IL285897A - Hydrometallurgical process for recovery valuable metals from spent lithium-ion batteries - Google Patents

Description

Hydrometallurgical process for recovery valuable metals from spent lithium-ion batteries.

FIELD OF THE INVENTION [Para 1] The present invention relates to an improved method for recovering valuable metals from waste material containing lithium-ion cylindrical electrochemical cells, (hereunder "Li-ion batteries" or "Li-ion cells"). More specifically, the invention provides a method for recovering cobalt and lithium together with other valuable metals from waste material.

BACKGROUND OF THE INVENTION AND PRIOR ART [Para 2] Li-ion batteries are used to store and supply electrical power for many products such as vehicles, computers, telephones, and any other product empowered by Li-ion batteries (hereinunder "material").

[Para 3] Li-ion batteries include at least one Li-ion cell that includes an electrode. The electrode includes: - one or more sheets of positive electrode (including intercalating lithium positive active material on the backing sheet) with a positive contact; - one or more sheets of negative electrodes (usually negative active material with lithium intercalation on the support sheet) with a negative contact; 20 - a separator (typically a sheet of microporous polyolefin), electrically separating any two electrodes; - an electrical separator, (may be a sheet of microporous polyolefin), constituting a conductive separation between any two electrodes.

[Para 4] The positive active material may comprise metal oxides such as Li, Co, Ni, Mn. The negative active material may comprise metals (copper foil) and Li cations. The support sheets are usually metal foils, such as aluminum and copper. The contacts are usually made of a metal such as nickel-plated steel.

[Para 5] The electrode, flat or rolled, is located inside a cell housing (herein- after "casing" or "housing"). A cell housing is typically made of metal (e.g., steel), plastic or foil. One or more cells make up a single Li-ion battery.

[Para 6] A Li-ion battery may include an electrolyte, (e.g., LiPF) in a solvent such as fluorinated alcohol (CnFn+2OH), to provide a conductive separation between any two electrodes.

[Para 7] In one particularly common Li-ion battery, a plastic, aluminum, or steel battery housing contains a plurality of cylindrical Li-ion cells and optionally monitoring electronics.

[Para 8] Each cylindrical Li-ion cell includes a cylindrical iron-containing (e.g., steel) housing that also serves as one of the two contacts in which is held a rolled-up electrode. The iron-containing casing is entirely or almost entirely covered with an insulating coating such as paint or plastic films.

[Para 9] Some of the metals in an electrode of a Li-ion cell are toxic and/or valuable. In addition, the presence of an alcohol-containing electrolyte in the composition of a cylindrical cell is inflammable and may cause an explosive situation if the tightness of such cell in air is violated. Therefore, it is beneficial to have an environmentally friendly and efficient method for recycling batteries containing Li-ion cells in order to recover valuable metals. For example, to prevent pollution of the environment with toxic transition metal oxides and to allow the reuse of these valuable metals in industry.

[Para 10] Recycling of batteries is becoming more and more important due to the increase in the number of used up batteries. Consequently, there is quite a lot of prior art on this subject.

[Para 11] Most of the prior art documents disclose dismantling the battery and converting it into powder form, through crushing, disassembling, dipping in alkali solution, sieving, washing, and pulverizing, before immersing into acids for recovery process.

[Para 12] It is known in the prior art to break or cut open the iron-containing housing and then to manually separate the electrodes from the housing remnants. Li-ion battery remnants are sometimes pre-crushed to prepare electrode material for hydrometallurgical processing. Since the electrolyte in Li-ion cells is toxic, corrosive and inflammable, complex and expensive methods are required to safely break or cut open the steel casing to access the electrodes and then to safely manipulate a separated electrode for further processing.

[Para 13] Other documents disclose the use of dilute acid instead of concentrated acids for leaching action along with sulphate and carbonate containing compounds as precipitating agents for the conversion.

[Para 14] Other documents disclose the use of mineral acid along with HO as a reductant of Co (III) cations to the Co (II) state to increase the rate of leaching of transition metal oxides from the cathode material. At the same time, liquid extraction methods using various organic solvents, in particular, tertiary amines or organophosphorus acids, are used to isolate cobalt and bound metals from the final solution.

[Para 15] One document provided, under additional category, a method that includes grinding batteries followed by leaching valuable metals from the resulting powder with a solution of mineral acid in the presence of hydrogen peroxide.

[Para 16] CN106229577A (Jinchuan Group Co Ltd 14.12.2016) discloses mixed leaching method for positive and negative electrode materials of waste nickel-metal hydride battery, and CN107326181B (Jinchuan Group Co Ltd 1.9.2017), that discloses a method for preparing ternary hydroxide from nickel cobalt manganese recycled from used Li-ion batteries through liquid phase method. Both patents disclose use of concentrated acid and hydrogen peroxide for leaching of various metals from waste battery powder. H2O2 acts as reducing agent and enhance the solubility of metals rather than acting as precipitating agent.

[Para 17] KR101841700B1(to Korea Institute of Geoscience and Mineral Resources, 26.3.2018) disclosed a method for recovering valuable metals selectively from mixed used batteries where the metals are leached from scrap powder obtained from battery using dilute sulphuric acid and then selectively precipitated by changing the pH-value using peroxide-based compounds (which act as oxidising agents) for recovery process.

[Para 18] Another example is EP2444507B1 (to Luidold, Stefan et al. .10.2010) which disclosed a method of recycling rare earth metals within a waste material (including batteries), wherein the method comprises acidic leaching of the waste material (particularly in a still pyrolysis solid matter, more particularly in the form of batteries reduced to small pieces are directly made subject of an acidic leaching) using a halogen acid (particularly hydrochloric acid) for solubilizing (or dissolving) metals of the waste material while maintaining nonmetallic materials (such as graphite, plastic or other organic materials) of the waste material in solid form, separating the remaining solid components of the leached waste material from a solution of the solubilized (or dissolved) metals, and precipitating selectively the rare earth metals in the solution while maintaining other metals in dissolved form.

