Method for recovering nickel, cobalt and lithium from iron-aluminum waste and application thereof

Abstract

The application provides a recovery method and application of nickel, cobalt and lithium in iron-aluminum waste, and the recovery method comprises the following steps: roasting the waste, and performing selective leaching on the roasting product to realize separation of iron and aluminum; performing value separation on the leaching solution to obtain a lithium-containing solution; performing dissolution on the leaching residue, and performing complexation and selective precipitation on the leaching residue by using an ammonia buffer to obtain iron mud and a nickel-cobalt-manganese solution, so that nickel, cobalt and manganese are recovered. The method provided by the application separates and purifies iron-aluminum solid waste, realizes separation of iron and aluminum, ensures enrichment and recovery of nickel, cobalt and manganese, reduces adverse effects on the environment, avoids resource waste, and meets the strategy of green development.

Description

Technical Field

[0001] This invention belongs to the field of resource recycling, specifically relating to a method and application for recovering nickel, cobalt, and lithium from iron and aluminum waste. Background Technology

[0002] Currently, metals such as nickel, cobalt, and manganese in waste batteries are often recycled using wet methods. This involves leaching waste battery powder with acid, then gradually removing impurity ions such as copper, iron, aluminum, calcium, and magnesium. After extraction, positive electrode materials are synthesized. Iron and aluminum waste is usually processed by adding sodium hydroxide or soda ash to the acid leaching solution after copper removal to adjust the pH. The iron and aluminum are converted into precipitates, which are then filtered and washed to form waste residue.

[0003] The iron and aluminum waste obtained using existing methods contains a considerable proportion of residual nickel, cobalt, and manganese; moreover, aluminum hydroxide adsorbs a small amount of lithium, resulting in metal loss and reducing the overall recovery rate. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method and application for the recovery of nickel, cobalt, and lithium from iron-aluminum waste. This method achieves rapid separation of iron and aluminum while efficiently recovering valuable metals such as nickel, cobalt, and lithium from iron-aluminum waste.

[0005] According to a first aspect of the present invention, a method for recovering nickel, cobalt, and lithium from iron and aluminum waste is provided, comprising the following steps:

[0006] S1: Roast the iron and aluminum waste, mix the roasted material with the aluminum removal agent solution, and then perform solid-liquid separation to obtain an aluminum-containing solution and aluminum removal slag.

[0007] S2: Mix the aluminum-containing solution obtained in step S1 with a neutralizing agent, perform solid-liquid separation, take the solid phase material for calcination and washing, and then perform solid-liquid separation again to obtain aluminum oxide and lithium-containing solution.

[0008] S3: The aluminum-removing slag obtained in step S1 is mixed with the solvent and the complexing precipitant in sequence, and solid-liquid separation is performed to obtain ferric hydroxide and nickel-cobalt-manganese-containing solution.

[0009] Preferably, the total mass percentage of nickel, cobalt, manganese, and lithium elements in the dry basis of the iron-aluminum waste is not less than 0.5%.

[0010] Preferably, in step S1, the calcination temperature is 600–900°C; and / or the calcination time is 0.5–2 hours.

[0011] More preferably, the roasting is carried out in a rotary kiln, and the energy source used for roasting is at least one of natural gas, biomass pellets, or electricity.

[0012] Preferably, step S1 further includes grinding the calcining material to obtain calcining powder; the calcining powder is the undersize material obtained by grinding the calcining material and passing it through a 150-325 mesh sieve.

[0013] Preferably, in step S1, the aluminum removal agent solution is at least one of sodium hydroxide solution or potassium hydroxide solution; and / or, the solid-liquid ratio of the calcined material to the aluminum removal agent solution is 1:4 to 8 kg / L.

[0014] Preferably, in step S1, the pH of the calcined material mixed with the aluminum removal agent solution is above 12.

[0015] More preferably, the pH of the calcined material mixed with the aluminum removal agent solution is 13-14.

[0016] Preferably, the calcining material is mixed with the aluminum removal agent for 1 to 2 hours.

[0017] Preferably, the molar ratio of the aluminum remover to the calcined feedstock is expressed as OH... - The ratio of Al is 3 to 7:1.

