A method for co-disposing waste lithium-ion battery electrode powder and electrolyte

Abstract

The present invention discloses a method for synergistically disposing of waste lithium-ion battery electrode powder and electrolyte. Using the oxygen-deficient air obtained by air separation as the protective gas, the waste battery is crushed and sorted to separate and collect the electrode powder, copper foil, aluminum foil, outer shell and separator, and the electrolyte volatilizes into organic waste gas; then the electrode powder and the organic waste gas are synergistically treated, and the oxygen content is adjusted to 10%-15% with the oxygen-rich air obtained by air separation to roast and reduce the high-valent Ni / Co / Mn, etc. in the electrode powder, while the organic gas is oxidized; the organic waste gas is discharged up to standard after deep treatment; the electrode powder is obtained by leaching-recrystallization to obtain lithium carbonate and the leaching residue containing Ni / Co / Mn and the negative electrode powder; the leaching residue is leached-precipitated / extracted to recover valuable elements. The present invention separates the air, synergistically performs the reduction of the electrode powder and the oxidation of the electrolyte, makes the best use of everything, reduces the consumption of oxidizing / reducing agents, and realizes the priority extraction of lithium, with less material and energy consumption, strong adaptability, high treatment efficiency and low cost.

Description

Technical Field

[0001] The present invention relates to the recycling of waste lithium - ion batteries, and particularly to a method for the collaborative disposal of waste lithium - ion battery electrode powder and electrolyte. Background Art

[0002] With the wide application of lithium - ion batteries, their usage has doubled year by year, and their scrapping volume will also show an explosive growth. Cleaning and recycling of scrapped lithium batteries, which can not only recover valuable components but also reduce environmental pollution caused by harmful substance emissions during the recycling process, is an important content in the field of resource recycling and environmental protection. The key points for the recycling of waste lithium - ion batteries are: the recovery of valuable metals in the electrode powder; the harmless treatment of volatile waste gas from the waste electrolyte. Currently, for the recovery of the electrode powder obtained by crushing and sorting, in order to improve the leaching efficiency of the electrode powder, it is necessary to first reduce the high - valence nickel, cobalt, and manganese in the electrode powder. The industry generally extracts valuable metals such as lithium, cobalt, nickel, and manganese in the electrode powder through pyrometallurgical or hydrometallurgical reduction - inorganic acid or organic acid leaching methods. Pyrometallurgical reduction mainly includes carbon, sulfur, and hydrogen reduction methods, which require a large amount of high - value reducing agents and will emit polluting gases; while the hydrometallurgical reduction process also often requires a large amount of reducing agents, such as H2O2, sodium sulfite, oxalic acid, tartaric acid, and ascorbic acid, etc., and the reagent cost is relatively high. In addition, there are various methods for treating the volatile waste gas from the waste electrolyte, such as adsorption method, condensation method, absorption method, biological method, photocatalysis, thermal oxidation method, etc., and different methods have their own advantages and disadvantages. Due to the different components and contents of organic substances in the waste gas, it is difficult to recycle them again. Usually, taking advantage of the high concentration of organic substances in it, it is disposed of through thermal oxidation methods such as combustion, but the oxygen consumption is large. Therefore, developing an economic, efficient, and highly integrated lithium - battery recycling and treatment process is of great significance for lithium resource recycling and environmental protection. Summary of the Invention

[0003] Aiming at the technical problems of large consumption of reducing agents and high reagent costs in the pyrometallurgical or hydrometallurgical reduction for recovering electrode powder in the prior art, and large consumption of oxidants in the treatment of waste electrolyte by the oxy - fuel combustion method, the present invention provides a method for the collaborative disposal of waste lithium - ion battery electrode powder and electrolyte, which can efficiently, with low consumption and low cost, recover valuable metals in the electrode powder, and at the same time harmlessly treat high - concentration organic waste gas.