[Para 19] The main disadvantage of the above-mentioned prior art is the fire and explosion hazard of the process of crushing used Li-ion batteries. To avoid such a result, it is necessary to use special equipment for crushing battery scrap in an inert atmosphere, vacuum or liquid environment, which significantly increases the operating and production costs.

[Para 20] The disclosed invention provides a method for recovering cobalt and lithium together with other valuable metals in a new safer and simple method.

SUMMARY OF THE INVENTION [Para 21] Some embodiments of the invention herein relate to the field of Li- ion batteries and, more particularly but not exclusively, to methods for processing Li-ion cells having steel or plastic housings. Specifically, some embodiments relate to methods of separating an electrode of a Li-ion cell from a steel housing that, in some embodiments, have one or more advantages compared to methods known in the art.

[Para 22] This hydrometallurgical method for removing metals from used Li- ion batteries teaches a method of dismantling and disassembling all types of waste material containing Li-ion batteries, mechanical physical destruction of the batteries and separation of mixed electrode cells with cathode material removed to be dissolved by mineral acid containing reduced agent ions, with the extraction of valuable metals from leaching products by traditional methods. 20 [Para 23] This process also allows a mixture of all types of Li-ion batteries to be processed, including polymer Li-ion batteries, with no costly battery scrap shredding in a liquid or inert environment.

[Para 24] This method shows good technological characteristics in terms of valuable metal recovery, efficiency, and economic feasibility.

[Para 25] The invention may be better understood with reference to the figures and experiments.

BRIEF DESCRIPTION OF THE FIGURES [Para 26] Fig. 1 – A general flowchart of preparatory steps of the embodiments.

[Para 27] Fig. 2 – A flowchart of an embodiment of the method of burning/pyrolysis of the Li-ion batteries as demonstrated in experiment 4.

[Para 28] Fig. 3 - Fig. 3 – A continuation of flowchart of fig.2 showing the options of final solution.

[Para 29] Fig. 4 –A flowchart of another embodiment of the method.

[Para 30] Fig. 5 – A continuation of flowchart of fig.4 showing the options of final solutions, refers to experiment 11.

[Para 31] Fig. 6 – a table showing the different results of experiment 5 when leaching the cathode material in FeSO.

[Para 32] Fig. 7 – is a picture of a typical cylindrical electrochemical cell in a steel housing with a protective insulating plastic film.

[Para 33] Fig. 8 – is a picture of a cylindrical cell in a steel housing without a protective insulating plastic film.

[Para 34] Fig. 9 – is a picture of a Li-ion cell in a steel housing without a protective insulating plastic film, after burning and manual separation of the burned batteries.

[Para 35] Fig. 10 - is a picture showing the Li-ion cell in dissolved iron housing.

[Para 36] Fig. 11 - is picture showing exposed mixed electrode material of crushed Li-ion cell.

[Para 37] Fig. 12 – is picture showing isolated cathode material after physic- mechanical separation of crushed electrodes material.

[Para 38] Fig. 13 – is a graph showing the results of X-ray phase analysis of the isolated cathode material.

[Para 39] Fig. 14- is a picture showing crushed burned Li-ion cells after magnet separation of crushed material.

[Para 40] Fig. 15 - A table– showing the effect of the concentration of H2SO on the time required to complete dissolving of iron housing of Li-ion cells in experiment 1.

[Para 41] Fig. 16 – A Table showing the effect of the pH-value of FeSO4 solution on the recovery of metals in test A of experiment 1.

[Para 42] Fig. 17 – A Table showing the effect of hydrochloric acid (HCl) on the duration of dissolving iron housing of Li-ion cells in experiment 2.

[Para 43] Fig. 18 - A Table showing the effect of pH-value of FeCl filtered solution on the recovery of metals in experiment 3.

[Para 44] Fig. 19 – A table showing the results of experiment 4 when using burned Li-ion batteries.

[Para 45] Fig. 20 – A table showing the results of burning out of regular Li-ion batteries 103 in experiment 7.

[Para 46] Fig. 21 – A table showing the results of burning out of polymer Li- ion batteries in experiment 8.

DETAILED DESCRIPTION OF THE DRAWINGS [Para 47] Fig. 1 is a general flowchart of step 1 of the embodiments. All presented embodiments start from dismantling the electronic equipment and separating the Li-ion batteries in order to get naked Li-ion batteries.

[Para 48] Fig.2 shows a flowchart of an embodiment of the method where the burned Li-ion cells in naked iron housing are magnetically separated as explained in experiment 4 and the results of the 3 tests performed on the leached FeSO4 solution are shown in the table in fig. 18.

[Para 49] Fig.3 shows the two final solutions as a continuation of fig. 2 for getting Fe alloys, cathode material and alloy steel for manufacturing.

[Para 50] A flowchart of another embodiment of the method for getting cathode material and alloy steel for manufacturing, is shown in figs 4 and .

[Para 51] A table showing the different results of experiment 5 when leaching the cathode material in FeSO4 is presented in fig. 6.

[Para 52] The table in Fig. 15 relates to experiment 1 showing the effect of the concentration of H2SO4 on the time required to complete dissolving of iron housing of Li-ion cells. The conclusion from the table teaches that the optimal conditions for completing the dissolving of iron housing is: H2SO concentration of 1.8-2.6 mol/dm3 and stirring for 16-18 hours.

[Para 53] The table in Fig. 16 relates to test 1 of experiment 1 showing the effect of the initial pH of the FeSO4 leach solution on the recovery of lithium and associated transition metals. The conclusion from the table teaches that the optimal pH-value range for leaching the cathode material is 0.4- 0.6, since in a more acidic environment, the solubility of aluminum and copper increases sharply.

