Energy-saving grinding device for graphite treatment and sodium sulfate recovery method

Abstract

The invention provides an energy-saving grinding device for graphite treatment and a sodium sulfate recovery method. The energy-saving grinding device comprises a bottom plate, a bearing frame, a driving mechanism, a rotating mechanism and a grinding assembly. The bearing frame is fixedly arranged on the upper surface of the bottom plate, the driving mechanism comprises a mounting frame, a positioning plate and a grinding motor, the mounting frame is mounted on the upper surface of the bearing frame through bolts, the positioning plate is fixedly arranged in the mounting frame, and the grinding motor is mounted in the positioning plate through bolts. A ratchet wheel is connected to a key groove of an output shaft at the bottom of the grinding motor, and a rotating ring is rotationally connected to the position, located outside the ratchet wheel, in the mounting frame. Inertia kinetic energy (mainly from revolution / autorotation, the rotating inertia of the grinding tank, grinding media and materials) generated in the shutdown or deceleration process of the grinding motor is converted into electric energy through the grinding motor; and the energy is recycled through an energy storage or feedback device, so that energy conservation of motor grinding is finally realized.

Description

Technical Field

[0001] The present invention relates to the technical field of energy-saving grinding, and in particular to an energy-saving grinding device for graphite processing and a sodium sulfate recovery method. Background Art

[0002] Commercial graphite and urea mixed and ground can be used to make graphite electrodes. In the current common lithium salt production process, such as lithium carbonate production, after the lithium carbonate product is obtained by precipitation, a large amount of lithium precipitation mother liquor will be produced. After the lithium precipitation mother liquor is further extracted to recover lithium, the remaining lithium-extracted liquid mainly contains a large amount of sodium sulfate, a small amount of potassium sulfate and trace amounts of lithium ions and other impurity ions. The common way to deal with the lithium-extracted liquid is to evaporate the water and sell the crystals as waste. This not only incurs a large evaporation cost, but also the crystals contain a large amount of sodium, and directly selling them as waste is a waste of resources.

[0003] The graphite electrodes made by grinding are used for electrolytic separation and extraction of sodium sulfate in the liquid after lithium extraction. Therefore, the grinding of graphite in the graphite electrode is crucial. The mixed grinding of commercial graphite and urea requires a reasonable grinding method based on the material properties (graphite has high hardness and urea is easy to absorb moisture) and the mixing uniformity requirements.

[0004] However, in the prior art, due to the high hardness of graphite, the motor is mostly rotated at a high speed during the grinding process. When the grinding is completed and the motor stops, due to the inertia factor of the medium, the motor will form an inertial rotation for a period of time during the process of slowing down from high speed to low speed. Therefore, the kinetic energy generated by the rotation cannot be well utilized, resulting in energy waste. In addition, the motor consumes the most electricity when it is started, which is not conducive to energy-saving grinding.

[0005] Therefore, it is necessary to provide an energy-saving graphite processing grinding device and a sodium sulfate recovery method to solve the above technical problems. Summary of the Invention

[0006] The present invention provides an energy-saving graphite processing grinding device and a sodium sulfate recovery method, which solve the technical problems in the related art that traditional grinding wastes a lot of kinetic energy and has poor energy saving when the motor is working.

