Methods for more efficient spheroidization of high-quality graphite articles

Abstract

A device for rounding a graphite material by impact action, comprising a process chamber, a feed device for supplying graphite material into the process chamber, and a plurality of rounding tools, which are preferably arranged on the outer circumference of a rotor rotating about an axis of rotation and in one direction of rotation, preferably in the form of a disk, which is located in the process chamber, wherein the rounding tools are designed such that they can act on graphite particles during operation in such a way that these are rounded by folding, and a separating device for separating fine material and ultrafine material as well as a product outlet, wherein the process chamber is equipped with a coolant feed device through which free coolant medium can be introduced into the process chamber, wherein the device preferably also includes a control for the process chamber temperature.

Description

[0001] The invention relates to a method for more efficiently rounding or spheroidizing high-quality graphite particles. TECHNICAL BACKGROUND

[0002] Lithium-ion batteries are currently the state of the art where accumulators are needed to power electrical devices - from laptops and hand tools to automobiles.

[0003] It is state-of-the-art to equip lithium-ion batteries with a graphite anode. The graphite anode's primary function is to conduct and dissipate electricity, a task for which graphite is inherently well-suited. Furthermore, with each current draw from the battery cell, lithium ions flow to the anode via the cell's electrolyte, which it then stores within its lattice structure.

[0004] Besides chemical purity, the morphology of the graphite plays a crucial role.

[0005] Spherical graphite (SG) is ideal for use as an anode material. Its smooth, significantly less anisotropic, and therefore universally receptive surface is well-suited to interact effectively with the Li ions stored in the anode material, thus providing high anode charging capacity. Furthermore, spherical graphite is less prone to flaking and the associated irreversible capacity loss, resulting in a longer lifespan. Overall, the use of spherical graphite allows for a higher energy density combined with a longer lifespan.

[0006] In nature, graphite occurs, among other forms, as so-called flake graphite distributed throughout rocks, as seen in... Fig. 2a shows.

[0007] Untreated flake graphite, with its layered morphology, exhibits pronounced basal planes. These are the planes that run parallel to the graphite's crystal structure. Along these planes, graphite is a very good thermal and electrical conductor, while graphite perpendicular to the basal planes—that is, between the individual planes—can be considered a thermal and electrical insulator. Flake graphite thus exhibits pronounced anisotropy.

[0008] For this reason, flake graphite must be processed to produce the required spherical graphite. The latter is largely free of this basal problem and is therefore much better suited for electrical applications. Fig. Figure 2b gives an impression of what spheroidized graphite material of fineness class SG 20 looks like.

[0009] Other fineness classes frequently requested in practice are SG 22, 18, and 10. As experts know, for example, the term SG 22 is used when the d 50 The material's equivalent diameter is 22 µm, meaning that 50% of the particles comprising the graphite material have an equivalent diameter of 22 µm or less, relative to the particle volume. The same principle applies to the other fineness classes.

[0010] The corresponding processing method is known in the state of the art, although it is a relatively new technology. It is called spheroidization.

[0011] Spheroidization is not achieved by grinding or cylindrically polishing individual particles of the flake graphite, but rather by multiple folding processes. This folding is accomplished by repeatedly colliding graphite flakes, carried by a carrier or process gas stream, with obstacles at a kinetic energy chosen such that the graphite particles are not shattered, but merely folded, i.e., deformed.

[0012] The standard procedure involves first subjecting the raw graphite to a grinding process in a classifier mill to pre-fine it and produce graphite flakes small enough to be used in a subsequent spheroidization step to produce spheroidal graphite of the desired quality or fineness. For this purpose, the pre-ground graphite material is fed in portions into a spheroidizer.

[0013] This device is equipped with internal components that subject the graphite particles to multiple folding, thereby spheroidizing them instead of unnecessarily crushing them further. Such a spheroidal classifier generates a strong turbulent flow internally during operation. While it does require an externally generated process gas stream, this flow is lower than in a comparable mill. After a specific treatment time, the desired product quality is achieved. The spheroidal classifier is then discharged. The resulting graphite mixture is fed to an integrated or external classifier, which separates the finished, spherical graphite particles from the accompanying fines that must be discarded.

