CN110872117B - Method and device for preparing spherical graphite with median particle size of 3-12 mu m - Google Patents
Method and device for preparing spherical graphite with median particle size of 3-12 mu m Download PDFInfo
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Abstract
The invention provides a method and a device for preparing spherical graphite for a power battery, which adopt a process of combining ultramicro primary grinding, ultramicro fine grinding and multiple ultramicro grading, and the prepared spherical graphite has good sphericity and narrow particle size distribution (D)503-12 μm), and the tap density is high, thereby meeting the use requirements of the cathode material of the high-end power battery; and can utilize preparation D50Is tailing generated in the process of spherical graphite with the particle size of 13-25 mu m and is used as preparation D50The device is a raw material of spherical graphite with small particle size of 3-12 microns, the utilization rate of the raw material of the graphite is improved by 25% -35%, the process flow is simple, the energy consumption is reduced, multiple groups of crushed single equipment are connected end to end, the raw material is crushed in one stage and then directly enters the next stage for circulating crushing and grading, a pipeline is arranged in the middle for conveying, the whole device is fully sealed, dust-containing air flow is collected after dust removal and then enters a blind ditch and then enters secondary dust removal treatment, and pollution-free discharge is achieved.
Description
Technical Field
The invention belongs to the technical field of graphite preparation, relates to a method and a device for preparing spherical graphite for a power battery, and particularly relates to a medium particle size D50A method and a device for preparing spherical graphite with the diameter of 3-12 mu m.
Background
Lithium ion batteries have become a new generation of secondary batteries following nickel-metal hydride batteries in the nineties of the last century because of their advantages of high operating voltage, high energy density, long cycle life, small self-discharge, no memory effect, etc. At present, the cathode material of commercial lithium ion batteries is still the dominant graphite material, and natural graphite is widely applied due to high charge and discharge capacity, good charge and discharge platform, wide source and low cost.
In recent years, with the miniaturization, light weight, multifunction and long-term use of electronic products, vehicles and energy storage equipmentThe requirement of time driving is continuously improved, and the requirements on high energy density and high rate performance of the lithium ion battery are continuously improved. The existing research shows that the smaller the median particle size of the spherical graphite is, the better the sphericity is, the shorter the distance between lithium ions embedded into the graphite sphere and separated from the graphite sphere is, the faster the charge-discharge speed under large current is, the better the multiplying power performance is, and the use requirement of the power battery can be met. The traditional preparation process of the spherical graphite adopts a jet mill to prepare the median particle diameter (D) of the spherical graphite through the procedures of multiple times of coarse crushing, fine crushing, spheroidizing shaping, classified screening and the like50) The minimum is 14 mu m, the median particle size of the spherical graphite is difficult to further reduce, and the use requirement of a high-end power battery cannot be met.
Disclosure of Invention
The invention aims to provide a preparation method and a device of spherical graphite for a power battery, wherein the preparation method and the device can effectively reduce the particle size of the spherical graphite and improve the product yield; the invention aims to solve the technical problem of preparing the D by using natural crystalline flake graphite and earthy graphite50Is spherical graphite with the diameter of 3-12 mu m, and meets the high-rate use requirement of high-end power batteries.
The invention mainly solves the technical problems through the following technical scheme:
a preparation method of spherical graphite comprises the following steps:
(1) superfine primary crushing: feeding natural crystalline flake graphite and earthy graphite with carbon content of more than 90% into one or more (for example, 2-5) groups of serially connected ultramicro primary crusher sets;
(2) superfine grinding: sending the graphite powder collected in the step (2) into one or more groups (for example, 3-7 groups) of superfine pulverizer sets connected in series;
optionally, (3) purifying and drying.
According to the invention, in the step (1), the superfine primary grinding machine set is used for grinding and grading graphite particles. The superfine primary crusher set comprises at least two superfine crushers, a superfine classifier and a cyclone collector; the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet, an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dedusting air outlet; the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed port of the cyclone collector, a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a next ultrafine primary crusher set or connected into a feed port of an ultrafine fine crusher set, and a dedusting air outlet of the cyclone collector is connected with dedusting equipment, such as a deduster and a high-pressure centrifugal fan;
according to the invention, the rotation speed of the grading impeller of the ultrafine grinder in the step (1) is increased from 800rpm to 1600rpm one by one, the rotation speed increase of each ultrafine grinder is equal or unequal from the 2 nd, and the grinding time of each ultrafine grinder is 15-25 minutes;
according to the invention, D of the graphite powder collected by the second discharge port of the classifier and the discharge port of the cyclone collector in the last group of superfine primary grinding units in the step (1)50Preferably 5-14 μm, and a tap density of 0.7-0.85g/cm3；
According to the invention, in the step (2), the superfine pulverizer set is used for shaping particles and regulating and controlling the particle size distribution of the particles. The superfine fine pulverizer set comprises at least two superfine pulverizers, a superfine classifier and a cyclone collector; the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet, an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dust removal air outlet; the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed port of the cyclone collector, and a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected with a feed port of the ultrafine crusher in the next ultrafine fine crusher set; in the last group of superfine pulverizer units, a second discharge port of the superfine classifier is connected to a first feed bin, and a discharge port of the cyclone collector is connected with a first tail feed bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan.
Still preferably, the discharge gate of cyclone collector and the discharge gate of dust remover access in parallel to first tail feed bin.
