Process for the recovery of copper from a battery powder

Abstract

The present application belongs to the technical field of lithium ion battery, and provides a method for recovering copper in battery powder, which comprises the following steps: performing alkali leaching on the battery powder to obtain alkali leaching powder; performing low-temperature oxidative acid leaching on the alkali leaching powder to obtain leaching residue and primary acid leaching solution; performing oxidative acid leaching on the leaching residue to obtain secondary leaching residue and secondary leaching solution; and sequentially performing extraction and electrodeposition on the primary acid leaching solution to complete the recovery of copper. In the present application, the alkali leaching is used for removing aluminum in the battery powder, the low-temperature oxidative acid leaching is used for improving the lithium leaching rate and the iron and phosphorus precipitation rate, then the leaching residue is subjected to oxidative acid leaching again for comprehensively improving the copper leaching rate, the extraction is used for realizing the separation of copper and lithium, and the electrodeposition for copper extraction is used for recovering copper, which can effectively improve the economic value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion batteries, in particular to a method for recovering copper in battery powder. BACKGROUND

[0002] At present, in the lithium ion battery wet recovery process, the pole piece powder is often used as raw material, concentrated sulfuric acid is used as leaching agent, and hydrogen peroxide is used as redox agent. Considering that the subsequent battery powder will become the main raw material, the content of copper, aluminum, fluorine and organic matter in the battery powder is higher than that in the pole piece powder. By treating the battery powder through the original pole piece powder treatment process, it can be found that the residual rate of aluminum, copper, fluorine and organic matter is high during the treatment of the battery powder, which is not conducive to the subsequent recovery process. Therefore, in the lithium ion battery wet recovery process, how to improve the removal rate of aluminum, fluorine and organic matter and the effective recovery of copper when the raw material is converted into battery powder is particularly important.

[0003] The difference between the two raw materials is that the content of aluminum, copper, fluorine and organic matter in the battery powder is higher than that in the pole piece powder. The effective treatment process is to first perform alkali leaching, and then perform oxidation leaching, extraction and copper electrodeposition to recover copper in the battery powder. The process first removes aluminum by alkali leaching, then extracts lithium and copper by oxidation leaching, and then separates copper and lithium by extraction, and recovers copper by electrodeposition. Due to the high content of aluminum, copper, fluorine and organic matter in the battery powder, how to improve the removal rate of aluminum, fluorine and organic matter and the leaching rate of copper is one of the technical problems to be solved in the field. SUMMARY

[0004] The purpose of the present application is to overcome the problems in the prior art and provide a method for recovering copper in battery powder.

[0005] In order to achieve the above-mentioned purpose of the application, the present application provides the following technical scheme:

[0006] The present application provides a method for recovering copper in battery powder, comprising the following steps:

[0007] (1) alkali leaching the battery powder to obtain alkali leaching powder;

[0008] (2) low-temperature oxidation acid leaching the alkali leaching powder to obtain leaching residue and primary acid leaching solution;

[0009] (3) oxidation acid leaching the leaching residue to obtain secondary leaching residue and secondary leaching solution;

[0010] (4) sequentially performing extraction and electrodeposition on the primary acid leaching solution to complete the recovery of copper.

[0011] As preferred, the solution of the alkali leaching in step (1) is sodium hydroxide solution; the concentration of the sodium hydroxide solution is 2-5%; the mass ratio of the sodium hydroxide solution to the battery powder is 4-6:1;

[0012] The time of the alkali leaching in step (1) is 40-60 min.

[0013] As preferred, the solution of the low-temperature oxidative acid leaching in step (2) comprises acid leaching solution and oxidant;

[0014] The pH of the acid leaching solution is 1.5-2.5;

[0015] The oxidant is hydrogen peroxide, and the concentration of the hydrogen peroxide is 40-60%;

[0016] The mass ratio of the solution of the low-temperature oxidative acid leaching to the alkali leaching powder is 3-4:1;

[0017] The mass ratio of the oxidant to the alkali leaching powder is 1:4-6.

[0018] As preferred, the temperature of the low-temperature oxidative acid leaching in step (2) is 10-70℃, and the time is 2-8 h.

[0019] As preferred, the solution of the oxidative acid leaching in step (3) comprises acid leaching solution and oxidant;

[0020] The pH of the acid leaching solution is 0.5-1.5;

[0021] The oxidant is hydrogen peroxide, and the concentration of the hydrogen peroxide is 40-60%;

[0022] The mass ratio of the solution of the oxidative acid leaching to the leaching residue is 3-4:1;

[0023] The mass ratio of the oxidant to the leaching residue is 1:4-6.