[0014] A spheroidizer rounds most effectively when small volumes of air flow through the system. Since considerable mechanical energy is introduced into the process chamber of the spheroidizer during spheroidization, the temperature inside the spheroidizer rises sharply during the rounding of a batch. This is because the small volumes of air flowing through the spheroidizer during the process, combined with the relatively small amount of graphite material removed for the intended rounding to a fine consistency, are insufficient to provide effective cooling. Temperatures exceeding 100 °C are therefore the norm. This poses a problem for the system's technology. Highly rotating components are used, which are designed to seal as tightly as possible with the stationary housing parts. Even this leads to problems due to the significant temperature fluctuations caused by the variable load profile of the spheroidization process.

[0015] To remedy this problem, the state of the art provides for cooling highly stressed plant components by means of a closed cooling water circuit.

[0016] Even when the bearings of the spheroidal classifier and other temperature-sensitive components are cooled in the manner described, a problem remains. The varying temperatures across each batch lead to constantly changing gap dimensions. This poses a problem for consistent product quality because the air volume fluctuates between each processing batch. Current technologies attempt to solve this problem by also connecting the grinding chamber jacket and / or the grinding tools to the closed cooling water circuit.

[0017] However, this type of cooling has not yet proven entirely satisfactory. In some cases, the surface area of ​​the process chamber of the respective spheroidal classifier is insufficient to guarantee truly effective cooling. This is particularly problematic with increasing spheroidal classifier size, as the surface area increases proportionally less than the energy introduced into the process chamber due to the larger size. In some cases, the conventional shell cooling method is also too slow to enable optimal process control, which translates into corresponding product quality. PROBLEM UNDERLYING THE INVENTION

[0018] The invention is based on the problem of providing a device and a method for spheroidization in which the temperature in the system can be better controlled. THE INVENTIONAL SOLUTION

[0019] According to the invention, this problem is solved by a device according to claim 1.

[0020] The device according to the invention is also known as a spheroidal classifier. By its design, it is a device for rounding a graphite material by means of impact action.

[0021] The device according to the invention comprises a process chamber and a feed device or access for supplying graphite material into the process chamber.

[0022] The device according to the invention further comprises a plurality of rounding tools. These are preferably arranged on the outer circumference of a rotor rotating about an axis of rotation and in one direction of rotation, which is located in the process chamber.

[0023] The rotor is preferably designed in the shape of a disk.

[0024] The rounding tools are designed such that, during operation, they can act on the graphite particles in the process chamber in such a way that these particles are rounded – at least predominantly – by folding. The device according to the invention is thus characterized by the fact that it does not primarily act on the graphite particles to be treated by crushing and / or grinding to bring about the required rounding, but rather predominantly by forming.

[0025] Additionally, and as a rule completely physically separate from the rotor already mentioned, the device according to the invention has a separating device for separating fine material and ultrafine material from the process chamber.

[0026] Finally, the device according to the invention has a product outlet.

[0027] The device according to the invention is characterized in that the process chamber is equipped with a coolant application device through which free cooling medium can be introduced into the process chamber, the device preferably also including a control for the process chamber temperature.

[0028] For patent law reasons, it must first be noted that pure air, pure graphite, or a mixture of air and graphite are not coolants within the meaning of the invention. Rather, in most cases, a coolant made from a carrier gas and a liquid is used.

[0029] The coolant is used as a free coolant, i.e., it does not flow through the process chamber in a closed line within which the coolant absorbs heat by means of heat exchange, but is released into the process chamber in such a way that it mixes with the graphite to be rounded.

[0030] Preferably, the device according to the invention is furthermore equipped with at least one guide apparatus and usually has a cover ring, which is typically mounted above the rounding tools.

