EA044283B1 - METHOD FOR RECYCLING LITHIUM BATTERIES - Google Patents

Description

The invention relates to a method for processing lithium batteries. In a second aspect, the invention relates to a recovery plant for recycling lithium batteries.

Lithium batteries are batteries in which electrical energy is stored through a lithium-based electrochemical reaction. Lithium batteries are widely used. But recycling lithium batteries poses a problem. Thus, until now it has been impossible to recycle the graphite contained in the electrodes with such quality that it could be reused for the manufacture of lithium batteries. Disposal of lithium is also a problem. In addition, as a rule, recycling of cobalt, nickel, and manganese, which may be contained in lithium batteries, is only possible to such a purity that their use in new lithium batteries becomes economically impractical. In general, it turns out that the material recycling efficiency of known recycling methods is below 50 wt.% of the total contents of the battery cell.

US 2004/0028585 A1 discloses a method for extracting vanadium from lithium metal polymer batteries. In this case, according to one option, the crushed material is treated with 30% diluted sulfuric acid. After this, vanadium is isolated from the resulting aqueous solution in the form of vanadium pentoxide. It is advisable to use such a method only when the vanadium content in the crushed material is sufficiently high. But, for example, this is not the case with commonly used lithium-ion batteries. In addition, additional metal components, such as cobalt, nickel and manganese, can only be extracted with difficulty. The use of concentrated sulfuric acid, among other things, is not recommended for safety reasons.

From US 2017/0077564 A1, a method for recycling lithium-ion batteries is known, in which the crushed material is leached with dilute sulfuric acid and an aqueous solution of hydrogen peroxide. The disadvantage of this method is that it requires high costs in order to achieve the highest degrees of recovery.

The article Acid leaching of mixed spent Li-ion batteries by Nayl et al., Arabian Journal of Chemistry, 2017, volume 10, pp. 3632-3639, also describes a method for leaching lithium batteries that uses dilute sulfuric acid and peroxide hydrogen. It was found that the degree of leaching with increasing concentration of sulfuric acid first increases, and above 3 M it decreases. The highest concentration tested is 4 M.

The invention is based on the objective of improving the recycling of lithium batteries.

The invention solves the problem by means of a method for recycling lithium batteries with the following steps: (a) opening the crushed material, which contains the crushed components of lithium battery electrodes, in particular with concentrated sulfuric acid, so that a waste gas and the cracked material are formed, (b) removing the waste gas and (c) liquid chemical recovery of at least one metal component of the exposed material, in particular at least one metal component (preferably two, three, four or more metal components) which is selected from the list which includes cobalt, lithium, manganese , nickel and titanium.

The opening is preferably carried out at an opening temperature of at least 100°C, preferably at least 120°C, particularly preferably at least 140°C. But it is also possible that the opening temperature is below 100°C.

According to a second aspect, the invention solves the problem by means of a recovery plant for recycling lithium batteries, in particular used lithium batteries, comprising (a) a reactor for opening crushed material, which contains crushed components of lithium battery electrodes, with concentrated sulfuric acid at an opening temperature of at least 100° C, (b) a sulfuric acid supply device for supplying sulfuric acid to the crushed material, and (c) an outlet device, which is designed to remove the exhaust gas from the reactor. In particular, the outlet device is designed such that it is impermeable to hydrogen fluoride. In other words, hydrogen fluoride cannot escape into the environment.

An advantage of the invention is that by exposing the ground material to sulfuric acid, which preferably means concentrated sulfuric acid, fluorine which may be present in the ground material can be completely displaced. Fluoride compounds can form hydrogen fluoride, which is extremely problematic for safety reasons. In addition, hydrogen fluoride exhibits a strong corrosive effect. By exposing the ground material to sulfuric acid, fluorine is removed from the ground material so that subsequent processing steps can be carried out with little precaution, with little wear on the material. Many separation methods (e.g. membrane separation methods, bipolar membrane electrodialysis) are completely impossible to perform in liquids with a high fluorine content, but are made possible by this pretreatment. In addition, no contamination from fluorinated substances can occur, so that, as a rule, other components of the crushed material can be recovered with high purity.

In addition, it is preferable that the battery graphite can be recycled with such high purity that it can be used to make new electrodes.

It is further advantageous that the process generally can be carried out such that the lithium is recovered in sufficiently high purity to be suitable for the manufacture of new lithium batteries. Also, cobalt, nickel and/or manganese, if contained in the crushed material, are often isolated in high purity to enable new battery applications.

In particular, it is preferred that recycling efficiencies greater than 50 wt.% can be achieved per battery cell in many cases.

It should be noted that the above benefits may be experienced, but do not necessarily have to be achieved.

Known methods focus on recovering cobalt and nickel, as they constitute the most valuable materials in waste lithium batteries. We had to accept that other components of used lithium batteries, such as graphite and/or lithium, could not be recovered. In known processes, the extraction of fluorine is not in the foreground, since its sales value is relatively low.

It is particularly advantageous that the method according to the invention can in most cases be carried out in such a way that, in contrast to pyrometallurgical methods, it results in significantly lower energy consumption. In particular, the method according to a preferred embodiment does not include any pyrometallurgical process step.

From DE 10 2015 207 843 A1 it is known that it is preferable to dry the batteries after grinding at a low temperature in order to prevent the possible formation of organofluorine substances. This drying removes the organic carbonates present in the electrolytes. Therefore, fluoride compounds remain in the crushed material. According to one preferred embodiment, there is an opening of the crushed material, which contains at least one fluorine compound.

In the context of this description, a method for recycling lithium batteries is understood in particular as a method in which the metal components of lithium batteries are recovered. In this sense, the method of the invention is also a method for extracting metal components from lithium batteries. For example, these metal components are lithium and/or metals of minor subgroups of the Periodic Table, in particular metals of the sixth, seventh and eighth subgroups. The secondary subgroup metals are preferably manganese and/or cobalt and/or nickel. In addition, it is preferable when copper and/or titanium are recovered.

In the context of this description, a lithium battery is understood in particular as a battery in which an electrochemical reaction of lithium and/or lithium ions and/or lithium compounds occurs. The battery contains at least galvanic cells.

Preferably, the lithium batteries are at least partially lithium-ion batteries. Particularly preferably, the crushed material contains at least 40 weight percent, in particular at least 60 weight percent, lithium-ion batteries. Lithium-ion batteries contain fluorinated liquid electrolyte, which makes lithium batteries very difficult to recycle.

The fluorine content of the ground material is preferably less than 7 percent by weight, in particular less than 5 percent by weight.

Preferably, the fluorine content of the ground material is at least 0.5% by weight, in particular at least 1% by weight.

By recycling plant is meant, in particular, a device by which 1, 2, 3 or more metal components of lithium batteries are separated from other components of a lithium battery, so that their subsequent recycling is possible.

When temperature values are given in the following description, they always refer to the average temperature in the respective object. For example, by opening at an opening temperature of at least 100°C is meant, in particular, that the temperature of the crushed material mixed with sulfuric acid is on average 100°C. It is immaterial that local higher or lower temperatures may occur. If the exact temperature is not specified, the corresponding process step is preferably carried out at room temperature and ambient pressure in an ambient atmosphere.

When the indefinite article is used, it should be understood to mean that there is at least one corresponding object. As an example, a recycling plant may have exactly one grinding unit, but also two, three, or more grinding units.

By opening, in particular, it is understood that dilute sulfuric acid is not used. In particular, at at least one point in time of the reaction, the concentration of sulfuric acid is higher than 90%, in particular 95%, especially preferably 98%.

In particular, the opening is carried out in such a way that fluorine in the form of gaseous fluoride compounds is removed. In particular, the opening is carried out in such a way that the fluorine components in the crushed material pass into the exhaust gas in the form of hydrogen fluoride. In other words, there is so little water in the mixture of crushed material and sulfuric acid that the concentration of water-soluble fluoride is below 100 milligrams per kilogram of material dissected, in particular, below 10 milligrams per kilogram of material dissected.

By the fact that the crushed material is opened in concentrated sulfuric acid, it is understood, in particular, that during the time interval of the method the concentration of sulfuric acid is so high that the above concentration of water-soluble fluorides per kilogram of opened material is achieved. The concentration of sulfuric acid in the process is preferably at least 95%, preferably at least 98%. Unlike the use of non-concentrated sulfuric acid, the use of concentrated sulfuric acid results in almost no fluoride in the exposed material.

In particular, opening is not leaching, since leaching is always carried out with an aqueous liquid.

In particular, the exposed material is solid. Unlike methods that do not use concentrated sulfuric acid, the reaction products, that is, in particular metal sulfates, are not dissolved in water and remain as solids.

By crushed material is meant in particular material which is obtained by grinding lithium batteries or at least one component of lithium batteries, in particular electrodes, and possibly subsequent processing, for example drying. Thus, after shredding, many separation steps may follow to separate shredded metal films (foils), polymer films, or cell shell and module components. Advantageously, the ground material contains at most 10% by weight, preferably at most 5% by weight, of polymeric materials and/or metallic impurities. The ground material may contain powdered lithium battery electrode components. Generally speaking, instead of ground material, uncomminuted material, in particular electrode material, can also be used. However, it is useful when this electrode material is crushed.

