Method for preparing lithium carbonate by recycling waste saggar and preparation equipment

Abstract

The invention provides a method for preparing lithium carbonate by recycling waste saggars and preparation equipment, and relates to the field of lithium carbonate preparation. The method for preparing lithium carbonate by recycling the waste saggar comprises the following steps: S1, taking the waste saggar generated in the manufacturing process of an LIB positive electrode material, performing crushing treatment on the waste saggar, and removing metal impurities; and S2, mixing the magnetically separated raw materials with 98% concentrated HSOs according to a solid-to-liquid ratio of 1: 1.5 (mass ratio), and carrying out static roasting at 240-300 DEG C for 2 h. According to the method for preparing lithium carbonate by recycling the waste saggar, provided by the invention, high-purity lithium carbonate is prepared and synthesized from a lithium resource in a waste saggar material to be used as a positive electrode material of a battery, waste utilization is performed on the waste saggar, the economic loss is reduced, the environmental burden is reduced, and through the synergistic effect of sulfation and water leaching, traditional gt is avoided; and compared with a direct carbonization method, the purification efficiency of the lithium carbonate precipitation method adopting selective precipitation of Li < + > is improved by 25%.

Description

Technical Field

[0001] This invention relates to the field of lithium carbonate preparation for battery materials, and more particularly to a method and equipment for preparing lithium carbonate by recycling waste crucibles. Background Technology

[0002] The increase in LIB supply is accompanied by an increase in cathode material production, and the waste crucibles generated during cathode material manufacturing can also be considered valuable lithium resources. To achieve high capacity and performance in lithium-ion batteries, cathodes based on lithium nickel manganese cobalt oxide (NCM) or lithium nickel cobalt aluminum oxide (NCA) are primarily used; these cathode materials are typically manufactured through a high-temperature reaction of lithium hydroxide (LiOH) and a mixture of precursors (NCM or NCA). As a reactant in the cathode material, LiOH is used in excess during the mixing and solid-state reaction process, while the precursors are loaded into crucibles.

[0003] However, excessive use of LiOH can induce high-temperature side reactions with the sagger material, in which molten Li penetrates and diffuses into the sagger, forming Li-Al-Si-O composite oxides. Therefore, reusing saggers in the manufacture of cathode materials leads to reduced recycling efficiency of the cathode material loaded on the sagger, and a shortened lifespan due to surface corrosion and impurity mixing. These problems necessitate periodic replacement of the saggers, which creates an economic and environmental burden due to their disposal.

[0004] In recent years, due to the rapidly increasing demand for LiB, the amount of waste crucibles generated during the manufacturing process of cathode materials has also increased significantly. However, due to the lack of suitable recycling technology, these waste crucibles, despite having a high lithium content (>1%), have been discarded. This invention mainly targets the lithium resources in waste crucible materials, employing steps such as sulfuric acid activation, low-temperature roasting, leaching, lithium phosphate precipitation, calcium chloride conversion, and carbonation precipitation to prepare and synthesize high-purity lithium carbonate for use as a cathode material in batteries.

[0005] Therefore, it is necessary to provide a method and equipment for preparing lithium carbonate by recycling waste crucibles to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention provides a method for preparing lithium carbonate by recycling waste crucibles, which solves the problem of reducing the economic and environmental burden caused by the waste crucibles.

[0007] To solve the above-mentioned technical problems, the present invention provides a method for preparing lithium carbonate using waste crucibles, comprising the following steps:

[0008] S1. Take the waste crucibles generated during the manufacturing process of LIB positive electrode material, crush the waste crucibles and remove metal impurities;

[0009] S2. Take the magnetically separated raw material and mix it with 98% concentrated H2SO4 at a solid-liquid ratio of 1:1.5 (mass ratio), and statically calcine it at a temperature of 240-300℃ for 2 hours.

[0010] S3. Mix the roasted product with pure water at a liquid-solid ratio of 5:1 and stir at 80℃ for 90 minutes to obtain the leachate.

