Method for recovering nickel from nickel matte in sulfide form

Abstract

One embodiment of the present invention discloses a method for recovering nickel from nickel matte in the form of a sulfide, comprising: an atmospheric leaching step of leaching nickel matte in the form of a sulfide at atmospheric pressure; and a pressure leaching step of leaching the atmospheric leaching residue of the nickel matte obtained in the atmospheric leaching step at a pressure higher than the atmospheric pressure, wherein the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step is in the range of 10 g / L to 40 g / L.

Description

[Technical Field]

[0001] The present invention relates to a method for recovering nickel from nickel matte, and more particularly to a method for recovering nickel from nickel matte in the form of sulfide, which can precipitate and remove iron (Fe) contained in the nickel matte. [Background technology]

[0002] To recover nickel from nickel matte, the nickel matte is leached in an acidic solution under atmospheric conditions. In the atmospheric leaching process, the reaction time must be maintained for a long period (e.g., 16 hours or more) to increase the leaching efficiency of the nickel component. This results in low production efficiency, increased gas or steam consumption, and reduced economic viability due to the cost of hydrogen peroxide (H2O2) input as an oxidizing agent. Furthermore, in the atmospheric leaching process, most of the iron (Fe) component is leached along with the nickel, necessitating an additional process to remove the iron. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to provide a method for recovering nickel from nickel matte in the form of sulfide, which can shorten the leaching time to improve production efficiency, and eliminates the need for an additional step for iron removal by removing iron through precipitation during the leaching process. [Means for solving the problem]

[0004] One embodiment of the present invention discloses a method for recovering nickel from nickel matte in the form of a sulfide, comprising: an atmospheric leaching step of leaching nickel matte in the form of a sulfide at atmospheric pressure; and a pressure leaching step of leaching the atmospheric leaching residue of the nickel matte obtained in the atmospheric leaching step at a pressure higher than the atmospheric pressure, wherein the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step is in the range of 10 g / L to 40 g / L.

[0005] In one embodiment, the post-pressure leaching liquor may be input into the atmospheric leaching process.

[0006] In one embodiment, the atmospheric leaching step is carried out at a pH range of 2.5 to 5.0, and iron components may be precipitated during the atmospheric leaching step.

[0007] In one embodiment, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step may be in the range of 10 g / L to 30 g / L.

[0008] In one embodiment, nickel matte in the form of sulfide may be further added to the pressure leaching process.

[0009] In one embodiment, oxygen gas and sulfuric acid solution may be introduced during the pressure leaching process.

[0010] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching process may be in the range of 110 g / L to 140 g / L.

[0011] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching process may be in the range of 110 g / L to 130 g / L.

[0012] In one embodiment, iron components may be precipitated in the form of hematite during the pressure leaching process.

[0013] In one embodiment, the method further includes a repulping step of stirring the pressure leaching residue of the nickel matte obtained in the pressure leaching step with water, and a purification step of purifying the atmospheric leaching solution of the nickel matte obtained in the atmospheric leaching step to recover a nickel component, and the repulping solution of the nickel matte formed in the repulping step may be input into the pressure leaching step. [Effects of the Invention]

[0014] According to the present invention, the leaching time can be shortened by the pressure leaching process in which nickel matte is leached at a pressure higher than atmospheric pressure, and production efficiency can be increased.

[0015] Furthermore, according to the present invention, acid is generated in the leaching process, thereby reducing the cost of adding an acid solution for leaching.

[0016] Furthermore, according to the present invention, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step is adjusted, thereby increasing the nickel leaching efficiency.

[0017] Furthermore, according to the present invention, the impurity iron component can be precipitated and removed simultaneously with nickel leaching, so that an additional step for removing the iron component can be omitted. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a flow diagram illustrating a method for recovering nickel from nickel matte in sulfide form according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The examples of the present invention are provided for the purpose of explaining the technical concept of the present invention, and the scope of the present invention is not limited to the examples presented below or the specific descriptions of these examples.

[0020] FIG. 1 is a flow diagram illustrating a method for recovering nickel from nickel matte in sulfide form according to one embodiment of the present invention.