[0018] Preferably, in step S2, the neutralizing agent is at least one of sodium carbonate, sodium bicarbonate, potassium carbonate, or potassium bicarbonate; and / or, the pH of the aluminum-containing solution after mixing with the neutralizing agent is 10.5 to 12.

[0019] More preferably, the cationic type of the neutralizing agent is the same as the cationic type of the aluminum removal agent in step S1.

[0020] Preferably, in step S2, after mixing the aluminum-containing solution with the neutralizing agent, solid-liquid separation is performed to obtain an aluminum-removing filtrate, which is used to prepare the aluminum-removing agent solution in step S1.

[0021] Preferably, in step S2, the calcination temperature is 850–1050°C, and the calcination time is 20–60 min.

[0022] Preferably, step S2 further includes: concentrating, crystallizing, and carbonizing the lithium-containing solution to obtain lithium carbonate.

[0023] More preferably, the carbonization process involves adding a sodium carbonate solution of 300–330 g / L.

[0024] Preferably, in step S3, the solvent is at least one of hydrochloric acid or sulfuric acid; and / or, the concentration of the solvent is 2 to 6 mol / L.

[0025] Preferably, in step S3, the complexing precipitant is an ammonia-ammonium salt mixed solution, wherein the mass fraction of the ammonia is 10% to 20%; and / or, the concentration of the ammonium salt is 1.0 to 1.5 mol / L.

[0026] Preferably, the ammonium salt is at least one of ammonium chloride, ammonium sulfate, ammonium bisulfate, ammonium carbonate, ammonium bicarbonate, or diammonium hydrogen phosphate.

[0027] Preferably, step S3 further includes: crystallizing the nickel-cobalt-manganese solution to obtain nickel sulfate, cobalt sulfate and manganese sulfate.

[0028] According to a second aspect of the present invention, the application of the recycling method as described in the first aspect of the present invention in the recycling of waste lithium batteries is proposed.

[0029] According to one embodiment of the present invention, at least the following beneficial effects are achieved:

[0030] (1) If ammonia is added directly to iron-aluminum slag for complexation, the dissolution rate of nickel, cobalt and manganese is not high and lithium will not be dissolved. If acid is used to dissolve iron-aluminum slag first and then ammonia is added for complexation reaction, lithium will be adsorbed by the hydrolysis products of iron and aluminum during complexation, the recovery rate is not high, and iron and aluminum cannot be effectively separated. The iron-aluminum slag produced still needs to be treated.

[0031] This invention first roasts the iron-aluminum slag, converting the metal compounds into metal oxides. This process utilizes the difference in properties between iron and aluminum to separate them. Furthermore, replacing ammonia water with a mixed solution of ammonia water and ammonium salts makes the pH of the system more stable and controllable during the complexation and precipitation process, which is beneficial for improving the recovery rate of nickel, cobalt, and manganese. Simultaneously, because lithium in the iron-aluminum slag is converted into lithium oxide during roasting, it is transferred to the liquid phase as the aluminum removal process proceeds, reducing the loss of lithium due to adsorption by iron hydrolysis products during the aluminum removal slag treatment. By recovering lithium metal from aluminum-containing materials and nickel, cobalt, and manganese from iron-containing materials, the secondary slag generated from the iron-aluminum slag treatment can also be utilized.

[0032] (2) The present invention effectively achieves the separation of iron and aluminum, as well as the separation of lithium from nickel, cobalt and manganese by synergistic use of roasting, aluminum removal, filtrate neutralization, filter residue dissolution and complexation precipitation, thereby improving the metal element recovery rate. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0034] Picture 1 This is a flowchart of Embodiment 1 of the present invention. Detailed Implementation

[0035] The following will describe the concept and technical effects of the present invention clearly and completely with reference to the embodiments, so as to fully understand the purpose, features and effects of the present invention.