According to the invention, the rotation speed of the grading impeller of the ultrafine grinder in the step (2) is gradually reduced from 1600rpm to 500rpm, the reduction amount of each rotation speed is equal or unequal, and the grinding time of each ultrafine grinder is 20-25 minutes; or, the rotation speed of the grading impeller of the ultrafine grinder in the step (2) is increased from 1000rpm to 2000rpm one by one, the increment of each rotation speed is equal or unequal, and the grinding time of each ultrafine grinder is 20-25 minutes; reducing the rotation speed from 1600rpm to 500rpm one by one, wherein the reduction amount of each rotation speed is equal or unequal, and the crushing time of each ultrafine crusher is 20-25 minutes;
according to the invention, the graphite particles D collected in the first silo in step (2)50Preferably 3 to 12 μm, for example, 3 to 5 μm, 5 to 7 μm, 8 to 10 μm, 11 to 12 μm, etc.; the graphite particle size range is preferably 1 to 45 μm, for example, 1 to 30 μm, 2 to 45 μm, 3 to 45 μm, 6 to 30 μm; tap density is more than or equal to 0.55g/cm3For example, 0.55 to 0.9g/cm3The specific surface area is 8.5-15.0m2(ii)/g; the graphite particles are spherical, approximately spherical, oval and potato-shaped, and the particle size distribution is uniform;
according to the invention, the structure of the ultrafine pulverizer in the step (1) is the same as that of the step (2), the ultrafine pulverizer integrates the double functions of ultrafine grinding and airflow classification, and can simultaneously complete two processing procedures of ultrafine grinding and ultrafine sorting, wherein the ultrafine pulverizer is at least one of an airflow ultrafine grinding classifier, a jet-flow ultrafine grinding classifier, a vertical ultrafine grinder and a horizontal ultrafine grinder, and preferably is an airflow ultrafine grinder; the ultramicro classifier is an airflow ultramicro classifier; the yield of each ultrafine grinder in the step (1) is 50-1500kg/h, preferably 800-1200 kg/h; the yield of each ultrafine grinder in the step (2) is 15-600kg/h, preferably 200-500 kg/h;
according to the invention, the purification in step (3) is carried out by reacting the material with an acidic aqueous solution. The acidic aqueous solution is one or more mixed aqueous solution of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid. Preferably, a mixture of a plurality of acids is used, and the ratio of the acids is preferably hydrochloric acid: hydrofluoric acid: nitric acid: sulfuric acid 0-4: 1-2: 0-4: 0-2. The temperature of the purification reaction is 50-120 ℃. The purification reaction time is 1-24 hours, and the fixed carbon content of the purified natural graphite is more than 99.95%. After the purification reaction in step (3) is completed, the material is preferably dried.
According to the invention, D of the natural crystalline flake graphite or earthy graphite in step (1)50Preferably 8 to 13 μm, for example, 8 to 10 μm, 9 to 11 μm, 10 to 12 μm, etc.; the graphite particle size range is preferably 1 to 45 μm, for example 5 to 40 μm, 1 to 30 μm, 3 to 30 μm, 5 to 45 μm;
according to the present invention, the natural crystalline flake graphite or earthy graphite in step (1) is not particularly limited, and may be graphite particles conventionally used for preparing power batteries, which are known to those skilled in the art; the preparation method of the natural crystalline flake graphite or the earthy graphite in the step (1) is also not particularly limited, and for example, the natural crystalline flake graphite or the earthy graphite prepared by the following method is selected:
(a) primary crushing: feeding natural crystalline flake graphite and earthy graphite with particle size larger than 0.05mm (such as 0.074-0.8 mm) and carbon content more than 90% into one or more (such as 2-4) primary pulverizer sets connected in series;
(b) fine crushing: conveying the graphite powder treated in the step (a) into one or more groups (for example, 1-3 groups) of secondary crusher sets connected in series;
(c) shaping: conveying the graphite powder treated in the step (b) into one or more groups (for example, 1-3 groups) of final-stage pulverizer sets connected in series;
optionally, (d) purifying and drying.
According to the invention, in step (a), the primary crusher set is used to effect primary crushing. Each group of primary crusher units comprises at least two crushers and a cyclone collector, each crusher comprises a crusher feeding port and a crusher discharging port, and each cyclone collector comprises a cyclone collector feeding port, a cyclone collector discharging port and a cyclone collector dedusting air outlet; the at least two crushers are connected with a cyclone collector in series, a discharge port of the cyclone collector is connected with a feed port of a crusher in the next primary crusher set or is connected with a feed port of a secondary crusher set, and a dedusting air outlet of the cyclone collector is connected with dedusting equipment, such as a deduster and a high-pressure centrifugal fan;
according to the invention, the rotation speed of the grading impeller of the pulverizer in the step (a) is increased from 1000rpm to 2000rpm one by one, and the increment of the rotation speed of each pulverizer is equal or unequal from the 2 nd station, and the pulverizing time of each pulverizer is 10-20 minutes; illustratively, step (a) includes 2 sets of primary crusher units connected in series, and each set of primary crusher units includes 3 crushers, so step (a) includes 6 crushers in total, wherein the rotation speed of the classifying impeller of the first crusher is 1000rpm, the rotation speed of the classifying impeller of the sixth crusher is 2000rpm, and the rotation speeds of the classifying impellers of the other 4 crushers sequentially increase in the material sequence, and the increasing amounts may be the same or different;
according to the invention, D of the powdered graphite collected in the cyclone collector of the last group of primary disintegrator groups in step (a)50Preferably 20-30 μm;
according to the invention, in step (b), the secondary crusher set is used to effect regrinding. Each set of secondary crusher comprises at least two crushers, a classifier and a cyclone collector, wherein each crusher comprises a crusher feeding port and a crusher discharging port, each classifier comprises a classifier feeding port, a classifier first discharging port and a classifier second discharging port, and each cyclone collector comprises a cyclone collector feeding port, a cyclone collector discharging port and a cyclone collector dedusting air outlet; the two crushers, the classifier and the cyclone collector are connected in series, the first discharge port of the classifier is connected with the feed port of the cyclone collector, the second discharge port of the classifier and the discharge port of the cyclone collector are connected in parallel to be connected into the feed port of the crusher in the next secondary crusher set or connected into the feed port of the last crusher set, and the dust removing air outlet of the cyclone collector is connected with dust removing equipment, such as a dust remover and a high-pressure centrifugal fan.
