Method for recovering valuable metals

Abstract

Provided, according to the present invention, is a method for recovering valuable metals, the method comprising the steps of: producing an alloy by reducing a waste lithium secondary battery powder comprising carbon and valuable metals; and producing nickel matte by inputting a thickener, a slag-forming agent, and oxygen (O2) into the alloy, wherein the waste lithium secondary battery powder comprises more than 0 wt% to 40 wt% or less of the carbon with respect to the total weight of the waste lithium secondary battery powder. According to the present invention, the recovery rate of valuable metals may be improved through a process of treating a large amount of waste resources through a dry process of collecting valuable metals in the form of a molten material dissolved in iron.

Description

Method for recovering valuable metals

[0001] The present invention relates to a method for recovering valuable metals.

[0002] Processes for recovering valuable metals from waste resources include dry and wet processes. Among these, the wet process has a relatively narrow range of applicable waste resource components, limiting flexibility in the selection of applicable raw materials.

[0003] Additionally, to reduce the load of the subsequent refining process, processes that concentrate the target valuable metal or remove impurities (e.g., de-ironization) are typically performed upstream. However, these processes are somewhat cumbersome, and for low-grade waste resources, the concentration process can be excessively expensive.

[0004] Accordingly, there is a need for a method that can recover valuable metals with a high recovery rate through large-scale facilities that can process large quantities of waste resources while utilizing waste resources economically.

[0005] One aspect of the present invention is to provide a method for improving the recovery rate of valuable metals from waste lithium secondary batteries.

[0006] A method for recovering valuable metals according to one aspect of the present invention comprises the steps of reducing waste lithium secondary battery powder containing carbon and valuable metals to produce an alloy; and adding a concentrate, a slag forming agent, and oxygen (O2) to the alloy to produce a nickel matte, wherein the waste lithium secondary battery powder contains carbon in an amount of more than 0 wt% and less than or equal to 40 wt% based on the total weight of the waste lithium secondary battery powder.

[0007] The above-mentioned waste lithium secondary battery powder may include a first powder and a second powder containing more carbon than the first powder.

[0008] The above first powder may contain less than 5 wt% of carbon based on the total weight of the waste lithium secondary battery powder.

[0009] The second powder may contain 5 to 40 wt% of carbon based on the total weight of the waste lithium secondary battery powder.

[0010] The above-mentioned waste lithium secondary battery powder may include a first powder of 50 wt% or more and less than 100 wt% and a second powder of more than 0 wt% and less than 50 wt%.

[0011] The above valuable metal may include at least one selected from the group consisting of nickel, cobalt, manganese, and lithium.

[0012] The step of manufacturing the above alloy may include a step of adding waste lithium secondary battery powder and a slag forming agent to a molten alloy; and a step of manufacturing the alloy by reducing the waste lithium secondary battery powder at a temperature of 1550°C to 1700°C.

[0013] After the step of manufacturing the nickel matte, a step of recovering the valuable metal from the nickel matte may be included.

[0014] The above concentrate may be sulfur (S).

[0015] The above slag forming agent may include silicon dioxide (SiO2).

[0016] The above-mentioned waste lithium secondary battery powder may contain 10 to 40 wt% of nickel based on the total weight of the waste lithium secondary battery powder.

[0017] More than 90% of the valuable metals contained in the above-mentioned waste lithium secondary battery powder can be recovered.

[0018] According to the present invention, waste resources can be processed in large quantities through a dry process in which valuable metals are captured in the form of a molten substance dissolved in iron.

[0019] According to the method for recovering valuable metals of the present invention, the recovery rate of valuable metals from waste lithium secondary batteries can be improved.

[0020] Figure 1 is a graph showing the equilibrium state of the reaction phase of the alloy molten metal according to the powder input ratio.

[0021] Figure 2 is a graph showing the alloy composition according to the powder input ratio.

[0022] Figure 3 is a graph showing the alloy composition according to the concentration process.

[0023] Figure 4 is a graph showing the concentration recovery rate over time.

[0024] Figure 5 is a graph showing the concentration recovery rate according to the iron removal rate.

[0025] Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention may be modified into various other forms, and the terminology used herein is for the purpose of describing the present invention and is not intended to limit the present invention.