[0011] S4. Adjust the pH of the leachate to 4-11, then add Na3PO4 to obtain Li3PO4 precipitate;

[0012] S5. Reflux the Li3PO4 precipitate with 1.2mol / L CaCl2 solution for no less than 3 hours. After reflux, filter to obtain the filtrate. Then, bubble CO2 into the filtrate until the pH of the filtrate is 8.0 to obtain Li2CO3.

[0013] Preferably, when the waste crucible is waste generated during the manufacturing process of LFP cathode material, 5% CaF2 additive is added to step S2, and the calcination temperature is reduced to 240°C.

[0014] Preferably, the pH of the leachate in S4 is first adjusted to 4.5 to precipitate Al(OH)3, and then the pH is adjusted to 10.5.

[0015] Preferably, the Li3PO4 precipitate is washed with 0.5 mol / L NH4Cl solution.

[0016] The present invention also provides an apparatus for preparing lithium carbonate by recycling waste crucibles, and a method for preparing lithium carbonate by recycling waste crucibles, comprising:

[0017] Crushing equipment, wherein the crushing equipment is mounted on a base;

[0018] A belt conveyor is provided below the discharge pipe of the crushing equipment;

[0019] Mounting frame, which is suspended above the belt conveyor;

[0020] A magnetic suction device, which is detachably mounted on the mounting frame;

[0021] A screen, which is suspended below the discharge end of the belt conveyor.

[0022] Preferably, the equipment for preparing lithium carbonate by recycling waste saggers further includes a paving assembly, which includes a baffle, a drive component, two sliding frames, and multiple combing components. The two sliding frames are respectively horizontally slidably installed on both sides of the belt conveyor. The baffle is slidably installed between the two sliding frames. A material conveying gap is left between the baffle and the conveying surface of the belt conveyor. The multiple combing components are spaced apart at the bottom of the baffle. The drive component is used to drive the baffle to reciprocate.

[0023] Preferably, the combing component includes a connecting block and a plurality of combing rods, the connecting block being installed at the bottom of the baffle, and the plurality of combing rods being installed in a row at intervals at the bottom of the connecting block.

[0024] Preferably, the paving assembly further includes a plurality of magnetic blocks, which are installed on the top of the baffle, and a magnetic attractor is installed at the bottom of the crushing equipment housing and above the magnetic blocks.

[0025] Preferably, the equipment for preparing lithium carbonate by recycling waste saggers further includes a drive device, which includes a reciprocating threaded rod, an assembly frame, a connector, a support rod, and a connecting frame. The reciprocating threaded rod is mounted on a roller of the belt conveyor via the connector. The assembly frame is threadedly connected to the reciprocating threaded rod. The support rod is mounted on the side plate of the belt conveyor. The assembly frame is sleeved on the support rod. The connecting frame connects the assembly frame and the screen.

[0026] Preferably, the driving component includes a driving arm and an assembly rod, one end of the driving arm is connected to the baffle, and the other end is inserted into the assembly frame through the assembly rod.

[0027] Compared with related technologies, the method for preparing lithium carbonate using waste crucibles provided by this invention has the following advantages:

[0028] This invention provides a method for preparing lithium carbonate from waste crucibles. By employing steps such as sulfuric acid activation, low-temperature roasting, leaching, lithium phosphate precipitation, calcium chloride conversion, and carbonation precipitation, high-purity lithium carbonate is synthesized for use as a cathode material in batteries. This method effectively utilizes waste crucibles, reducing economic losses and environmental burden. Furthermore, the synergistic effect of sulfation and water leaching avoids traditional high-temperature roasting (>900℃), reducing energy consumption by 60%. The lithium carbonate precipitation method utilizes selective precipitation of Li. + The purification efficiency is increased by 25% compared to the direct carbonization method. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the steps of the method for preparing lithium carbonate using waste crucibles provided by the present invention.

[0030] Figure 2 This is a schematic diagram of the equipment for preparing lithium carbonate using waste crucibles provided by the present invention;

[0031] Figure 3 for Figure 2 The diagram shows the structure of the belt conveyor, paving assembly, screen, and drive unit.

[0032] Figure 4 This is a schematic diagram of the structure of the paving component provided by the present invention;

[0033] Figure 5 for Figure 1 The diagram shown is a structural schematic of the equipment used to prepare lithium carbonate from recycled waste crucibles after the magnetic suction device has been removed.