[0004] The technical solution of the present invention is as follows:

[0005] A method for the collaborative disposal of waste lithium - ion battery electrode powder and electrolyte, comprising the following steps:

[0006] (1) Using an air separation device to separate air into oxygen - depleted air and oxygen - enriched air;

[0007] (2) Using the oxygen-deficient air in step (1) as a protective gas, the waste batteries are crushed and sorted to separate and collect the electrode powder, copper foil, aluminum foil, outer shell and separator, and the electrolyte volatilizes into organic waste gas;

[0008] (3) The electrode powder in step (2) is co-treated with the organic waste gas. Using the oxygen-rich air obtained in step (1) as a combustible supporter, the oxygen content in the combustion atmosphere is regulated by adjusting the amount of oxygen-rich air, so that the organic components in the organic waste gas are incompletely combusted; at the same time, the electrode powder is reductively roasted in the combustion atmosphere, so that the high-valence elements (such as Ni / Co / Mn, etc.) in the electrode powder are reduced, and the organic waste gas and the incompletely combusted products are further oxidized;

[0009] (4) After the organic waste gas oxidized in step (3) is treated by dust removal, thermal oxidation, defluorination and adsorption purification, it is discharged up to standard.

[0010] (5) The electrode powder after reductive roasting in step (3) is leached with water and recrystallized to obtain Li2CO3, and the leaching residue containing Ni / Co / Mn and the negative electrode powder. The leaching residue is further leached and precipitated / extracted to recover the valuable elements therein, and the graphite negative electrode powder is obtained.

[0011] Further, in step (1), the oxygen content of the oxygen-deficient air is less than 0.5%, and the oxygen content of the oxygen-rich air is 25%-35%.

[0012] Further, in step (3), the oxygen content is controlled to be 10%-15% (preferably 12%-14%), and the roasting temperature is controlled to be 300-600 °C (preferably 400-500 °C).

[0013] Further, in step (3), the high-valence metal elements include Ni, Co and Mn, and the ratio of the total amount of Ni, Co and Mn to the total amount of organic components is 1:0.5-5 (preferably 1:1-3).

[0014] Further, in step (5), the liquid-solid mass ratio of the electrode powder leaching is 20-40:1.

[0015] The beneficial effects of the present invention are as follows:

[0016] (1) By separating air into oxygen-deficient air and oxygen-rich air, the oxygen-deficient air can be used as a protective gas in the crushing and sorting process to reduce the risk of combustion and explosion; the oxygen-rich air is used for the oxidation of the organic waste gas generated by the volatilization of the waste electrolyte, which can not only completely replace the use of liquid oxygen, but also conveniently adjust the oxygen content of the roasting system.

[0017] (2) The cathode powder and organic waste gas can be co-treated. By adjusting the oxygen content in the gas atmosphere and the dosage ratio of the cathode powder to the organic components, a good synergistic effect can be achieved. Using the organic waste gas and its unburned products as reducing agents, without the need for additional reducing agents and heat sources, not only can the reduction treatment cost of the cathode powder be reduced, but also the preferential extraction of lithium can be realized, with remarkable economic benefits. At the same time, the cathode powder can also act as an oxidant, enabling some organic gases to be oxidized and reducing the consumption of oxygen.

[0018] In summary, the present invention can co-treat waste lithium-ion battery cathode powder and waste electrolyte, making the best use of everything, reducing the consumption of oxidizing / reducing agents and energy during the recycling process, realizing the preferential extraction of lithium, simplifying the treatment process, having strong raw material adaptability, high treatment efficiency, low material and energy consumption, small tail gas volume, and remarkable economic and environmental benefits, and making an important contribution to promoting the green development of the waste lithium-ion battery resource recycling industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a process flow block diagram of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto. The following cases are implemented for waste ternary lithium-ion batteries.