[Para 54] The table in Fig. 17 relates to experiment 2 showing the effect of the concentration of hydrochloric acid (HCl) on the duration of dissolving iron housing of Li-ion cells. The conclusion from the table teaches that the optimal conditions for dissolving iron housing is by immersing the Li-ion cells in 1.4-1.8M of hydrochloric acid (HCl) solution for 12-18h.

[Para 55] The table in Fig. 18 relates to experiment 3 showing the effect of the pH-value range on FeCl filtered solution on the recovery of lithium and associated transition metals. The conclusion from the table teaches that, the optimal pH-value range for leaching the cathode material is 0.5-0.8, since in the more acidic region, the solubility of aluminum and copper increases sharply.

[Para 56] The table in Fig. 19 relates to experiment 4 showing the tests of leaching burned cathode materials in sulfuric acid (HSO) solution with pH-value of 0.50 recovered a relatively low rate of metals (table in fig. line 2).

[Para 57] The table in fig. 20 relies to experiment 7 showing that the optimal results for burning-out of regular Li-ion batteries 103 is in temperature range of 250c - 650c.

[Para 58] The table in fig. 21 relies to experiment 8 showing that the optimal results for burning-out of Li-ion polymer batteries 400 is in temperature above 400c.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Para 59] An embodiment is an example or implementation of the inventions.

The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[Para 60] Reference in the specification to "one embodiment", "an embodiment", "some embodiments" or "other embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment, but not necessarily all embodiments, of the inventions. The invention is not necessarily limited in its application to the details of construction and the arrangement of components, or the methods set forth herein. The invention may be practiced in other ways or implemented in various ways.

It is understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

[Para 61] The present invention relates to an improved process and method for recovering cobalt and lithium together with other valuable metals from Li- ion batteries. The method includes physical separation processes, dismantling and disassembling panels with automotive Li-ion batteries and other battery waste with the release of plastic, electronic waste and finger Li-ion batteries into separate products, as well as chemical operations, in particular, dissolving the iron body of finger batteries with a sulfuric acid (H2SO4) solution in the presence of hydrogen peroxide.

[Para 62] The method hereunder described is performed on solid waste containing Li-ion cells with iron housing. The Li-ion cells having electrodes contained within an iron housing (fig 8).

[Para 63] As is known in the art, Li-ion cells are typically a component of a Li- ion battery. The battery has a plastic or metal outer housing that houses a plurality of cylindrical Li-ion cells and electronics for monitoring. Each Li- ion finger cell has a cylindrical body containing iron, which is completely or almost completely covered with an insulating coating such as paint or plastic film (fig. 7).

[Para 64] In general, Li-ion cells do not have an open iron housing, but rather the iron housing is covered with an insulated coating and are held inside the battery housing.

[Para 65] As used herein, the term "iron-containing body" refers to a cell housing made of iron or a ferromagnetic iron-alloy containing at least 80% by weight of iron, preferably at least 95% by weight of iron.

[Para 66] As used herein, the term "exposed electrode cells" refers to electrode cells that, after dissolving of the steel body, carry at least 15% by weight of residual iron, preferably 2-5% by weight of iron. The electrode cells, when immersed in a reduced solution, at least 40% (preferably at least 60%, at least 80%, at least 90% and even 100%) of the housing outer surface is exposed to contact with the reduced solution. The balance of the housing outer surface that is not exposed to contact with the reduced solution may be coated or covered, e.g., by paint or plastic film.

[Para 67] Provided solid waste containing Li-ion cells having electrodes within an iron-containing housing without an insulating coating includes any number of such Li-ion cells, for example, at least 5% by weight of such Li- ion cells. However, as discussed in more detail below, a particular utility of the teaching herein is such that the teachings are preferably applied to solid waste that includes a relatively higher proportion of Li-ion cells having electrodes inside an exposed iron-containing housing, in some embodiments at least 10%, at least 30%, at least 60% and even at least 75%.

In some embodiments, at least 95% by weight of the provided solid waste comprises Li-ion cells having an electrode within an iron-containing housing.

[Para 68] The first step in some embodiments is mechanical separation of Li- ion cells 100 from battery waste, mainly plastic and electronics by dismantling and disassembling 101 EV and all types of Li-Ion batteries and isolate the Li-Ion batteries 102.

[Para 69] In some embodiments, the separation of the Li-ion cells from the waste material comprises mechanical procedures. Mechanical processing of waste material includes any suitable method or combination of methods known in the field that separate the Li-ion cells from the other battery components such as battery housing and control electronics, without breaking the Li-ion cell housing.

[Para 70] Such methods include selective crushing of the plastic housing of a battery, separation of plastic, electronics, and Li-ion finger cells and then removing the insulating coating, for example, by placing the batteries in a metal tube equipped with a horizontal hydraulic press, where the plastic housing is destroyed by the impact of the press. After that, the material is unloaded and then, by manual separation, electronics and finger-type Li- ion cells 303 are isolated from the crushed plastic. The finger-type Li-ion cells are transported along a conveyor to an adjacent apparatus, where the insulating coating is removed from the finger-type Li-ion cells 305 with the help of different methods, including rotating metal brushes.

[Para 71] In one embodiment, is provided a method for processing Li-ion polymer batteries 400 having an insulating cover film. The insulating cover film is removed 401, getting naked Li-ion polymer batteries 402.

[Para 72] In another embodiment is provided a method for processing Li-ion having iron-containing housing covered by plastic film (fig.7).

[Para 73] The Li-ion batterie's plastic housings are destructed 300 following a manual separation of the destructed batteries 301 into crushed plastic 3 and electronic scrap 303 getting cylindrical EC cells in iron (metal) housing, the insulation film of the iron housing is removed 305, getting naked Li- ion cylindrical EC cells in naked iron housing 306.