[0034] Figure 6 This is a schematic diagram illustrating the reciprocating movement of the screen provided by the present invention, wherein... Figure 6 (a) is a schematic diagram showing the screen moving to the bottom of the position shown in the diagram. Figure 6 (b) is a schematic diagram showing the screen moving to the top of the position shown in the diagram;

[0035] Figure 7 This is a schematic diagram of the magnetic block on the top of the baffle adsorbed on the bottom of the crushing equipment housing, as provided by the present invention.

[0036] Numbering on the map:

[0037] 1. Base;

[0038] 2. Crushing equipment; 21. Discharge pipe;

[0039] 3. Belt conveyor; 31. Roller; 32. Side plate; 321. Mounting frame;

[0040] 4. Magnetic suction device;

[0041] 5. Screen;

[0042] 6. Paving components; 61. Baffles; 62. Sliding frames; 63. Drive components; 64. Combing components; 65. Magnetic blocks;

[0043] 631. Drive arm; 632. Assembly rod; 641. Connecting block; 642. Combing rod;

[0044] 7. Drive unit; 71. Reciprocating threaded rod; 72. Assembly frame; 73. Connector; 74. Support rod; 75. Connecting frame; 721. Assembly hole;

[0045] 8. Installation frame. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] This invention provides a method for preparing lithium carbonate using waste crucibles.

[0048] Please refer to the following: Figure 1 In one embodiment of the present invention, the method for preparing lithium carbonate using waste crucibles includes the following steps:

[0049] S1. Take the waste crucibles generated during the manufacturing process of LIB positive electrode material, crush the waste crucibles and remove metal impurities;

[0050] S2. Take the magnetically separated raw material and mix it with 98% concentrated H2SO4 at a solid-liquid ratio of 1:1.5 (mass ratio), and statically calcine it at a temperature of 240-300℃ for 2 hours.

[0051] S3. Mix the roasted product with pure water at a liquid-solid ratio of 5:1 and stir at 80℃ for 90 minutes to obtain the leachate.

[0052] S4. Adjust the pH of the leachate to 4-11, then add Na3PO4 to obtain Li3PO4 precipitate;

[0053] S5. Reflux the Li3PO4 precipitate with 1.2mol / L CaCl2 solution for no less than 3 hours. After reflux, filter to obtain the filtrate. Then, bubble CO2 into the filtrate until the pH of the filtrate is 8.0 to obtain Li2CO3.

[0054] This invention utilizes lithium resources from waste crucible materials through steps such as sulfuric acid activation, low-temperature roasting, leaching, lithium phosphate precipitation, calcium chloride conversion, and carbonation precipitation to synthesize high-purity lithium carbonate for use as a cathode material in batteries. This process effectively recycles waste crucibles, reducing economic losses and environmental burden. Furthermore, the synergistic effect of sulfation and water leaching avoids traditional high-temperature roasting (>900℃), reducing energy consumption by 60%. The lithium carbonate precipitation method, employing selective precipitation of Li+, improves purification efficiency by 25% compared to direct carbonation.

[0055] In S5: Li3PO4 + 3CaCl2 reflux 3LiCl + Ca3(PO4)2↓;

[0056] The generated Ca3(PO4)2 can be used as a raw material for phosphate fertilizer, with a P2O5 content ≥40%. The process involves reflux at 105℃ for 3 hours.

[0057] LiCl solution concentration: 1.2-1.5 mol / L.

[0058] The product specifications of this invention are: Li2CO3 purity ≥ 99.5% (GB / T 11075-2013), particle size D50 = 5-8 μm (laser particle size analyzer);

[0059] In S1, the waste box and sagger are crushed to <2mm.

[0060] Specifically:

[0061] Example 1: When the raw material comes from the waste box and mortar of NCM (lithium nickel cobalt manganese oxide) cathode (Li2O content 5.7%, Fe < 0.3%).

[0062] 1. Sulfation:

[0063] 1 kg of raw material was mixed with 1.5 kg of concentrated H2SO4 and calcined at 280 °C for 2 h. XRD showed that the Li2SO4 conversion rate was 96.2%.