In particular, the ground material may be material that has not been subjected to pyrometallurgical processing, in particular neither calcination nor combustion. True, it would also be possible and covered by the invention that the crushed material was subjected to a pyrometallurgical treatment.

By exhaust gas removal it is understood in particular that the exhaust gas is removed from the opening site in at least as large a quantity as possible. It is possible that the exhaust gas is being sucked off. The exhaust gas typically contains a fluorine compound, in particular hydrogen fluoride. It is possible, but not necessary, that hydrogen fluoride is removed from the exhaust gas, in particular by precipitation, in particular with a calcium compound. It is also possible that the off-gas is sent to a chemical process.

By liquid chemical extraction is meant, in particular, that a substance which, at a pressure of 1013 hPa and room temperature, is liquid or is in a liquid state when added to the recovered material or to a substance which comes from the recovered material, resulting in at least separate a substance that contains a metal or is itself a metal.

The sulfuric acid is preferably at least 90% strength, in particular preferably at least 95% strength. However, it is possible that a lower concentration of sulfuric acid is added to the ground material. In this case, the opening temperature is preferably the temperature required to evaporate such an amount of water from the sulfuric acid that it has a concentration of at least 90%, in particular at least 95%. Percentage values always refer to percentage by mass.

Opening the crushed material preferably includes the step of mixing the crushed material with sulfuric acid. Mixing may include sulfuric acid spraying and/or forced mixing, such as extruding, kneading or kneading.

The opening temperature is preferably lower than the boiling point of the sulfuric acid to prevent evaporation of the sulfuric acid. Therefore, the opening temperature is preferably below 335°C. The opening temperature is preferably less than the decomposition temperature of the binder that binds the active material to its carrier. Alternatively, the opening temperature is higher than the decomposition temperature of the binder. This prevents the binder from contaminating the graphite. However, it should be pointed out that it is possible, but not necessary, for the ground material to contain a suitable binder. Particularly preferably, the temperatures are in the range from 150 to 250°C.

To avoid oxidation of graphite - as in other technological stages - opening can be carried out in a protective gas, for example, nitrogen or argon. It is possible, but not necessary, that other process steps are also carried out under protective gas.

Like other technological stages, opening can be carried out in a non-continuous (batch) or continuous mode.

According to one preferred embodiment, the opened material contains at most 15% water, in particular less than 10% water, preferably less than 5% water. If little or no water is present, the fluorine volatilizes as hydrogen fluoride, so that almost no water remains.

- 3 044283 or no fluoride compounds at all.

The opening is preferably carried out until the exhaust gas reaches a hydrogen fluoride concentration below 0.83 mg per cubic meter. The concentration of hydrogen fluoride is preferably below the detection limit. In particular, the detection threshold refers to the measurement by infrared spectrometry. In this way, it is ensured that hydrogen fluoride cannot enter subsequent technological stages in significant quantities.

Alternatively or additionally, the opening is carried out until the concentration of fluorine C _F water-soluble fluorides in the opened material reaches a value below 100 milligrams per kilogram of the opened material, preferably below 10 mg/kg, and especially preferably below the detection limit.

According to one preferred embodiment, breaking up the particulate material includes the steps of: (a) mixing concentrated sulfuric acid and the particulate material so that a mixture is formed, (b) determining the temperature of the mixture, and (c) adjusting (i) the metered mass flow of sulfuric acid and/or (ii) ) the added mass flow of crushed material so that the temperature of the mixture remains within the specified temperature range of the mixture. The upper limit of the mixture temperature range is preferably not more than 330°C, in particular not more than 300°C, especially preferably not more than 270°C. The lower limit of the mixture temperature range is less important since the reaction is usually exothermic. For example, the lower limit of the interval is 0°C.

Preferably, (a) dispense concentrated sulfuric acid into the crushed material at a metered mass flow rate so that a mixture is obtained, (b) determine the temperature of the mixture, and (c) adjust the metered mass flow rate so that the temperature of the mixture remains within a predetermined temperature range of the mixture.

For example, crushed material is charged into a reactor and then sulfuric acid is added. By addition is meant in particular that sulfuric acid is added to the ground material in such a way that it is ensured that the addition of sulfuric acid can be so greatly reduced, in particular can be stopped, when the temperature of the mixture becomes higher than a predetermined temperature range of the mixture. Preferably, but not necessarily, the addition is carried out such that the mass flow is known and/or can be controlled.

Sulfuric acid is preferably added to the ground material in at least a stoichiometric, preferably superstoichiometric, ratio. By this, in particular, it is meant that so much sulfuric acid is added that all the base metals and copper in the ground material can be recovered and, according to one preferred embodiment, recovered in a subsequent process step. In particular, so much sulfuric acid is added that all base metals and copper in the crushed material go into solution at least 99 percent by weight. It should be pointed out that even with superstoichiometric addition of sulfuric acid, due to the finite reaction rate and the resulting chemical equilibrium, there may remain metal residues that have not reacted with sulfuric acid.

Concentrated sulfuric acid is preferably used in a mass ratio to the mass of ground material of at most 40 to 1, in particular at most 20 to 1, preferably at most 10 to 1. In other words, at most 40 kg of concentrated sulfuric acid is added per kilogram of ground material.

For example, it is useful to add at least 1.8 g H2SO4 per gram of cathode material, in particular at least 1.8 g H2SO4 per gram of electrode active material. The cathode material is, in particular, LiMO ₂ where M denotes a transition metal or aluminum. The cathode is the electrode that is positively charged when discharged.

The method preferably includes the step of separating hydrogen fluoride from the exhaust gas, in particular precipitating hydrogen fluoride from the exhaust gas. For example, this occurs using a calcium compound so that calcium fluoride is formed.

The method preferably involves leaching the exposed material. The leaching is preferably carried out with an aqueous liquid, in particular water. The weight ratio of the exposed material to the aqueous liquid is preferably from 1:2 to 1:20. Leaching is carried out for at least 1 minute and preferably no longer than 10 hours.

When leaching, the pH value is preferably between -0.7 and 4. Leaching is preferably carried out at room temperature, but this is not necessary.

The method preferably involves separating the graphite so that a rough liquid is obtained. This occurs after leaching. The separation is preferably filtered. But it is also possible that the graphite is separated by centrifugation or other means. As a result of opening with sulfuric acid, it is generally achieved that the concentration of metal, in particular metal ions, in the graphite becomes so low that the graphite is suitable as electrode graphite for the manufacture of new lithium batteries or other batteries.

It is possible that the method includes the step of purifying the separated graphite, which can be performed, for example, with water or dilute inorganic acid. Therefore, it is preferable

- 4 044283 among other things, silicon is removed.

The cleaning is preferably carried out so intensively that only no more than 10 mg/kg of metal ions are present in the wash water. It has been found that in known methods the crystalline structure of graphite can be damaged so severely that its use as electrode graphite becomes impossible. Because, in one preferred embodiment of the method, no liquid chemical or thermal oxidation is carried out before separating the graphite, the crystalline structure of the graphite is so little damaged that it can generally be reused in batteries.

Purification of graphite preferably involves heating the graphite to a binder decomposition temperature TZ of at least 250°C and/or at most 700°C, in particular at most 430°C. At this temperature, the remaining binder, which often consists of polyvinylidene fluoride, decomposes. At higher temperatures, graphite can be damaged. Heating can be carried out in a vacuum, in particular at a pressure not exceeding 300 hPa, but this is not necessary.

The heating can be carried out in an oxidizing atmosphere, for example air or oxygen, preferably air or oxygen being supplied.

Alternatively, heating can be carried out in an inert atmosphere, for example, in an atmosphere that consists of nitrogen and/or argon.

Alternatively, heating can be carried out in a reducing atmosphere. For example, then the atmosphere contains hydrogen.

In addition, refining graphite may include classifying the graphite so that at least one fine fraction and one coarse fraction are formed. The classification is preferably carried out such that the proportion of binder in the fine fraction is at least twice that of the coarse fraction. For example, the classification may be sieving (screening).

Alternatively or additionally, purification of graphite may involve flotation of the graphite or binder, particularly in an aqueous flotation fluid.

Again alternatively or additionally, purification involves removing the binder from the graphite with a solvent. Suitable solvents include, for example, water, N-methylpyrrolidone or a mixture of both. Purification is preferably carried out until the binder proportion is less than a predetermined maximum binder content. The maximum binder content is preferably at most 2% by weight, in particular at most 1% by weight. As a rule, the maximum binder content is allowed at levels above 0.1 ppm.

Removal is preferably carried out at a solvent temperature of at least 20°C, in particular at least 40°C, particularly preferably at least 60°C.