[Para 74] In another embodiment there is provided a method for separating cylindrical Li-ion cells from battery waste by burning/pyrolysis of battery scrap 200.

[Para 75] Burned batteries 204 contain cinder. Powdered cinder is the residue of burned components. In embodiments in which the burned batteries include polymer batteries 400, (which do not have an iron housing or electrodes within the iron housing), the residue also contains carbonized polymer battery cells.

[Para 76] In some embodiments, the burnt-out batteries are Li-ion cells having electrodes contained in an exposed iron-containing housing that is further processed in accordance with the teachings herein.

[Para 77] The Li-ion cells from burned-out batteries are either manually separated from powdered residue, or by gravity separation, or by magnetic separation 207, using an electrostatic separator. The separated Li-ion cells are further processed as hereunder described. The carbonaceous waste may be used in the manufacturing of cinder blocks.

[Para 78] When the burned-out residue contains electrodes, the carbonaceous materials are further processed to recover metals from them, for example, by manual separation or by a vibrating screen.

[Para 79] In some embodiments, residue of electronic components found in common battery cinder are separately processed. In other embodiments, residue of electronic components and polymer batteries are recycled together with Li-ion cells as hereunder described.

[Para 80] The advantage of separating Li-ion cells from plastic components of common batteries by burning is that at least 60-80% of plastic components of Li-ion batteries significantly reduces the volume of recyclable materials and removes nearly 100% of the insulating film from the iron housing of cylindrical electrochemical cells, toxicity is reduced, and the risk of inflammation or explosion no longer exists, since in combustion, the fluorinated alcohol contained in electrolyte burns-out, and the fluorinated burned-out products are removed through the corresponding safety valve.

[Para 81] Another advantage of separating Li-ion cells from plastic battery components by burning is that when burning predominantly polymer batteries containing a small amount of plastic, significant fuel consumption is required to achieve an optimal combustion temperature (see figs 20 & 21). Adding regular batteries 103 to polymer batteries 400 with a high plastic content, allows reducing gas consumption by 20-30% or diesel fuel by 15-20%.

[Para 82] Another advantage of separating Li-ion cells from plastic battery components, by burning the batteries, is that the cinder can be crushed by a standard hammer mill without the risk of inflammation or explosion.

[Para 83] The crushed material of the burned-out butteries is subjected to magnetic separation, for extracting iron, then electronic circuit elements are separated by manual separation, after which the cathode material is isolated by gravity separation and screening methods (fig. 12).

[Para 84] The separated cathode material is leached with an iron sulfate solution (FeSO4) obtained by dissolving the previously separated iron with a dilute solution of sulfuric acid. Moreover, burning speeds up dissolution of iron.

[Para 85] The hydrometallurgical process for recovering valuable metals from spent Li-Ion batteries may be performed in the following ways.

[Para 86] One embodiment comprises the steps of: a) dismantling and disassembling panels of all types of Li-ion batteries 101; b) destruction of the plastic housing of the Li-ion batteries 300 for manual separation 3 and getting plastic waste 302, electronic components 303 and Li-ion cylindrical electrochemical cells in iron housing 304; c) removing the protective insulating coating from the metal housing of the Li-ion cylindrical electrochemical cells 305, may be carried out by rotating metal brushes or by abrasive powder; d) dissolving the iron housing of the cylindrical Li-ion cells in mineral acid to form a solution containing Fe2+ - ions. The mineral acid is selected from the group consisting of sulfuric acid (HSO), hydrochloric acid (HCl) and may be carried-out with diluted HSO solution for 16-18 h or with HCl solution for 12-18h; e) crushing the Li- ion cells without the metal housing; f) physical-mechanical separation of the crushed mixed electrodes to obtain an enriched cathode material may be carried-out by sifting and gravity separation; g) leaching of the cathode material with a solution containing Fe2+ -ions or a mixture of FeSO4 solution and organic acid to recover valuable metals may be carried-out in pH-value range of 0.4-0.6, liquid being in solid phase ratio 5:1 in room temperature or leaching the cathode material with FeCl2 solution carried-out in pH-value range of 0.5-0.8, in same conditions. The productive leaching solution FeSO or FeCl may be used for further treatments of new cathode material.

The productive leaching solution FeSO4 or FeCl2, after first leaching operation, acidifies from pH-value 1.5 to 0.40-0.60. The leaching of the cathode material may also be a mixture of FeSO solution with citric acid and Fe2+- -ions. The leaching of the cathode material may also be a mixture of FeCl solution with citric acid and Fe2+- -ions; h) recovery of cobalt, nickel, manganese and lithium from the final solution by traditional methods. i) to obtain a collective precipitate of iron, cobalt, nickel and manganese oxalates, the final leach solution is pre-neutralized with NaHCO solution to pH-value 4, then, with continuous stirring, oxalic acid powder is added in a ratio of 1.5 mol of acid for each mol of iron, cobalt, nickel and manganese salts contained in the solution (see experiment 10).

[Para 87] In this case, the pH-value of the solution is adjusted to 9.8 with an alkaline solution. The precipitation of iron, cobalt, nickel and manganese oxalates is filtered, washed, dried and Calcinated in 550C to obtain ferromagnetic cobalt trioxide, Ni oxide and Mn dioxide (see experiment ).

[Para 88] Iron is magnetically removed from the ferromagnetic iron oxide. The magnetic separation is carried-out in a low-frequency electromagnetic field of 160 W/g with a frequency of 5.2 kHz.

[Para 89] To successively recover Mn(II) and Fe(II), from final productive solution by liquid-liquid extraction the pH-value of the initial productive solution is brought to 2.56 then mixed with of an organic solvent selected from the group of phosphor organic acid (e.g. Cyanex 272 in kerosene) at a ratio of O: L = 1: 1. The organic solution is stirred for 15 min. At the first stage, iron and manganese are extracted and stripped by diluted HSO solution at a ratio of O:L= 8:1. Manganese and iron are retreived from the sulfuric acid solution in the form of hydroxides (fig. 5).