According to the invention, the rotating speed of the grading impeller of the pulverizer in the step (b) is increased from 2500rpm to 4000rpm one by one, the increment of each rotating speed is equal from the 2 nd station, and the pulverizing time of each pulverizer is 20-35 minutes;
according to the invention, D of the graphite powder collected at the discharge port of the cyclone collector and the second discharge port of the classifier in the last group of secondary crusher units in the step (b)50Preferably 13-25 μm, tap density < 0.9g/cm3The graphite particles are spherical, approximately spherical, oval and potato-shaped, and a large amount of fine powder is arranged on the surfaces of the graphite particles, the surfaces are rough and the sphericity is poor;
according to the invention, in step (c), the final pulverizer set is used for shaping and controlling particle size distribution. Each group of last-stage crusher sets comprises at least two crushers, a classifier and a cyclone collector; the crusher comprises a crusher feeding port and a crusher discharging port, the classifier comprises a classifier feeding port, a classifier first discharging port and a classifier second discharging port, and the cyclone collector comprises a cyclone collector feeding port, a cyclone collector discharging port and a cyclone collector dedusting air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, and a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a feed port of a crusher in the next last-stage crusher set; in the last group of the last crusher units, a second discharge port of the classifier is connected to a second bin, and a discharge port of the cyclone collector is connected to a second tail bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan.
Preferably, the discharge port of the cyclone collector and the discharge port of the dust removing device are connected in parallel to a second tail stock bin.
Still preferably, the discharge gate of cyclone collector and the discharge gate parallel connection of dust remover insert the second tail feed bin.
According to the invention, in the step (c), the rotating speed of the grading impeller of the pulverizer is gradually reduced from 2000rpm to 600rpm, the reduction amount of each rotating speed is equal or unequal, and the pulverizing time of each pulverizer is 20-25 minutes;
according to the invention, the graphite particles collected at the second discharge port of the classifier in the last group of the last pulverizer set in the step (c) are spherical, approximately spherical, oval or potato-shaped; graphite particles D50Preferably 13 to 25 μm, for example, 14 to 16 μm, 15 to 17 μm, 17 to 19 μm, 20 to 23 μm, etc.; the graphite particle size range is preferably 3.5-60 μm, for example 5-60 μm, 5-45 μm, 6-50 μm, 7-60 μm; tap density is more than or equal to 0.9g/cm3For example, 0.9 to 1.2g/cm3The specific surface area is 4.5-8.5m2(ii)/g; fine powder is not on the surface of the graphite particles, the surface is smooth, and the sphericity is good;
according to the invention, the particles D of the graphite tailings collected in the second tailing silo of step (c)50Preferably 8 to 13 μm, for example, 8 to 10 μm, 9 to 11 μm, 10 to 12 μm, etc.; the graphite particle size range is preferably 1 to 45 μm, for example 5 to 40 μm, 1 to 30 μm, 3 to 30 μm, 5 to 45 μm; tap density is more than or equal to 0.75g/cm3For example, 0.75 to 0.9g/cm3；
According to the invention, the graphite tailings collected in the second tailing bin in the step (c) are used as the raw material in the step (1).
According to the invention, the purification in step (d) is carried out by reacting the feed with an aqueous acidic solution. The acidic aqueous solution is one or more mixed aqueous solution of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid. Preferably, a mixture of a plurality of acids is used, and the ratio of the acids is preferably hydrochloric acid: hydrofluoric acid: nitric acid: sulfuric acid 0-4: 1-2: 0-4: 0-2. The temperature of the purification reaction is 50-120 ℃. The purification reaction time is 1-24 hours, and the fixed carbon content of the purified natural graphite is more than 99.95%. After the purification reaction of step (d) is completed, the material is preferably dried.
According to the invention, the pulverizer in the step (a), the step (b) and the step (c) has the same structure and mainly comprises a turbine, a main shaft, a grading impeller, a screen and other components, wherein the pulverizer is at least one of an airflow vortex micro pulverizer, a high-pressure pulverizer, a rod-type mechanical micro pulverizer, an impact micro pulverizer and a pendulum mill, and is preferably the airflow vortex micro pulverizer; the classifier is at least one of an airflow classifier, a jet flow classifier and a micron classifier; the yield of each pulverizer in the step (a) is 50-1500kg/h, preferably 800-1200 kg/h; the output of each pulverizer in the step (b) and each pulverizer in the step (c) is 30-800kg/h, preferably 200-500 kg/h;
the present invention also provides an apparatus for preparing spheroidal graphite, the apparatus comprising: one or more groups of superfine primary crusher sets and one or more groups of superfine fine crusher sets; the above devices are connected in series in turn. Optionally, the apparatus further comprises a first bin and a first tail bin; the superfine primary crusher set and the superfine fine crusher set are connected in series; and the superfine fine pulverizer set is connected with the first bin and the first tailing bin.
According to the invention, the first bunker is used for collecting graphite particles obtained from the superfine pulverizer set,
according to the invention, the first tailing bin is used for collecting graphite tailing particles obtained from an ultrafine fine grinding machine set.
According to the invention, the superfine primary pulverizer set comprises at least two superfine pulverizers, a superfine classifier and a cyclone collector; the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet, an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dedusting air outlet; the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed port of the cyclone collector, a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to a next ultrafine primary crusher set or connected in parallel to a feed port of an ultrafine fine crusher set, and a dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan;
according to the invention, the ultrafine fine grinding machine set comprises at least two ultrafine grinding machines, an ultrafine classifier and a cyclone collector; the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet, an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dedusting air outlet; the system comprises at least two ultrafine crushers, an ultrafine classifier and a cyclone collector, wherein the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed port of the cyclone collector, a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a next ultrafine fine crusher set, a second discharge port of the ultrafine classifier in the last group of ultrafine fine crusher sets is connected into a first feed bin, and a discharge port of the cyclone collector in the last group of ultrafine fine crusher sets is connected into a first tail feed bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan.
According to the invention, the discharge port of the cyclone collector and the discharge port of the dust removing equipment (such as the discharge port of the dust remover) are connected in parallel to a first tailing bin.
According to the invention, the apparatus further comprises one or more primary crusher sets, one or more secondary crusher sets, one or more final crusher sets; the above devices are serially linked in turn. Optionally, the apparatus further comprises a second bin and a second tail bin; the primary crusher set, the secondary crusher set and the final crusher set are connected in series; the last-stage pulverizer set is connected with a second bin and a second tailing bin; and the second material bin is connected with an ultramicro primary crushing unit.