[0007] In order to solve the above technical problems, the present invention provides an energy-saving graphite processing grinding device, which includes a base plate, a carrier, a driving mechanism, a rotating mechanism and a grinding assembly; The carrier is fixed on the upper surface of the base plate, and the driving mechanism includes a mounting frame, a positioning plate and a grinding motor. The mounting frame is mounted on the upper surface of the carrier frame by bolts, the positioning plate is fixed inside the mounting frame, and the grinding motor is mounted inside the positioning plate by bolts. The bottom output shaft of the grinding motor is connected to a ratchet by a keyway, and a swivel is rotatably connected inside the mounting frame and outside the ratchet. The inner wall of the swivel is rotatably connected to a spring ratchet, and the keyway at the bottom axis of the swivel is connected to a driving pulley; The rotating mechanism includes a mounting seat, a driving gear and a driven pulley, the mounting seat is fixedly arranged on the upper surface of the carrier, the driving gear is rotatably connected to the internal axis of the mounting seat, the driving gear axis is connected to the driven pulley with a keyway, the outer walls of the driven pulley and the driving pulley are sleeved with a belt, the outer wall of the driving gear is meshed and connected with four linkage gears, the axis centers of the four linkage gears are all connected with key rods with keyways, and the tops of the four key rods are rotatably connected to the main turntable; The grinding assembly includes four grinding jars, four auxiliary turntables and four positioning plates, the four auxiliary turntables are connected to the top of the four key rods by keyways, the four positioning plates are installed above the four auxiliary turntables, and the four grinding jars are placed on the upper surfaces of the four positioning plates; The grinding motor is electrically connected to a PLC, a motor controller, a bidirectional converter, a temperature measurement module and an energy storage module through wires. The temperature measurement module is electrically connected to the PLC, and the bidirectional converter is electrically connected to the energy storage module through wires.

[0008] Preferably, the grinding motor, bidirectional converter and energy storage module are electrically connected in series, the motor controller, PLC and grinding motor are electrically connected in parallel, and the PLC, temperature measurement module and grinding motor are electrically connected in series.

[0009] Preferably, the ratchet and the spring ratchet teeth are engaged with each other, and the axes of the driving pulley and the driven pulley are rotatably connected to the supporting frame through bearings.

[0010] Preferably, the driving gear is rotatably connected to the axis of the mounting seat, the four linkage gears are meshed with the inner gear ring, the four linkage gears are equidistantly distributed in a ring shape about the axis of the driving gear, and the main turntable is rotatably connected to the inner wall of the mounting seat.

[0011] Preferably, a slide groove is provided inside the positioning plate, a positioning block is installed inside the slide groove, a fastening bolt is threadedly connected inside the positioning block, a slider is slidably connected inside the slide groove and located on one side of the positioning block, a guide wheel is rotatably connected inside the slider, and a return spring is fixed on the opposite side of the slider and the positioning block; Side plates are fixed on the upper surface of the positioning plate and located on both sides of the grinding jar, a fixing plate is installed inside the side plate, a fixing screw is threadedly connected to the middle position of the fixing plate, a nut is threadedly connected to the upper surface of the fixing plate and located on the outer wall of the fixing screw, and a clamping plate is rotatably connected to the bottom end of the fixing screw and located on the top of the grinding jar; Two guide rails are fixedly arranged on the upper surface of the bottom plate, and the tops of the two guide rails are slidably connected with shields.

[0012] Preferably, the outer wall of the guide wheel fits with the outer wall of the grinding jar, the bottom end of the fastening bolt extends to the bottom of the slide groove, and the cross-section of the slider is a "T"-shaped structure.

[0013] Preferably, it further includes an auxiliary mechanism; The auxiliary mechanism includes a first gear, a movable frame and a mounting cover, the first gear keyway is connected to the top output shaft of the grinding motor, the top of the mounting frame is installed with a top plate by bolts, the movable frame is installed above the top plate, the mounting cover is fixedly provided on the upper surface of the movable frame, the lower surface of the movable frame is fixedly provided with a slide plate, the upper surface of the carrier frame and located on one side of the mounting frame are fixedly provided with a limit plate, the interior of the limit plate is slidably connected to a sliding rod, the outer end of the sliding rod is fixedly provided with a connecting plate, and the outer wall of the connecting plate is rotatably connected to an adjusting screw; The upper surface of the movable frame is rotatably connected to the fourth gear located inside the mounting cover, the axis of the fourth gear is connected to a rotating shaft via a keyway, and the top keyway of the rotating shaft is connected to the third gear; A fixed frame is fixed on the upper surface of the movable frame, a feeding barrel is fixed inside the fixed frame, a feeding screw is rotatably connected inside the feeding barrel, a second gear is connected to the keyway at the outer end of the feeding screw, and two hoses are installed above the feeding barrel.