It is useful when the purification includes the steps of solvent recovery by (i) reducing the solubility of the binder, in particular by lowering the temperature of the solvent and filtering the binder, or (ii) evaporating the solvent and recondensing the solvent. Alternatively, the solvent may be replaced frequently until the proportion of binder in it is below the maximum binder content.

Again alternatively or additionally, cleaning graphite involves rinsing and/or washing with an acid, in particular an inorganic acid, preferably sulfuric acid. Purification is preferably carried out until the concentration of metal impurities is at most 10,000 ^ppm . Graphite purified in this way can replace newly obtained graphite in many applications.

The method preferably includes the step of separating copper from the rough liquid, so that a decontaminated rough liquid is obtained. It is possible, but not certain, that copper recovery represents a liquid chemical process occurring immediately after leaching. In particular, it is also possible that other metals were separated before the copper was isolated. In particular, we are talking about the selective release of copper. The copper recovery temperature is preferably between 0°C and 100°C. The isolation is preferably carried out for from more than 1 to 720 minutes.

The release may, for example, be cementation. During cementation, an electrochemical reaction of copper ions occurs so that elemental copper is formed. For example, cementation is carried out using an iron-containing substrate.

Alternatively, the isolation is precipitation. For example, copper can be precipitated as copper sulfide. To do this, a precipitating substance, for example, a sulfur-containing substance, is added to the draft liquid. In this case, we can talk about sodium hydrosulfide. In this case, copper sulfide, in particular CuS, precipitates. It is advantageous when the precipitating agent is added superstoichiometrically, so that the concentration of copper ions in the decontaminated rough liquid is preferably below 10 mg per liter, particularly preferably below 1 mg per liter.

The method preferably includes the step of oxidizing the depurified solution. This is preferably accomplished by introducing an oxidizing agent. For example, hydrogen peroxide can be used as an oxidizing agent.

The oxidation is preferably carried out so that iron ions are oxidized. Useful when after

- 5 044283 this is followed by the stage of iron deposition. In particular, Fe ²⁺ ions in the deferred roughing fluid can be oxidized to Fe ³⁺ ions. This can be accomplished using an oxidizing agent, such as an oxygen compound. The oxygen compound may be, for example, hydrogen peroxide or ozone.

Precipitation of iron is preferably carried out in the form of hydroxide. Particularly useful when aluminum is precipitated, preferably in hydroxide form. It is also advantageous when the titanium present is precipitated, preferably in the form of titanium oxide. Precipitation of iron and/or aluminum produces a clear liquid.

Precipitation of iron and/or aluminum and/or titanium is preferably carried out by adding NaOH, Na ₂ CO ₃ , KOH, MgO or ammonium hydroxide.

It should be pointed out that the concept of a pure liquid should only mean that metals considered as impurities, such as iron, and possibly also copper, aluminum and titanium, have been removed. In particular, the concept of a pure liquid in no way provides any information about the concentration of other substances.

By the fact that an oxygen compound is used for oxidation, it is meant that during a redox reaction, oxygen changes its oxidation state. Alternatively, the oxidizing agent may be, for example, a compound that contains oxygen but does not change its oxidation state during the redox reaction.

Oxidation is preferably carried out until the electrochemical potential is between 0.8 and 1.4 Volts relative to a standard hydrogen electrode. In this voltage range the reaction Fe ²⁺ ;+Fe ³⁺ +e' occurs.

The oxidation pH value is preferably no more than 8.7. During precipitation, the pH value is preferably at least 4.3, in particular at least 4.8. In particular, the pH value during precipitation is not more than 8.7, preferably not more than 7.8. This ensures that iron and/or aluminum and/or titanium precipitate to a very large extent.

According to one preferred embodiment, the method includes the step of performing ion exchange. For this, an ion exchanger is used. The ion exchange is preferably carried out in such a way that metallic impurities are removed. Metal impurities are zinc and/or copper and/or aluminum and/or iron. It is possible that all four elements are removed, three of these elements, two of these elements, or just one element. For example, for ion exchange, an ion exchanger is used that contains a chelating complexing agent with aminophosphonic acid groups as functional groups.

It is useful when ion exchange is carried out after the deposition of iron and/or aluminum. Thus, the amount of iron and/or aluminum that must be removed by ion exchange is small.

According to one preferred embodiment, the method includes the step of removing residual solvent from the electrolyte, in particular by filtration and/or adsorption. This is preferably performed before ion exchange and/or after or simultaneously with the removal of iron and/or aluminum. Particularly preferably, the removal takes place in a decontaminated rough liquid and/or a clean liquid. Adsorption is preferably carried out using activated carbon.

It is possible, but not necessarily, that the removal of residual electrolyte solvent is carried out in such a way that activated carbon is added in bulk and then removed, in particular filtered.

Manganese is preferably removed from the pure liquid, in particular by liquid-liquid extraction, preferably by means of a manganese-binding complexing agent, which is, for example, dissolved in the lipophilic liquid. The lipophilic liquid may be, for example, a petroleum product, for example kerosene. The manganese-binding complexing agent can be, for example, di(2-ethylhexyl)phosphoric acid. The pH value for manganese removal is preferably between 1 and 9.

It has been found that it is preferable to extract manganese before cobalt. Cyanex 301 (bis(2,4,4-trimethylpentyl)dithiophosphic acid) is then unnecessary for transition metal removal, which reduces equipment costs.

The method preferably involves liquid-liquid extraction of cobalt. It is preferably made from a pure liquid or from a liquid from which the manganese has been removed. Particularly useful for this purpose is the use of a cobalt-binding complexing agent, for example a complexing agent dissolved in a lipophilic liquid. The lipophilic liquid may be, for example, a petroleum product, for example kerosene. One possibility is to use an organic phosphinic acid, for example Cyanex 272 (bis(2,4,4-trimethylpentyl)phosphinic acid). The pH value for cobalt extraction is preferably between 1 and 10.

The method preferably includes the step of removing nickel. In one preferred embodiment, nickel removal is liquid-liquid extraction of nickel. This is preferably carried out with a nickel-binding complexing agent. It can be, for example, di- 6 044283 (2-ethylhexyl)phosphoric acid. The pH value is then preferably between 1 and 10. Alternatively, the nickel-binding complexing agent is neodecanoic acid. In this case, the pH value is preferably between 2 and 10. The complexing agent is preferably dissolved in a lipophilic liquid, for example a petroleum product such as kerosene. It is useful when liquid-liquid extraction is performed from a pure liquid from which manganese and cobalt have been removed.

In an alternative embodiment, nickel removal involves precipitation of nickel hydroxycarbonate. Nickel hydroxycarbonate has the general formula xNiCO ₃ -yNi(OH) ₂ -zH ₂ O. Precipitation is preferably carried out at a temperature in the temperature range of 0-100°C, in particular at at least 70°C. The pH value during precipitation is preferably higher than pH 7, in particular higher than pH 9.9.

It has also been found that it is preferable to extract cobalt and nickel before manganese. In this case, the manganese may be precipitated, making liquid-liquid extraction unnecessary.

According to one preferred embodiment for the extraction of transition metals, cobalt and nickel can be extracted in a combined pure liquid extraction process such that a liquid depleted in cobalt and nickel is obtained.

For the extraction of nickel and/or cobalt, for example, Cyanex 301 (bis(2,4,4trimethylpentyl)dithiophosphinic acid), which can be used dissolved in kerosene, is suitable. In this case, a saturated organic phase is formed. Nickel and/or cobalt can be re-extracted from the saturated organic phase, for example using hydrochloric acid or sulfuric acid. From the cobalt- and nickel-containing solution thus obtained, the cobalt can be removed by means of a cobalt-binding complexing agent. For example, this is done using a complexing agent dissolved in a lipophilic liquid. The lipophilic liquid may be, for example, a petroleum product, for example kerosene. It is possible to use organic phosphinic acid, for example Cyanex 272 (bis(2,4,4-trimethylpentyl)phosphinic acid).

The nickel is then crystallized out as nickel chloride or nickel sulfate. For example, cobalt can also be re-extracted using hydrochloric acid and/or sulfuric acid from a saturated organic phase and then crystallized as cobalt chloride or cobalt sulfate.

By removing nickel and cobalt, a solution depleted in nickel and cobalt is obtained. Manganese can be removed from this solution, in particular by liquid-liquid extraction, preferably by means of a manganese-binding complexing agent. For example, it could be di-(2-ethylhexyl)phosphoric acid. The pH value for manganese removal is preferably 1-9. A saturated organic phase is thereby obtained from which the manganese can be re-extracted. From the solution thus obtained, manganese chloride and/or manganese sulfate can then be crystallized.

Alternatively, manganese can be precipitated from a nickel-cobalt-depleted solution, for example as a carbonate. For this purpose, a carbonate, for example sodium carbonate, is preferably added to the manganese-containing liquid. The pH value is preferably higher than 7, in particular higher than 10.5.