According to the invention, the second silo is used for collecting graphite particles obtained from the last-stage pulverizer group;
according to the invention, the second tailing bin is used for collecting graphite tailing particles obtained from a final-stage pulverizer set;
according to the invention, the primary crusher set comprises at least two crushers and a cyclone collector, the crushers comprise crusher feed inlets and crusher discharge outlets, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dedusting air outlet; the at least two crushers are connected with a cyclone collector in series, a discharge port of the cyclone collector is connected with a feed port of a crusher in the next primary crusher set or is connected with a feed port of a secondary crusher set, and a dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan;
according to the invention, the secondary crusher set comprises at least two crushers, a classifier and a cyclone collector, wherein each crusher comprises a crusher feed inlet and a crusher discharge outlet; the classifier comprises a classifier feeding hole, a classifier first discharging hole and a classifier second discharging hole, and the cyclone collector comprises a cyclone collector feeding hole, a cyclone collector discharging hole and a cyclone collector dedusting air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to a feed port of a crusher in the next-stage crusher set or connected in parallel to a feed port of a last-stage crusher set, and a dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan;
according to the invention, the last-stage pulverizer group comprises at least two pulverizers, a classifier and a cyclone collector, wherein each pulverizer comprises a pulverizer feeding port and a pulverizer discharging port; the classifier comprises a classifier feeding hole, a classifier first discharging hole and a classifier second discharging hole, and the cyclone collector comprises a cyclone collector feeding hole, a cyclone collector discharging hole and a cyclone collector dedusting air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, a second discharge port of the classifier and a discharge port of the cyclone collector are connected into a feed port of a crusher in the next last-stage crusher set in parallel, a second discharge port of the classifier in the last-stage crusher set is connected into a second bin, and a discharge port of the cyclone collector in the last-stage crusher set is connected into a second tail bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment, such as a dust remover and a high-pressure centrifugal fan.
According to the invention, the discharge port of the cyclone collector and the discharge port of the dust removing equipment (such as the discharge port of the dust remover) are connected in parallel to a second tailing bin.
According to the invention, the primary crusher set, the secondary crusher set, the final crusher set, the ultramicro primary crusher set and the ultramicro fine crusher set are connected through a conveying pipeline.
The invention has the beneficial effects that:
1. the invention adopts the process of combining ultramicro primary grinding and ultramicro fine grinding, wherein the ultramicro primary grinding rotating speed is sequentially increased, thereby avoiding the generation of a large amount of particles with the diameter less than 1 mu m in the grinding process of the natural graphite and improving the product yield. The superfine grinding speed is increased and then decreased or the superfine grinding speed is decreased sequentially and the superfine grading technology is adopted for multiple times, so that the prepared spherical graphite has good sphericity and narrow particle size distribution (D)503-12 μm), has high tap density, and meets the use requirement of the cathode material of the high-end power battery;
2. preparation D is utilized in the invention50Is tailing generated in the process of spherical graphite with the particle size of 13-25 mu m and is used as preparation D50The graphite is a raw material of spherical graphite with small particle size of 3-12 mu m, the utilization rate of the graphite raw material is improved by 25-35%, and meanwhile, industrial waste is changed into valuable, the product yield is high, the process flow is simple, and the energy consumption is reduced;
3. the preparation device of the invention is characterized in that a plurality of groups of crushed single devices are connected end to end, raw materials are directly fed into the next stage for cyclic crushing and grading after being crushed in the first stage, a pipeline is arranged in the middle for conveying, the whole device is fully sealed, dust-containing airflow is collected after dust removal and then fed into a blind ditch for secondary dust removal treatment, and pollution-free discharge is achieved.
Drawings
FIG. 1 shows a preparation D according to the invention50Is a process flow diagram of a preferred embodiment of 3-12 μm.
FIG. 2 shows a schematic view of a preferred embodiment of the present invention D50Scanning electron micrographs of 8 μm product.
FIG. 3 shows a preparation D of the present invention50A process flow diagram according to a preferred embodiment of 13 to 25 μm.
FIG. 4 shows a schematic view of a preferred embodiment of the present invention D50Scanning electron micrographs of 17 μm product.
Detailed Description
The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the description of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalents also fall within the scope of the present invention, and the process flow diagram of the present invention is shown in fig. 1 and fig. 3.
In FIG. 1, 4 is the first material bin, and 7 is the first material bin, D50A bin with the size of 3-12 mu m, 41 and 51 ultrafine crushers, 12 cyclone collectors, 32 an airflow ultrafine classifier, 5 a dust remover, 6 a high-pressure centrifugal fan and 8 a first tail bin.
In FIG. 3, 1 is the second material bin, 11, 21 and 31 are the airflow vortex micro-disintegrators, 12 is the cyclone collector, 22 is the airflow classifier, and 2 is the second material bin, namely D50A stock bin of 13-25 μm, a second tail stock bin 3, a dust remover 5 and a high-pressure centrifugal fan 6.