[0031] Because the coolant is introduced into the process chamber as a free coolant, it can mix with the graphite material to be rounded. This allows it to absorb, convert (e.g., through coolant evaporation), and / or remove at least some of the energy introduced into the graphite material by the rounding tools particularly intensively and quickly. This can be achieved, for example, by drawing off the coolant and the energy it has absorbed via the separation device. In this way, the process chamber can be cooled more effectively than before—essentially independent of the chamber's design and the size of the system. Due to the significantly lower reaction inertia of the cooling system compared to simple jacket cooling, a much more effective control (in the sense of "closed-loop control") of the cooling chamber temperature can also be implemented.

[0032] Since the cooling system according to the invention reduces the temperature spread that occurs during batch processing, batch processing can not only be carried out faster (because less attention needs to be paid to the amount of energy input when introducing energy via the rounding tools), but the rounding quality also increases. In many cases, the batch size can also be increased, since the higher energy input required to process a larger batch in the same time no longer drives the temperature to unacceptable levels. FURTHER OPTIONAL DESIGN OPTIONS FOR THE INVENTION

[0033] It is particularly preferred if the coolant application device includes at least one coolant atomizer. Such an atomizer atomizes the coolant before and / or while it enters the process chamber. The use of a coolant mist, and especially a water mist, usually made from distilled or demineralized water, has proven ideal in order to prevent residues, and in particular limescale crystals, from forming in the graphite. Wetting or moistening of the graphite particles to such an extent that there is a risk of clumping is avoided wherever possible. Rather, the aim is generally to avoid changing the residual moisture content of the graphite particles throughout the batch process, at least to a more than negligible degree.

[0034] A particularly advantageous option has proven to be the design of the coolant delivery device to include at least one, preferably several, two-fluid nozzles. Such a two-fluid nozzle can be supplied, for example, with coolant, especially water, and simultaneously with air. It then generates a water mist—generally above the dew point from the outset—whose droplets evaporate completely when they mix with the heated graphite particle in the process chamber to form a graphite-air aerosol. In doing so, they extract energy from the contents of the process chamber via their enthalpy of vaporization, namely significantly more energy (nine to ten times more) than would be extracted by simply reheating a liquid without a phase change, as would occur, for example, with jacket cooling.

[0035] Ideally, the process chamber is closed by a lid, preferably a top-mounted lid, and the coolant injection device penetrates the lid, thus creating a port through which the coolant can be injected into the process chamber. Experiments have shown that injection of the coolant from above, i.e., through the lid, is the most effective method, as this best utilizes the flow conditions present in the process chamber.

[0036] Ideally, the coolant application device should protrude freely into the process chamber beyond its supporting environment, preferably by less than 5 mm. This eliminates the risk, especially when using cooling mist, of the freshly applied cooling mist wetting the housing, cover, or internal surface and remaining there as a film or droplet instead of evaporating directly.

[0037] In many cases, it is particularly advantageous for the coolant to be introduced into the process chamber at an overpressure of at least one bar. It then enters the chamber and mixes very quickly and intensively with the turbulent graphite-air aerosol in the grinding chamber. The water and gas pressure in the two-component nozzle influences the droplet size in the spray. Particularly small droplets are highly desirable to maximize contact with the surface area. The stresses during spheroidization lead to significant heating of the individual particles with short-term temperature peaks that are considerably higher than the gas temperature inside the spheroidizer. Accordingly, rapid evaporation is ensured with a sufficiently small droplet size and good atomization.

[0038] In many cases, it is advantageous for the coolant to leave the process chamber at least partially, preferably predominantly or even substantially, via the separating device. It is particularly advantageous if the device has at least one sensor for the process chamber temperature, and this sensor is preferably positioned at least half a nominal process chamber diameter away from the at least one coolant injection device on the circular path. This prevents the sensor from being struck by a coolant surge or jet that has just been introduced into the process chamber, which would cause it to erroneously measure a lower temperature than the relevant temperature in the process chamber.

[0039] It is particularly preferred to position the temperature sensor in the lid and ideally on at least substantially the same radius as the coolant application device - then preferably offset by 90° to 270° angularly to the coolant application device.