Again, alternatively or additionally, manganese is converted into manganese hydroxide by precipitation. For this purpose, a hydroxide, for example sodium hydroxide, is preferably added to the manganese-containing target liquid. The pH value is preferably higher than 7, in particular higher than 10.5.

By removing cobalt, nickel and/or manganese, the target liquid is obtained.

According to one preferred embodiment, lithium is recovered from the target liquid. Lithium is preferably precipitated from the target liquid. For example, this can be accomplished by adding a phosphate, eg sodium phosphate, or a carbonate, eg sodium carbonate. Lithium precipitation is preferably carried out at pH 7-14.

It is advantageous when a concentration step is first included before lithium deposition so that the lithium concentration is increased. Alternatively, the lithium can be precipitated as lithium phosphate, for example by adding sodium phosphate. Concentration can be accomplished, for example, by reverse osmosis and/or evaporation.

When the pure liquid no longer contains cobalt, nickel or manganese, lithium is preferably precipitated from the pure liquid. This situation occurs when, for example, lithium iron phosphate batteries are used exclusively to produce shredded material.

Alternatively, lithium is recovered through liquid-liquid extraction. For this purpose, a lithium-binding complexing agent is preferably used, for example Cyanex 936 from Solvay. After stripping with inorganic acid, a concentrated lithium solution is obtained, from which lithium can be precipitated or crystallized.

The ground material preferably includes powdered lithium ion battery electrode material. From the crushed lithium-ion batteries, the crushed electrode foils, separator films, other films, cell shell materials (batteries), and battery module peripheral components are separated so that powdered active electrode material is obtained.

Shredded material resulting from battery shredding and simultaneous and/or subsequent

- 7 044283 inactivation of the raw material crushed material thus obtained is preferably obtained by drying. It is especially useful when grinding is carried out under an inert gas atmosphere and/or vacuum. When grinding occurs under vacuum, the pressure is preferably no higher than 300 hPa. The temperature is preferably not higher than 100°C, preferably not higher than 80°C. This prevents the formation of organofluorine substances. Fluorine remains in the crushed material and, as described above, is displaced by sulfuric acid upon opening.

According to one preferred embodiment, after inactivation, the shredded metal foils of the current leads, separator films, cell shell components and module components are separated so that shredded material is obtained.

It is advantageous when the ground material, after grinding, is heated to an electrolyte removal temperature TE above 80° C., so that the electrolyte present in the ground material evaporates. During inactivation, low-boiling components of the electrolyte are removed. However, it is possible that higher boiling electrolyte components remain in the crushed material. They can hinder subsequent processing steps, so it is preferable to remove them. The electrolyte removal temperature TE is preferably at least 100°C, in particular at least 150°C, and at most 300°C, in particular at most 250°C.

The batteries are preferably pre-discharged and/or obtained by dismantling battery systems or battery modules.

In the recovery plant according to the invention, the reactor is preferably a rotary tube furnace or, in particular, a heated forced mixer. This ensures thorough mixing of sulfuric acid with the crushed material. For example, the reactor provides temperature control or regulation whereby the temperature of the mixture of crushed material and sulfuric acid is brought to and maintained at tamper temperature. Dissection can be performed in a continuous or batch mode.

According to one preferred embodiment, the recovery plant has a metering device for adding a metered mass flow qm of concentrated sulfuric acid to the crushed material so that a mixture is formed, and (b) a mixture temperature detector for determining the temperature TM of the mixture. The dosing device is preferably configured to regulate the dosed mass flow q _m so that the mixture temperature T _M remains within a given mixture temperature range I. It was found that a significant amount of heat was generated when sulfuric acid was added. To prevent the temperature TM of the mixture from increasing too much, the temperature of the TM mixture is monitored and the dosed mass flow qm is adjusted so that the specified required value of the TM temperature, _required , is not exceeded. mixtures.

According to one preferred embodiment, the recovery plant includes a leach device for leaching the exposed material in an aqueous environment.

The recovery plant preferably has a fluorine separator to capture hydrogen fluoride. For example, hydrogen fluoride may be precipitated. But it is also possible that hydrogen fluoride is diverted to react with another substance, such as an organic substance.

It is useful when the recycling unit is made mobile. In other words, it is possible to move the recovery plant without having to dismantle it. The recovery unit is preferably housed in a 20-foot container or a 40-foot container.

Transporting crushed material is often risky as it contains flammable substances and fluoride compounds. There is therefore - perhaps an acceptably small - risk that this will lead to a fire releasing hydrogen fluoride. It is therefore beneficial when the electrolyte, cell components, electrode foils and electrode powder are separated in a decentralized manner. It is therefore preferable for the recycling plant to have a battery recycling plant for shredding lithium batteries, as described in DE 10 2015 207 843 A1. It is then possible, but not necessary, that the reactor, the sulfuric acid supply device and the outlet device, as well as, if necessary, additional devices that are indicated in the claims, are made movable, and preferably placed together in a 20-foot container or a 40-foot container .

The recovery plant preferably includes a graphite recovery device, which has a graphite separation device, in particular a filter, for separating the graphite, and which is located downstream of the reactor in the direction of flow of the material.

According to one preferred embodiment, the graphite recovery device includes a washing device for washing away adhering alkaline solution from the graphite. This washing device is preferably designed to wash away the alkaline solution with an aqueous liquid.

The recovery plant preferably includes a fluoride detector for detecting fluoride compounds, in particular hydrogen fluoride. The fluorine detector is preferably a hydrogen fluoride meter for measuring the concentration of hydrogen fluoride in the exhaust gas.

According to one preferred embodiment, the recovery plant includes a control unit which is coupled to a fluorine detector and is capable of automatically

- 8 044283 control the reactor so that it maintains the opening temperature until the fluorine concentration, in particular the hydrogen fluoride concentration, in the exhaust gas falls below a predetermined limit value.

According to one preferred embodiment, the recovery plant includes a sludge settling tank for separating, in particular filtering, precipitated Cu or Cu compounds.

It is advantageous if the recovery plant has a transition metal extraction device, in particular a liquid extraction device, for extracting cobalt, manganese and/or nickel, which is located downstream of the graphite extraction device in the direction of flow of the material.

In addition, the recovery plant preferably has a Fe/Al/Ti sediment separator for separating, in particular filtering, precipitated iron and/or aluminum and/or titanium compounds. The Fe/Al/Ti precipitate separator is preferably located downstream of an inactivation device, for example a rotary tube kiln, and in front of a possible transition metal removal device for removing cobalt, nickel and/or manganese, for example in the form of a liquid-liquid extraction device.

According to one preferred embodiment, the recovery plant has an ion exchanger for performing ion exchange in which zinc and/or copper and/or iron and/or aluminum are removed. In particular, the ion exchanger is designed such that cobalt and/or nickel and/or manganese are not removed during ion exchange. The ion exchanger is preferably located downstream of the copper extractor to extract copper from the rough fluid. Particularly preferably, the ion exchanger is located in the direction of material flow behind the Fe/Al/Ti sediment separator.

The recovery plant preferably has an activated carbon filter to remove organic compounds, in particular electrolyte components. The activated carbon filter is preferably located behind the Fe/Al/Ti sediment separator.

The maximum temperature to which the crushed material or exposed material is exposed is preferably not higher than 1000°C, preferably not higher than 700°C, in particular less than 335°C. The crushed material is preferably not subjected to cracking processing.

The recycling plant of the invention preferably includes a shredder unit for shredding lithium batteries so that shredded material is obtained. In addition, the recovery plant preferably includes an inactivation device for inactivating the crushed material. Advantageously, the inactivation device includes a drying device that is configured to dry the crushed material until the electrolyte content of the crushed material becomes so low that an electrochemical reaction is no longer possible.

It is possible that the recovery plant has an electrolyte removal device for heating the inactivated crushed material to an electrolyte removal temperature (TE) above 80°C, in particular above 120°C. The electrolyte removal device is located in the direction of material movement behind the inactivating device.

The recovery unit preferably has a vacuum unit which is connected to the drying device to create a vacuum in the drying device.

It is useful when the vacuum installation is configured to create a vacuum of at least 300 hPa. In other words, the vacuum installation is designed such that a pressure is achieved that is 300 hPa or less. To reduce equipment costs, the vacuum installation is preferably configured such that the maximum achievable pressure is greater than 0.01 Pa, preferably greater than 1 Pa.

The recovery plant preferably has a solid metal separation device for removing solid metal from the crushed material. By hard metal separating device is meant, in particular, a device for separating fragments of peripheral components of a battery system, battery cells and/or current terminals of lithium batteries. For example, a solid metal separation device includes a magnetic separation device and/or a classifier (screen), in particular a cross-flow separator and/or a zigzag separator.

Alternatively or additionally, the recovery plant preferably includes a light fraction separation device for separating the light fraction, which, for example, includes a separator film and a coating material. The light cut separator preferably includes a zigzag separator and/or an air separator, and it is advantageous if air is supplied to the light cut separator in a closed loop (ie circulated). This reduces the impact of dust on the environment. By air separator we are talking, for example, about an air-pass sieve.