[0064] 2. Water leaching:

[0065] The calcined product was stirred at 80℃ for 90 min at a liquid-to-solid ratio of 5:1, and the Li leaching rate was 93.1% (ICP detection).

[0066] 3. Lithium phosphate precipitation:

[0067] The pH of the leachate was adjusted to 10.5, and Na3PO4 (1.05 times the theoretical amount) was added to obtain Li3PO4 precipitate (purity 98.5%, yield 90.4%).

[0068] 4. Lithium carbonate conversion:

[0069] Li3PO4 was refluxed with 1.2 mol / L CaCl2 solution for 3 h, and the filtrate was purged with CO2 until pH=8.0 to obtain Li2CO3 (purity 99.6%, D50=6.8μm).

[0070] The total lithium recovery rate was 89.7%; energy consumption was 10.8 kWh / kg Li; and by-products included Ca3(PO4)2 (a raw material for phosphate fertilizer with a P2O5 content ≥40%).

[0071] Example 2: When the waste crucible is waste generated during the manufacturing process of LFP (lithium iron phosphate) cathode material (Li2O3.2%, containing 12% Al2O3);

[0072] Adding 5% CaF2 additive to step S2 and lowering the calcination temperature to 240℃ still resulted in a Li conversion rate of 94.8%.

[0073] First, adjust the pH of the leachate in S4 to 4.5 to precipitate Al(OH)3 (aluminum removal rate 99.2%), and then adjust the pH to 10.5.

[0074] The Li3PO4 precipitate was washed with 0.5 mol / L NH4Cl solution, and the purity of Li3PO4 was increased to 99.1%.

[0075] Among them, the Li leaching rate was 91.3%, the Li2CO3 purity was 99.3% (Al residue <50ppm), and the processing cost was reduced by 18% (due to the decrease in roasting temperature).

[0076] The present invention also provides an apparatus for preparing lithium carbonate by recycling waste crucibles.

[0077] Please see Figure 2 An apparatus for preparing lithium carbonate using waste crucibles, and a method for preparing lithium carbonate using waste crucibles, comprising:

[0078] Crushing equipment 2, which is mounted on base 1;

[0079] A belt conveyor 3 is located below the discharge pipe 21 of the crushing equipment 2.

[0080] Mounting frame 8, which is suspended above the belt conveyor 3;

[0081] Magnetic suction device 4, which is detachably installed on the mounting frame 8;

[0082] Screen 5 is suspended below the discharge end of belt conveyor 3.

[0083] The equipment for preparing lithium carbonate by recycling waste crucibles described in this invention is specifically used in step S1 to crush the waste crucible material and remove metal impurities. This equipment is mainly suitable for laboratory use. Currently, crushing solid materials and removing metal impurities usually requires different equipment. After crushing the solid material, it is transferred to the metal removal equipment, which is a rather cumbersome operation.

[0084] The magnetic attraction device 4 includes a mounting box and an electromagnet. The electromagnet is installed at the bottom of the mounting box and is square or round, suspended above the belt conveyor device 3.

[0085] The equipment for preparing lithium carbonate using waste crucibles proposed in this invention first sends the crushed waste crucibles to the crushing equipment 2. After being crushed by the crushing equipment 2, the material falls onto the belt conveyor 3 and is then conveyed to the screen 5. After passing through the screen 5, the material falls into a pre-set container. Material that does not meet the particle size requirements is filtered out by the screen 5. During the conveying process, when the material on the belt conveyor 3 passes through the magnetic attraction device 4, the magnetic attraction device 4 adsorbs and removes the metal mixed in the material, thereby realizing the crushing of the waste crucibles and the adsorption and removal of metal from the crushed particles.

[0086] After the belt conveyor 3 has completely transported the material to the placed container, the magnetic suction device 4 is powered off. At this time, the magnetic suction device 4 does not have magnetic force, and the attracted metal materials will fall onto the belt conveyor 3 by gravity. At this time, the belt conveyor 3 can reverse the conveyor to transport the metal materials to the collection container set at the other end of the belt conveyor 3; thus realizing the separate collection of waste crucible material particles and metal materials.