[0040] Further applications, design possibilities, modes of operation and advantages of the invention will become apparent from the exemplary embodiment and the explanations found below under "Miscellaneous". LIST OF FIGURES Fig. Figure 1 shows the spheroidal sifter in a sectional view (mid-longitudinal section). Fig. Figure 1A shows a close-up of the Fig. 1 Fig. 1B shows the spheroidal classifier according to Fig. 1 in a top view, the two ports 5a, 5b according to the invention for the coolant supply and the temperature measurement in the spheroidal classifier can now also be seen. Fig. 1C shows a view into the spheroidal classifier according to... Fig. 1B seen from below (underside cut away perpendicular to the main axis of rotation). Fig. Figure 2a shows untreated flake graphite. Fig. Figure 2b shows spheroidized graphite material of fineness class SP 22. Fig. 2c to 2e show further product results. EXAMPLE OF EXECUTION

[0041] Fig. Figure 1 shows a device according to the invention, which is also called a spheroidal classifier and serves to round graphite flakes GF of a graphite material GM or even to round its precursor such as green coke, which is not explicitly emphasized in each case below - however, without the coolant inlet or the associated temperature sensor for the temperature in the process chamber being visible in this schematic view.

[0042] According to the Fig. 1 The device 1 preferably comprises a housing 2 designed approximately as a standing cylinder, on the top of which a feed device 3 for supplying the graphite material GM is arranged, in particular a feed device 3 for supplying graphite flakes GF.

[0043] In particular, in the illustrated embodiment, the feed device 3 is designed as a drop tube, but it can also be provided that the graphite material GM is fed via an injector feed.

[0044] The graphite material GM encounters rounding tools 5, which are also referred to as beaters. In this process, the graphite flakes GF are folded and wrapped around a core of the respective graphite flake GF.

[0045] This process results in a lower irreversible capacity and a longer lifespan when using rounded graphite particles (SG) in batteries. The smooth surface of the rounded graphite particles (SG) prevents flaking or splintering. The powder containing rounded graphite particles (SG) has an increased tapped density and therefore a high energy density in battery applications.

[0046] This powder is particularly suitable for the production of lithium-ion batteries because the lithium ions have easier access to the graphite through the cavities formed between the rounded graphite particles (SG). In particular, the lithium ions are deposited in the planes between the folded graphite flakes. After rounding, and before use in battery production, etc., the powder with the rounded graphite particles is chemically purified again and then coated.

[0047] Preferably, the device 1 has, as shown in the Fig. As can be seen in Figure 1, a plurality of rounding tools 5 are arranged on a rotor or, more precisely, on a rotatably movable disk 7 within its process chamber. The graphite material GM, introduced into the interior of the device via the feed device 3, is gripped by the rounding tools 5, accelerated, and guided against an impact surface 6, which here is usually characterized by impact ramps that have an inclination relative to the inner surface of the housing.

[0048] The impact surface 6 represents in particular an area of ​​the cylindrically shaped inner surface 21 of the housing 2.

[0049] The rounding tools 5 are, according to the Fig. 1 and in the Fig. 1A, in particular, are arranged all around and at regular intervals to one another on the outer circumference of a rotating disk 7, which is arranged via a first drive shaft 8 on a drive (not shown). The impact surface 6 and the rounding tools 5 are designed such that the graphite material GM impacts the rounding tools 5 at different angles, thereby achieving a particularly advantageous deformation, in particular folding, of the graphite flakes GF. The rounding tools 5 are optimized in particular for the highest possible number of particle impacts at different impact angles.

[0050] The processing of graphite material GM to spheroidized graphite SG is carried out in batches. The processing time per batch depends not only, but significantly, on the power that the rounding tools 5 can transfer to the graphite material being processed. The higher the power input, and thus the energy input per unit of time, the more the contents of the process chamber heat up, and consequently, so do the process chamber and its internal components. This leads to the problems mentioned at the beginning.