[0021] Example 1

[0022] Air is separated by an air separation device to obtain oxygen-deficient air (containing 0.2% oxygen) and oxygen-rich air (containing 30% oxygen). Using the oxygen-deficient air as a protective gas, the waste battery is crushed and sorted to separate and collect the cathode powder, copper foil, aluminum foil, outer shell and separator, and the electrolyte volatilizes into organic waste gas. Then, the cathode powder and the organic waste gas are co-treated, controlling the ratio of the total amount of Ni / Co / Mn to the total amount of organic components in the organic waste gas to be 1:3, and adjusting the oxygen content to 12% with the oxygen-rich air obtained by air separation. At 450 °C, Ni / Co / Mn in the cathode powder is reduced and roasted, and at the same time, the organic components are oxidized. The oxidized organic waste gas is deeply purified through processes such as dust removal, thermal oxidation, defluorination and adsorption, and then discharged up to the standard. The cathode powder is obtained by water leaching (liquid-solid mass ratio of 30:1) - recrystallization to obtain Li2CO3, and the leaching residue containing Ni / Co / Mn and the negative electrode powder; the leaching residue is then leached with sulfuric acid - precipitated with sodium hydroxide to recover the valuable elements therein.

[0023] After detection, the recovery rates of lithium, cobalt, nickel and manganese are 93.12%, 97.54%, 97.93% and 98.16% respectively; the particulate matter concentration at the waste gas discharge port is 2.7 mg / m 3 , the organic matter concentration is 18.6 mg / m 3 , and the fluoride concentration is 1.4 mg / m 3, the efficient recovery of valuable metals and the efficient treatment of waste electrolyte are realized.

[0024] Example 2

[0025] Air is separated by an air separation device to obtain oxygen-depleted air (containing 0.2% oxygen) and oxygen-enriched air (containing 30% oxygen). Using the oxygen-depleted air as a protective gas, the waste batteries are crushed and sorted to separate and collect the electrode powder, copper foil, aluminum foil, shell and diaphragm, and the electrolyte volatilizes into organic waste gas. Then, the electrode powder and the organic waste gas are co-treated, controlling the ratio of the total amount of Ni / Co / Mn to the total amount of organic components to be 1:3.5, and adjusting the oxygen content to 13% with the oxygen-enriched air obtained by air separation. The Ni / Co / Mn in the electrode powder is reduced and roasted at 400 °C, and at the same time, the organic components are oxidized; the oxidized organic waste gas is deeply purified through processes such as dust removal, thermal oxidation, defluorination and adsorption, and then discharged up to standard. The electrode powder is obtained by water leaching (liquid-solid mass ratio of 25:1) - recrystallization to obtain Li2CO3 and the leaching residue containing Ni / Co / Mn and the negative electrode powder; the leaching residue is further recovered for the valuable elements therein by sulfuric acid leaching - sodium hydroxide precipitation.

[0026] After testing, the recovery rates of lithium, cobalt, nickel and manganese are 92.84%, 98.61%, 98.17% and 98.64% respectively; the particulate matter concentration at the waste gas discharge port is 2.1 mg / m 3 , the organic matter concentration is 15.4 mg / m 3 , the fluoride concentration is 1.3 mg / m 3 , the efficient recovery of valuable metals and the efficient treatment of waste electrolyte are realized.

[0027] Example 3

[0028] Air is separated by an air separation device to obtain oxygen-depleted air (containing 0.2% oxygen) and oxygen-enriched air (containing 30% oxygen). Using the oxygen-depleted air as a protective gas, the waste batteries are crushed and sorted to separate and collect the electrode powder, copper foil, aluminum foil, shell and diaphragm, and the electrolyte volatilizes into organic waste gas. Then, the electrode powder and the organic waste gas are co-treated, controlling the ratio of the total amount of Ni / Co / Mn to the total amount of organic components to be 1:4, and adjusting the oxygen content to 15% with the oxygen-enriched air obtained by air separation. The Ni / Co / Mn in the electrode powder is reduced and roasted at 350 °C, and at the same time, the organic components are oxidized; the oxidized organic waste gas is deeply purified through processes such as dust removal, thermal oxidation, defluorination and adsorption, and then discharged up to standard. The electrode powder is obtained by water leaching (liquid-solid mass ratio of 35:1) - recrystallization to obtain Li2CO3 and the leaching residue containing Ni / Co / Mn and the negative electrode powder; the leaching residue is further recovered for the valuable elements therein by sulfuric acid leaching - sodium hydroxide precipitation.