[0087] The crushing equipment 2 is a small jaw crusher, but a hammer crusher, cone crusher, or ball mill can also be used. One end of the belt conveyor 3 is located below the discharge pipe 21 of the crushing equipment 2.

[0088] Please see Figure 5 The mounting frame 8 is installed on the shell of the crushing equipment 2, and a placement groove is provided on the top of the mounting frame 8; the mounting box of the magnetic suction device 4 is placed in the placement groove of the mounting frame 8, and the electromagnet passes through the mounting frame 8 and is suspended above the belt conveyor 3, thereby enabling the installation of the magnetic suction device 4.

[0089] Please see Figure 3 In this embodiment, the equipment for preparing lithium carbonate by recycling waste saggers further includes a spreading assembly 6. The spreading assembly 6 includes a baffle 61, a driving component 63, two sliding frames 62, and multiple combing components 64. The two sliding frames 62 are respectively horizontally slidably installed on both sides of the belt conveyor 3. The baffle 61 is slidably installed between the two sliding frames 62. A material conveying gap is left between the baffle 61 and the conveying surface of the belt conveyor 3. The multiple combing components 64 are spaced apart at the bottom of the baffle 61. The driving component 63 is used to drive the baffle 61 to move back and forth.

[0090] The paving component 6 is located between the discharge pipe 21 and the magnetic suction device 4.

[0091] By setting up the spreading component 6, when the crushed material enters the belt conveyor 3 through the discharge pipe 21, the material at the top is blocked by the baffle 61. The material is conveyed through the conveying gap, so that the material can be spread in a layer on the surface of the belt conveyor 3. At the same time, the driving component 63 drives the baffle 61 to move back and forth, which can drive the combing component 64 to move back and forth in a direction perpendicular to the conveying direction. The combing component 64 can spread the material more evenly on the conveyor belt of the belt conveyor 3, and at the same time, it can avoid the material blocking the conveying gap and affecting the material conveying. By spreading the material evenly on the conveyor belt, when passing through the magnetic adsorption device 4, the metal components mixed in the material can be more thoroughly adsorbed and removed.

[0092] Please see Figure 3 On both side plates 32 of the belt conveyor 3, there are mounting brackets 321. Two sliding brackets 62 are slidably mounted on the two mounting brackets 321. Multiple sliding holes are opened on the mounting brackets 321. Multiple sliding rods are horizontally installed inside the sliding brackets 62. The multiple sliding rods pass through the sliding holes, thereby realizing that the sliding brackets 62 are slidably mounted on both sides of the belt conveyor 3.

[0093] Among them, the two side plates 32 in the belt conveyor device 3 are used to support and install the conveyor rollers, and the belt drive is connected to the conveyor rollers.

[0094] Please see Figure 4 As an optional embodiment, the combing component 64 includes a connecting block 641 and a plurality of combing rods 642. The connecting block 641 is installed at the bottom of the baffle 61, and the plurality of combing rods 642 are installed in a row at intervals at the bottom of the connecting block 641.

[0095] By arranging multiple combing rods 642 in a row in each combing component 64, the combing range can be increased, the combing effect on the material can be improved, and the material can be spread more evenly on the conveyor belt.

[0096] The combing rod 642 is a tapered rod, which reduces the resistance generated by the interaction between the combing rod 642 and the material when it moves in the material.

[0097] As another alternative embodiment, the combing member 64 can be a combing bar 642, and multiple combing bars 642 can be installed adjacent to each other at the bottom of the baffle 61.

[0098] Please refer to it again. Figure 4 As a preferred embodiment, the paving assembly 6 further includes a plurality of magnetic blocks 65, which are installed on the top of the baffle 61, and a magnetic attractor is installed at the bottom of the housing of the crushing device 2 and above the magnetic blocks 65.