[0026] Unless otherwise defined, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which this invention pertains. Terms defined in the dictionary are to be interpreted to have meanings consistent with the relevant technical literature and the present disclosure.

[0027] The method for recovering valuable metals of the present invention comprises the steps of reducing waste lithium secondary battery powder containing carbon and valuable metals to produce an alloy; and adding a concentrate, a slag forming agent, and oxygen (O2) to the alloy to produce a nickel matte, wherein the waste lithium secondary battery powder contains carbon in an amount of more than 0 wt% and less than 40 wt% based on the total weight of the waste lithium secondary battery powder.

[0028] The above valuable metal may include at least one selected from the group consisting of nickel, cobalt, manganese, and lithium. More specifically, it may include nickel and cobalt.

[0029] A waste lithium secondary battery includes a positive electrode and a negative electrode, and the positive electrode contains a large amount of valuable metals to be recovered in the present invention. Typically, when recovering valuable metals from a lithium secondary battery, the active material is separated from the electrode current collector, and the valuable metals are recovered therefrom. Since a secondary battery is formed by alternately stacking positive and negative electrodes, for the convenience of the process, a process of simultaneously separating the electrode active material and the electrode current collector is performed without separately separating the positive and negative electrodes.

[0030] The powder obtained from the above-mentioned waste lithium secondary battery contains carbon and precious metals. The carbon contained in the powder is derived from the negative electrode material (graphite), and the precious metals contained in the powder are derived from the positive electrode material. The positive electrode material contains nickel, cobalt, manganese, etc., and the present invention aims to recover the precious metals contained in the waste lithium secondary battery powder.

[0031] The method for recovering valuable metals of the present invention can recover valuable metals by introducing waste lithium secondary battery powder containing valuable metals into a molten alloy, melting it, and reducing it.

[0032] The above-mentioned molten alloy can be manufactured by melting pig iron (Fe) in an induction furnace. The pig iron can act as a reducing agent to reduce the valuable metal contained in the powder.

[0033] Specifically, the molten alloy may include at least one selected from the group consisting of molten pig iron (molten iron) generated in the ironmaking process, molten iron obtained by melting scrap iron, molten iron obtained by melting iron contained in waste resources themselves during a dry process, and molten ferronickel, which is an intermediate or finished product of the ferronickel process. By utilizing the materials described above as the molten alloy, the cost of the valuable metal recovery process can be reduced and economic feasibility can be improved.

[0034] For example, pig iron (Fe) can be used as a master alloy molten metal. The pig iron can be melted to produce a master alloy molten metal. The master alloy molten metal is used to capture valuable metals contained in waste resources. The pig iron reacts with oxygen contained in the waste lithium secondary battery powder to form iron oxide and reduce the waste lithium secondary battery powder. The temperature of the master alloy molten metal can be 1550°C to 1700°C. The waste lithium secondary battery powder and a slag forming agent can be added to the master alloy molten metal to produce an alloy molten metal.

[0035] The powder of the waste lithium secondary battery, which is the waste resource, is injected into the molten metal, and the precious metal oxide is reduced by the molten iron and converted into a metallic phase, and the metal can melt and form an alloy in the molten metal. Specifically, the oxides of nickel, cobalt, manganese, and lithium contained in the positive electrode material can be reduced by iron and converted into nickel, cobalt, manganese, and lithium metals. Meanwhile, the carbon constituting the negative electrode material can act together with the oxidized iron as a reducing agent for the precious metal oxide. Therefore, the carbon can react with oxygen to produce CO2, which can be removed from the molten metal as a gas.

[0036] The powder containing a valuable metal to be injected into the molten metal is not particularly limited, and may be a powder containing 10 to 40 wt% of nickel based on the total weight of the waste lithium secondary battery powder.

[0037] Meanwhile, the waste lithium secondary battery powder may contain carbon in an amount of more than 0 wt% and less than 40 wt% based on the total weight of the waste lithium secondary battery powder. If the carbon content in the powder is 0 wt%, a lot of processing may be required in the pretreatment process for obtaining the powder, which may increase the process cost, and if it exceeds 40 wt%, there is a problem in that the powder does not melt.