[0021] Referring to FIG. 1, a method for recovering nickel from nickel matte in sulfide form may include an atmospheric leaching step (S100), a pressure leaching step (S200), a repulping step (S300), and a refining step (S400).

[0022] Nickel matte is an intermediate product produced by smelting oxide ores and sulfide ores. Nickel matte may contain at least nickel, cobalt, copper, and iron. In one embodiment, nickel matte may contain 70% or more nickel. The nickel content in nickel matte may be higher than the content of other elements. The nickel content in nickel matte may be in the form of sulfides. For example, the nickel content in nickel matte may be in the form of Ni3S2.

[0023] The nickel matte may be in a pulverized state. In one embodiment, the method for recovering nickel from nickel matte in sulfide form may include a raw material crushing step prior to the atmospheric leaching step (S100). In the raw material crushing step, the nickel matte raw material may be crushed.

[0024] Atmospheric leaching process (S100)

[0025] In the atmospheric leaching step (S100), nickel matte is leached at atmospheric pressure. Oxygen (O2) gas may be added in the atmospheric leaching step (S100). In the atmospheric leaching step (S100), nickel matte may be leached as a post-atmospheric leaching solution of nickel matte. The remainder of the nickel matte excluding the post-atmospheric leaching solution is a nickel matte atmospheric leaching residue.

[0026] The atmospheric pressure may be atmospheric pressure. For example, the atmospheric pressure may be 0.1 MPa or 1.0 bar. Nickel matte may be added in the atmospheric leaching step (S100). Alternatively, as described below, the post-pressure leaching solution of nickel matte obtained in the pressure leaching step (S200) may be added to the atmospheric leaching step (S100).

[0027] The atmospheric leaching step (S100) may be carried out at a temperature in the range of 80°C to 95°C. The atmospheric leaching step (S100) may be carried out at a temperature in the range of 85°C to 95°C. For example, the atmospheric leaching step (S100) may be carried out at 90°C. If the atmospheric leaching step (S100) is carried out at a temperature below 80°C, the leaching efficiency may decrease and the nickel recovery rate may decrease. If the atmospheric leaching step (S100) is carried out at a temperature above 95°C, water will evaporate and the amount of liquid will decrease, making it necessary to add industrial water, which may increase process costs.

[0028] The atmospheric leaching step (S100) may be carried out for 1 to 4 hours. For example, the atmospheric leaching step (S100) may be carried out for 3 hours. If the atmospheric leaching step (S100) is carried out for less than 1 hour, the precipitation efficiency of the iron component may decrease. If the atmospheric leaching step (S100) is carried out for more than 4 hours, this may lead to an increase in process costs and an increase in the unit cost of the operating process.

[0029] The atmospheric leaching step (S100) may be carried out at a pH range of 2.5 to 5.0. In the atmospheric leaching step (S100), the nickel matte is introduced into the pressure leached solution of the nickel matte and leached, thereby neutralizing the acid remaining in the pressure leached solution of the nickel matte.

[0030] In the atmospheric leaching step (S100), iron components may be precipitated. In the atmospheric leaching step (S100), iron components may be precipitated in the form of goethite (FeO(OH)). In one embodiment, the atmospheric leaching step (S100) is performed at a pH range of 2.5 to 5.0, and iron components may be precipitated. In the atmospheric leaching step (S100), nickel matte is added to the pressure leached solution of nickel matte, so that the acid remaining in the pressure leached solution can be neutralized. Therefore, iron components may be precipitated in the atmospheric leaching step (S100). If the pH in the atmospheric leaching step (S100) is greater than 5.0, precipitation of nickel and cobalt components may occur. Preferably, the atmospheric leaching step (S100) is performed at a pH range of 2.5 to 4.0.