[0024] As preferred, the time of the oxidative acid leaching in step (3) is 2-8 h.

[0025] As preferred, the concentration of the extractant of the extraction in step (4) is 10-15%; the volume ratio of the extractant to the primary acid leaching solution is 1-2:1-2.

[0026] As preferred, the extraction in step (4) is performed for ≥4 times, and the single extraction time of the extraction is 5-10 min.

[0027] As preferred, the distance between the two stages of the electrodeposition in step (4) is 50-100 mm.

[0028] As preferred, the voltage of the electrodeposition in step (4) is 1-3 V, the current density is 150-250 A / m 2 , and the time is 70-80 h.

[0029] The application provides a method for recovering copper from battery powder, comprising the following steps: performing alkali leaching on the battery powder to obtain alkali leaching powder; performing low-temperature oxidative acid leaching on the alkali leaching powder to obtain leaching residue and primary acid leaching solution; performing oxidative acid leaching on the leaching residue to obtain secondary leaching residue and secondary leaching solution; and sequentially performing extraction and electrodeposition on the primary acid leaching solution to complete the recovery of copper. In the application, the alkali leaching is used to remove aluminum in the battery powder, the low-temperature oxidative acid leaching is used to improve the lithium leaching rate and the iron and phosphorus precipitation rate, and then the leaching residue is subjected to oxidative acid leaching again to comprehensively improve the copper leaching rate. The extraction is used to separate copper and lithium, and the electrodeposition for copper extraction is used to recover copper, which can effectively improve the economic value.

[0030] In the application, the aluminum removal rate can reach more than 70% through alkali leaching. Through the first step of relatively low-temperature oxidative acid leaching, the lithium leaching rate can reach more than 90% when the temperature is controlled at 10-70 ℃, and the hydrogen peroxide consumption is about 0.7-0.9 m 3 / (fold of lithium sulfate). Through the second step of oxidative acid leaching without temperature control, the iron and phosphorus residue with the lithium and copper content both being ≤0.1% can be obtained. After the extraction process, the copper extraction rate can reach 99%. Through the electrodeposition for copper extraction, 95% of the copper ions in the copper extraction solution can be converted into sponge copper with a purity of ≥95%. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a flowchart of the method for recovering copper from battery powder in the application. DETAILED DESCRIPTION

[0032] The application provides a method for recovering copper from battery powder, comprising the following steps:

[0033] (1) performing alkali leaching on the battery powder to obtain alkali leaching powder;

[0034] (2) performing low-temperature oxidative acid leaching on the alkali leaching powder to obtain leaching residue and primary acid leaching solution;

[0035] (3) performing oxidative acid leaching on the leaching residue to obtain secondary leaching residue and secondary leaching solution;

[0036] (4) sequentially performing extraction and electrodeposition on the primary acid leaching solution to complete the recovery of copper.

[0037] In the application, the solution for alkali leaching in step (1) is sodium hydroxide solution; the concentration of the sodium hydroxide solution is preferably 2-5%, further preferably 2.5-4.5%, and more preferably 3-4%; and the mass ratio of the sodium hydroxide solution to the battery powder is preferably 4-6:1, further preferably 4.5-5.5:1, and more preferably 4.8-5.2:1.

[0038] In the present application, the time of the alkali leaching in step (1) is preferably 40-60 min, further preferably 45-55 min, and more preferably 48-52 min.

[0039] In the present application, the reaction principle of the alkali leaching in step (1) is as follows:

[0040] 2NaOH + Al2O3 + 3H2O = 2Na[Al(OH)4]

[0041] 2Al + 2NaOH + 6H2O = 2Na[Al(OH)4] + 3H2↑

[0042] In the present application, the solution of the low-temperature oxidative acid leaching in step (2) comprises an acid leaching solution and an oxidizing agent.

[0043] In the present application, the pH of the acid leaching solution is preferably 1.5-2.5, further preferably 1.6-2.4, and more preferably 1.8-2.2.

[0044] In the present application, the acid leaching solution is prepared by using a sulfuric acid aqueous solution, and the concentration of the sulfuric acid aqueous solution is preferably 1-4 M, further preferably 2-3 M, and more preferably 2.4-2.6 M.

[0045] In the present application, the oxidizing agent is hydrogen peroxide, and the concentration of the hydrogen peroxide is preferably 40-60%, further preferably 45-55%, and more preferably 48-52%.