[0014] Preferably, the slide plate and the top plate are connected by sliding, the connecting plate and the movable frame are connected by fixed connection, and the adjusting screw and the limiting plate are connected by thread; The outer wall of the rotating shaft is rotatably connected to the axis of the mounting cover, the second gear and the third gear are meshed with each other, and the first gear and the fourth gear are adapted to each other.

[0015] The sodium sulfate recovery method comprises the following steps: S1; Preparation of modified graphite: Commercial graphite and urea are mixed, ground evenly, and then calcined in a tube furnace under an argon atmosphere to obtain nitrogen-doped graphite. The grinding process needs to be completed in the grinding assembly 6; The mixing ratio of graphite and urea is 0.5:1-3:1, and the grinding is carried out at 500 r / min for 2 hours. The calcination temperature in the tube furnace is 300-1000°C, and the calcination time is 30-300 minutes. S2: Preparation of electrode: Disperse modified graphite in ethanol and add a binder, disperse evenly by ultrasonication, wash and dry the nickel foam, drop the graphite dispersion onto the surface of the nickel foam, dry it, and compact it using a tablet press; The dosage ratio of modified graphite to binder is 20:1-5:1, and the dispersion mass of modified graphite on the surface of nickel foam is 10-200 mg / cm 2 ; S3; Assembly of the electrolysis system: A modified graphite electrode was used as the working electrode, a calomel electrode was selected as the reference electrode, and a platinum electrode was selected as the counter electrode. A three-electrode system was assembled, and the lithium extraction solution was selected as the electrolyte. The system was connected to an electrochemical workstation. The potassium and sodium concentrations of the lithium precipitation mother solution were 9.3 g / L and 67.5 g / L, respectively. S4: Electrolysis process: After setting the working voltage, the electrolysis degree is controlled by controlling the electrolysis time, which is 5-60 minutes; S5: Sodium sulfate recovery: Collect the electrolyte after electrolysis and evaporate and crystallize to obtain high-purity sodium sulfate.

[0016] Compared with related technologies, the energy-saving graphite processing grinding device and sodium sulfate recovery method provided by the present invention have the following beneficial effects: Based on the principle of "safe braking first, supplemented by efficient energy recovery," this solution reduces overall energy consumption for batch graphite grinding through the process of "motor generation → power conversion → energy storage / feedback → reuse," taking into account the inertial characteristics of grinding and braking scenarios. By selecting appropriate motors, converters, and supercapacitors, and combining them with PLC control logic to achieve an energy closed loop, this solution can reduce overall energy consumption for batch graphite grinding. By improving the energy-saving performance of the grinding motor, the recovered electric energy is mainly used in the starting phase of the grinding motor (energy consumption is highest at startup, about 1.5-2 times the rated power) or low-load operation phase. The core is to convert the inertial kinetic energy generated during the shutdown or deceleration of the grinding motor (mainly from the revolution / rotation, grinding tank, grinding media and rotational inertia of materials) into electrical energy through the grinding motor, and then recycle it through energy storage or feedback devices, ultimately achieving energy saving in motor grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0018] Figure 1 A schematic diagram of the best structure provided by the present invention; Figure 2A side view schematic diagram of the structure provided by the present invention; Figure 3 for Figure 2 Schematic diagram of the driving mechanism structure shown; Figure 4 for Figure 3 The enlarged structural diagram of point A is shown; Figure 5 for Figure 1 The schematic diagram of the structure of the supporting frame as shown is viewed from above; Figure 6 A bottom view schematic diagram of the rotating mechanism provided by the present invention; Figure 7 A schematic diagram of the connection and cooperation of the rotating mechanism provided by the present invention; Figure 8 for Figure 1 Schematic diagram of the grinding assembly structure shown; Figure 9 This is a diagram of the energy-saving process of the grinding motor provided by the present invention; Figure 10 A schematic diagram of the auxiliary mechanism structure provided by the present invention; Figure 11 for Figure 10 The feed barrel and mounting cover are shown in the cross-sectional structural diagram.