[0031] Pressure leaching process (S200)

[0032] In the pressure leaching step (S200), the atmospheric leaching residue of nickel matte obtained in the atmospheric leaching step (S100) can be leached. Nickel matte in the form of sulfide may be further added in the pressure leaching step (S200). In the pressure leaching step (S200), the atmospheric leaching residue of nickel matte may be added together with the nickel matte. Therefore, in the pressure leaching step (S200), the atmospheric leaching residue of nickel matte and the nickel matte can be leached. In the pressure leaching step (S200), the nickel matte or the atmospheric leaching residue of nickel matte may be leached as a post-pressure leaching solution of nickel matte. The remainder of the nickel matte or the atmospheric leaching residue of nickel matte, excluding the post-pressure leaching solution, may be the pressure leaching residue of nickel matte.

[0033] The pressure leaching step (S200) may be carried out at a pressure higher than atmospheric pressure. In one embodiment, the pressure leaching step (S200) may be carried out at a pressure in the range of 0.8 MPa to 1 MPa. For example, the pressure leaching step (S200) may be carried out at a pressure of 0.9 MPa. If the pressure leaching step (S200) is carried out at a pressure less than 0.8 MPa, the oxygen gas input rate may be reduced, which may decrease the iron precipitation rate. If the pressure leaching step (S200) is carried out at a pressure greater than 1 MPa, there may be operational risks due to the increased pressure, and the process cost may increase.

[0034] The pressure leaching step (S200) may be carried out in a pressure device, which may be, for example, an autoclave facility. The pressure device may include an agitator.

[0035] The pressure leaching step (S200) may be carried out at a temperature of 150° C. or higher. If the pressure leaching step (S200) is carried out at a temperature below 150° C., the leaching rate of the nickel component decreases, which may result in a decrease in the recovery rate of the nickel component.

[0036] The pressure leaching step (S200) may be carried out for 5 to 10 hours. For example, the pressure leaching step (S200) may be carried out for 7 hours. If the pressure leaching step (S200) is carried out for less than 5 hours, the recovery rate of the nickel component may decrease. If the pressure leaching step (S200) is carried out for more than 10 hours, the process cost increases and the operation may become unsuitable.

[0037] The solid density of the nickel matte in the pressure leaching step (S200) may be 130 g / L to 180 g / L. For example, the solid density of the nickel matte may be 150 g / L. In the pressure leaching step (S200), the solid density of the nickel matte is the sum of the mass of the nickel matte atmospheric leaching residue and the mass of newly added nickel matte relative to the volume of liquid in the pressure equipment in which the pressure leaching step (S200) is performed. If the solid density of the nickel matte is less than 130 g / L, the amount of liquid increases during raw material processing, which may increase the scale of the equipment and the amount of liquid. If the solid density of the nickel matte exceeds 200 g / L, the agitator in the pressure equipment may not operate smoothly.

[0038] In the pressure leaching step (S200), oxygen (O2) gas and an acid solution may be added. In one embodiment, oxygen gas and a sulfuric acid solution may be added in the pressure leaching step (S200). Oxygen gas may be used as an oxidizing agent. Acid may be generated in the pressure leaching step (S200). The acid generated in the pressure leaching step (S200) may be used in the pressure leaching step (S200), and the post-pressure leaching solution may be added to the atmospheric leaching step (S100), thereby reducing the cost of adding acid. The reaction formulas for leaching nickel into the raw material may be represented by the following [Reaction Formula 1] to [Reaction Formula 4].

[0039] [Reaction Scheme 1] Ni3S2+H2SO4+0.5O2→NiSO4+2NiS+H2O

[0040] [Reaction Scheme 2] 4NiS+H2SO4+0.5O2→NiSO4+Ni3S4+H2O

[0041] [Reaction Scheme 3] NiS+2O2→NiSO4

[0042] [Reaction Scheme 4] Ni3S4+H2O+7.5O2→3NiSO4+H2SO4

[0043] The nickel component may be leached from the nickel matte or the atmospheric leaching residue of the nickel matte according to [Reaction Formula 1]. At this time, approximately 50% to 60% of the nickel component of the nickel matte or the atmospheric leaching residue of the nickel matte may be leached.