It is advantageous if the recovery plant has a separation device, in particular a sorting device, for separating the active material from the carrier, in particular by means of an air-pass screen and/or by means of a second grinding stage, so that an active material fraction and a carrier fraction are obtained. The carrier fraction includes, in particular, aluminum and copper foil.

- 9 044283

It is possible, but not necessary, for the recycling plant to have an unloading device for unloading the crushed material into a transport container. By means of this transport container, the crushed material can optionally be transported over a long distance, which for example can be at least 1 km. The crushed material can then be introduced from the transport container into the reactor.

Alternatively, it is also possible that the recovery plant does not have an unloading device for unloading the crushed material into a transport container. In this case, the crushed material, after grinding, is preferably transferred by means of continuous or intermittent conveyors to the reactor and there introduced into the reactor.

The invention is explained in more detail below with the help of the accompanying drawings. They show:

fig. 1 is a flow chart of the method according to the invention and FIG. 2 is a schematic view of a recovery plant according to the invention, FIG. 3 is a flow diagram of the processing method according to the invention of cobalt-, nickel- and manganese-free crushed material, FIG. 4 is a flow diagram of a method for processing cobalt- and nickel-free manganese-containing crushed material and FIG. 5 is a technological block diagram of the processing method according to the invention of manganese- and nickel-free cobalt-containing crushed material, FIG. 6 - technological block diagram of processing of manganese-free, cobalt- and nickel-containing crushed material, FIG. 7 shows a grinding unit of a recovery plant according to the invention, FIG. 8a and 8b show a flowchart of the method according to the invention, FIG. 9 shows a recovery plant according to the invention according to a further embodiment, and FIG. 10 schematically shows a graphite purification plant of a recycling plant according to the invention.

Fig. 1 shows a flowchart of the method according to the invention. First, ground material is provided, for example in the form of ground electrode active material. This can be done, for example, in the manner described in DE 10 2015 207 843 A1, which is incorporated here by reference. In particular, it is possible that the batteries are first shredded, resulting in a rough shredded material (grind product). In a subsequent step, the rough ground material is inactivated by drying, resulting in an inactivated rough ground material.

Inactivation is preferably drying. Drying is carried out, for example, in an atmosphere of inert gas or in a vacuum. It is useful when the drying pressure is not higher than 300 hPa and the drying temperature is not higher than 80°C. This results in crushed material 10, which can no longer enter into an electrochemical reaction to a significant extent, since the content of low-boiling components of the electrolyte is too low.

After inactivation, the method may include the step of removing the electrolyte. To do this, the inactivated crushed material 10 is loaded into a container 11 and heated there to the electrolyte removal temperature TE, preferably above 100°C, in particular above T=15O°C. It is possible, but not necessarily, that the container 11 is a vacuum chamber in which a vacuum of, for example, at least 300 hPa can be created by means of a vacuum pump that forms part of the recovery plant. In container 11, the electrolyte that could not be removed during inactivation is removed from the crushed material 10.

According to a preferred embodiment of the method, after inactivation and possibly heating to the electrolyte removal temperature TE, the active electrode material is separated from the rough ground material. This is preferably accomplished by a combination of mechanical action, magnetic separation, non-ferrous metal separation, screening and density separation. Screening in an air stream is beneficial because it produces clean sieved material with a finer grain size of the separated fraction.

This ground material 10 is mixed with sulfuric acid 12. For example, the mixing may be mixing using a stirrer. However, it is also possible that mixing is accomplished simply by addition. In particular, this is possible when the ground material 10 is located in a reactor, for example in the form of a rotary kiln.

It is also possible that the crushed material and sulfuric acid are mixed with each other in the reaction vessel. The mixed crushed material thus obtained is then placed in a reactor, in particular a rotary tube furnace.

It is useful when the sulfuric acid 12 is dosed using the sulfuric acid supply device 43 (see FIG. 2). Described in connection with FIGS. 2 preferred embodiments of this sulfuric acid supply device are also suitable for the one described in FIG. 1 way.

- 10 044283

Sulfuric acid 12 is preferably at least 95% strength. The crushed material and sulfuric acid 12 are brought to the opening temperature T _A , which is, for example, at least T _a =140°C, in particular at least 150°C. If the pH value can be determined, it is below pH 1.5 for a mixture of crushed material and sulfuric acid. However, as a rule, the water content of the mixture is too low to determine the pH value.

Upon opening, an exhaust gas 14 is formed, which in particular contains hydrogen fluoride HF. The opening is carried out until, in a periodic comparative test in a vessel without continuous addition of material, the fluoride content, in particular the hydrogen fluoride content, is achieved in the exhaust gas 14 below a predetermined threshold value, for example, 0.83 mg per cubic meter. This is monitored using a fluoride detector 15, which continuously measures the fluoride concentration.

If the opening is carried out in a batch mode, then the opening is carried out until the fluoride content, in particular the hydrogen fluoride content, is achieved below a predetermined threshold value, for example, 0.83 mg per cubic meter.

Alternatively or additionally, dissection is continued until the dissected material achieves a concentration of fluorine CF water-soluble fluoride below 100 milligrams per kilogram of dissected material, preferably below 10 mg/kg, and particularly preferably below the detection limit. In other words, the residence time of the crushed material 10 and sulfuric acid 12 is selected such that the exposed material has a fluorine concentration CF based on water-soluble fluoride that does not exceed the specified values.

In addition, an exposed material 16 is obtained which, to a good approximation, can be considered fluoride-free. The exposed material 16 is treated with water 18 and thereby leached. Leaching can be carried out in the same container in which the crushed material was opened, but this is not necessary. For example, it is also possible that the opened material is loaded into a container which preferably already contains water. Leaching is carried out at a pH value from 0.7 to 4 and, preferably, without active addition or removal of heat.

After leaching, the graphite 20 is separated using the graphite separation device 22. Here, the graphite separation device 22 is a filter with a pore size of no more than 15 micrometers, preferably no more than 10 micrometers. It is useful when the pore size is at least 0.5 micrometer.

Graphite 20 can be purified in a subsequent processing step. For example, this is done by adding water, alcohol, an organic solvent or an inorganic acid, so that electrode graphite is obtained. Electrode graphite is graphite that is suitable for producing electrodes, in particular for lithium batteries. When separating graphite 20, a draft liquid 24 is also obtained.

Purification of graphite 20 may involve heating to a decomposition temperature T ₂₀ at ^(^250°^ in particular, T _z >350°C. Preferably, T _Z <=430°C is true. Heating decomposes binder residues, which, for example, consist of polyvinylidene fluoride (PVDF) This is preferably done in a closed container.

Alternatively or additionally, purification includes classification. But classification is not mandatory. Binder residues typically have a smaller diameter than graphite particles, so screening out smaller components can reduce the binder residue content.

Alternatively or additionally, purification may include flotation. For example, flotation is carried out in an aqueous liquid.

If the purification involves the introduction of an inorganic acid, for example hydrofluoric acid or hydrochloric acid, the silicon content is also reduced, which is advantageous.

Metallic copper Cu is obtained from the rough liquid 24, for example by carburizing. To do this, for example, metallic iron is brought into contact with the roughing liquid 24, so that the iron ions go into solution and metallic copper is deposited.

Alternatively, copper is precipitated as copper sulfide. For example, this is accomplished by precipitation by adding sodium hydrogen sulfide NaHS. By isolating copper, a decontaminated draft liquid 26 is obtained. It has a pH value in the range from 0 to 4, for example, pH 1.

Then, in the decontaminated draft liquid 26, Fe ²⁺ ions are oxidized to Fe ³⁺ ions. In this case, this is done by adding hydrogen peroxide H ₂ O ₂ . However, another oxidizing agent may also be used. The pH value of the deferred roughing fluid 26 before oxidation is below 4.3. This step is preferably carried out without actively adding or removing heat.

In a subsequent step, iron, aluminum and, if necessary, titanium in the form of hydroxide are removed. To do this, increase the pH value to a value between 4.3 and 8.7. This is accomplished by adding sodium hydroxide and then separating, in particular by filtration or centrifugation, the precipitate formed. Thus, along with the precipitated hydroxides, pure liquid 28 is obtained.

It is possible, but not necessary, that the clean liquid 28 is purified of organic components by means of an activated carbon filter 27'. In particular, when cleaning has already been carried out previously, in particular by means of activated carbon 27, this becomes unnecessary.

It is possible, but not certain, that the zinc and/or copper and/or iron and/or aluminum are removed by ion exchange. This is accomplished using an ion exchanger 29. The stationary phase of the ion exchanger 29 is preferably a chelating complexing agent with aminophosphonic acid groups as functional groups.

Nickel and cobalt are extracted from the pure liquid 28 by liquid-liquid extraction. In this case, this is done using Cyanex 301, which is dissolved in an organic solvent, usually kerosene.