[Para 90] For the complete separation of cobalt from the first raffinate, the pH- value of the aqueous phase is brought to 5.4 and it is possible to transfer 94% of cobalt and only 2.2% of nickel into the organic solution.

[Para 91] For recovering the cobalt, the organic solution is immersed in HSO solution at O: L ratio of 8:1. The cobalt isolated from the solution is in the form of oxalate. The oxalate is washed, dried, and burned at 550°C. The trioxide obtained is with a content of less than 2.5% metal impurities.

[Para 92] The nickel from the second raffinate is precipitated at pH-value 9. in the form of insoluble oxalate (see experiment 11).

[Para 93] Another embodiment comprises the steps of a) dismantling and disassembling panels of all types of Li-ion batteries 101; b) burning or /pyrolysis of the Li-ion batteries 200 may be carried-out in temperature range of 450-650C. Spent lithium-ion batteries may be burned without oxygen in pyrolysis mode in temperature range of less than 450C.

[Para 94] Spent polymer Batteries 400 are quicker to burn-out than Li-ion ordinary batteries103 in between 10-60%; c) removal of electronic components and Li-ion cells in iron housing from cinder by manual separation and mixing and dissolving the iron housing, in mineral acid to form a solution containing Fe2+ -ions.; The mineral acid is selected from a group consisting of sulfuric acid (HSO), hydrochloric acid (HCl) and may be carried-out with HSO solution during 16-18 h or with 1.4-1.8 M HCl solution during 12-18h; d) crushing the non-hazardous Li-ion cells; e) removing iron from the crushed electrochemical cells by magnetic separation to obtain cathode material; f) dissolving the iron housing of the Li-ion cells in mineral acid to form a solution containing Fe2+ -ions: leaching the cathode material in a solution containing Fe2+ -ions to recover valuable metals; [Para 95] The process of the destruction of plastic housing of Li-Ion batteries 300 may be carried-out in a metallic tube by horizontally hydraulic press; [Para 96] The impact force of the horizontally hydraulic press is regulated by a programmable regulator so that the impact energy does not exceed 2- kJ; [Para 97] In the following, some experiments performed by inventor will be described.

[Para 98] Experiment 1. 20 kg of wasted material (plastic cartridges for laptop computers containing from 6 to 8 cylindrical Li-ion cells). 2. The Li-ion batteries were opened by a metal pipe comprising a horizontal hydraulic press, the impact force of which is regulated by a programmable regulator, and the impact energy varied from 1.0 to 8. kg. In the course of work, it was found that the optimal work of the press is achieved with an impact energy of 2.0-6.0 kg. 3. Manual dismantling and disassembling. Receiving:18% (by weight) crushed plastic, 4% electronic scrap, and 78% cylindrical electrochemical cells in an iron housing were obtained. 4. The cylindrical electrochemical cells (15.6 kg) with protective insulation were placed in a powder mill, where the plastic protective insulation was removed in 15 minutes. 15.48 kg of cylindrical EC cells in naked iron housing were obtained.

. The cylindrical EC cells in naked iron housing were loaded into 100 liter of plastic reactor containing 78 liters of 2.4M sulfuric acid solution (HSO). 6. The solution was continuously mechanically stirred (300 rpm) during the course of 18 hours. After 18 hours, the solution was drained. (See table in fig. 10) 7. The exposed electrode cells were neutralized with wash water. 8. The wash water was mixed with a ferrous sulfate solution (FeSO4). 9. The washed naked il-io cells weighing 13.4 kg were crushed by a hammer mill to metal particles, (copper and aluminum foil) of 2–3 mm.

. The rest was powdered graphite, carbon and cathode material (mixture of oxides of cobalt, nickel, manganese and lithium). 11. The crushed material was separated in sieving and gravity table releasing metals foil particles (Cu, Al) and heavy fraction of the cathode material weighing 3.432 kg. 12. The cathode material was divided into 3 equal portions of 1.144 kg for comparative experiments.

[Para 99] Test A: 1. 1/3 quantity of cathode material was mixed with 6 liters of ferrous sulfate solution (FeSO4) at pH-value 0.54. 2. The mixture was stirred continuously. 3. The mixed cathode material was leached at room temperature for hours. 4. Thereafter, the productive solution and the insoluble residue were separated by vacuum filtration.

. The precipitate was washed, and the solution was depleted. 6. The insoluble residue in the form of a carbonaceous substance, underwent further decomposition in a solution of aqua regia. 7. The content of valuable metals in both solutions was determined by ICP spectroscopy method. The degree of extraction of valuable metals into the productive solution was determined by the formula: [Cme (p) / (Cme (r) + Cme (p))] x 100% = Eme,%, where Cme (p) is the metal content in the productive solution, Cme (r) is the metal content in the solid residue. 8. As a result of leaching the cathode material with an iron sulfate solution (FeSO) at room temperature, the extraction of valuable metals into a productive solution of cobalt, nickel, manganese, and lithium was 98.6%, 94.4%, 92.2%, and 92.6%, respectively. 9. To study the effect of the initial pH-value on the leaching solution for recovery of lithium and associated transition metals, 5 portions of 100g of insulated cathode material were leached with an iron (II) sulfate solution containing 0.56 mol/dm Fe with pH-value range 0.20-0. for 3 hours in room temperature. The test results are presented in the table in fig.13.

[Para 100] Test B: 1. 1/3 quantity of cathode material was mixed with 6 liters of ferrous sulfate solution (FeSO4) with pH-value 0.48. 2. The mixture was stirred continuously. 3. The mixed cathode material was leached at room temperature for hours. 4. Thereafter, the leached mixture was separated by vacuum filtration into productive solution and insoluble residue.