[0044] NiS produced by [Reaction Scheme 1] is a stable substance at atmospheric pressure. Therefore, if NiS reacts with a sulfuric acid solution at atmospheric pressure, the nickel component may not be leached. In an embodiment of the present invention, the nickel component may be leached by reacting NiS with oxygen gas and a sulfuric acid solution at high pressure according to [Reaction Scheme 2] to [Reaction Scheme 4] in the pressure leaching step (S200). In other words, since the nickel component of NiS is also leached, the leaching rate of the nickel component may be increased.

[0045] In the pressure leaching step (S200), the iron component may be precipitated in the form of hematite (Fe2O3). In detail, oxygen gas is introduced, and during pressure leaching, the iron component is precipitated as Fe 2+ The oxygen gas introduced causes the leaching of Fe 3+ The reaction can be expressed as the following [Reaction Scheme 5] and [Reaction Scheme 6].

[0046] [Reaction Scheme 5] FeS+H2SO4+0.5O2→FeSO4+H2O+S

[0047] [Reaction Scheme 6] 2Fe 2+ +2H + +1 / 2O2 → 2Fe 3+ +H2O

[0048] Then, according to the following [Reaction Scheme 7], Fe 3+ The iron component leached in the form of may precipitate in the form of hematite.

[0049] [Reaction Scheme 7] Fe2(SO4)3+4H2O→Fe2O3+3H2SO4+H2O

[0050] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching step (S200) may be 140 g / L or less. If the concentration of the sulfuric acid solution is 140 g / L or less, most of the nickel component may be leached. If the concentration of the sulfuric acid solution is higher than 140 g / L, the leaching efficiency of the nickel component may be reduced. This may be because NiS does not react under strong acid conditions (e.g., when the concentration of the sulfuric acid solution is higher than 140 g / L). Therefore, the leaching efficiency of the nickel component may be reduced. Furthermore, if the concentration of the sulfuric acid solution is higher than 140 g / L, the iron component may not precipitate and may be leached.

[0051] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching step (S200) may be 130 g / L or less. If the concentration of the sulfuric acid solution is lower than 130 g / L, most of the iron components may precipitate.

[0052] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching step (S200) may be 110 g / L or more. If the concentration of the sulfuric acid solution in the pressure leaching step (S200) is lower than 110 g / L, the leaching rate of the nickel component decreases, which may be unsuitable.

[0053] In one embodiment, the concentration of the sulfuric acid solution added in the pressure leaching step (S200) may be in the range of 110 g / L to 140 g / L. Preferably, the concentration of the sulfuric acid solution added in the pressure leaching step (S200) may be in the range of 110 g / L to 130 g / L.

[0054] The acid concentration of the post-pressure leaching solution can be adjusted by adjusting the concentration of the acid solution (e.g., the concentration of the sulfuric acid solution) added. In one embodiment, the acid concentration of the post-pressure leaching solution of the nickel matte obtained in the pressure leaching step (S200) may be 40 g / L or less. The acid concentration of the post-pressure leaching solution may be the concentration of sulfuric acid contained in the post-pressure leaching solution. When the acid concentration of the post-pressure leaching solution is 40 g / L or less, most of the nickel elements can be leached. For example, 99% or more of the nickel elements can be leached in nickel matte. When the acid concentration of the post-pressure leaching solution is higher than 40 g / L, the leaching rate of the nickel elements may be reduced.

[0055] In one embodiment, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step (S200) may be 30 g / L or less. When the acid concentration of the pressure leached solution is 30 g / L or less, the precipitation rate of iron components can be significantly improved. For example, the iron components in the nickel matte can be precipitated at 85% or more.

[0056] In one embodiment, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step (S200) may be 10 g / L or more. If the acid concentration of the pressure leached solution is lower than 10 g / L, the nickel leaching efficiency may decrease.

[0057] In one embodiment, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step (S200) may be in the range of 10 g / L to 40 g / L. Preferably, the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step (S200) may be in the range of 10 g / L to 30 g / L.

[0058] The pressure leached solution of nickel matte may be input into the atmospheric leaching step (S100). By inputting nickel matte into the pressure leached solution of nickel matte in the atmospheric leaching step (S100) and leaching it, the acid remaining in the pressure leached solution of nickel matte can be neutralized.