[0019] Description of Figure Numbers: 1. Bottom plate; 2. Guide rail, 3. Protective cover; 4. Driving mechanism, 41. Mounting frame, 42. Positioning plate, 43. Top plate, 44. Grinding motor, 45. Ratchet, 46. Rotating ring, 47. Spring ratchet, 48. Driving pulley; 5. Rotating mechanism, 51. Driven pulley, 52. Belt, 53. Mounting seat, 54. Internal gear ring, 55. Linking gear, 56. Main turntable, 57. Driving gear, 58. Key rod; 6. Grinding assembly, 61. Auxiliary turntable, 62. Positioning plate, 63. Slide, 64. Positioning block, 65. Fastening bolt, 66. Slider, 67. Guide wheel, 68. Return spring, 69. Side plate, 610. Fixing plate, 611. Grinding jar, 612. Stabilizing screw, 613. Nut, 614. Clamp; 7. Auxiliary mechanism, 71. First gear, 72. Moving frame, 73. Slide plate, 74. Mounting cover, 75. Limiting plate, 76. Sliding rod, 77. Adjusting screw, 78. Connecting plate, 79. Fixed frame, 710. Feeding barrel, 711. Hose, 712. Second gear, 713. Third gear, 714. Fourth gear, 715. Rotating shaft, 716. Feeding screw; 8. Carrying frame. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] The present invention provides an energy-saving graphite processing grinding device and a sodium sulfate recovery method.

[0022] First embodiment: Please combine Figures 1 to 9 , an energy-saving graphite processing grinding device, comprising a base plate 1, a carrier frame 8, a driving mechanism 4, a rotating mechanism 5 and a grinding assembly 6; The carrier frame 8 is fixed to the upper surface of the base plate 1, and the driving mechanism 4 includes a mounting frame 41, a positioning plate 42 and a grinding motor 44. The mounting frame 41 is mounted on the upper surface of the carrier frame 8 by bolts, the positioning plate 42 is fixed inside the mounting frame 41, and the grinding motor 44 is mounted inside the positioning plate 42 by bolts. The bottom output shaft keyway of the grinding motor 44 is connected to a ratchet 45, and a swivel 46 is rotatably connected inside the mounting frame 41 and outside the ratchet 45. The inner wall of the swivel 46 is rotatably connected to a spring ratchet 47, and the keyway at the bottom axis of the swivel 46 is connected to a driving pulley 48; Preferably, the grinding motor 44 can use a double-headed permanent magnet synchronous motor (with encoder), support four-quadrant operation, and have a power generation efficiency of ≥90%.

[0023] See also Figure 3 and Figure 4 : The grinding motor 44 rotates counterclockwise, and when it rotates counterclockwise, it can synchronously drive the ratchet 45 to rotate counterclockwise, so that the ratchet 45 rotates counterclockwise to affect the control spring ratchet 47 to control the rotating ring 46 to rotate in the mounting frame 41, and when the rotating ring 46 rotates, it drives the pulley 48 to rotate synchronously.

[0024] The rotating mechanism 5 includes a mounting seat 53, a driving gear 57 and a driven pulley 51. The mounting seat 53 is fixed to the upper surface of the carrier 8. The driving gear 57 is rotatably connected to the internal axis of the mounting seat 53. The driven pulley 51 is connected to the keyway at the axis of the driving gear 57. The outer walls of the driven pulley 51 and the driving pulley 48 are covered with a belt 52. The outer wall of the driving gear 57 is meshed with four linkage gears 55. The axis of the four linkage gears 55 is connected to a key rod 58 with a keyway. The tops of the four key rods 58 are rotatably connected to the main turntable 56. The grinding assembly 6 includes four grinding jars 611, four auxiliary turntables 61 and four positioning plates 62. The four auxiliary turntables 61 are connected to the top of the four key rods 58 by keyways. The four positioning plates 62 are installed above the four auxiliary turntables 61. The four grinding jars 611 are placed on the upper surfaces of the four positioning plates 62. See also Figure 5 : When the driving pulley 48 rotates, the transmission belt 52 drives the driven pulley 51 to rotate in the carrier 8; See also Figure 6 and Figure 7 : When the driven pulley 51 rotates, it will affect the rotation of the driving gear 57. When the driving gear 57 rotates, the driving gear 57 will engage and control the four linkage gears 55 around it to rotate. Since the linkage gear 55 and the inner gear ring 54 are engaged, the linkage gear 55 is affected by the meshing rotation of the driving gear 57 and meshes with the inner wall of the inner gear ring 54 to form a driving gear 57. During the rotation process, the four linkage gears 55 can be driven along the axis of the inner gear ring 54, which can complete the orbital rotation and self-rotation at the same time, thereby realizing the rotation of the four key rods 58 in the main turntable 56, and the main turntable 56 can also rotate as a whole.