[0046] In the present application, the mass ratio of the solution of the low-temperature oxidative acid leaching to the alkali leaching powder is preferably 3-4:1, further preferably 3.2-3.8:1, and more preferably 3.4-3.6:1.

[0047] In the present application, the mass ratio of the oxidizing agent to the alkali leaching powder is preferably 1:4-6, further preferably 1:4.5-5.5, and more preferably 1:4.8-5.2.

[0048] In the present application, the temperature of the low-temperature oxidative acid leaching in step (2) is preferably 10-70℃, further preferably 20-60℃, and more preferably 30-50℃; and the time is preferably 2-8 h, further preferably 3-7 h, and more preferably 4-6 h.

[0049] In the present application, the oxidative acid leaching in step (2) is carried out in the temperature range of 10-70℃, which can relatively reduce the unit consumption of hydrogen peroxide.

[0050] In the present application, the solution of the oxidative acid leaching in step (3) comprises an acid leaching solution and an oxidizing agent.

[0051] In the present application, the pH of the acid leaching solution is preferably 0.5-1.5, further preferably 0.6-1.4, and more preferably 0.8-1.2.

[0052] In the present application, the acid leaching solution is prepared by using sulfuric acid aqueous solution, and the concentration of the sulfuric acid aqueous solution is preferably 1-4 M, further preferably 2-3 M, and more preferably 2.4-2.6 M.

[0053] In the present application, the oxidizing agent is hydrogen peroxide, and the concentration of the hydrogen peroxide is preferably 40-60%, further preferably 45-55%, and more preferably 48-52%.

[0054] The mass ratio of the oxidizing acid leaching solution to the leaching residue is preferably 3-4:1, further preferably 3.2-3.8:1, and more preferably 3.4-3.6:1.

[0055] In the present application, the mass ratio of the oxidizing agent to the leaching residue is preferably 1:4-6, further preferably 1:4.5-5.5, and more preferably 1:4.8-5.2.

[0056] In the present application, the time for the oxidizing acid leaching in step (3) is preferably 2-8 h, further preferably 3-7 h, and more preferably 4-6 h.

[0057] In the present application, the secondary leaching solution can continue to be used as the bottom solution for the oxidizing acid leaching in step (2) for the next cycle.

[0058] In the present application, the principle of the oxidizing acid leaching is as follows:

[0059] 2LiFePO4+H2O2+H2SO4=2FePO4+Li2SO4+2H2O

[0060] Cu+H2SO4+H2O2=CuSO4+2H2O

[0061] In the present application, the extractant for the extraction in step (4) is DZ984N extractant, and the concentration of the extractant is preferably 10-15%, further preferably 11-14%, and more preferably 12-13%; the volume ratio of the extractant to the primary acid leaching solution is preferably 1-2:1-2, further preferably 1.2-1.8:1.2-1.8, and more preferably 1.4-1.6:1.4-1.6.

[0062] In the present application, the number of times for the extraction in step (4) is preferably ≥4, further preferably ≥8, and more preferably ≥12, and the ratio of the number of times for the forward extraction to the number of times for the reverse extraction is 1:3; the single extraction time for the extraction is preferably 5-10 min, further preferably 6-9 min, and more preferably 7-8 min.

[0063] In the present application, the principle of the extraction is as follows:

[0064]

[0065] In the present application, the extracted copper solution is subjected to electrodeposition.

[0066] In the present application, the anode in step (4) is Pb-Sb alloy and the cathode is stainless steel; the distance between the two stages is preferably 50-100 mm, further preferably 60-90 mm, and more preferably 70-80 mm.

[0067] In the present application, the voltage in step (4) is preferably 1-3 V, further preferably 1.5-2.5 V, and more preferably 1.8-2.2 V; the current density is preferably 150-250 A / m 2 , further preferably 160-240 A / m 2 , and more preferably 180-220 A / m 2 ; and the time is preferably 70-80 h, further preferably 72-88 h, and more preferably 74-86 h.

[0068] In the present application, the principle of electrodeposition is as follows:

[0069] Cu 2+ +2e - =Cu

[0070] The flow chart of the method for recovering copper from battery powder in the present application is shown in Figure 1 .

[0071] The technical solutions provided by the present application will be described in detail below in conjunction with the examples, but they should not be understood as limiting the scope of protection of the present application.