[0099] By vertically sliding baffle 61 onto sliding frame 62, baffle 61 can be raised. This allows baffle 61 to be raised during reverse conveying of metal components to the collection container, and the magnetic block 65 at the top of baffle 61 to be attracted to the magnetic suction component. Figure 7 This limits the position of the baffle 61, and the combing component 64 moves upward accordingly, so that the combing component 64 will not block the material conveyed by the belt conveyor 3. When the material crushed by the crushing equipment 2 has no metal components, the baffle 61 is lifted, so that the baffle 61 and the combing component 64 will not block the material conveying; thus, the equipment can be applied to a variety of usage scenarios.

[0100] The magnetic attractor can be a magnet with the opposite polarity to the magnetic block 65, or a metal sheet that can be attracted to the magnetic block 65.

[0101] The number of magnetic blocks 65 is no less than two, and in this embodiment there are three. The number of adsorption components is set accordingly to ensure the stability of the adsorption of the baffle 61.

[0102] In other embodiments, bolts can be threaded onto the side of the sliding frame 62. After the baffle 61 is raised, the bolts can be tightened so that their ends press against the baffle 61 to limit its movement.

[0103] Please see Figure 3 In this embodiment, the equipment for preparing lithium carbonate by recycling waste crucibles further includes a drive device 7. The drive device 7 includes a reciprocating threaded rod 71, an assembly frame 72, a connector 73, a support rod 74, and a connecting frame 75. The reciprocating threaded rod 71 is mounted on a roller 31 of the belt conveyor 3 through the connector 73. The assembly frame 72 is threadedly connected to the reciprocating threaded rod 71. The support rod 74 is mounted on the side plate 32 of the belt conveyor 3. The assembly frame 72 is sleeved on the support rod 74. The connecting frame 75 connects the assembly frame 72 and the screen 5.

[0104] The conveyor roller in the belt conveyor device 3 includes a support roller section and a roller shaft 31. The support roller section is mounted on the roller shaft 31, and the roller shaft 31 is rotatably mounted on two side plates 32. The conveyor belt is sleeved on the support roller section. The drive device in the belt conveyor device 3 drives the roller shaft 31 of one of the conveyor rollers to rotate.

[0105] By setting the drive device 7, the screen 5 can be driven to vibrate back and forth, so that the material on the screen 5 can fall stably and will not stay on the screen 5.

[0106] In this design, the reciprocating threaded rod 71 is connected to one of the rollers 31 via a connector 73. When the belt conveyor 3 is working, i.e., when the drive device drives the roller 31 to rotate and drive the conveyor belt, the roller 31 drives the reciprocating threaded rod 71 to rotate via the connector 73. The reciprocating threaded rod 71 drives the assembly frame 72 to move back and forth along the surface of the reciprocating threaded rod 71. The assembly frame 72 drives the screen 5 to vibrate back and forth via the connecting frame 75, thereby achieving stable material feeding. Furthermore, the belt conveyor 3 is used as the driving force of the drive device 7 to drive the screen 5 to vibrate back and forth, simplifying the drive structure.

[0107] The assembly frame 72 includes a mounting plate and a threaded sleeve. The threaded sleeve is installed in the middle of the mounting plate and is threadedly connected to the reciprocating threaded rod 71. When the reciprocating threaded rod 71 rotates in one direction, the threaded sleeve moves back and forth along the reciprocating threaded rod 71.

[0108] The drive unit 7 may also include a motor and a mounting bracket. The motor is mounted on the side plate 32 of the belt conveyor 3 via the mounting bracket. The output shaft of the motor is connected to the reciprocating threaded rod 71 to drive the reciprocating threaded rod 71 to rotate.

[0109] The screen 5 is suspended below the belt conveyor 3 by being mounted on the connecting frame 75;

[0110] Alternatively, a separate bracket can be installed to support the side frame of the screen 5, so that the screen 5 can be suspended below the belt conveyor 3.

[0111] Please refer to it again. Figure 3 As an optional embodiment, the driving member 63 includes a driving arm 631 and an assembly rod 632. One end of the driving arm 631 is connected to the baffle 61, and the other end is inserted into the assembly frame 72 through the assembly rod 632.

[0112] The baffle 61 is connected to the assembly frame 72 by the drive component 63, so that the drive device 7 can be used to drive the baffle 61 to move back and forth, further simplifying the drive structure.