[0051] To remedy this, this embodiment is provided with at least one additional connection or port 5a for supplying coolant to the interior of the process chamber, preferably on its upper cover. Ideally, a second connection or port 5b is also provided. This holds a sensor for the process chamber temperature. The aforementioned ports are located in Fig. 1B is clearly visible.

[0052] A coolant is introduced into the process chamber through port 5a as a free coolant. In the process chamber, it can mix with the graphite material GM to be rounded and therefore absorb at least some of the energy introduced into the graphite material GM by the rounding tools 5 particularly intensively and quickly (e.g., through coolant evaporation).

[0053] For those from the Fig. 1 and Fig. In the device shown in 1A, a temperature increase of approximately 130 °C occurs during batch processing without cooling.

[0054] If, on the other hand, a water mist cooling system according to the invention is used and air at 15 °C is drawn in from the environment for this purpose, which has a relative humidity of 65% and an initial water content of approximately 8.9 g / m³ 3If this is the case, then a water quantity of 42 kg / h is sufficient to ensure a stable process temperature between 60 °C and 70 °C, because the average power input over the entire batch is around 50 kW.

[0055] Accordingly, approximately 60% of the input power must be cooled to establish a stable operating point within the target range. Therefore, in the devices according to the invention, the coolant supply is designed such that 1 kg of water per 1 kg of feed product is introduced into the process chamber. More broadly, it can be defined that designs in which between 0.5 kg and 1.5 kg of water per kg of feed product is introduced into the process chamber are desirable.

[0056] The control variable is usually, as in this embodiment, the temperature in the process chamber. When this reaches a value of, for example, 60 °C, the propellant of the two-fluid nozzle, which is preferred here and generally used, is first activated. In this embodiment, this is dry compressed air. Ideally with a time delay, predominantly between 5 and 30 seconds, the valve for the amount of water used here is then regulated. This injection quantity defines the cooling capacity.

[0057] The Fig. Figure 1B shows a particularly favorable installation situation for port 5a. This is because the coolant inlet is positioned approximately 90° offset in the direction of rotation from the product outlet 17, from which in Fig. Figure 1B shows the extraction nozzle. The temperature measurement is ideally positioned directly opposite the coolant inlet.

[0058] The coolant supply should not be placed too close to the aforementioned extraction port to ensure that no moist product is extracted.

[0059] In the of Fig. In the situation shown in Figure 1B, the material moistened by the coolant supply must travel another 270° around the system before reaching the aforementioned extraction nozzle. To ensure that the product exits the system dry, the coolant supply should be switched off during extraction.

[0060] Based on the Fig. Figure 1C shows that the radial position of at least port 5a for coolant supply is ideally radially outside the guide ring 41. Here, the temperature of the graphite material is typically highest, and there is little influence from the cold air in the gap.

[0061] The device 1 further comprises a separation device 10, for example a wind classifier with classifier wheel 11.

[0062] During the rounding of the graphite flakes GF, abrasion in the form of fine material and / or ultrafine material FM can occur. Since the desired end product EP should preferably consist only of rounded graphite particles SG, the fine material and / or ultrafine material FM is separated directly within the device 1 from the rounded graphite particles SG and removed from the device 1. The separating device 10 is arranged above the disk 7 with the rounding tools 5.

[0063] The classifier wheel 11 is connected via a second drive shaft, which is not shown in detail, to a second drive, which is also not depicted here. In particular, it is possible that the first drive shaft 8 and the second drive shaft are arranged coaxially.

[0064] Process air PL is supplied from bottom to top via a supply nozzle 14 in the lower area of ​​the device 1, in particular below the rotating disk 7 with the rounding tools 5. This air is directed to the rounding area and, via the guide elements 25, to the separating device 10. The process air PL carries the fine material and / or ultrafine material FM with it and discharges it from the device 1 via the extraction nozzles 16.