[0038] More specifically, as the powder of the waste lithium secondary battery, two types of powders having different carbon contents may be used, such as a first powder and a second powder containing more carbon than the first powder. For example, the first powder may be a low carbon content waste resource (Low Carbon Black Powder, LC BP) that contains less than 5 wt% of carbon, and the second powder may be a high carbon content waste resource (High Carbon Black Powder, HC BP) that contains 5 to 40 wt% of carbon.

[0039] In addition, it was confirmed that when the carbon content contained in the powder is within the above range, the slag content can be lowered compared to when using waste resources with low carbon content by considering the thermodynamic characteristics of the reaction phase and alloy composition in the induction furnace.

[0040] By adjusting the input ratio of the first powder and the second powder having different carbon contents and containing precious metals, a powder having the above-described carbon content can be provided.

[0041] The above-mentioned waste lithium secondary battery powder may include a first powder of 50 wt% or more and less than 100 wt% and a second powder of more than 0 wt% and less than 50 wt%. When the waste lithium secondary battery powder includes 0 wt% or more of the second powder, the content of slag can be lowered and the content of alloy can be increased. When the waste lithium secondary battery powder includes more than 50 wt% of the second powder, there is a problem that carbon does not dissolve. Therefore, when the waste lithium secondary battery powder includes more than 0 wt% and less than 50 wt% of the second powder, carbon can be dissolved while simultaneously lowering the content of slag and increasing the content of alloy.

[0042] By adjusting the input ratio of the first and second powders, the reaction equilibrium state of the alloy molten metal according to the input ratio of the second powder within the entire powder is shown in Fig. 1. In addition, the alloy composition according to the powder input ratio is shown in Fig. 2.

[0043] In Fig. 1, the powder input ratio (%) can be calculated using the following equation 1.

[0044] [Formula 1]

[0045] Powder input ratio (%) = Input amount of second powder (kg) / {Input amount of first powder (kg) + Input amount of second powder (kg)} X 100%

[0046] As can be seen from Fig. 1, the slag content is significantly reduced by mixing the second powder with a high carbon content into the first powder with a low carbon content.

[0047] The above-mentioned waste lithium secondary battery powder can be added to the molten metal in a crushed or uncrushed state.

[0048] The method for recovering valuable metals of the present invention comprises a step of reducing waste lithium secondary battery powder containing carbon and valuable metals to produce an alloy. As described above, the reduction is performed by using pig iron constituting the molten metal and, in addition, carbon contained within the powder, acting as a reducing agent to convert metal oxides within the powder into metal, thereby forming an alloy.

[0049] The above alloy is in a molten state and is liquid. The alloy may include iron, which serves as a reducing agent and remains, and reduced nickel, cobalt, manganese, etc., as components constituting the molten metal. Furthermore, it may also include metals such as silicon included in the negative electrode material and copper and aluminum, which are components of the electrode current collector.

[0050] Meanwhile, gases such as carbon monoxide (CO) and carbon dioxide (CO2) may be emitted as gases generated during the above reduction process.

[0051] In addition, oxides such as iron produced by oxidation of precious metals can float on the molten material as slag, and thus the molten alloy can be recovered and the slag can be removed by solid-liquid separation.

[0052] When manufacturing an alloy by melting and adding waste lithium secondary battery powder to the above-mentioned mother alloy molten metal, a slag forming agent may be added. The slag forming agent may contribute to the easier reduction of valuable metal oxides in the waste lithium secondary battery powder.

[0053] The above slag forming agent is not limited thereto and may include, for example, silicon dioxide (SiO2), calcium oxide (CaO), aluminum oxide (Al2O3), magnesium oxide (MgO), calcium carbonate (CaCO3), calcium fluoride (CaF2) or sodium oxide (Na2O).

[0054] The above slag forming agent is not limited thereto, but may be included in an amount of, for example, more than 0 wt% and less than 20 wt% based on the content of the waste lithium secondary battery powder.

[0055] In the manufactured alloy melt, some oxides float to the top of the melt in the form of slag and separate. The slag can be separated to obtain the alloy. By removing the slag from the molten alloy solution, the molten alloy containing nickel and cobalt as valuable metals, and additionally iron, manganese, etc., can be recovered.