[0059] Repulping process (S300)

[0060] In the repulping step (S300), the pressure leaching residue of nickel matte obtained in the pressure leaching step (S200) may be stirred with water. The repulping step (S300) may be a step for recovering water-soluble nickel components remaining in the pressure leaching residue. If the repulping step (S300) is not performed, recovery losses of nickel components may occur.

[0061] The repulping step (S300) may be performed at 60°C. In one embodiment, the water input into the repulping step (S300) may be at 60°C.

[0062] The repulping step (S300) may be performed for 1 to 2 hours. For example, the repulping step (S300) may be performed for 1 hour. If the repulping step (S300) is performed for less than 1 hour, it may be difficult to dissolve all of the nickel component. If the repulping step (S300) is performed for more than 2 hours, the process cost may increase.

[0063] In the repulping step (S300), the solid to liquid ratio may be in the range of 130 g / L to 180 g / L. For example, in the repulping step (S300), the solid to liquid ratio may be 150 g / L. If the solid to liquid ratio in the repulping step (S300) is higher than 200 g / L, the liquid may not be stirred smoothly in the repulping step (S300).

[0064] In the repulping step (S300), a post-repulping liquor of nickel matte may be formed. The post-repulping liquor of nickel matte may contain nickel components. The post-repulping liquor of nickel matte may be input into the pressure leaching step (S200). Therefore, in order to recover the nickel components from the nickel matte, the atmospheric leaching step (S100), the pressure leaching step (S200), and the repulping step (S300) may be performed in a cycle, allowing the recovery of the nickel components to be continued.

[0065] The pressure leaching residue of the nickel matte after the repulping step (S300) excluding the post-repulping liquor of the nickel matte may be the final residue of the nickel matte. In one embodiment, the final residue of the nickel matte may include hematite.

[0066] Purification process (S400)

[0067] The nickel matte atmospheric leaching solution may be purified in the purification step (S400). In the purification step (S400), the nickel matte atmospheric leaching solution may be purified to recover the nickel component.

[0068] The method for recovering nickel from sulfide-form nickel matte according to an embodiment of the present invention includes a pressure leaching step (S200) for pressure leaching the nickel matte, which can shorten the process time. This can increase production efficiency. Furthermore, acid is generated in the pressure leaching step (S200), which can reduce the cost of acid input. Furthermore, by adjusting the concentration of the acid solution to a post-pressure leaching solution acid concentration of 40 g / L or less, nickel leaching efficiency can be increased and iron impurities can be precipitated simultaneously with the leaching of nickel components. In particular, by adjusting the concentration of the acid solution to a post-pressure leaching solution acid concentration of 30 g / L or less, 85% or more of the iron impurities can be precipitated. Therefore, an additional step for removing the iron impurities can be omitted.

[0069] Example

[0070] The raw material used was nickel matte containing 73.4% nickel (Ni), 0.49% cobalt (Co), 0.18% copper (Cu), and 3.61% iron (Fe). The content ratios are in mass %. The composition of the nickel matte raw material is shown in Table 1 below.

[0071] [Table 1]

[0072] The leaching step was carried out using the method for recovering nickel from sulfide-form nickel matte according to the embodiment of the present invention described above. The solid density of the input raw material was set to 150 g / L. The atmospheric leaching step (S100) was carried out at a temperature of 90°C and a pH of 3.5 for 3 hours. The pressure leaching step (S200) was carried out at a temperature of 150°C and a pressure of 0.9 MPa for 7 hours. The repulping step (S300) was carried out at a temperature of 60°C for 1 hour. The solid to liquid ratio in the repulping step (S300) was 150 g / L.