[0065] Within the device 1, the graphite material GM comes into contact at least once with at least one rounding tool 5, thereby imparting a swirl to the graphite material GM. The guide elements 25 redirect the swirl-impregnated graphite flakes GF, the swirl-impregnated rounded graphite particles SG, and the swirl-impregnated fine material and / or ultrafine material FM in a perpendicular direction, in particular perpendicular to the rotating disk 7, and thus reach the cutting device 10 at least largely without swirl. This ensures optimal flow to the cutting device 10, resulting in high separation efficiency.

[0066] According to one embodiment of the invention, the graphite material GM is fed into the process chamber 40 of the device 1 via the feed device 3. The graphite material GM strikes the guide ring and is thereby guided past the classifier wheel 11, so that any fine dust already present is sifted out.

[0067] The graphite material GM then hits the disk 7 with the rounding tools 5, which provide the energy for the rounding.

[0068] In particular, the graphite material GM is gripped by the disk 7 with the rounding tools 5, accelerated, and flung against the impact surface 6. During these first two process steps, the product outlet 17 is closed.

[0069] The process air PL enters the housing 2 of the device 1 via the supply nozzle 14 and flows through a gap 45 formed between the disk 7 with the rounding tools 5 and the impact surface 6.

[0070] As the air flows through the gap 45, the graphite particles in question are directed by the airflow through the guide ring 41 to the classifier wheel 11. The material, which now comprises at least partially rounded graphite particles, returns in an internal flow to the disk 7 with the rounding tools 5. The fine dust, in particular fine material and / or ultrafine material FM, leaves the device with the process air PL via the extraction nozzle 16.

[0071] The rounded graphite particles SG are removed via a suction device, as is the case with the Fig. Figure 1B shows that the suction takes place directly on the inside of the guide ring 41. This ensures that no graphite material GM is drawn from the device 1 that has not previously passed the classifier wheel 11.

[0072] The graphite material GM is processed in the device for a defined time, during which it repeatedly comes into contact with the rotating rounding tools 5, causing the graphite flakes GF to fold and be transformed into rounded graphite particles SG. After a predefined time, it can be assumed that the graphite material GM consists almost entirely of rounded graphite particles SG. The final product, in the form of rounded graphite particles SG, can then be removed from the device 1 via a product outlet 17 and used, for example, in the production of batteries.

[0073] To further improve the stress on the graphite material GM by means of improved flow guidance, it may be provided that a cover ring 18 is arranged over each of the rounding tools 5, cf. Fig. 1 and Fig.1A. The cover ring 18 advantageously extends over all rounding tools 5 arranged on the circumference of the rotating disk 7. It enables advantageous circulation of the graphite particles to be rounded, since the flow guidance of the graphite particles within the device 1 is optimized by the cover ring 18.

[0074] The cover ring creates a zone of very high energy density by narrowing the open area in the region of the beaters. The flow velocity of the circulating gas increases significantly in this area due to the closure of the channels between the beaters. This facilitates the removal of the particles rejected by the classifier, thanks to the greater pressure gradient across the diameter of disk 7 resulting from the higher velocity.

[0075] This cover ring 18 prevents, in particular, the coarse graphite material GM, especially the graphite flakes GF and / or already rounded graphite particles SG, from being flung upwards and circulating through the process chamber 40 without contact with the rounding tools 5. The cover ring 18 ensures, in particular, multiple points of effective contact between the rounding tools 5 and the coarse graphite material GM.

[0076] According to one embodiment, the device 1 further comprises a control device not shown in figures, by means of which, for example, the first drive and / or the second drive and thus the rotational speed of the classifier wheel 11 and / or the rotational speed of the disk 7 with the rounding tools 5 is regulated and / or controlled. MISCELLANEOUS

[0077] The German patent application with the official file number DE 10 2023 122 651, which was attached to these documents upon their submission, describes a complete device with which rounded graphite of different classes can be produced particularly efficiently in several steps.

[0078] The complete device and method described in DE 10 2023 122 651 can be operated particularly efficiently if, in at least one and preferably all stages where the use of a spheroidal classifier is planned, a spheroidal classifier according to the present invention is used. With this in mind, the entire disclosure content of the attached German application DE 10 2023 122 651 is incorporated by reference into the subject matter of this application.