[0056] The method for recovering valuable metals of the present invention comprises a step of concentrating the valuable metal, which is the target metal to be obtained in the present invention, from the molten alloy obtained above. To this end, the method for recovering valuable metals of the present invention comprises a step of producing nickel matte by adding a concentrate, a slag forming agent, and oxygen (O2) to the molten alloy solution.

[0057] In the manufacturing step of nickel matte, a concentrate is first added to the alloy. The concentrate may be a sulfur (S)-containing compound. Alternatively, the concentrate may be sulfur (S). In this step, the sulfur-containing compound is added to the alloy, thereby causing a sulfurization reaction between the valuable metal and sulfur within the alloy.

[0058] The above sulfur-containing compound may include, for example, at least one of sulfur powder, molten sulfur, and iron sulfide.

[0059] By adding the above concentrate, a nickel-containing mat can be manufactured by performing a reaction as shown in the following reaction scheme 1.

[0060] [Reaction Formula 1]

[0061] 3Ni + 2S = Ni3S2

[0062] That is, valuable metals such as nickel, which have a high affinity for sulfur, present in the molten alloy solution through the reaction of the above reaction formula 1 are converted into sulfides, and iron within the molten alloy metal is preferentially oxidized and separated into slag. Accordingly, the recovery rate of valuable metals can be further improved.

[0063] In the step of manufacturing nickel matte, a step of subsequently adding a slag forming agent may also be included. The slag forming agent is a secondary raw material, and the slag forming agent described above may also be used in this step.

[0064] By introducing the above slag forming agent, slag that is easy to work with is generated, so the concentration efficiency of valuable metals is improved, and productivity can be further improved.

[0065] The above slag forming agent is not limited thereto, but may be included in an amount of 5 to 25 wt% based on the total weight of the nickel mat.

[0066] In addition, the step of manufacturing the nickel mat may include a step of introducing oxygen (O2). By introducing the oxygen, iron in the molten alloy can be preferentially oxidized, thereby causing it to float to the top of the molten alloy as slag in the form of iron oxide, thereby increasing the concentration of valuable metals including nickel in the molten alloy.

[0067] The oxygen injection step can be performed for 60 to 90 minutes. As the carbon injection time increases, the iron removal rate increases, while the nickel and cobalt recovery rates tend to decrease. When the oxygen injection step is performed for 60 to 90 minutes, both the iron removal rate and the nickel / cobalt recovery rate can be secured.

[0068] At this time, as the de-ironization process is performed through the reaction between the iron and oxygen, a nickel matte enriched with valuable metals can be formed. Specifically, the reaction in the de-ironization process can be represented by the following reaction formula 2.

[0069] [Reaction Formula 2]

[0070] 2Fe + O2= 2FeO

[0071] The above oxygen injection may be performed using at least one of a lance and a tuyere. However, the present invention is not limited thereto, and oxygen may be injected using various methods known in the art.

[0072] By injecting the above-described concentrate, slag forming agent and oxygen, a nickel matte having improved grade of valuable metals such as nickel can be manufactured.

[0073] For example, in the step of manufacturing nickel matte, the temperature of the alloy may be 1300 to 1500°C. Since the step of manufacturing nickel matte is an exothermic reaction, the temperature may be controlled within the above range to prevent the temperature of the alloy from rising excessively. If the temperature of the alloy is lower than 1300°C, the captured valuable metal and / or slag may solidify or the viscosity may become excessively high, thereby reducing the reactivity for concentration. Furthermore, if the temperature of the alloy exceeds 1500°C, the durability may be reduced, such as due to the erosion of the refractory material due to the reaction between the refractory material and the slag within the reactor.

[0074] The method for recovering valuable metals of the present invention comprises a step of recovering the valuable metals from nickel matte.

[0075] The above-mentioned valuable metal can be recovered by a leaching method, and one or more of acid leaching, ammonia leaching, and high-pressure oxidation leaching can be applied as the leaching method of the above-mentioned valuable metal. However, the present invention is not limited thereto, and various methods can be applied as a method for recovering the valuable metal as long as the effects of the present invention are not impaired.