Fig. 1 shows that two liquid-liquid extraction steps are included within each other. First, cobalt and nickel are extracted using Cyanex 301, which is dissolved in kerosene. Re-extraction with an acid, in particular hydrochloric or sulfuric acid, gives solution 30, which contains nickel and cobalt. After further separation using Cyanex 272, they are crystallized separately from each other.

When, as here or generally in the description, the name of a metal, for example manganese, is indicated, then in principle this means metals in elemental form, as well as in the form of compounds that contain this metal, generally including metal ions. The expression that manganese, cobalt and nickel are extracted also means that manganese, cobalt and nickel ions and such compounds are removed, in particular also ions which contain manganese, cobalt and nickel.

By extracting cobalt and nickel, a manganese-containing target liquid 32 is obtained. The pH value of the target liquid 32 can be between -0.7 and 10.5.

There are (at least) three alternatives for further processing of the target liquid 32. In a first alternative, manganese is removed from the manganese-containing target liquid 32 by liquid-liquid extraction. For example, this can be accomplished by di-(2ethylhexyl)phosphoric acid (D2EHPA) which is dissolved in kerosene.

According to the second and third alternatives, the manganese is removed by precipitation, which, for example, can be accomplished by adding sodium hydroxide. According to a third alternative, precipitation can be carried out by adding sodium carbonate.

By removing the manganese, the target liquid 34 is obtained. This liquid contains lithium ions as an important component. According to the first alternative, lithium can be isolated in the form of phosphate. To do this, for example, sodium phosphate is added to the target liquid 34.

According to the second alternative, lithium is precipitated from the target liquid 34 in the form of carbonate. For example, this is done using sodium carbonate. A suitable temperature is no more than 30 Kelvin below the boiling point of the target liquid of 34 and preferably above 50°C. Optionally, the lithium carbonate is washed with water at 50-100°C, preferably 80-100°C, and/or ethanol.

It is useful when the deposition is preceded by a concentration step, resulting in an increased lithium concentration. Alternatively, the lithium can be precipitated as lithium phosphate by adding, for example, sodium phosphate. Concentration can be accomplished, for example, by reverse osmosis and/or evaporation.

According to the third alternative, lithium is extracted by liquid-liquid extraction. Details can be found in the description of FIG. 8b. Therefore, the components of the lithium liquid-liquid extraction unit 84 for performing liquid-liquid extraction are shown only schematically.

Fig. 2 shows a schematic view of a recycling plant 36 according to the invention for recycling lithium batteries, in this case in the form of shredded material 10 that is derived from lithium batteries. Alternatively, it is also possible that the recycling plant processes electrode material that does not have to be shredded. Here, the recovery unit 36 includes a reactor 40 in which the ground material 10 is exposed to sulfuric acid 12. The ground material 10 and the sulfuric acid 12 are mixed together by a mixer 42. A mixer 42 is preferred, but not required. The reactor 40 may be a rotary tube furnace, but is not required to be. In particular, the reactor 40, as here, may be a vessel which may have a stirrer.

The sulfuric acid 12 is added via a sulfuric acid supply device 43, which can be, for example, a dosing device that includes a sulfuric acid container 45 and an adjustable valve 47. However, it is also possible that the sulfuric acid 12 is poured from the container.

It is possible that the crushed material 10 is first loaded into the reactor 40, for example using a conveyor. After this, using an adjustable valve 47, sulfuric acid 12 is dosed in. Using the mixture temperature determination device 41, it is determined whether the temperature TM of the mixture 39 remains within the specified range I of the mixture temperature. For example, the mixture temperature determination device 41 is a thermometer. But it is also possible that the mixture temperature determining device 41 has a chamber and an evaluation unit so that the development of foam in the mixture 39 can be quantitatively or qualitatively determined when foaming is a measure of the temperature TM of the mixture 39.

If the temperature TM of the mixture 39 goes beyond the temperature range of the mixture, the dosed mass flow qm of sulfuric acid is reduced by additionally or completely closing the valve 47.

If the mixture temperature TM again falls within the mixture temperature interval I, valve 47 (optional) is opened.

Alternatively or additionally, sulfuric acid 12 is first introduced into the reactor 40 and then the crushed material 10 is added, for example, through a conveyor 37, such as a belt conveyor or a screw feeder. If the temperature TM of the mixture goes beyond the temperature range of the mixture, then the added mass flow q ₁₀ of the crushed material 10 is reduced, in particular, to zero. If the temperature T _M of the mixture is again within the range I of the mixture temperature, the added mass flow q ₁₀ is increased.

Again alternatively, sulfuric acid 12 and ground material 10 are added simultaneously. If the temperature TM of the mixture goes beyond the temperature range of the mixture, then the added mass flow q ₁₀ of the crushed material 10 is reduced, or either the dosed mass flow qm or the added mass flow q ₁₀ is reduced, or both of them, in particular, to zero.

The recovery unit 36 includes an outlet device 44 in the form of an off-gas conduit, which can be connected to a device for creating a reduced pressure, so that the off-gas 14 is sucked out of the reactor 40. Alternatively, it is possible that the increased pressure generated in the reactor 40 forces the off-gas 14 through outlet device 44. The outlet device 44 may have a scrubber for washing out hydrogen fluoride. For example, the exhaust gas 14 in this scrubber is brought into contact with a calcium compound, such as an aqueous solution that contains calcium ions, so that hydrogen fluoride is washed out from the exhaust gas 14.

It goes without saying that other methods for removing hydrogen fluoride from the exhaust gas 14 are also conceivable. It is also possible that the exhaust gas 14 is supplied via an outlet device 44 to another reactor in which the hydrogen fluoride reacts, for example, with organic matter. The fluorine concentration C _F is measured using a fluorine detector 15.

Behind the reactor 40 in the direction M of the material movement there is a leaching device 46, in which the exposed material 16 is leached, for example, with water.

Behind the leaching device 46 in the direction M of material movement there is a graphite extraction device 48, which in this case only has a graphite separation device 22 in the form of a filter. An optional flushing device for flushing adhering alkaline solution from the graphite is not shown. It is also possible that the graphite is first loaded into a transport container, and the adhering alkaline solution is washed out after transport to another location.

The graphite recovery device 48 may include a graphite purification unit 49, which has a leaching reactor 51 and/or a furnace 53 and/or a classifier 55.

The leaching reactor 51 is configured to leach graphite 20 with an inorganic acid, in particular hydrofluoric acid or hydrochloric acid.

The furnace 53 is configured to heat the graphite 20 to a decomposition temperature TZ. The furnace 53 may be connected to a gas supply 57, which introduces an oxidizing gas, in particular oxygen or air, when heating must be carried out in an oxidizing atmosphere. If heating is carried out in a reducing atmosphere, then a reducing gas, for example hydrogen, is supplied through the gas supply 57. If the heating is carried out in an inert atmosphere, a protective gas, for example nitrogen or argon, is supplied through the gas supply 57, or, alternatively or additionally, a vacuum unit is connected to the furnace 53 to create a vacuum of at least 300 hPa in the furnace.

The classifier 55 is configured to create at least one fine fraction and one coarse fraction, wherein the binder content in the fine fraction is higher than in the coarse fraction.

The graphite purification unit 49 may further have a flotation device for flotation of the graphite, by which the residual binder can be separated from the graphite 20. It is possible that the graphite purification unit 49 has one, two, three or four of these components. Installation 49 of graphite cleaning is also optional.

The recovery unit 36 may have an ion exchanger 29, as described above for the embodiment of Figure 1. Alternatively or additionally, the recovery unit 36 may have one or two activated carbon filters 27, 27'.

Behind the graphite extraction device 48, in the direction M of the material movement, a copper extractor 50 is located. According to a first alternative, the copper extractor includes a vessel 52 for cementing the copper after the addition of iron, particularly in the form of iron sheets or iron filings, and a sediment separator 54 for separating selected copper compounds. Under the sediment separator 54 there can be, for example, a filter. The filter pore size is preferably less than 50 micrometers and at least 1 micrometer.

In an alternative embodiment, the precipitate separator is configured to separate copper sulfide, and the vessel 52 reacts the rough liquid 24 with NaHS so that copper sulfide precipitates.

Behind the copper extractor 50 in the direction of material movement there is a sediment separator 56

- 13 044283

Fe/Al/Ti, in which an oxidizing agent 58 is added to the deferred roughing liquid 26. This can be done in the first container 60.1. After this, the resulting solution is transferred to a second container 60.2, for example, pumped. A hydroxide, in particular an alkali metal hydroxide, is added to this second container 60.2.

For example, sodium hydroxide is added. In this way, aluminum, iron and possibly titanium are removed in the form of hydroxide or, respectively, in the form of hydrated oxide. By means of a subsequent particle separator 62 in the direction of movement of the material, the sediment is removed. The particle separator 62 is designed, for example, as a filter, which may have a pore size of a maximum of 15 micrometers.