The present invention will be described in further detail with reference to the accompanying drawings and examples. The preparation method of the spherical graphite with the median particle size of 3-12 mu m comprises the following steps:
(1) feeding the first raw material into 2-5 groups of serially connected ultramicro primary crusher sets by using a high-pressure feeding sealed pipeline with the pressure of 0.3-0.6 MPa, wherein the rotating speed is 800-1600 rpm, the rotating speed is gradually increased, and the crushing time of each crusher is 10-20 minutes;
the superfine pulverizer can simultaneously complete superfine pulverizing andand (3) micro powder classification, wherein the first raw material is crushed at a lower rotating speed for a shorter time, and the graphite particles with qualified particle sizes automatically flow into the classifier along with air flow for secondary classification, so that the situation that a large amount of graphite particles with diameters smaller than 1 micrometer are generated in the ultramicro crushing process of the first raw material is avoided. The rotation speed of each primary crusher is gradually increased, and D of graphite particles50Gradually decreasing to 5-14 μm, and tap density of 0.7-0.8g/cm3；
(2) Sending the graphite powder collected in the step (1) into 3-7 groups of serially connected superfine pulverizer sets through a high-pressure feeding sealed pipeline with the pressure of 0.3-0.6 MPa, wherein the rotating speed is gradually reduced from 1600rpm to 500rpm, and the pulverizing time of each superfine pulverizer is 20-35 minutes; or, the rotating speed of the grading impeller of the ultrafine grinder in the step (2) is increased from 1000rpm to 2000rpm one by one, the increment of the rotating speed of each impeller is equal or unequal, and the grinding time of each ultrafine grinder is 20-25 minutes; reducing the rotation speed from 1600rpm to 500rpm one by one, wherein the reduction amount of each rotation speed is equal or unequal, and the crushing time of each ultrafine crusher is 20-25 minutes;
the grading impeller has high rotating speed and long action time in the initial stage of the superfine fine grinding process, the impact force on the graphite particles is large, and the D of the graphite particles50Rapidly reducing until reaching the granularity (D) of the cathode material of the rate type lithium ion battery503-12 μm), the graphite particles become spherical, approximately spherical, oval or potato-shaped, but a large amount of fine graphite particles appear, the particle size is not uniform, and the tap density is less than 0.5g/cm3(ii) a Although the particle size of graphite particles (D) at this time503-12 μm) meets the use requirement of the cathode material of the rate lithium ion battery, but the tap density is less than 0.5g/cm3The use requirements cannot be met; with the continuous reduction of the rotating speed of the superfine pulverizer, the impact force on graphite particles is smaller, the specific surface is gradually polished to be smooth, the shape and the particle size of the graphite particles are basically not changed, a large amount of fine powder is discharged by the superfine classifier and the cyclone collector, the particle size distribution of the graphite particles is uniform, no fine powder exists on the surfaces of the graphite particles, the surfaces are smooth, and the sphericity is good (see figure 2); d of graphite particles collected at the second outlet of the ultramicro classifier503-12 μm, tap densityDegree is more than 0.75g/cm3The discharge port of the cyclone collector and the discharge port of the optional dust removing equipment collect waste materials;
(3) and (3) purification: using the spherical natural graphite in a mass ratio of 0-4: 1-2: 0-4: 0-2 hydrochloric acid-hydrofluoric acid-nitric acid-sulfuric acid mixed acid solution reacts for 1-24 hours at 50-120 ℃, then is washed to be neutral and dried, and the fixed carbon content of the purified natural graphite is more than 99.95%.
The raw material in the first raw material bin 4 may be prepared by a method known in the art, and the particle size is D50Preferably 8-12 μm, and a tap density of 0.75-0.9g/cm3The graphite particles of (3) can also be prepared by the following method:
(a) feeding natural crystalline flake graphite and earthy graphite with the granularity of 0.074-0.8 mm and the carbon content of not less than 90% into 2-4 primary pulverizer groups connected in series through a high-pressure feeding sealed pipeline with the pressure of 0.3-0.6 MPa, wherein the rotating speed is 1000-2000 rpm, the rotating speed is gradually increased, and the pulverizing time of each pulverizer is 10-20 minutes.
D of graphite particles with increasing rotation speed of each pulverizer50The impact force on the graphite particles is smaller under the conditions of lower rotating speed and shorter time, so that the condition that a large amount of particles with the diameter less than 4 mu m are generated in the primary crushing process of the graphite raw material is avoided, and the product yield is improved;
(b) feeding the material in the step (a) into 1-3 sets of secondary crusher sets connected in series by a high-pressure feeding sealed pipeline with the pressure of 0.3-0.6 MPa, wherein the rotating speed is 2500-4000 rpm, the rotating speed is gradually increased, and the crushing time of each crusher is 20-35 minutes;
the pulverizer has high rotating speed and long pulverizing time in the secondary pulverizing process, the impact force on the graphite particles is large, and the D of the graphite particles50Rapidly reducing until reaching the particle size of the cathode material of the capacity type lithium ion battery, changing the shape of graphite particles into spherical, approximately spherical, oval or potato shape, but generating a large amount of fine graphite particles with uneven particle size, wherein the tap density of the graphite particles is less than 0.9g/cm3；
(c) Feeding the material in the step (b) into 1-3 groups of serially connected final-stage pulverizer sets through a high-pressure feeding sealed pipeline with the pressure of 0.3-0.6 MPa, wherein the rotating speed is reduced from 2000rpm to 600rpm one by one, and the pulverizing time of each pulverizer is 20-25 minutes;
the particle size (D) of the graphite particles after the treatment in step (b)5013-25 μm) meets the use requirement of the negative electrode material of the capacity type lithium ion battery, but the tap density is less than 0.9g/cm3The use requirements cannot be met; the rotation speed of the last-stage pulverizer is lower, the impact force on graphite particles is smaller, the specific surface is gradually polished to be smooth, the shape and the particle size of the graphite particles are basically not changed, a large amount of fine powder is discharged by a classifier and a cyclone collector, the particle size distribution of the graphite particles is uniform, no fine powder exists on the surfaces of the graphite particles, the surfaces are smooth, and the sphericity is good (see figure 4); d of graphite particles collected by the second discharge port of the last group of classifiers5013-25 μm, tap density > 0.9g/cm3(ii) a Collecting graphite tailings and tailings graphite particles D from a discharge port of a cyclone collector and an optional discharge port of a dust removal device50Preferably 8-12 μm, and a tap density of 0.75-0.9g/cm3(ii) a And (3) collecting the graphite tailings in a second tailing bin to be used as the raw material in the step (1), namely the raw material in the first raw material bin.
Examples 1 to 9
The process flow for examples 1-9 is as described above, the specific process parameters are shown in Table 1, the test data for examples 1-9 are shown in Table 2, and the process parameters for preparation examples 1-7 are shown in Table 3.
TABLE 1 Process parameters for examples 1-9
In the above table, 3 sets of 2 micronizer units in the micronization step (1) represent 3 sets of micronizer units in series, wherein 2 micronizer units are connected in series in each set of micronizer unit; the other stations such as 4 groups and 2 stations have the same meaning, and are not described herein.
In the table, 2 sets of ultrafine grinding units in the ultrafine grinding of step (2) are connected in series at 1000 rpm-2000 rpm and gradually increased, each time is 20min, 5 sets of 2 sets are connected in series at 1600 rpm-500 rpm and gradually decreased, and each time is 20min, which means that 7 sets of ultrafine grinding units in series are adopted, wherein each set of ultrafine grinding units is connected in series with 2 ultrafine grinding machines, and the rotating speeds of the first two sets of ultrafine grinding units are gradually increased from 1000 rpm-2000 rpm; the rotating speed of the last five groups of superfine pulverizer sets is gradually reduced from 1600rpm to 500 rpm; other embodiments have the same meaning, and are not described herein.