[0072] Example 1

[0073] The battery powder and 3% sodium hydroxide solution are mixed in a ratio of 1:5, and the alkali leaching powder is obtained by alkali leaching for 50 min;

[0074] An acid leaching solution with pH 2 is prepared using 3M aqueous sulfuric acid solution, the acid leaching solution and 50% hydrogen peroxide (the mass ratio of hydrogen peroxide to alkali leaching powder is 1:5) are mixed to obtain a low-temperature oxidation acid leaching solution, and the low-temperature oxidation acid leaching solution and the alkali leaching powder are mixed in a mass ratio of 3:1, and then soaked at 50°C for 6 h to obtain leaching residue and primary acid leaching solution;

[0075] An acid leaching solution with pH 1.5 is prepared using 3M aqueous sulfuric acid solution, the acid leaching solution and 50% hydrogen peroxide (the mass ratio of hydrogen peroxide to leaching residue is 1:5) are mixed to obtain an oxidation acid leaching solution, and the oxidation acid leaching solution and the leaching residue are mixed in a mass ratio of 3:1, and then soaked for 6 h to obtain secondary leaching residue and secondary leaching solution;

[0076] The primary acid leaching solution is extracted with DZ984N extractant with a concentration of 12%, the volume ratio of the extractant to the primary acid leaching solution is 1:1, one extraction, three back extractions, and the single extraction time is 10 minutes to obtain a copper extraction solution.

[0077] The Pb-Sb alloy is used as an anode, the stainless steel is used as a cathode, the electrode plate spacing is 80 mm, the voltage is 2 V, and the current density is 200 A / m 2 , and the time is 72 h to obtain sponge copper.

[0078] The products obtained in this example are subjected to component analysis, and the results are shown in Table 1.

[0079] Table 1 Chemical composition of products

[0080] Item Li Fe P Cu Al Battery powder 3.23％ 28.08％ 16.19％ 2.74％ 1.70％ Primary acid leach 6.80 g / L 11.10 g / L 5.01 g / L 7.41 g / L 1.96 g / L Secondary leach residue 0.096％ 0.027％ Copper extraction solution 48.47 g / L Sponge copper 98.97％

[0081] Example 2

[0082] The battery powder and 2.5% sodium hydroxide solution are mixed at a ratio of 1:6, and the alkaline leaching powder is obtained after alkaline leaching for 45 minutes;

[0083] An acid leaching solution with a pH of 1.5 is prepared using a 2M aqueous sulfuric acid solution, the acid leaching solution and 45% hydrogen peroxide (the mass ratio of hydrogen peroxide to alkaline leaching powder is 1:5) are mixed to obtain a low-temperature oxidation acid leaching solution, and the low-temperature oxidation acid leaching solution and the alkaline leaching powder are mixed at a mass ratio of 3.5:1, and then soaked at 60°C for 4 hours to obtain leaching residues and a primary acid leaching solution;

[0084] An acid leaching solution with a pH of 1 is prepared using a 2M aqueous sulfuric acid solution, the acid leaching solution and 50% hydrogen peroxide (the mass ratio of hydrogen peroxide to leaching residues is 1:5) are mixed to obtain an oxidation acid leaching solution, and the oxidation acid leaching solution and the leaching residues are mixed at a mass ratio of 3.5:1, and then soaked for 6 hours to obtain secondary leaching residues and a secondary leaching solution;

[0085] The primary acid leaching solution is extracted with DZ984N extractant with a concentration of 11%, the volume ratio of the extractant to the primary acid leaching solution is 1:1, one extraction, three back extractions, and the single extraction time is 5 minutes to obtain a copper extraction solution.

[0086] The Pb-Sb alloy is used as an anode, the stainless steel is used as a cathode, the electrode plate spacing is 70 mm, the voltage is 1.5 V, and the current density is 180 A / m 2 , and the time is 74 h to obtain sponge copper.

[0087] The products obtained in this example are subjected to component analysis, and the results are shown in Table 2.

[0088] Table 2 Chemical composition of products

[0089] Item Li Fe P Cu Al Battery powder 3.23％ 28.08％ 16.19％ 2.74％ 1.70％ Primary acid leach 7.24 g / L 10.97 g / L 5.07 g / L 7.44 g / L 1.87 g / L Secondary leach residue 0.078％ 0.018％ Copper extraction solution 49.52 g / L Sponge copper 99.23％

[0090] Example 3

[0091] The battery powder and 4.2% sodium hydroxide solution are mixed in a ratio of 1:4.5, and the alkali leaching powder is obtained by alkali leaching for 55 min;

[0092] The acid leaching solution with pH of 2.3 is prepared by using 3M sulfuric acid aqueous solution, the low-temperature oxidation acid leaching solution is obtained by mixing the acid leaching solution and 57% hydrogen peroxide (the mass ratio of hydrogen peroxide to alkali leaching powder is 1:5.2), and the leaching residue and the first acid leaching solution are obtained by mixing the low-temperature oxidation acid leaching solution and the alkali leaching powder in a mass ratio of 4:1 and leaching at 15℃ for 7h;