[0076] For example, when valuable metals are derived from waste resources, more than 90% of the valuable metal can be recovered from the waste resources. The recovery rate can be calculated by dividing the weight of the valuable metal contained in the nickel matte by the weight of the valuable metal contained in the nickel matte and slag. Thus, by recycling the slag generated during the nickel matte formation process, the valuable metals contained in the slag can also be recovered, maximizing the recovery effect of the valuable metals.

[0077] According to the method for recovering valuable metals of the present invention, more than 90% of valuable metals contained in waste lithium secondary battery powder can be recovered.

[0078] Hereinafter, the present invention will be described in more detail through examples. However, it should be noted that the following examples are intended only to illustrate and further illustrate the present invention and are not intended to limit the scope of the invention. This is because the scope of the invention is determined by the matters set forth in the patent claims and matters reasonably inferred therefrom.

[0079] Example

[0080] Example 1

[0081] 2.5 kg of pig iron was melted in an induction furnace to produce a molten master alloy and maintained at 1600°C. Thereafter, while stirring the molten master alloy, the composition as shown in Table 1 was measured using the ICP (Inductively Coupled Plasma) method, and 1.25 kg of the first powder and 1.25 kg of the second powder and 0.25 kg of silicon dioxide (SiO2) as a slag forming agent were added to produce the molten alloy.

[0082] Some oxides from the manufactured alloy melt floated to the top of the melt in the form of slag and separated. After separating the slag, the remaining alloy weighed 3.5 kg, and its composition is shown in Table 2. The weight fraction of each component is expressed as wt% based on the total alloy weight (100 wt%).

[0083] The composition of the separated slag is shown in Table 3. The weight fraction of each component is expressed as weight% based on the slag weight (100 wt%).

[0084] The nickel (Ni) recovery rate was calculated as the mass of nickel in the alloy compared to the mass of nickel contained in the first and second powders introduced, and the nickel recovery rate was 97.53%.

[0085] Similarly, the cobalt (Co) recovery rate was calculated as the mass of cobalt in the alloy compared to the mass of cobalt contained in the first and second powders introduced, and the cobalt recovery rate was 91.20%.

[0086] The Ni / Co recovery rate was calculated as the sum of the masses of nickel and cobalt in the alloy compared to the sum of the masses of nickel and cobalt contained in the first and second powders, and the Ni / Co recovery rate was 94.96%.

[0087] Element (wt%) LiNiCoMnFeAlCuCaSiPCS First powder 6.770 34.930 11.180 9.520 0.020 0.062 < 0.001 0.013 0.012 0.011 2.49 00.091 Second powder 3.940 16.100 7.890 7.680 0.037 2.580 1.07 0.042 0.18 0.21 36.200 0.12

[0088] Alloy composition (wt%)Ni / Co recovery rateAlloy weight[kg]FeNiCoMnCS55.514.25.294.382.550.01794.963.5kg

[0089] Slag composition (wt%)MgONiOCoOMnOLi2OFeOSiO2CaOAl2O3P2O5CS0.210.150.0431.3435.080.3632.090.2411.070.050.240.35

[0090] In the step of manufacturing the above alloy, 2.2 kg of the collected alloy was melted in an induction furnace, 300 g of sulfur (S) was added as a concentrate, and the temperature of the molten metal was maintained at 1300 to 1400°C. Thereafter, 150 g of silicon dioxide (SiO2) was added as a slag forming agent while stirring, and oxygen (O2) was blown at 5 L / min.

[0091] As sulfur was added, valuable metals nickel and cobalt were concentrated within the alloy, while iron was oxidized and separated in the form of slag. Furthermore, the selective oxidation of iron by oxygen blowing facilitated the separation of valuable metals and secondary slag. The mixture was concentrated to an iron (Fe) concentration of approximately 30 wt%, yielding 0.64 kg of nickel matte and the remainder secondary slag.

[0092] The composition of nickel mat is shown in Table 4. The weight fraction of each component is expressed in weight% based on the total weight of nickel mat (100 weight%).

[0093] The composition of the second slag is shown in Table 5. The weight fraction of each component is expressed in weight% based on the total weight of the second slag (100 weight%).