. The insoluble residue was decomposed with aqua regia. 6. Both solutions were analyzed by the ICP spectroscopy method. 7. The recovery of nickel, manganese, and lithium was 32.3%, 44.2%, 36.7%, and 28.4%, respectively.

[Para 101] Test C: 1. 1/3 quantity of cathode material was mixed with 6 liters of ferrous sulfate solution (FeSO) with pH-value 0.48. 2. 0.43M concentration of hydrogen peroxide solution ( НО) was fed into the mixture. 3. The mixture was stirred at room temperature continuously for 3 hours. 8. The mixture was separated by vacuum filtration into the productive solution and the insoluble residue. 4. The insoluble residue was decomposed with aqua regia.

. Both solutions were analyzed by the ICP spectroscopy method. 6. The recovery of nickel, manganese, and lithium was 63.7%, 68.3%, 56.8%, and 72.2%, respectively.

[Para 102] The results of the tests show that, in equal conditions, ferrous sulfate solution (FeSO 4) with pH-value 0.54 is a more effective leaching agent than ferrous sulfate solution with pH-value 0.48, even in the presence of hydrogen peroxide H2O2 as a reducing agent (see fig. 12).

[Para 103] Experiment 2 1. Treating15 kg of Li-ion cells with protective insulation with rotating metal brushes. The plastic protective insulation was removed in 5 minutes. 2. 15 kg of cleaned Li-ion cells were loaded into a 100-liter plastic reactor containing 80 liters of 1.6 M hydrochloric acid (HCl) solution. 3. The solution was continuously mechanically stirred (300 rpm) for hours, obtaining dissolved Li-ion electrochemical cells. (See table in fig. 14).

[Para 104] Experiment 3 1. Leaching 100g of isolated cathode material with ferric chloride (FeCl) solution with initial pH-value range of 0.20-0.80 and 0.52mol/dm Fe2+ in room temperature for 3 hours. 2. The objective of the experiment was to learn the optimal pH range for leaching cathode material with ferric chloride (FeCl2) solution for recovering lithium and associated transition metals. The experiment results are presented in fig.15.

[Para 105] Experiment 4 1. Taking 10kg of burnt naked Li-ion cells with electrodes. 2. Crushing the Li-ion cells, with a hammer mill into different sizes of iron particles of about 2–3 mm. 3. The crushed material was magnetically separated (18% by weight). 4. The non-magnetic fractions were separated in a sieving and gravity table. 2.5kg cathode material contaminated with graphite and cinders was release.

. The cathode material was divided into three equal portions of 833g each.

[Para 106] Test A: 1. The first portion of cathode material was mixed with FeSO 4 solution with pH-value 0.50. 2. The sulfate solution was obtained by dissolving the magnetic fraction in 2.04M sulfuric acid (H2SO4) solution. 3. The solution was continuously mechanically stirred (300 rpm) during the course of 18 hours. After 18 hours, the solution was drained. 4. The cathode material was mixed with FeSO 4 solution.

. The mixture was leached. 6. The leached products were analyzed by ICP spectroscopy method. 7. The following metals were recovered: 98.2% cobalt, 96.4% nickel, 94.3% manganese and 97.2% lithium, as described in the table of fig. 16 line 1.

[Para 107] Test B 1. The second portion of cathode material was mixed with FeSO solution with pH-value 0.50. 2. The sulfate solution (FeSO 4) was obtained by dissolving the magnetic fraction in 2.04M sulfuric acid (H2SO4) solution. 3. The solution was continuously mechanically stirred (300 rpm) during the course of 18 hours. After 18 hours, the solution was drained. 4. The cathode material was mixed with FeSO 4 solution.

. The mixture was leached. 6. The leached mixture was analyzed by ICP spectroscopy method. 7. The following metals were recovered: 58.3% cobalt, 29.6% nickel, 38.8% manganese and 44.3% lithium, as described in the table of fig. 16 line 2.

[Para 108] Test C 1. The experiment on the third portion of cathode material repeated test B but the sulfate solution (FeSO) was obtained by dissolving the magnetic fraction in 2.04M sulfuric acid (H2SO4) solution in the presence of hydrogen peroxide (HO). 2. In this case, the following metals were recovered: 62.3% cobalt, 57.5% nickel, 42.3% manganese and 42.6% lithium, as described in the table of fig. 16 line 3.

[Para 109] The tests showed that the leaching of the burned cathode materials in sulfuric acid (H2SO4) solution with pH-value of 0.50 recovered a relatively low rate of metals (table in fig.16 line 2).

[Para 110] Furthermore, the increased rate of the metals recovery, when adding hydrogen peroxide (H2O2), is insignificant (table in fig.16 line 3).

[Para 111] At the same time, leaching of the burned cathode material in iron sulfate (FeSO4) solution increases the recovery rate of metals, in comparison with the results of Experiment 1(table in fig.16 line 3).

[Para 112] The conclusion is that, burned iron (II) ions leached in a sulfate medium reduces more effectively cobalt ions (III) to a bivalent state of cobalt (II). It may be assumed that the above factors disrupt the structure of the mixed oxide compound of the cathode material, thus increasing the dissolution of the metal oxides.

[Para 113] Experiment 5: 1. Taking 10kg of burnt Li-ion cells with electrodes. 2. The Li-ion cells were manually separated, receiving cylindrical EC cells in naked iron housing and iron scrap. 3. The EC cells in naked iron housing were placed in a plastic reactor. 4. 50 liters of 20% sulfuric acid HSO were added to the plastic reactor.

. The mixture was mechanically stirred for 11 hours. 6. 80% of the steel housing of 100% of the Li-ion cells was dissolved. 7. FeSOsolution was obtained with pH-value 0.44. 8. The dissolved Li-ion cells were separated from the solution. 9. The separated Li-ion cells were rinsed with water and dried.

