C. in a condition of a pH of 6.5 to 10.0.