[0094] The final nickel and cobalt recovery rates were calculated as the mass in the nickel mat compared to the mass contained in the capture alloy, and the final nickel recovery rate was 96.73%, and the final cobalt recovery rate was 87.91%.

[0095] Nickel mat composition (wt%) Nickel mat weight [kg] FeNiCoMnCS 3 3.1 3 3.7 1 1.5 0.0 1 8 0.0 0 4 18.2 7 0.6 4 kg

[0096] Second slag composition (wt%)MgONiOCoOMnOLi2OFeOFe2O3SiO2CaOAl2O3P2O5CS0.160.790.6763.670.0844.7021.6012.750.091.640.270.023.94

[0097] Comparative Example 1

[0098] 2.5 kg of pig iron was melted in an induction furnace to produce a molten master alloy, which was maintained at 1600°C. Thereafter, while stirring the molten master alloy, 2.5 kg of the first powder and 0.25 kg of silicon dioxide (SiO2) as a slag forming agent were added to produce a molten alloy.

[0099] Some oxides from the manufactured alloy melt floated to the top of the melt in the form of slag and separated. After separating the slag, the remaining alloy weighed 1.8 kg, and its composition is shown in Table 6. The weight fraction of each component is expressed as wt% based on the total weight of the melt (100 wt%).

[0100] The composition of the separated slag is shown in Table 7. The weight fraction of each component is expressed as weight% based on the slag weight (100 wt%).

[0101] The recovery rates of nickel and cobalt were calculated as the mass of nickel and cobalt in the alloy compared to the mass of nickel and cobalt in the first powder introduced. The nickel recovery rate was 97.53%, and the cobalt recovery rate was 91.20%.

[0102] Alloy composition (wt%)Ni / Co recovery rateAlloy weight[kg]FeNiCoMnCS49.7038.111.10.050.00620.01296.03%1.8kg

[0103] Slag composition (wt%)MgONiOCoOMnOLi2OFeOSiO2CaOAl2O3P2O5CS6.140.690.4728.268.8062.526.200.000.870.070.060.08

[0104] In the step of manufacturing the above alloy, 1.8 kg of the collected alloy was melted in an induction furnace, 200 g of sulfur (S) was added as a concentrate, and the temperature was maintained at 1300 to 1400°C. Thereafter, 400 g of silicon dioxide (SiO2) was added as a slag former while stirring, and oxygen (O2) was blown at 5 L / min. As sulfur was added, valuable metals nickel and cobalt were concentrated in the alloy, and iron was oxidized and separated in the form of slag. In addition, the valuable metal and the second slag were easily separated due to the selective oxidation of iron by oxygen blowing. The nickel matte was 1.11 kg and the remainder of the second slag was obtained by concentrating until the iron (Fe) concentration was approximately 5 wt%.

[0105] The composition of the nickel mat is shown in Table 8. The composition of each component shown in Table 8 is expressed as the weight fraction of each component based on the total weight of the nickel mat (100 wt%).

[0106] The composition of the second slag is shown in Table 9. The composition of each component shown in Table 9 is expressed as the weight fraction of each component based on the total weight of the second slag (100 wt%).

[0107] Nickel mat composition (wt%) Nickel mat weight [kg] FeNiCoMnCS4.0567.75.110.0030.00917.711.11kg

[0108] Second slag composition (wt%)MgONiOCoOMnOLi2OFeOSiO2CaOAl2O3P2O5CS6.054.625.3560.060.0354.8020.640.001.700.050.020.04

[0109] The final nickel and cobalt recovery rates were calculated as the mass contained in the nickel mat compared to the mass contained in the nickel mat. The final nickel recovery rate was 89.07%, and the final cobalt recovery rate was 34.67%. That is, in the case of the comparative example, it was found that the recovery rates of Ni and Co were measured lower than those of the example.

[0110] Experimental example

[0111] The iron removal rate and recovery rate according to the oxygen treatment time of Comparative Example 1 are shown in Table 10.

[0112] In the nickel matte manufacturing step, the time before oxygen was introduced after the thickener and slag forming agent were added was set as the reference time of 0 min. The time was measured simultaneously with the start of oxygen introduction, and the iron removal rate, nickel recovery rate, and cobalt recovery rate according to the oxygen introduction time were measured, and are shown in Table 10 and Figure 4.