The pure liquid 28 thus obtained is supplied to a transition metal recovery device 63, which in this case is a liquid-liquid extraction device 64 that includes a Co/Ni liquid-liquid extraction device 66. It includes a plurality of reaction vessels 38.1, 38.2, etc., which are connected to each other, as shown in Figure 2. The structure of the liquid extraction device is known in the prior art and therefore is not explained in more detail. As a result, manganese-containing target liquid 32 is obtained.

The target liquid 32 is supplied to a liquid-liquid extraction device 70 for manganese, in which the target liquid 34 is obtained.

According to one alternative, the manganese-containing target liquid 32 is supplied to a second precipitation reactor 72, in which the manganese is precipitated as manganese hydroxide after the addition of a hydroxide, in particular an alkali metal hydroxide, such as, for example, sodium hydroxide.

According to a third alternative, the manganese-containing target liquid 32 is sent to a precipitation reactor 74. There, the manganese after the addition of carbonate, in particular after the addition of sodium carbonate, is precipitated or recovered as manganese carbonate.

Lithium is precipitated in appropriate containers according to the first alternative in the form of carbonate by adding sodium carbonate, according to the second alternative - in the form of phosphate after adding sodium phosphate. It is possible that the recovery unit 36 has a concentrator 74 to remove water from the target liquid 34 to promote precipitation. According to the third alternative, lithium is extracted using a liquid-liquid extraction method. Details can be found in the description of FIG. 8b.

It is possible, but not necessary, that the recovery unit 36 has a graphite purification unit 49. The graphite purification unit 49 may have a leach reactor 51 and/or a furnace 53. Again, alternatively or additionally, the graphite purification unit 49 may have a classifier 55. This is generally true for all embodiments of the invention.

Fig. 3 shows a process flow diagram of a method according to the invention for processing cobalt-, nickel- and manganese-free ground material and/or electrode material. It can be seen that this method corresponds to the method of FIG. 1, and those stages that relate to the extraction of cobalt, nickel and manganese are excluded. Activated carbon filters 27, 27' are also optional, as is ion exchanger 29.

Fig. 4 shows a process flow diagram for processing manganese-containing and cobalt- and nickel-free ground material and/or electrode material. For manganese extraction, only the liquid extraction option is given. Shown in FIG. 1 and 2, three alternative options for manganese removal are also possible for the process of FIG. 4 and represent preferred embodiments. The three alternatives are manganese carbonate precipitation, manganese hydroxide precipitation, and liquid-liquid extraction.

Alternative options for recovering lithium are precipitation as lithium phosphate or as lithium carbonate.

Activated carbon filters 27, 27' are also optional, as is ion exchanger 29.

Fig. 5 shows a process flow diagram of a process for processing manganese-free, nickel-free, cobalt-containing electrode and/or ground material. Alternative options for lithium recovery are precipitation as lithium phosphate or as lithium carbonate. Activated carbon filters 27, 27' are also optional, as is ion exchanger 29.

Fig. 6 shows a process flow diagram of a method according to the invention for processing cobalt- and nickel-containing, manganese-free electrode and/or ground material. Alternative options for lithium recovery are precipitation as lithium phosphate or as lithium carbonate. Activated carbon filters 27, 27' are also optional, as is ion exchanger 29.

Fig. 7 shows a second embodiment of a recovery plant 36 according to the invention, with downstream components downstream of the leach device 46 being omitted for clarity.

It can be seen that the recovery unit 36 has a grinding unit 118 as well as an inactivation device 126. The inactivation device 126 is configured as a drying device.

First, lithium batteries 110.1, 110.2, etc., in particular battery systems consisting of multiple battery modules or battery packs, which in turn consist of multiple battery cells, are discharged in the discharge unit 112 This is followed by disassembly of the lithium batteries 110 at an optional dismantling station 114 when necessary since the battery systems cannot otherwise be placed in the shredding unit 118 for geometric or gravimetric reasons. to the extent that modules or packages can be removed individually. It is also possible that individual lithium battery cells could be separated from the control electronics.

The thus formed subunits (modules/packages) and/or elements 116.1, 116.2, etc. are sent to a shredding unit 118. The shredding unit 118, for example, may include a rotary shredder with at least one rotor and at least one stator. The grinding unit 118 may further include a single rotor or multiple rotor blade crusher.

The grinding unit 118 grinds the lithium batteries 110.i under a shielding gas 120, which is supplied, for example, from a shielding gas cylinder 122. Alternatively or additionally, liquid nitrogen from liquid nitrogen source 119 may be introduced. The protective gas can be, for example, nitrogen, noble gas, carbon dioxide, laughing gas (nitrous oxide), or another, preferably non-toxic gas.

The grinding produces crushed material 124, which is introduced into the inactivation device in the form of a drying device 126. Between the grinding unit 118 and the drying device 126 is a gateway 128, which is so gas-tight that the drying device 126 is highly gas-tightly separated from the grinding unit 118.

The drying device 126 is connected to a vacuum unit 129, which has a vacuum pump 130 and creates a vacuum. The drying device 126 is dominated by a pressure p ₁₂₆ with p ₁₂₆ =100±60 hPa, preferably 50 hPa. It should be noted that in the context of the present description, a vacuum pump in particular generally refers to a device that creates a vacuum. It is possible and preferable, but not necessary, for the vacuum pump to simultaneously act as a compressor, so that gas is supplied from it at a pressure that is higher than the ambient pressure.

In shown in FIG. 7, under the vacuum pump we are talking about a compressor that sucks the gas 131 located in the drying device 126 and compresses it. Alternatively or additionally, the vacuum unit 129 has a jet pump in which a jet of medium in the form of a liquid flows at high speed through at least one Venturi nozzle. The jet medium is preferably alkaline and has a pH value of at least pH 13, and is, for example, a 10% potassium hydroxide solution.

The vacuum unit 129 includes a gas cleaning device 132, which is located between the drying device 126 and the vacuum pump 130 and which in this case includes a condenser 134 and/or an activated carbon filter 136. The condenser is operated at a temperature of, for example, -10°C, so that dimethyl carbonate (dimethyl carbonate) and ethyl methyl carbonate (ethyl methyl carbonate) are condensed and can be discharged to the condensate tank 138. In addition, any water that may be present freezes. The control valve 140 is configured to open when the pressure p ₁₂₆ becomes too high, and close when the pressure p ₁₂₆ becomes too low, that is, lower than a predetermined threshold value.

Preferably, the material to be dried is transferred in the drying device 126. For example, this can be achieved by mixing with an agitator 141, such as an anchor agitator or a finger agitator, for example, with rods placed perpendicular to the agitator shaft. Alternatively, by means of a movable drying vessel.

By drying the crushed material 124, inactivated crushed material 10 is obtained, which is sent to the mixer 42.

Alternatively, the inactivated ground material 10 is loaded under vacuum and/or protective gas into a transport container 146. The transport container 146 is preferably gas-tight. It is possible, but not necessary, for the transport container 146 to be filled with inert gas prior to shipment so that it remains at normal pressure. Alternatively, it is also possible that the transport container is closed and transported in a vacuum state. It is possible that vacuum-sealed foil, for example multilayer aluminum foil, is chosen as an alternative to the transport container.

Through the supply line 148, a protective gas 120 is introduced into the grinding unit 118 using a vacuum pump 130. If the vacuum pump 130 also operates as a compressor, as in this case, which is a preferred embodiment, then the protective gas 120 can be supplied to the cylinder 150 with compressed gas. Alternatively or additionally, the shielding gas 120, if necessary after further purification, can be released into the environment.

Fig. 8a shows several variants of an additional method according to the invention. Fig. 8a shows that from pure liquid 28, manganese-containing target liquid 32 is obtained by extraction of cobalt, nickel and silicon.

According to the first alternative, manganese sulfate or manganese chloride is obtained from the manganese-containing target liquid 32 by crystallization.

According to a second alternative, manganese carbonate is obtained by precipitation with a carbonate, for example sodium carbonate.

As a third alternative, manganese hydroxide is precipitated by adding, for example, sodium hydroxide. From the manganese-containing target liquid 32, a manganese-free target liquid 76 is formed, from which the cobalt is removed, for example, by Cyanex 272. This produces a cobalt-containing liquid 78, from which the cobalt is crystallized out as cobalt sulfate or cobalt chloride. Along with the cobalt-containing liquid 78, a cobalt-free liquid 80 is formed, which contains nickel and lithium.

Fig. 8b shows further processing of the cobalt-free liquid 80. Nickel is first extracted, or in a first alternative by liquid-liquid extraction, and nickel is crystallized from the resulting nickel-containing liquid 82 as nickel sulfate or nickel chloride. Alternatively, the nickel is precipitated, for example by adding sodium carbonate. From the target liquid 34 thus obtained, lithium is precipitated according to a first alternative as lithium carbonate, according to a second alternative as lithium phosphate, or according to a third alternative it is extracted, for example using Cyanex 936, and then precipitated as lithium carbonate.

Fig. 9 shows a recovery plant according to the invention according to a further embodiment.