[0036] Elemental analysis was performed on the iron and aluminum waste used in the following examples and comparative examples, and the results are shown in Table 1:

[0037] Table 1. Detection results of major elements in iron and aluminum waste (%)

[0038] Fe Al Ni Co Mn Li 13.80 9.48 0.80 0.79 0.59 0.218

[0039] Example 1

[0040] This embodiment provides a method for recovering nickel, cobalt, and lithium from iron and aluminum waste, such as... Picture 1 As shown, it includes the following steps:

[0041] (1) Iron and aluminum waste is fed into a rotary kiln and roasted at 750°C for 1 hour. After the roasted sand is cooled, it is fed into a Raymond mill and ground to 150 mesh.

[0042] (2) Take 100g of the powder from step (1), add 300ml of water to make a slurry, then add 44g of sodium hydroxide, add 150mL of pure water, stir for 1 hour and then separate the solid and liquid to obtain aluminum-free filter residue and aluminum-containing filtrate.

[0043] (3) Add 100 mL of sulfuric acid with a concentration of 2 mol / L to the aluminum-removing filter residue from step (2), stir for 1 h, then continue to pass in a mixed solution of 150 mL of 10% wt ammonia water and 1 mol / L ammonium chloride, and stir again for 1 h. Filter and separate, wash the filter residue with pure water to obtain ferric hydroxide, and concentrate and crystallize the filtrate to obtain nickel sulfate, cobalt sulfate and manganese sulfate.

[0044] (4) Add 200g / L sodium carbonate neutralizing agent solution dropwise to the aluminum-containing filtrate until the pH is 10.5. Filter to separate and obtain aluminum hydroxide precipitate. First, send the precipitate into a rotary kiln and calcine at 1100℃ for 20 minutes. Then, wash the calcined product with pure water to obtain a pure solution containing Li and aluminum oxide product.

[0045] (5) The Li-containing solution from step (4) is heated to 70°C to concentrate the Li content in the solution to above 20 g / L. Then, 300 g / L of sodium carbonate solution is added, and the solution is evaporated and crystallized again at 70°C to separate the sodium-containing filtrate and lithium carbonate crystals. The sodium-containing filtrate is reused to prepare sodium carbonate solution. The crystals are washed and dried to obtain lithium carbonate.

[0046] Example 2

[0047] The only difference from Example 1 is that in step (1), the iron and aluminum waste is roasted at 600°C for 2 hours.

[0048] Example 3

[0049] The only difference from Example 1 is that in step (1), the iron and aluminum waste is roasted at 820°C for 1 hour.

[0050] Example 4

[0051] The only difference from Example 1 is that in step (1), the iron and aluminum waste is roasted at 660°C for 1.5 hours.

[0052] Example 5

[0053] The only difference from Example 1 is that in step (1), the iron and aluminum waste is roasted at 900°C for 0.5h.

[0054] Example 6

[0055] The only difference from Example 1 is that in step (2), sodium hydroxide is replaced with an equal amount of potassium hydroxide, and in step (4), sodium carbonate neutralizing agent solution is replaced with potassium carbonate solution of equal concentration.

[0056] Example 7

[0057] The only difference from Example 1 is that the stirring time in step (2) is 2 hours.

[0058] Example 8

[0059] The only difference from Example 1 is that in step (3), sulfuric acid is replaced with an equal amount of hydrochloric acid, and the concentration of the hydrochloric acid is 6 mol / L; the filtrate of step (3) is concentrated and crystallized to obtain nickel chloride, cobalt chloride and manganese chloride.

[0060] Example 9

[0061] The only difference from Example 1 is that in step (3), sulfuric acid is replaced with an equal amount of hydrochloric acid, and the concentration of the hydrochloric acid is 4 mol / L; the filtrate of step (3) is concentrated and crystallized to obtain nickel chloride, cobalt chloride and manganese chloride.

[0062] Example 10

[0063] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 10% wt ammonia and 1 mol / L ammonium sulfate.

[0064] Example 11

[0065] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 15% wt ammonia and 1 mol / L ammonium bisulfate.

[0066] Example 12

[0067] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 13% wt ammonia and 1 mol / L ammonium carbonate.

[0068] Example 13

[0069] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 15% wt ammonia and 1 mol / L ammonium bicarbonate.

[0070] Example 14

[0071] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 20% wt ammonia and 1 mol / L diammonium hydrogen phosphate.