[0093] The acid leaching solution with pH of 0.8 is prepared by using 3M sulfuric acid aqueous solution, the oxidation acid leaching solution is obtained by mixing the acid leaching solution and 57% hydrogen peroxide (the mass ratio of hydrogen peroxide to leaching residue is 1:6), and the second leaching residue and the second leaching solution are obtained by mixing the oxidation acid leaching solution and the leaching residue in a mass ratio of 4:1 and leaching for 2h;

[0094] The first acid leaching solution is extracted by using 15% DZ984N extractant, the volume ratio of extractant to first acid leaching solution is 1:1, one extraction and three back extractions are carried out, and the process of one extraction and back extraction is repeated once, and the copper extraction solution is obtained by extracting for 10 min each time.

[0095] The Pb-Sb alloy is used as an anode, the stainless steel is used as a cathode, the distance between the electrodes is 90mm, the voltage is 2.5V, the current density is 230A / m 2 , and the time is 76h to carry out the electrodeposition to obtain the sponge copper.

[0096] The products obtained in the example are subjected to component analysis, and the results are shown in Table 3.

[0097] Table 3 Chemical composition of products

[0098]

[0099]

[0100] As can be seen from the above examples, the application provides a method for recovering copper in battery powder, after the first step of low-temperature oxidation acid leaching, a first copper and lithium containing solution with a content of ≥5g / L can be obtained, after the second step of oxidation acid leaching without temperature control, a leaching residue with a content of copper and lithium ≤0.1% can be obtained, after extraction and back extraction, a copper-rich solution with a content of ≥45g / L can be obtained, and after electrodeposition for copper extraction, sponge copper with a purity of ≥95% can be obtained.

[0101] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as falling within the protection scope of the present application.

Claims

1. A process for the recovery of copper from battery powders, characterized in that, The method comprises the following steps: 1) performing alkaline leaching on the battery powder to obtain alkaline leaching powder; 2) performing low-temperature oxidative acid leaching on the alkaline leaching powder to obtain leaching residue and primary acid leaching solution; 3) performing oxidative acid leaching on the leaching residue to obtain secondary leaching residue and secondary leaching solution; 4) sequentially performing extraction and electrodeposition on the primary acid leaching solution to complete copper recovery; The solution for low-temperature oxidative acid leaching in step 2) comprises acid leaching solution and oxidizing agent; The pH of the acid leaching solution is 1.5-2.5; The oxidizing agent is hydrogen peroxide, and the concentration of the hydrogen peroxide is 40-60%; The mass ratio of the solution for low-temperature oxidative acid leaching to the alkaline leaching powder is 3-4:1; The mass ratio of the oxidizing agent to the alkaline leaching powder is 1:4-6; The temperature for low-temperature oxidative acid leaching in step 2) is 10-70℃, and the time is 2-8h; The solution for oxidative acid leaching in step 3) comprises acid leaching solution and oxidizing agent; The pH of the acid leaching solution is 0.5-1.5; The oxidizing agent is hydrogen peroxide, and the concentration of the hydrogen peroxide is 40-60%; The mass ratio of the solution for oxidative acid leaching to the leaching residue is 3-4:1; The mass ratio of the oxidizing agent to the leaching residue is 1:4-6; The concentration of the extractant for extraction in step 4) is 10-15%; and the volume ratio of the extractant to the primary acid leaching solution is 1-2:1-2.

2. The process for recovery of copper from battery powder as claimed in claim 1 wherein, The solution for alkaline leaching in step 1) is sodium hydroxide solution; the concentration of the sodium hydroxide solution is 2-5%; and the mass ratio of the sodium hydroxide solution to the battery powder is 4-6:1; The time for alkaline leaching in step 1) is 40-60min.

3. The process for recovery of copper from battery powder as claimed in claim 2 wherein, The time for oxidative acid leaching in step 3) is 2-8h.

4. The method of claim 3, wherein the copper is recovered from the battery powder by, The number of times for extraction in step 4) is ≥4, and the single extraction time for extraction is 5-10min.

5. The process of claim 4, wherein the copper is recovered from the battery powder by, The distance between two stages for electrodeposition in step 4) is 50-100mm.

6. The method of claim 5, wherein the copper is recovered from the battery powder by, The voltage for the electrodeposition in step 4) is 1-3 V, the current density is 150-250 A / m 2 and the time is 70-80 h.

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