The physical and chemical indexes of the spherical graphite of the above examples 1 to 9 were measured, and specifically, the following were measured: measuring the sphericity of the sample by using an image particle method analyzer; testing the particle size distribution of a sample by using a laser particle size analyzer; measuring the Tap density of the sample by a Quantachrome Auto Tap densitometer; measuring the specific surface area by adopting a nitrogen adsorption BET method; measuring the fixed carbon content of the sample by adopting an atomic absorption instrument; testing the micro-morphology of the sample by adopting a scanning electron microscope; the test structure is as follows:
table 2 test data for graphite powder collected at the second outlet of the last group of attritors in step (2) of examples 1-9
Wherein: product yield-first bin graphite quality/first raw material bin quality
TABLE 3 Process parameters of preparation examples 1 to 7
The physical and chemical indexes of the spherical graphite prepared in the preparation examples 1 to 7 are as follows: measuring the sphericity of the sample by using an image particle method analyzer; testing the particle size distribution of a sample by using a laser particle size analyzer; measuring the Tap density of the sample by a Quantachrome Auto Tap densitometer; measuring the specific surface area by adopting a nitrogen adsorption BET method; measuring the fixed carbon content of the sample by adopting an atomic absorption instrument; testing the micro-morphology of the sample by adopting a scanning electron microscope; the test structure is as follows:
TABLE 4 test data of graphite powder collected at the second outlet of the last classifier and tailings collected at the outlets of the cyclone collector and the dedusting apparatus in step (c) of preparation examples 1 to 7
Wherein: product yield-second bin graphite quality/raw material quality
As can be seen from the above examples and preparations, D can be prepared by the process of the present invention50The graphite is spherical graphite with the particle size of 3-12 mu m, has good sphericity and high tap density, and meets the requirement of the power battery industry on the spherical graphite with small particle size; and can utilize preparation D50Is tailing generated in the process of spherical graphite with the particle size of 13-25 mu m and is used as preparation D50Is a raw material of spherical graphite with small grain size of 3-12 mu m, and the utilization rate of the graphite raw material is improved by 25-35 percent.
The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (27)
1. A preparation method of spherical graphite comprises the following steps:
(1) superfine primary crushing: feeding natural crystalline flake graphite and earthy graphite with carbon content of more than 90% into 2-5 groups of serially connected ultramicro primary grinding units; the superfine primary crusher set comprises at least two superfine crushers, a superfine classifier and a cyclone collector; the rotation speed of the grading impeller of the ultrafine grinder is increased from 800rpm to 1600rpm one by one, the increment of the rotation speed of each impeller is equal or unequal from the 2 nd, and the grinding time of each ultrafine grinder is 15-25 minutes;
(2) superfine grinding: sending the graphite powder collected in the step (1) into 3-7 groups of serially connected superfine pulverizer sets; the superfine pulverizer set comprises at least two superfine pulverizers, a superfine classifier and a cyclone collector; the rotating speed of the grading impeller of the ultrafine grinder in the step (2) is reduced from 1600rpm to 500rpm one by one, the reduction amount of each rotating speed is equal or unequal, and the grinding time of each ultrafine grinder is 20-25 minutes; or, the rotation speed of the grading impeller of the ultrafine grinder in the step (2) is increased from 1000rpm to 2000rpm one by one, the increment of each rotation speed is equal or unequal, and the grinding time of each ultrafine grinder is 20-25 minutes; reducing the rotation speed from 1600rpm to 500rpm one by one, wherein the reduction amount of each rotation speed is equal or unequal, and the crushing time of each ultrafine crusher is 20-25 minutes;
optionally, (3) purifying and drying;
d of the natural crystalline flake graphite or the earthy graphite in the step (1)508-13 μm; the graphite particle size range is 1-45 μm;
the graphite particles D collected in the step (2)503-12 μm, graphite particle size range of 1-45 μm, tap density not less than 0.55g/cm3。
2. The method according to claim 1, wherein in step (1), the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dust removal air outlet; at least two superfine grinders, an ultramicro classifier and a whirlwind loading head series connection, the first discharge gate of superfine classifier links to each other with whirlwind loading head feed inlet, the first discharge gate of ultramicro classifier and the parallelly connected super little just rubbing crusher group of next of the access of whirlwind loading head discharge gate, perhaps parallelly connected access ultramicro fine crusher group's feed inlet, dust collecting equipment is connected to whirlwind loading head dust removal air outlet, dust collecting equipment is dust remover and high-pressure centrifugal fan.
3. The method of claim 2, wherein D is the graphite powder collected at the discharge port of the cyclone collector and the second discharge port of the classifier in the last micronizer group in step (1)505-14 μm, tap density of 0.7-0.85g/cm3。
4. The method of claim 1, wherein in step (2), the micronizer comprises an micronizer feed inlet and an micronizer discharge outlet, the micronizer comprises a micronizer feed inlet, an ultramicro classifier first discharge outlet and an ultramicro classifier second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dust removal air outlet; the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed port of the cyclone collector, and a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected with a feed port of the ultrafine crusher in the next ultrafine fine crushing unit; in the last group of superfine pulverizer units, a second discharge port of the superfine classifier is connected to a first feed bin, and a discharge port of the cyclone collector is connected with a first tail feed bin; the dust removal air outlet of the cyclone collector is connected with dust removal equipment, and the dust removal equipment comprises a dust remover and a high-pressure centrifugal fan.
5. The method according to claim 4, characterized in that the discharge port of the cyclone collector and the discharge port of the dust remover are connected in parallel into the first tailing bin.
6. The method of claim 1, wherein the output per micronizer in step (1) is from 50 to 1500kg/h and the output per micronizer in step (2) is from 15 to 600 kg/h.
7. The method of claim 1, wherein the purification in step (3) is carried out by reacting the material with an acidic aqueous solution; the acidic aqueous solution is one or more mixed aqueous solution of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid.
8. The method of claim 7, wherein a mixture of a plurality of acids is used, the ratio of the acids being hydrochloric acid: hydrofluoric acid: nitric acid: sulfuric acid = 0-4: 1-2: 0-4: 0-2.