[0025] The grinding motor 44 is electrically connected to a PLC, a motor controller, a bidirectional converter, a temperature measurement module and an energy storage module via wires. The temperature measurement module is electrically connected to the PLC, and the bidirectional converter is electrically connected to the energy storage module via wires.

[0026] The grinding motor 44, bidirectional converter and energy storage module are electrically connected in series, the motor controller, PLC and grinding motor 44 are electrically connected in parallel, and the PLC, temperature measurement module and grinding motor 44 are electrically connected in series.

[0027] The ratchet 45 and the spring ratchet 47 are meshed with each other, and the axes of the driving pulley 48 and the driven pulley 51 are rotatably connected to the supporting frame 8 through bearings.

[0028] The driving gear 57 is rotatably connected to the axis of the mounting seat 53, the four linkage gears 55 are meshed with the inner gear ring 54, the four linkage gears 55 are equidistantly distributed in a ring around the axis of the driving gear 57, and the main turntable 56 is rotatably connected to the inner wall of the mounting seat 53.

[0029] The working principle of this embodiment is as follows: S1: commercial graphite and urea grinding; During grinding, the user starts the grinding motor 44 to rotate counterclockwise. The counterclockwise rotating grinding motor 44 drives the ratchet 45 to affect the rotating ring 46 to control the driving pulley 48 to drive the driven pulley 51 to rotate. When the driven pulley 51 rotates, it can drive the driving gear 57 to affect the linkage gear 55 to control the key rod 58 to rotate in the main turntable 56. At the same time, the main turntable 56 rotates as a whole. S2: The key rod 58 drives the auxiliary turntable 61 to control the positioning plate 62 to affect the grinding tank 611 to form a planetary motion, which can be both revolving and rotating. The commercial graphite and urea in the grinding tank 611 are mixed and ground. The graphite and urea are mixed in a ratio of 0.5:1-3:1. The grinding is carried out at 500 r / min for 2 hours. S3: Braking signal triggering and state switching; When grinding is completed (e.g., the PLC receives a “grinding time up” signal), or the operator presses a “stop” button, the PLC sends a “brake command” to the motor controller (e.g., a vector frequency converter), and simultaneously locks the drive of the grinding tank 611 ; The motor controller immediately switches the grinding motor 44 from "motor mode" (electrical energy → mechanical energy) to "generator mode" (mechanical energy → electrical energy). At this time, the grinding jar 611 and the medium continue to rotate due to inertia, driving the rotor of the grinding motor 44 to rotate, cutting the stator magnetic field to generate induced electromotive force (alternating current), achieving the initial conversion of "kinetic energy → electrical energy". S4: Power conversion and voltage stabilization; The grinding motor 44 outputs variable frequency AC power in the power generation mode (the voltage and frequency decrease as the speed decreases. For example, the output is 380V / 50Hz at an initial speed of 500r / min, and may drop to 100V / 10Hz when the speed drops to 100r / min). This power needs to be processed by a bidirectional converter (including a rectifier bridge and a DC / DC converter). First, the AC power is converted into DC power through a rectifier bridge (e.g. 380V AC → 520V DC); The unstable DC power is then stabilized to the rated voltage of the energy storage module (such as the rated voltage of the supercapacitor is 200V) through a DC / DC converter to prevent voltage fluctuations from damaging the energy storage components. This embodiment