[0072] Example 15

[0073] The only difference from Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of mixed solution of 10% wt ammonia and 1 mol / L diammonium hydrogen phosphate.

[0074] Comparative Example 1

[0075] The only difference from Example 1 is that the roasting process in step (1) is replaced by drying the material at 120°C to constant weight.

[0076] Comparative Example 2

[0077] The only difference from Comparative Example 1 is that in step (3), the mixed solution of 10% wt ammonia and 1 mol / L ammonium chloride is replaced with an equal amount of ammonia with the same mass fraction.

[0078] Test case

[0079] Elemental analysis was performed on the ferric hydroxide and aluminum oxide obtained in the recovery methods of Examples 1-15 and Comparative Examples 1-2, and the results are shown in Table 2:

[0080] Table 2. Element detection results of the examples and comparative examples.

[0081]

[0082]

[0083]

[0084] As shown in Table 2, the nickel, cobalt, and manganese content in the ferric hydroxide obtained in the examples is less than 0.11%, and the lithium content in the alumina product is less than 0.1%. This indicates that the present invention achieves efficient separation and productization of iron and aluminum in iron and aluminum waste, while also achieving the separation of nickel, cobalt, manganese, and lithium, improving the recovery of each metal, and reducing metal loss.

[0085] The nickel sulfate, cobalt sulfate, and manganese sulfate obtained in the above embodiments can be used to prepare battery precursors, and iron hydroxide can be used to prepare pigments or building materials.

[0086] The above embodiments are only some embodiments of the present invention, not all embodiments, and should not be construed as limiting the scope of protection of the present invention. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

Claims

1. A method for recovering nickel, cobalt, and lithium from iron-aluminum waste, characterized in that, Includes the following steps: S1: The iron and aluminum waste is roasted, and the roasted material is mixed with the aluminum removal agent solution. After solid-liquid separation, an aluminum-containing solution and aluminum removal slag are obtained. S2: Mix the aluminum-containing solution obtained in step S1 with a neutralizing agent, perform solid-liquid separation, take the solid phase material for calcination and washing, and then perform solid-liquid separation again to obtain aluminum oxide and lithium-containing solution. S3: The aluminum-removing slag obtained in step S1 is mixed with solvent and complexing precipitant in sequence, and after solid-liquid separation, ferric hydroxide and nickel-cobalt-manganese-containing solution are obtained. In step S1, the aluminum removal agent solution is at least one of sodium hydroxide solution or potassium hydroxide solution; In step S3, the solvent is at least one of hydrochloric acid or sulfuric acid.

2. The recycling method according to claim 1, characterized in that, The total mass percentage of nickel, cobalt, manganese, and lithium in the dry basis of the iron and aluminum waste shall not be less than 0.5%.

3. The recycling method according to claim 1, characterized in that, In step S1, the calcination temperature is 600~900℃; and / or the calcination time is 0.5~2h.

4. The recycling method according to claim 1, characterized in that, In step S1, the solid-liquid ratio of the calcined material to the aluminum removal agent solution is 1:4~8 kg / L.

5. The recycling method according to claim 1, characterized in that, The molar ratio of the aluminum removal agent solution to the calcined material is expressed as OH. - The ratio of Al is 3 to 7:

1.

6. The recycling method according to claim 1, characterized in that, In step S2, the neutralizing agent is at least one of sodium carbonate, sodium bicarbonate, potassium carbonate, or potassium bicarbonate; and / or, the pH of the aluminum-containing solution after mixing with the neutralizing agent is 10.5 to 12.

7. The recycling method according to claim 1, characterized in that, In step S2, the burning temperature is 850~1050℃, and the burning time is 20~60min.

8. The recycling method according to claim 1, characterized in that, In step S3, the concentration of the solvent is 2~6 mol / L.

9. The recycling method according to claim 1, characterized in that, In step S3, the complexing precipitant is an ammonia-ammonium salt mixed solution, wherein the mass fraction of the ammonia is 10%~20%; and / or, the concentration of the ammonium salt is 1.0~1.5 mol / L.

10. The application of the recycling method according to any one of claims 1-9 in the recycling of waste lithium batteries.

Images