. The Li-ion cells were crushed with a hammer mill. 20 11. The crushed electrode material contained large strips of metal foil (copper and aluminum), particles of plastics (2-3 mm), fine graphite (0.1-0.2 mm) and heavy particles of cathode material (0.2-0.3 mm). 12. Sieving/gravity table was used for separating the crushed material.

Copper and aluminum particles, and cathode material, containing less than 10-15% carbon, were received. 13. The cathode material weighing 2.68 kg was divided into two portions of 1.34 kg each.

[Para 114] Test A 1. The first portion of cathode material was leached in ferrous sulfate (FeSO4) with pH-value 0.44 containing mol/dm3 of: 0.014 Al, 0.0031 Co, 0.0020 Cu, 0.50 Fe, 0.011 Li, 0.0032 Mn, 0.0012 Ni at room temperature for 3 hours. 2. Receiving FeSO4 with pH-value 1.8 containing, mol/dm3 of: 0.03 Al, 0.

Co, 0.031 Cu, 0.53 Fe, 0.92 Li, 0.026 Mn, 0.063 Ni. 3. The extracted metals were Co 98.82%, Ni 95.83%, Mn 95.61% and Li 97.62% as shown in table at line 1 of fig. 3).

[Para 115] Test B 1. The second portion of cathode material included ferrous sulfate (FeSO) with pH-value 0.52 containing mol/dm3 of: 0.03 Al, 1.29 Co, 0.031 Cu, 0.53 Fe, 0.92 Li, 0.026 Mn, 0.063 Ni + HSO. 2. The mixture was leached in room temperature for 3 hours. 3. The extracted metals were Co 94.56%, Ni 90.67%, Mn 92.34%, and Li 87.42% as shown in table at line 2 of fig. 3) 520.

[Para 116] It should be noted that the slight increased recovery of metals in this experiment in comparison to the table in fig.13, results from the direct dissolution of the steel housing of the Li-ion cells. There are losses of cathode material when magnetically separated from crushed material, as described in experiment 1.

[Para 117] Experiment 6. 1. 1.5 kg of crushed electrode material containing, in addition to graphite, carbon and cathode material, 6.3% copper and 2.6% aluminum. 2. The crushed material was mixed with a mixture of 20% citric acid solution (CHO) and ferrous sulfate solution (FeSO) with a pH-value of 0.64 in ratio of 4: 1. 3. The mixture was stirred (300 rpm) and leached in room temperature for 3 hours to solid ratio of 5:1. 4. The extraction of lithium and transition metals was, wt: 96.52% Li, 94.56% Co, 97.35% Ni and 93.72% Mn.

. At the same time, the extraction level of aluminum and copper particles from the solution did not exceed 2.6% and 5.3%, respectively. 6. Particles of copper and aluminum foil remained practically unaffected in the leaching process and may be additionally recovered by screening.

[Para 118] The conclusion of the experiment teaches that the use of citric acid (C6H8O7) in combination with a solution of ferrous sulfate (FeSO4) as a leaching agent makes it possible to reduce the number of technological operations without reducing the efficiency of the main technological indicators.

[Para 119] Experiment 7: 1. 10 kg of regular Li-ion batteries were divided into four parts and burned in temperature range of 250c-650c. 2. The analysis of the burnt Li-ion polymer batteries showed that the optimal complete burning conditions occurs at temperatures between 350c - 500c. (fig.17) [Para 120] Experiment 8: 1. 10 kg of polymer Li-ion batteries were divided into four parts and burned in temperature range of 250c-650c. 2. The analysis of the burnt Li-ion polymer batteries showed that the optimal complete burning condition occurs at temperatures above 400c. (fig.18) [Para 121] Experiment 9. 1. 10 kg of polymer Li-ion batteries were mixed with 3 kg of Li-ion batteries in plastic housing and burned in temperature of 400c. 2. Due to the combustion of the plastic, the temperature in the burning equipment rose to 500C, and the mixed butteries were completely burned-out. 3. The conclusion of the experiment shows that the burning of mixed battery waste containing more than 20% of Li-ion batteries in plastic housing can reduce the initial operating temperature from 550c to 400c, which accordingly reduces fuel consumption and economize the process.

[Para 122] Experiment 10: 1. 11L of a productive solution composed of, mol/dm3: 0.03 Al, 0.73 Co, 0.031 Cu, 0.53 Fe, 0.92 Li, 0.026 Mn, 0.063 Ni was prepared for isolating lithium, cobalt, nickel and manganese. 2. The solution was neutralized with NaHCO3 solution to pH-value 4. 3. The neutralized solution was continuously stirred and oxalic acid powder HCO was added in ratio of 1.5 mol of acid for each mol of iron, cobalt, nickel and manganese salts contained in the solution. 4. The pH-value of the solution was adjusted to 9.8 with an alkaline solution.

. The cumulative oxalate precipitate was completed within 3 hours. 6. The precipitate was filtered, washed, and dried. 7. The filtered precipitate was burned at 550c for 3 hours. 8. The resulting sediment weighing 0.111 kg contained, wt: 52.2% Co, 36.9% Fe, 4.8% Ni, 2.01% Mn, 0.004% Al and 0.16% Cu. 9. The phases of resulting sediment: cobalt was in the form of trioxide Co3O4, iron in the form of Fe3O4, nickel in the form of (Nickel (II) oxide) NiO, and manganese in the form of (Manganese (II) oxide) MnO.

. Since magnetite (FeO) is a ferromagnetic compound, cobalt trioxide is paramagnetic, and nickel and manganese oxides are non-ferromagnetic, iron oxide was selectively isolated from the mixture by low-frequency electromagnetic field of 160W/g with a frequency of 5.2 kHz. 11. The Degree of extraction of iron was 86% and loss of cobalt was 8.6%. 12. The resulting product of the magnetic separation in mass of 0.069.4 kg may be additionally purified and used in the production of cathode material. 13. Lithium was isolated and filtrated from the entire oxalate precipitate by evaporation of the solution to a lithium content of 1.8 mol/dm3.