9. The method of claim 1, wherein the temperature of the purification reaction is 50-120 ℃; the purification reaction time is 1-24 hours, and the fixed carbon content of the purified natural graphite is more than 99.95 percent; and (4) drying the materials after the purification reaction in the step (3) is finished.
10. The method according to any one of claims 1 to 9, wherein the natural crystalline flake graphite or earthy graphite in step (1) is prepared by the following method:
(a) primary crushing: feeding natural crystalline flake graphite and earthy graphite with the particle size of more than 0.05mm and the carbon content of more than 90% into 2-4 groups of primary crushing units connected in series; the primary crusher set comprises at least two crushers and a cyclone collector; the rotating speed of a grading impeller of the pulverizer in the step (a) is increased from 1000rpm to 2000rpm one by one, the increment of each rotating speed is equal or unequal from the 2 nd, and the pulverizing time of each pulverizer is 10-20 minutes;
(b) fine crushing: feeding the graphite powder treated in the step (a) into 1-3 secondary pulverizer sets connected in series; the secondary crusher set comprises at least two crushers, a classifier and a cyclone collector; in the step (b), the rotating speed of the grading impeller of the pulverizer is increased from 2500rpm to 4000rpm one by one, the increment of each rotating speed is equal from the 2 nd station, and the pulverizing time of each pulverizer is 20-35 minutes;
(c) shaping: feeding the graphite powder treated in the step (b) into 1-3 groups of serially connected final-stage pulverizer sets; the last-stage pulverizer set comprises at least two pulverizers, a classifier and a cyclone collector; in the step (c), the rotating speed of the grading impeller of the pulverizer is gradually reduced from 2000rpm to 600rpm, the reduction amount of each rotating speed is equal or unequal, and the pulverizing time of each pulverizer is 20-25 minutes;
optionally, (d) purifying and drying.
11. The method of claim 10, wherein in step (a), the pulverizer includes a pulverizer feed inlet and a pulverizer discharge outlet, and the cyclone collector includes a cyclone collector feed inlet, a cyclone collector discharge outlet, and a cyclone collector dust outlet; the at least two crushers are connected with a cyclone collector in series, a discharge port of the cyclone collector is connected to a feed port of a crusher in the next primary crusher set or a feed port of a secondary crusher set, a dust removal air outlet of the cyclone collector is connected with dust removal equipment, and the dust removal equipment is a dust remover and a high-pressure centrifugal fan.
12. The method of claim 10, wherein the cyclone collector in the last set of primary crusher units in step (a) collects D of graphite powder50Is 20-30 μm.
13. The method of claim 10, wherein in step (b), the secondary crusher set comprises at least two crushers, a classifier and a cyclone collector, the crushers comprise a crusher feed inlet and a crusher discharge outlet, the classifier comprises a classifier feed inlet, a classifier first discharge outlet and a classifier second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dust outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a feed port of a crusher in a next-stage crusher set or connected into a feed port of a last-stage crusher set, a dust removal device is connected with a dust removal outlet of the cyclone collector, and the dust removal device is a dust remover and a high-pressure centrifugal fan.
14. The method of claim 13, wherein the second discharge port of the classifier and the discharge port of the cyclone collector in the last set of secondary crusher units in step (b) collect the graphite powder D5013-25 μm, tap density less than 0.9g/cm3。
15. The method of claim 10, wherein in step (c), the pulverizer comprises a pulverizer feed inlet and a pulverizer discharge outlet, the classifier comprises a classifier feed inlet, a classifier first discharge outlet, and a classifier second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet, and a cyclone collector dust removal air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, and a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a feed port of a crusher in the next last-stage crusher set; in the last group of the last crusher units, a second discharge port of the classifier is connected to a second bin, and a discharge port of the cyclone collector is connected to a second tail bin; the dust removal air outlet of the cyclone collector is connected with dust removal equipment, and the dust removal equipment comprises a dust remover and a high-pressure centrifugal fan.
16. The method according to claim 15, characterized in that the discharge port of the cyclone collector and the discharge port of the dust-removing device are connected in parallel into a second tailing bin.
17. The method of claim 15, wherein the second outlet of the classifier in the last set of final pulverizer groups in step (c)The graphite particles collected by the material port are spherical, approximately spherical, oval and potato-shaped; graphite particles D50Is 13-25 μm; the particle size range of the graphite is 3.5-60 mu m; tap density is more than or equal to 0.9g/cm3The specific surface area is 4.5-8.5m2/g。
18. The method of claim 15, wherein the particles D of graphite tailings collected in the second tailings bin of step (c) are508-13 μm; the graphite particle size range is 1-45 μm; tap density is more than or equal to 0.75g/cm3。
19. The method of claim 15, wherein the graphite tailings collected in the second tailings silo of step (c) are used as the raw material for step (1).
20. The method of claim 10, wherein the purification in step (d) is by reacting the material with an acidic aqueous solution; the acidic aqueous solution is one or more mixed aqueous solution of hydrochloric acid, hydrofluoric acid, nitric acid and sulfuric acid.
21. The method of claim 20, wherein a mixture of a plurality of acids is used, the ratio of the acids being hydrochloric acid: hydrofluoric acid: nitric acid: sulfuric acid = 0-4: 1-2: 0-4: 0-2.
22. The method of claim 10, wherein the temperature of the purification reaction is 50-120 ℃; the purification reaction time is 1-24 hours, and the fixed carbon content of the purified natural graphite is more than 99.95 percent.
23. The method of claim 10, wherein the output of each mill in step (a) is from 50 to 1500kg/h, and the output of each mill in step (b) and each mill in step (c) is from 30 to 800 kg/h.
24. The method according to claim 1, characterized in that it is carried out on the basis of an apparatus for preparing spheroidal graphite comprising: 2-5 groups of superfine primary crusher sets and 3-7 groups of superfine fine crusher sets; the devices are connected in series in sequence; the device also comprises a first bin and a first tail bin; the superfine primary crusher set and the superfine fine crusher set are connected in series; the superfine pulverizer set is connected with the first bin and the first tailing bin;
the first bin is used for collecting graphite particles obtained from the superfine pulverizer set, and the first tailing bin is used for collecting graphite tailing particles obtained from the superfine pulverizer set;
the superfine primary grinding unit comprises at least two superfine grinders, a superfine classifier and a cyclone collector; the superfine pulverizer set comprises at least two superfine pulverizers, a superfine classifier and a cyclone collector.