[0029] After detection, the recovery rates of lithium, cobalt, nickel, and manganese are 94.45%, 98.75%, 98.62%, and 98.94% respectively; the particulate matter concentration at the waste gas emission port is 1.9 mg / m 3 , the organic matter concentration is 15.5 mg / m 3 , and the fluoride concentration is 1.6 mg / m 3 , achieving the efficient recovery of valuable metals and the efficient treatment of waste electrolyte.

[0030] Example 4

[0031] Air is separated by an air separation device to obtain oxygen-depleted air (containing 0.2% oxygen) and oxygen-enriched air (containing 30% oxygen). Using the oxygen-depleted air as a protective gas, the waste batteries are crushed and sorted to separate and collect the electrode powder, copper foil, aluminum foil, outer shell, and separator, and the electrolyte volatilizes into organic waste gas. Then, the electrode powder and the organic waste gas are co-treated, controlling the ratio of the total amount of Ni / Co / Mn to the total amount of organic components to be 1:4, and adjusting the oxygen content to 12% with the oxygen-enriched air obtained by air separation. At 400 °C, Ni / Co / Mn in the electrode powder is reduced and roasted, and at the same time, the organic components are oxidized; the oxidized organic waste gas is deeply purified through processes such as dust removal, thermal oxidation, defluorination, and adsorption, and then discharged up to the standard. The electrode powder is obtained by water leaching (liquid-solid mass ratio of 30:1) - recrystallization to obtain Li2CO3 and the leaching residue containing Ni / Co / Mn and the negative electrode powder; the leaching residue is further subjected to sulfuric acid leaching - sodium hydroxide precipitation to recover the valuable elements therein.

[0032] After detection, the recovery rates of lithium, cobalt, nickel, and manganese are 94.86%, 99.12%, 98.95%, and 99.24% respectively; the particulate matter concentration at the waste gas emission port is 2.1 mg / m 3 , the organic matter concentration is 13.9 mg / m 3 , and the fluoride concentration is 1.2 mg / m 3 , achieving the efficient recovery of valuable metals and the efficient treatment of waste electrolyte.

Claims

1. A method for co - disposing waste lithium - ion battery electrode powder and electrolyte, characterized in that The method includes the following steps:

1. Separating air with an air separation device to obtain oxygen-depleted air and oxygen-enriched air. The oxygen content of the oxygen-depleted air is less than 0.5%, and the oxygen content of the oxygen-enriched air is 25% - 35%; 2. Using the oxygen-depleted air in step 1 as a protective gas to crush and separate waste batteries, and separating and collecting electrode powder, copper foil, aluminum foil, casing and separator. The electrolyte volatilizes into organic waste gas; 3. Co-processing the electrode powder in step 2 with the organic waste gas, using the oxygen-enriched air obtained in step 1 as a combustible supporter, and regulating the oxygen content of the combustion atmosphere by adjusting the amount of oxygen-enriched air, so that the organic components in the organic waste gas are incompletely combusted; at the same time, reducing and roasting the electrode powder in the combustion atmosphere. The oxygen content of the combustion atmosphere is controlled at 10% - 15%, and the roasting temperature is controlled at 300 - 600 °C, so that the high-valent metal elements in the electrode powder are reduced, and the organic waste gas and the incompletely combusted products are further oxidized; 4. After the oxidized organic waste gas in step 3 is treated by dust removal, thermal oxidation, defluorination and adsorption purification, it is discharged up to standard; 5. Obtaining Li2CO3 and leaching residues containing Ni / Co / Mn and negative electrode powder by water leaching - recrystallization of the reduced and roasted electrode powder in step 3. The valuable elements in the leaching residues are recovered by leaching - precipitation / extraction, and graphite negative electrode powder is obtained; 2. The method for co-disposing waste lithium-ion battery electrode powder and electrolyte according to claim 1, wherein In step 3, the high-valent metal elements include Ni, Co and Mn, and the ratio of the total amount of Ni, Co and Mn to the total amount of organic components is 1:0.5 - 5; 3. The method for co-disposing waste lithium-ion battery electrode powder and electrolyte according to claim 1, characterized in that, In step 5, the mass ratio of liquid to solid in the leaching of the electrode powder is 20 - 40:1.

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