[0079] In this sense, in the context of the present application, independent protection may be claimed, not only, but also, for a complete device for the production of spheroidized graphite, which consists of a classifier mill and several devices connected in series and thereby feeding each other in accordance with DE 10 2023 122 651 according to one of the claims set out below in this application.

[0080] Furthermore, a process for producing spheroidized graphite may be claimed at a later date, comprising the following steps: filling the process chamber of a spheroidizer constructed according to this present application, preferably according to one of the preceding claims 1 to 12, with a batch of preferably pre-ground graphite; introducing rotational energy into the process chamber of the spheroidizer; and temperature control of the process chamber by introducing a free coolant into the process chamber. The temperature control is preferably achieved to a process temperature between 40 °C and 120 °C, ideally to a process temperature between 40 °C and 100 °C.

[0081] Furthermore, at the appropriate time, protection may also be claimed for a process for producing graphite particles of certain different fineness classes rounded by impact action, using several spheroidizers connected in series according to this present patent application, which is characterized in that the graphite material to be rounded is pre-crushed, and then a first spheroidizer produces spheroidized graphite material of a first fineness class from it by folding, which is discharged from the process as the end product, and simultaneously separates graphite material that can predominantly not be processed into graphite material of this first fineness class because it is too finely crushed, wherein the separated, excessively crushed graphite material is fed to a second spheroidizer, which can produce spheroidized graphite material of a second, finer fineness class from it by folding.which is also removed as a final product from the process.

[0082] Furthermore, at the appropriate time, protection may also be claimed for a process for producing graphite particles of certain different fineness classes rounded by impact action, which is characterized in that the intensity with which pre-milling or pre-crushing is carried out is adjusted so that more than 50 wt.% of the graphite material fed onto the first spheroidal classifier carried out in accordance with this application is separated via its classifier wheel and can then be fed onto the second classifier, preferably also carried out in accordance with the present invention, which produces graphite material of a finer fineness class. REFERENCE MARK LIST 1 Device or spheroidal classifier 2 cases 3. Task submission 4 Not assigned 5 rounding tools 5a Connection or port for supplying free coolant to the process chamber 5b Process room, connection or port for recording the process room temperature 6 Impact area 7 disc 8 First drive shaft 9 Not assigned 10 Separating device 11 Sifter wheel 12 Not assigned 13 Not assigned 14 inlet ports 15 Not assigned 16 extraction ports 17 Product outlet 18 Cover ring 19 Not assigned 20 Not assigned 21 Inner surface area 22 to 24 not assigned 25 guiding elements 26 to 39 not assigned 40 Process room 41 Guide ring 42 to 44 not assigned 45 gap GF Graphite Flakes GM graphite material SG rounded graphite particles FM fine or ultrafine material EP End product PL Process Air D axis of rotation DR Direction of rotation QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2023 122 651 [0077, 0078, 0079]