[0113] That is, when the belt conveyor 3 is conveying materials, the drive device 7 can simultaneously drive the screen 5 to vibrate for stable material feeding, and drive the baffle 61 to move the combing component 64 back and forth to comb the material so that the material can be spread evenly in one layer. Figure 6 (a) and Figure 6 (b)

[0114] The assembly frame 72 has an assembly hole 721, and the assembly rod 632 is inserted into the assembly hole 721 to achieve insertion. By means of insertion, without removing the metal, when the baffle 61 is lifted, the assembly rod 632 can be directly separated from the assembly frame 72. The installation and separation of the baffle 61 and the assembly frame 72 are simple and convenient.

[0115] In one embodiment, the connecting member 73 can be a coupling that connects the roller shaft 31 and the reciprocating threaded rod 71.

[0116] In another embodiment, the connector 73 is a one-way bearing. The outer ring of the one-way bearing is mounted on the roller 31 via a mounting seat, and the reciprocating threaded rod 71 is mounted on the inner ring of the one-way bearing. Therefore, when the belt conveyor 3 transports the metal component away from the screen 5, it will not cause the reciprocating threaded rod 71 to rotate, meaning the drive device 7 will not operate.

[0117] When the belt conveyor 3 is conveying material normally, the roller 31 can drive the reciprocating threaded rod 71 to rotate through the one-way bearing, that is, the drive device 7 can drive the screen 5 and the baffle 61 to move back and forth.

[0118] The working principle of the equipment for preparing lithium carbonate using waste crucibles provided by this invention is as follows:

[0119] First, the crushed waste crucible is fed into the crushing equipment 2. After being crushed by the crushing equipment 2, it falls onto the belt conveyor 3 and is then conveyed to the screen 5. After passing through the screen 5, the material falls into a pre-set container. Material that does not meet the particle size requirements is filtered out by the screen 5. During the conveying process, when the material on the belt conveyor 3 passes through the magnetic attraction device 4, the magnetic attraction device 4 adsorbs and removes the metal mixed in the material, thereby realizing the crushing of the waste crucible and the adsorption and removal of metal from the crushed particles.

[0120] When the belt conveyor 3 has completely conveyed the material to the placed container, the magnetic suction device 4 is powered off. At this time, the magnetic suction device 4 does not have magnetic force, and the attracted metal materials will fall onto the belt conveyor 3 by gravity. At this time, the belt conveyor 3 can reverse the conveyor to transport the metal materials to the collection container set at the other end of the belt conveyor 3; thus realizing the separate collection of waste crucible material particles and metal materials.

[0121] When the crushed material enters the belt conveyor 3 through the discharge pipe 21, the material at the top is blocked by the baffle 61. The material is conveyed through the conveying gap, so that the material can be in a layer on the surface of the belt conveyor 3. At the same time, the drive component 63 drives the baffle 61 to move back and forth, which can drive the combing component 64 to move back and forth in a direction perpendicular to the conveying direction. The combing component 64 can make the material spread more evenly on the conveyor belt of the belt conveyor 3. At the same time, it can avoid the material blocking the conveying gap and affecting the material conveying. By spreading the material evenly on the conveyor belt, the metal components mixed in the material can be more thoroughly adsorbed and removed when passing through the magnetic adsorption device 4.

[0122] The reciprocating threaded rod 71 is connected to one of the rollers 31 via the connector 73. When the belt conveyor 3 is working, that is, when the drive equipment drives the roller 31 to rotate and drive the conveyor belt to work, the roller 31 drives the reciprocating threaded rod 71 to rotate via the connector 73. The reciprocating threaded rod 71 drives the assembly frame 72 to move back and forth along the surface of the reciprocating threaded rod 71. The assembly frame 72 drives the screen 5 to vibrate back and forth via the connector 75 to achieve stable material feeding. At the same time, the baffle 61 is driven to move back and forth between the drive component 63 and the assembly frame 72.

[0123] When conveying materials, the belt conveyor 3 can simultaneously drive the screen 5 to vibrate for stable feeding using the drive device 7, and drive the baffle 61 to move the combing component 64 back and forth to comb the materials so that the materials can be spread evenly in one layer.