Fig. 10 schematically shows an embodiment of a graphite purification plant 49 that has a washer 86. The washer 86 has a container 88 in which graphite 20 is mixed with a solvent 90. The solvent 90, in this case water with 10 weight percent Nmethylpyrrolidone, is heated to a temperature of T _9O =6О°С. The mixture of solvent 90 and graphite is stirred using a stirrer. By means of the separator 92, the solvent is removed from the container 88, the temperature is reduced so that the solubility of the residual binder in the solvent decreases, and the precipitated residual binder is separated, for example, filtered. Solvent 90 is then returned to container 88.

List of reference items crushed material, container, sulfuric acid, off-gas, fluorine detector, opened material, water, graphite, graphite separation device, draft liquid, deferred draft liquid, activated carbon filter, pure liquid, ion exchanger, solution, manganese-containing target liquid , target liquid, disposal unit, conveyor, electrode material, mixture, reactor, mixture temperature determination device, mixer, sulfuric acid supply device, outlet device, sulfuric acid container, leaching device, adjustable valve, graphite extraction device, graphite purification unit, copper extractor, leaching reactor,

- 16 044283 container, furnace, sediment separator, classifier, Fe/Al/Ti sediment separator, gas supply, oxidizer, container, particle separator, transition metal extraction device, liquid extraction device, Co/Ni liquid extraction device, reaction vessel, liquid extraction device Mn extraction, precipitation reactor, concentrator, manganese-free target liquid, cobalt-containing liquid, cobalt-free liquid, nickel-containing liquid, lithium liquid-liquid extraction unit, washing device, container, solvent, separator,

110 lithium battery,

114 dismantling station,

116 elements,

118 grinding unit,

119 liquid nitrogen source,

120 shielding gas,

124 crushed material,

126 drying device,

128 gateway,

129 vacuum installation,

130 vacuum pump,

131 gas,

132 gas cleaning device,

134 capacitor,

136 activated carbon filter,

138 condensate container,

140 adjustable valve,

141 mixing devices,

146 transport capacity,

148 supply pipeline,

150 compressed gas cylinder,

CF fluoride concentration,

M direction of material movement, qm dosed mass flow,

T _A opening temperature, TZ decomposition temperature.

-

Claims (22)

CLAIM 1. A method for processing lithium batteries, including the stages: (a) reacting the ground material (10), which contains ground components of lithium battery electrodes, with concentrated sulfuric acid (12) at an opening temperature (TA) of at least 100°C, in particular at least 140°C, so that off-gas (14) and recovered material (16), (b) removal of off-gas (14) and (c) hydrometallurgical chemical recovery of at least one metal component of the recovered material (16). 2. Method according to claim 1, characterized in that the opening of the crushed material (10) includes the following stages: (a) mixing concentrated sulfuric acid (12) and crushed material (10), resulting in a mixture (39), (b) determining the temperature (TM) of the mixture (39), and (c) controlling or adjusting (i) the metered mass flow (qm) sulfuric acid (12) and/or (ii) added mass flow (q ₁₀ ) of crushed material (10), so that the mixture temperature (TM) remains within a given mixture temperature interval (I). 3. Method according to claim 1, characterized in that the opening of the crushed material (10) includes the following stages: (a) adding concentrated sulfuric acid (12) with a metered mass flow (qm) to the crushed material (10) so that a mixture (39) is obtained, (b) determining the temperature ( _TM ) of the mixture (39) and (c) adjusting the metered mass flow (q _m ) so that the mixture temperature (T _M ) remains within the specified interval (I) of the mixture temperature. 4. The method according to any of the preceding paragraphs, characterized by the steps: (a) leaching the exposed material (16), in particular with an aqueous liquid (18), and (b) before hydrometallurgical chemical recovery of at least one metal component of the exposed material (16), in particular after leaching of the exposed material (16), carrying out ion exchange, in which metal impurities are removed, in particular zinc and/or copper and/or iron and/or aluminum. 5. The method according to any of the preceding paragraphs, characterized by the step of: before hydrometallurgical chemical recovery of at least one metal component of the exposed material (16), in particular after leaching of the exposed material (16), carrying out an ion exchange in which cobalt and/or nickel and/or manganese and/or lithium are not removed . 6. The method according to any of the preceding paragraphs, characterized by the step of: before hydrometallurgical chemical recovery of at least one metal component of the exposed material (16), in particular after leaching of the exposed material, adsorption of organic components, in particular by means of activated carbon. 7. The method according to any of the preceding paragraphs, characterized by the steps: (a) separating, in particular filtering, the graphite (20), resulting in a rough liquid (24), and (b) purifying the graphite (2) so that the content of non-metallic impurities, in particular binder and silicon, is reduced. 8. Method according to claim 7, characterized in that the cleaning comprises heating to a binder decomposition temperature T _Z of at least 250°C and/or at most 700°C, in particular at most 430°C. 9. The method according to claim 8, characterized in that the heating is carried out in (a) an oxidizing atmosphere, (b) an inert atmosphere or (c) a reducing atmosphere. 10. Method according to claim 7 or 8, characterized by the stages: (a) classification of graphite (2) so that at least one fine fraction and one coarse fraction are formed, the proportion of binder in the fine fraction being at least twice as high as in the coarse fraction, and/or (b) flotation of graphite (2 ) or binder, particularly in aqueous flotation fluid. 11. Method according to any one of claims 7 to 10, characterized in that the cleaning includes dissolving the graphite binder with a solvent. 12. Method according to any one of claims 7 to 11, characterized in that (a) cleaning includes rinsing and/or washing with an acid, in particular sulfuric acid, and - 18 044283 (b) purification is carried out until the concentration of metal impurities is at most 10,000 ^ppm . 13. A method according to any one of claims 7 to 12, characterized in that (a) the purification includes leaching and/or washing with an oxidizing agent, and (b) the purification is carried out until the concentration of metal impurities is at most 10,000 ^ppm . 14. The method according to any of the preceding paragraphs, characterized by the stages: (a) separating graphite (20) from the exposed material (16), resulting in a rough liquid (24), (b) separating copper from the rough liquid (24), so that a decontaminated rough liquid (26) is formed, (c) carrying out ion exchange after the release of copper. 15. The method according to any of the preceding paragraphs, characterized by the stages: (a) removal of cobalt, in particular liquid-liquid extraction of cobalt by means of a cobalt sequestering agent, and/or (b) removal of nickel, in particular liquid-liquid extraction of nickel by means of a nickel sequestering agent, and/or (c) removal of manganese, in particular liquid-liquid extraction of manganese by manganese-binding complexing agent, so that the target liquid is obtained (34). 16. A method according to any of the preceding claims, characterized in that the hydrometallurgical chemical extraction (a) extracts manganese before cobalt and/or (b) extracts cobalt before nickel. 17. Method according to any one of claims 15, 16, characterized in that the removal of nickel involves precipitation of nickel hydroxycarbonate from the clean liquid (28). 18. Method according to any one of claims 15 to 17, characterized by the step of: extracting lithium by liquid-liquid extraction from the target liquid (34), in particular by means of a lithium-binding complexing agent. 19. The method according to any one of the preceding claims, characterized by the step of: after grinding, heating the crushed material to an electrolyte removal temperature (TE) above 80°C, so that the electrolyte in the crushed material (10) evaporates. 20. A recycling unit (36) for implementing the lithium battery recycling method according to any one of the preceding claims, comprising: (a) a grinding unit (118) for grinding lithium batteries (110) so that crushed material (124) is obtained, (b) a drying device (126) for drying the crushed material (124) so that crushed material (10) is obtained, (c) a reactor (40), in particular a heated forced mixer or rotary kiln, for reacting the ground material (10), which contains ground lithium battery electrode components, with concentrated sulfuric acid (12) at a tampering temperature (TA) of at least 100°C, (d) a sulfuric acid supply device (43) for supplying sulfuric acid (12) to the crushed material (10) and (e) an outlet device (44) configured to discharge waste gas (14) from the reactor (40 ). 21. Recycling plant (36) according to claim 20, characterized by (a) a metering device (43) for supplying a metered mass flow (qm) of concentrated sulfuric acid (12) to the crushed material (10) so that a mixture (39) is formed, and a mixture temperature determination device (41) for determining the temperature (TM) of the mixture, wherein the dosing device (43) is designed to regulate or control the metered mass flow (qm) so that the temperature (TM) of the mixture remains within a given interval (I) of the mixture temperature, and/or (b) a conveyor (37) for adding crushed material (10) to the sulfuric acid (10) and a mixture temperature determining device (41) for determining the temperature (TM) of the mixture, wherein the conveyor (37) is designed to regulate or control the added mass flow (q ₁₀ ) so that the temperature (TM) of the mixture remains within the specified interval (I) of the mixture temperature. 22. Recycling plant (36) according to claim 21, characterized by (a) a sludge separator (54) for separating, in particular filtering, precipitated Cu or Cu compounds, and/or (b) a Fe/Al sludge separator (56) /Ti for separating, in particular filtering, precipitated -