[0073] Examples 1 to 4

[0074] In Examples 1 to 4, the concentration of the sulfuric acid solution in the post-pressure leaching solution was adjusted, and the final leaching yield of nickel components and the precipitation yield of iron components were compared using methods for recovering nickel from sulfide-form nickel matte according to examples of the present invention. In Example 1, the initial sulfuric acid solution concentration was adjusted to 110 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 10 g / L. In Example 2, the initial sulfuric acid solution concentration was adjusted to 120 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 20 g / L. In Example 3, the initial sulfuric acid solution concentration was adjusted to 130 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 30 g / L. In Example 4, the initial sulfuric acid solution concentration was adjusted to 140 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 40 g / L.

[0075] Comparative Examples 1 to 3

[0076] In Comparative Examples 1 to 3, the sulfuric acid concentration in the post-pressure leaching solution was adjusted, and the final leaching rate of nickel components and the precipitation rate of iron components were compared. In Comparative Example 1, the initial sulfuric acid solution concentration was set to 180 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 80 g / L. In Comparative Example 2, the initial sulfuric acid solution concentration was set to 190 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 90 g / L. In Comparative Example 3, the initial sulfuric acid solution concentration was set to 200 g / L, and the sulfuric acid concentration in the post-pressure leaching solution was adjusted to 100 g / L. The other experimental conditions were the same as those in the Examples.

[0077] [Table 2]

[0078] According to Table 2, when the concentration of the initial sulfuric acid solution was adjusted so that the sulfuric acid concentration in the post-pressure leaching solution was 10 g / L to 40 g / L, the nickel leaching rate was 99% or more. Furthermore, when the concentration of the initial sulfuric acid solution was adjusted so that the sulfuric acid concentration in the post-pressure leaching solution was 10 g / L to 30 g / L, approximately 85% or more of the iron components precipitated. In contrast, when the initial sulfuric acid concentration was increased so that the sulfuric acid concentration in the post-pressure leaching solution was 80 g / L or more, the leaching rate of the nickel components decreased to approximately 60%, and most of the iron components did not precipitate.

[0079] Although the technical concept of the present invention has been described above by way of some embodiments and examples shown in the accompanying drawings, it will be understood that various substitutions, modifications and changes can be made within the scope of the technical concept and scope of the present invention that are understandable to those skilled in the art to which the present invention pertains. Furthermore, such substitutions, modifications and changes should be considered to fall within the scope of the appended claims.

Claims

1. an atmospheric leaching step of atmospherically leaching the nickel matte in sulfide form; a pressure leaching step of leaching the nickel matte atmospheric leaching residue obtained in the atmospheric leaching step at a pressure higher than atmospheric pressure, The method for recovering nickel from nickel matte in the form of sulfide, wherein the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step is in the range of 10 g / L to 40 g / L.

2. 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein the post-pressure leaching liquor is input into the atmospheric leaching step.

3. The atmospheric leaching step is carried out at a pH range of 2.5 to 5.0, 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein iron components are precipitated in the atmospheric leaching step.

4. 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein the acid concentration of the pressure leached solution of the nickel matte obtained in the pressure leaching step is in the range of 10 g / L to 30 g / L.

5. 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein nickel matte in sulfide form is further input in the pressure leaching step.

6. 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein oxygen gas and a sulfuric acid solution are introduced in the pressure leaching step.

7. 7. The method for recovering nickel from nickel matte in sulfide form according to claim 6, wherein the concentration of the sulfuric acid solution added in the pressure leaching step is in the range of 110 g / L to 140 g / L.

8. 8. The method for recovering nickel from nickel matte in sulfide form according to claim 7, wherein the concentration of the sulfuric acid solution added in the pressure leaching step is in the range of 110 g / L to 130 g / L.

9. 2. The method for recovering nickel from nickel matte in the form of sulfides according to claim 1, wherein iron components are precipitated in the form of hematite in the pressure leaching step.

10. a repulping step of stirring the nickel matte pressure leaching residue obtained in the pressure leaching step with water; and a purification step of purifying the atmospheric leaching solution of the nickel matte obtained in the atmospheric leaching step to recover a nickel component, 2. The method for recovering nickel from nickel matte in sulfide form according to claim 1, wherein a post-repulping solution of the nickel matte formed in the repulping step is input into the pressure leaching step.

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