[0113] Time (min) Efficiency (%) De-Feralization rate Ni recovery rate Co recovery rate Ni / Co recovery rate Initial 00.00100.00100.00100.0023046.0398.1588.4695.7736077.6597.3787.6695.3049093.7189.0746.5380.92 Final 9094.8289.0734.6780.23

[0114] According to Table 10, it can be confirmed that the iron removal rate increases over time, while the recovery rates of Ni and Co decrease. To secure both the iron removal rate and the Ni / Co recovery rate, it is desirable to conduct the concentration process through oxygen blowing for 60 to 90 minutes.

[0115] The alloy composition according to the concentration process of Comparative Example 1 is shown in Figure 3. The concentration direction shown in Figure 3 represents the passage of time. As the concentration process progresses, the nickel content increases and the iron content decreases. It can be confirmed that the nickel and iron contents are inversely proportional.

[0116] The concentration recovery rate over time of Comparative Example 1 is shown in Figure 4. It was confirmed that the de-ironization rate increased over time, and the recovery rates of Ni and Co decreased.

[0117] And, the concentration recovery rate according to the de-ironization rate of Comparative Example 1 is shown in Figure 5. It can be confirmed that as the de-ironization rate increases, the recovery rates of Ni and Co decrease. It was confirmed that when the de-ironization rate is 80% or less, the recovery rate of Ni can be achieved at 97% or more, and the recovery rate of Co can be achieved at 87% or more.

[0118] In this way, it was confirmed that the recovery rate of valuable metals could be improved by introducing two types of powder, the first powder and the second powder.

[0119] The above embodiments are merely examples and the present invention is not limited thereto. Anything that has substantially the same configuration and achieves the same operational effects as the technical concepts described in the claims of the present invention is included within the technical scope of the present invention.

Claims

1. A step of manufacturing an alloy by reducing waste lithium secondary battery powder containing carbon and precious metal; and Comprising a step of manufacturing nickel matte by adding a concentrate, a slag forming agent and oxygen (O2) to the above alloy, A method for recovering valuable metals, wherein the waste lithium secondary battery powder contains carbon in an amount of more than 0 wt% and less than 40 wt% based on the total weight of the waste lithium secondary battery powder.

2. In paragraph 1, A method for recovering valuable metals, wherein the above-mentioned waste lithium secondary battery powder comprises a first powder and a second powder containing more carbon than the first powder.

3. In paragraph 2, A method for recovering valuable metals, wherein the first powder contains less than 5 wt% of carbon based on the total weight of the waste lithium secondary battery powder.

4. In paragraph 2, A method for recovering valuable metals, wherein the second powder contains 5 to 40 wt% of carbon based on the total weight of the waste lithium secondary battery powder.

5. In paragraph 2, A method for recovering valuable metals, wherein the above-mentioned waste lithium secondary battery powder comprises a first powder of 50 wt% or more and less than 100 wt% and a second powder of more than 0 wt% and less than 50 wt%.

6. In paragraph 1, A method for recovering a valuable metal, wherein the valuable metal comprises at least one selected from the group consisting of nickel, cobalt, manganese and lithium.

7. In paragraph 1, The steps for manufacturing the above alloy are: Step of adding waste lithium secondary battery powder and slag forming agent to the mother alloy molten metal; and A method for recovering valuable metals, comprising: a step of reducing the waste lithium secondary battery powder at a temperature of 1550°C to 1700°C to produce an alloy.

8. In paragraph 1, A method for recovering valuable metal, comprising a step of recovering the valuable metal from the nickel matte after the step of manufacturing the nickel matte.

9. In paragraph 1, A method for recovering valuable metals, wherein the above concentrate is sulfur (S).

10. In paragraph 1, A method for recovering valuable metals, wherein the slag forming agent comprises silicon dioxide (SiO2).

11. In paragraph 1, A method for recovering valuable metals, wherein the waste lithium secondary battery powder contains 10 to 40 wt% of nickel based on the total weight of the waste lithium secondary battery powder.

12. In paragraph 1, A method for recovering valuable metals, which recovers 90% or more of the valuable metals contained in the above-mentioned waste lithium secondary battery powder.

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