Claims

[1] Device (1) or spheroidal classifier for rounding a graphite material (GM) by impact action comprising a process chamber (40), a feed device (3) for feeding graphite material (GM) into the process chamber (40), and a plurality of rounding tools (5) which are preferably arranged on the outer circumference of a rotor rotating about an axis of rotation (D) and in a direction of rotation (DR), preferably in the form of a disk (7) located in the process chamber (40), wherein the rounding tools (5) are designed such that they can act on graphite particles during operation in such a way that these are rounded by folding, and a separation device (10) for separating fine material and very fine material (FM) as well as a product outlet (17), characterized by the fact that the process chamber (40) is equipped with a coolant application device through which free cooling medium can be introduced into the process chamber (40), wherein the device (1) preferably also includes a control for the process chamber temperature. [2] Device (1) according to claim 1, characterized by , that the coolant application device includes at least one coolant atomizer or at least one coolant evaporator (which evaporates and / or atomizes the coolant before and / or while it enters the process chamber (40) and before it wets or moistens the graphite particles). [3] Device (1) according to any one of the preceding claims, characterized by that the coolant application device comprises at least one, preferably several, two-fluid nozzles. [4] Device (1) according to any one of the preceding claims, characterized bythat the coolant application device is supplied with water and preferably also with air, ideally with dehumidified air. [5] Device (1) according to any one of the preceding claims, characterized by , that the coolant application device generates a liquid and preferably a water mist, which it introduces into the process chamber (40) as a free cooling medium. [6] Device (1) according to any one of the preceding claims, characterized by , that the process chamber (40) is closed by a cover and preferably by a top cover, and the coolant application device penetrates the cover. [7] Device (1) according to claim 6, characterized by that the coolant application device projects freely into the process chamber (40) beyond the surrounding environment supporting it, preferably by less than 7.5 mm, better by less than 5 mm. [8] Device (1) according to any one of the preceding claims, characterized bythat the coolant application device is associated with a - preferably controlled - coolant temperature control unit which tempers the coolant before its introduction into the process chamber (40) so that it does not fall below its dew point in the process chamber (40). [9] Device (1) according to any of the preceding claims, characterized by , that the coolant is introduced into the process chamber (40) at an overpressure of at least one bar. [10] Device (1) according to any of the preceding claims, characterized by , that the coolant leaves the process chamber (40) via the separation device (10) and / or via the product outlet (17). [11] Device (1) according to any of the preceding claims, characterized by, that the device (1) has at least one sensor for the process chamber temperature and that this sensor is preferably arranged at least half a process chamber nominal diameter away from the at least one coolant application device, particularly preferably in the lid and ideally on substantially the same radius as the coolant application device and then preferably angularly displaced by 90° to 270° to the coolant application device. [12] Complete apparatus for the production of spheroidized graphite, comprising a classifier mill and several spheroidizers connected in series and thereby feeding each other according to one of the preceding claims. [13] Method for producing spheroidized graphite comprising the following steps: Filling the process chamber (40) of a spheroidal classifier (1) preferably according to one of the preceding claims 1 to 12 with a batch of preferably pre-ground graphite, Introduction of rotational energy into the process space (40) of the spheroidal classifier (1), Temperature control of the process chamber (40) by introducing a free coolant into the process chamber (40), preferably to a process temperature between 40 °C and 120 °C, ideally to a process temperature between 40 °C and 100 °C. [14] Method for producing graphite particles (SG) rounded by impact action of certain different fineness classes, using several spheroidal classifiers (1) connected in series according to one of claims 1 to 12, characterized by , that the graphite material (GM) to be rounded is pre-crushed, and then a first spheroidizer (1) produces spheroidized graphite material (GM) of a first fineness class from it by folding, which is discharged from the process as the final product, and simultaneously precipitates graphite material (GM) that is predominantly not processable into graphite material (GM) of this first fineness class because it is too finely ground, wherein the separated, excessively crushed graphite material (GM) is fed to a second spheroidizer (1) which can produce spheroidized graphite material (GM) of a second, finer fineness class by folding, which is also removed from the process as an end product. [15] Method for producing graphite particles (SG) of certain different fineness classes rounded by impact action according to claim 14, characterized by, that the intensity with which pre-milling or pre-crushing is adjusted so that more than 50 wt. %, of the graphite material (GM) fed to the first spheroidal classifier (1) is separated via its classifier wheel (11) and can then be fed to the second spheroidal classifier (1), which produces graphite material (GM) of a finer fineness class. [16] Method for producing graphite particles (SG) of certain different fineness classes rounded by impact action according to claim 14 or 15, characterized by , that two spheroidal separators (1) are connected in series, each of which produces a final product. [17] Method for producing graphite particles (SG) of certain different fineness classes rounded by impact action according to any one of the preceding claims 14 to 16, characterized by, that the fine material (FM) separated by the first spheroidal screener (1) is fed to the second spheroidal screener (1) without being screened and / or filtered again outside the first spheroidal screener (1).

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