[0124] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for preparing lithium carbonate using waste crucibles, characterized in that, Includes the following steps: S1. Take the waste crucibles generated during the manufacturing process of LIB positive electrode material, crush the waste crucibles and remove metal impurities; S2. Take the magnetically separated raw material and mix it with 98% concentrated H2SO4 at a solid-liquid ratio of 1:1.5 (mass ratio), and statically calcine it at a temperature of 240-300℃ for 2 hours. S3. Mix the roasted product with pure water at a liquid-solid ratio of 5:1 and stir at 80℃ for 90 minutes to obtain the leachate. S4. Adjust the pH of the leachate to 4-11, then add Na3PO4 to obtain Li3PO4 precipitate; S5. Reflux the Li3PO4 precipitate with 1.2mol / L CaCl2 solution for no less than 3 hours. After reflux, filter to obtain the filtrate. Then, bubble CO2 into the filtrate until the pH of the filtrate is 8.0 to obtain Li2CO3.

2. The method for preparing lithium carbonate using waste crucibles according to claim 1, characterized in that, When the waste crucible is waste generated during the manufacturing process of LFP cathode material, 5% CaF2 additive is added to step S2, and the calcination temperature is reduced to 240°C.

3. The method for preparing lithium carbonate using waste crucibles according to claim 2, characterized in that, First, adjust the pH of the leachate in S4 to 4.5 to precipitate Al(OH)3, and then adjust the pH to 10.

5.

4. The method and equipment for preparing lithium carbonate using waste crucibles according to claim 2, characterized in that, The Li3PO4 precipitate was washed with 0.5 mol / L NH4Cl solution.

5. An apparatus for preparing lithium carbonate using waste crucibles, characterized in that, The method for preparing lithium carbonate from waste crucibles as described in any one of claims 1-4 comprises: Crushing equipment, wherein the crushing equipment is mounted on a base; A belt conveyor is provided below the discharge pipe of the crushing equipment; Mounting frame, which is suspended above the belt conveyor; A magnetic suction device, which is detachably mounted on the mounting frame; A screen, which is suspended below the discharge end of the belt conveyor.

6. The equipment for preparing lithium carbonate by recycling waste crucibles according to claim 5, characterized in that, The equipment for preparing lithium carbonate by recycling waste saggers also includes a paving assembly, which includes a baffle, a drive component, two sliding frames, and multiple combing components. The two sliding frames are respectively horizontally slidably installed on both sides of the belt conveyor. The baffle is slidably installed between the two sliding frames. A material conveying gap is left between the baffle and the conveying surface of the belt conveyor. Multiple combing components are installed at intervals at the bottom of the baffle. The drive component is used to drive the baffle to reciprocate.

7. The equipment for preparing lithium carbonate by recycling waste crucibles according to claim 6, characterized in that, The combing component includes a connecting block and a plurality of combing rods. The connecting block is installed at the bottom of the baffle, and the plurality of combing rods are installed in a row at intervals at the bottom of the connecting block.

8. The equipment for preparing lithium carbonate by recycling waste crucibles according to claim 6, characterized in that, The paving assembly also includes a plurality of magnetic blocks, which are installed on the top of the baffle, and a magnetic attractor is installed at the bottom of the crushing equipment housing above the magnetic blocks.

9. The equipment for preparing lithium carbonate by recycling waste crucibles according to claim 6, characterized in that, The equipment for preparing lithium carbonate by recycling waste crucibles also includes a drive device, which includes a reciprocating threaded rod, an assembly frame, a connector, a support rod, and a connecting frame. The reciprocating threaded rod is mounted on a roller of the belt conveyor via the connector. The assembly frame is threadedly connected to the reciprocating threaded rod. The support rod is mounted on the side plate of the belt conveyor. The assembly frame is sleeved on the support rod. The connecting frame connects the assembly frame and the screen.

10. The equipment for preparing lithium carbonate by recycling waste crucibles according to claim 9, characterized in that, The driving component includes a driving arm and an assembly rod. One end of the driving arm is connected to the baffle, and the other end is inserted into the assembly frame through the assembly rod.

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