Thereafter, NaHCO was added to the solution with vigorous stirring. 14. The formation of poor soluble lithium carbonate ended within 2 hours.

. The precipitate was separated from the solution by vacuum filtration, washed, and dried. 16. The resulting product may be used together with the collective precipitate of cobalt, nickel and manganese oxides in the production of cathode material for Li-ion cells.

[Para 123] Experiment 11: 1. Manganese (II), iron (II) and cobalt (II) were successively extracted from a productive solution with a final pH-value of 1.8 composing mol/dm: 0.03 Al, 0.73 Co, 0.031 Cu, 0.53 Fe, 0.92 Li, 0.026 Mn, 0.063 by liquid- liquid extraction with 0.5 M solution of Cyanex in kerosene. 2. For this, the pH-value of the initial productive solution was brought to 2.86 using 2.5M NaOH solution. 3. The solution was mixed with organic solvent at a phase ratio O:L =1: and stirred for 15 min. 4. As a result, it was possible to isolate 89% iron and 92% manganese into the organic solution in the first stage, while cobalt was extracted only by 3.4%.

. From the organic solvent, iron and manganese were mixed with a 1.

M HSO solution at a ratio of O:L = 8:1. 6. For the complete separation of cobalt from the first raffinate, the pH- value of the aqueous phase was brought to 5.4 and, in equal conditions, it was possible to transfer 94% of cobalt and only 2.2% of nickel into the organic phase. 7. Cobalt was re-extracted with 2.1M HSO solution at O: L ratio of 8:1. 8. Manganese and iron were precipitated from the sulfuric acid solution in the form of hydroxides. 9. The cobalt isolated from solution in the form of oxalate was washed, dried, Calcinated at 550° C, and trioxide was obtained with a content of less than 2.5% of associated metal impurities.

. Nickel from the second raffinate was precipitated at pH-value 9.8 in the form of insoluble oxalate.

Claims (10)

Claims

1. The hydrometallurgical process for recovering valuable metals from spent Li-Ion batteries, the method comprising: dismantling and disassembling the panels of all types of Li-ion batteries; destruction of the plastic housings of the Li-ion batteries; removing the protective insulating coating from the iron housing by rotating metal brushes or by abrasive powder; dissolving the iron housing of the Li-ion cells in mineral acid, wherein the mineral acid is selected from a group of sulfuric acid or hydrochloric acid solution for a pre-programmed time; crushing the Li-ion cells without the iron housing; mechanically separating the crushed mixed electrodes, wherein the separation may be by sifting and gravity separation; leaching the cathode material with a solution containing Fe2+ -ions or a mixture of solution containing Fe2+ with organic acid, wherein the mixture is in pH-value range of 0.4-0.6, liquid being in solid phase ratio 5:1 in room temperature; Pre-neutralization of the final leached solution with NaHCO3 solution to pH- value 4, adding oxalic acid powder and adjusting the pH-value of the solution to 9.8 with an alkaline solution; filtering, washing, and drying the precipitation of iron, cobalt, nickel and manganese oxalates; Calcining oxalates at 550°C obtaining ferromagnetic iron oxide, cobalt trioxide, Ni oxide and Mn dioxide; Removing the ferromagnetic iron oxide from the oxides mixture by means of magnetic separation.

2. The method of claim 1 wherein the leaching of the cathode material is with FeCl solution in pH-value between 0.5-0.8.

3. The method of claim 1 wherein the leaching of the cathode material may be a mixture of FeSO4 solution and citric acid with Fe2+ -ions.

4. The method of claim 1 wherein the leaching of the cathode material may be a mixture of FeCl solution and citric acid with Fe2+ -ions.

5. The method of claim 1 wherein Mn(II) and Fe(II) are recovered from the solution of claim 3 by liquid-liquid extraction where the productive solution in pH-value 2.86 is mixed with an organic solvent wherein the organic solvent is selected from the group of phosphor organic acid at a ratio of O: L = 1: 1.

6. The method of claim 5 wherein the iron and manganese are stripped by diluted H2SO4 solution at a ratio of O:L= 8:1, then manganese and iron are retrieved from the sulfuric acid solution in the form of hydroxides.

7. The method of any one of claims 5 and 6 wherein for the complete extracting of cobalt from the Liquid-liquid extraction (first raffinate), the pH-value of aqueous phase is adjusted to 5.4 and mixed with organic solvent wherein the organic solvent is selected from the group of phosphor organic acid

8. The method of any one of claims 5 to 7 wherein for recovering the cobalt from the organic solution, the organic solution is mixed with diluted H2SO4 solution at O:L ratio of 8:1 and then retrieved cobalt oxalate from stripped solution, washed, dried, and calcined at 550°C.

9. The method of any one of claims 5 to 8 wherein the nickel from the aqueous phase with Ni2+(second raffinate) is precipitated at pH value 9.8.

10. The hydrometallurgical process for recovering valuable metals from spent Li-Ion batteries, the method comprising: dismantling and disassembling the panels of all types of Li-ion batteries; destruction of the plastic housings of the Li-ion batteries; burning or/pyrolysis spent Li-ion batteries with oxygen in temperature range of 450-650C; burning spent Li-ion batteries without oxygen in pyrolysis mode may be in temperature range of less than 450 C; removal of electronic components and Li-ion cylindrical electrochemical cells in iron housing from cinder by manual separation; mixing and dissolving the iron housing in mineral acid wherein the mineral acid is selected from a group of sulfuric acid (HSO), hydrochloric acid (HCl) for a preprogrammed time; crushing the cylindrical Li-ion electrochemical cells; removing iron from the crushed electrochemical cells by magnetic separation and obtaining cathode material; leaching the cathode material in a solution containing Fe2+ -ions.