25. The method of claim 24, wherein the micronizer comprises a micronizer feed inlet and a micronizer discharge outlet, the micronizer comprises a micronizer feed inlet, a first micronizer discharge outlet, and a second micronizer discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet, and a cyclone collector dust outlet; the system comprises at least two ultrafine crushers, an ultrafine classifier and a cyclone collector, wherein the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed inlet of the cyclone collector, a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a next ultrafine primary crushing unit or connected into a feed inlet of the ultrafine primary crushing unit in parallel, and a dust removal air outlet of the cyclone collector is connected with dust removal equipment;
the ultrafine grinder comprises an ultrafine grinder feed inlet and an ultrafine grinder discharge outlet, the ultrafine grinder comprises an ultrafine grinder feed inlet, an ultrafine grinder first discharge outlet and an ultrafine grinder second discharge outlet, and the cyclone collector comprises a cyclone collector feed inlet, a cyclone collector discharge outlet and a cyclone collector dedusting air outlet; the system comprises at least two ultrafine crushers, an ultrafine classifier and a cyclone collector, wherein the at least two ultrafine crushers, the ultrafine classifier and the cyclone collector are connected in series, a first discharge port of the ultrafine classifier is connected with a feed inlet of the cyclone collector, a second discharge port of the ultrafine classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a next ultrafine fine crushing unit, a second discharge port of the ultrafine classifier in the last group of ultrafine fine crushing units is connected into a first stock bin, and a discharge port of the cyclone collector in the last group of ultrafine fine crushing units is connected into a first tail stock bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment.
26. The method of claim 24, wherein the apparatus further comprises 2-4 primary pulverizer groups, 1-3 secondary pulverizer groups, 1-3 final pulverizer groups; the devices are sequentially connected in series; the device also comprises a second bin and a second tail bin; the primary crusher set, the secondary crusher set and the final crusher set are connected in series; the last-stage pulverizer set is connected with a second bin and a second tailing bin; the second material bin is connected with an ultramicro primary crushing unit;
the second bin is used for collecting graphite particles obtained from the last-stage pulverizer set; the second tailing bin is used for collecting graphite tailing particles obtained from a final-stage pulverizer set.
27. The method of claim 26, wherein the primary crusher set comprises at least two crushers and a cyclone collector, the crushers comprising a crusher feed inlet and a crusher discharge outlet, the cyclone collector comprising a cyclone collector feed inlet, a cyclone collector discharge outlet, and a cyclone collector dust outlet; the at least two crushers are connected with a cyclone collector in series, a discharge port of the cyclone collector is connected to a feed port of a crusher in the next primary crusher set or a feed port of a secondary crusher set, and a dedusting air outlet of the cyclone collector is connected with dedusting equipment;
the secondary crusher set comprises at least two crushers, a classifier and a cyclone collector, and the crushers comprise crusher feed inlets and crusher discharge outlets; the classifier comprises a classifier feeding hole, a classifier first discharging hole and a classifier second discharging hole, and the cyclone collector comprises a cyclone collector feeding hole, a cyclone collector discharging hole and a cyclone collector dedusting air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to a feed port of a crusher in a next-stage crusher set or connected in parallel to a feed port of a last-stage crusher set, and a dust removal air outlet of the cyclone collector is connected with dust removal equipment;
the last-stage pulverizer set comprises at least two pulverizers, a classifier and a cyclone collector, wherein each pulverizer comprises a pulverizer feeding port and a pulverizer discharging port; the classifier comprises a classifier feeding hole, a classifier first discharging hole and a classifier second discharging hole, and the cyclone collector comprises a cyclone collector feeding hole, a cyclone collector discharging hole and a cyclone collector dedusting air outlet; the at least two crushers, the classifier and the cyclone collector are connected in series, a first discharge port of the classifier is connected with a feed port of the cyclone collector, a second discharge port of the classifier and a discharge port of the cyclone collector are connected in parallel to be connected into a feed port of a crusher in the next last-stage crusher set, a second discharge port of the classifier in the last-stage crusher set is connected into a second bin, and a discharge port of the cyclone collector in the last-stage crusher set is connected into a second tail bin; and the dust removal air outlet of the cyclone collector is connected with dust removal equipment.
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| US17/269,688 US20210316994A1 (en) | 2018-08-31 | 2019-08-28 | Spherical Graphite for Lithium Battery and Preparation Method thereof |
| PCT/CN2019/103064 WO2020043131A1 (en) | 2018-08-31 | 2019-08-28 | Spherical graphite used for lithium batteries and preparation method therefor |
| ZA2021/01828A ZA202101828B (en) | 2018-08-31 | 2021-03-18 | Spherical graphite for lithium battery and preparation method thereof |
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| CN201120305Y (en) * | 2007-10-23 | 2008-09-24 | 湛江市新蓄能源科技有限公司 | Full-automatic product line for producing spherical plumbago ultramicro powder body |
| CN101905883B (en) * | 2010-08-11 | 2013-01-02 | 黑龙江省牡丹江农垦奥宇石墨深加工有限公司 | Production method of spherical graphite |
| CN202265413U (en) * | 2011-10-25 | 2012-06-06 | 阚志强 | Full-automatic production line for natural crystal spheroidized graphite |
| CN102800854B (en) * | 2012-09-03 | 2014-12-17 | 湛江市聚鑫新能源有限公司 | Modification method of natural crystalline flake graphite for lithium-ion battery |
| WO2015146864A1 (en) * | 2014-03-25 | 2015-10-01 | 東ソー株式会社 | Negative electrode active material for lithium ion secondary battery, and method for producing same |
| CN205361599U (en) * | 2016-02-05 | 2016-07-06 | 青岛田庄恒源石墨有限公司 | Novel crushing production line of super microballonization of full -automatic spherical graphite |
| CN105776191B (en) * | 2016-02-19 | 2017-12-01 | 青岛田庄恒源石墨有限公司 | A kind of production technology of spherical graphite |
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