[0030] Based on the principle of "safe braking first, supplemented by efficient energy recovery," this solution reduces overall energy consumption for batch graphite grinding through the process of "motor generation → power conversion → energy storage / feedback → reuse," taking into account the inertial characteristics of grinding and braking scenarios. By selecting appropriate motors, converters, and supercapacitors, and combining them with PLC control logic to achieve an energy closed loop, this solution can reduce overall energy consumption for batch graphite grinding. By improving the energy-saving performance of the grinding motor 44, the recovered electric energy is mainly used in the startup phase of the grinding motor 44 (energy consumption is highest during startup, about 1.5-2 times the rated power) or the low-load operation phase. The core is to convert the inertial kinetic energy generated during the shutdown or deceleration of the grinding motor 44 (mainly from the revolution / rotation, the grinding tank 611, the rotational inertia of the grinding medium and the material) into electric energy through the grinding motor 44, and then recycle it through the energy storage or feedback device, ultimately achieving energy saving in motor grinding.

[0031] Second embodiment: See also Figure 2 and Figure 8 A slide groove 63 is provided inside the positioning plate 62, a positioning block 64 is installed inside the slide groove 63, a fastening bolt 65 is threadedly connected inside the positioning block 64, a slider 66 is slidably connected inside the slide groove 63 and located on one side of the positioning block 64, a guide wheel 67 is rotatably connected inside the slider 66, and a return spring 68 is fixed on the opposite side of the slider 66 and the positioning block 64; Side plates 69 are fixed to the upper surface of the positioning plate 62 and located on both sides of the grinding jar 611. A fixing plate 610 is installed inside the side plate 69. A fixing screw 612 is threadedly connected to the middle position of the fixing plate 610. A nut 613 is threadedly connected to the upper surface of the fixing plate 610 and located on the outer wall of the fixing screw 612. A clamping plate 614 is rotatably connected to the bottom end of the fixing screw 612 and located at the top of the grinding jar 611. Two guide rails 2 are fixedly provided on the upper surface of the bottom plate 1 , and a shield 3 is slidably connected to the top of the two guide rails 2 .

[0032] The outer wall of the guide wheel 67 is fitted with the outer wall of the grinding tank 611 , the bottom end of the fastening bolt 65 extends to the bottom of the slide groove 63 , and the cross section of the slider 66 is T-shaped.

[0033] The working principle of this embodiment is as follows: S1: Before grinding, the user needs to position and clamp the grinding jar 611 on the positioning plate 62. Before positioning, the bottom end of the grinding jar 611 needs to be aligned with the guide wheel 67. After alignment, the grinding jar 611 is pressed down with force. At this time, the guide wheel 67 is subjected to the downward pressure and controls the return spring 68 to be compressed through the slider 66, thereby realizing the guide wheel 67 automatically centering the grinding jar 611. S2: After positioning is completed, grinding balls, commercial graphite and urea need to be placed inside the grinding jar 611, the jar cover is closed, the fixing plate 610 is inserted into the side plate 69, and finally the fixing screw 612 is rotated to drive the clamping plate 614 to clamp the grinding jar 611 and lock the grinding jar 611 on the positioning plate 62. In this way, the grinding jar 611 is loaded with materials. This embodiment

[0034] Automatic centering and positioning of the grinding jars 611 solves the problems of offset center of gravity of the grinding jars 611 and fluctuation in the rotation speed of the main turntable 56 and the auxiliary turntable 61. This prevents asymmetric centrifugal forces generated during rotation and overall vibration of the equipment. When the rotation is balanced, the forces acting on each grinding jar 611 are uniform, and the motion trajectories (falling, impacting, and rolling) of the grinding balls are more regular. The uniformity of the grinding intensity and frequency of the material is improved, and the uniform force applied reduces ineffective movement of the grinding balls (such as disordered collisions and idling), allowing energy to be more concentratedly converted into material crushing / grinding work. By achieving rotational balance and uniform force, vibration loss, friction loss, ineffective grinding energy consumption, and additional energy consumption for equipment maintenance and dynamic adjustment can be reduced, which can significantly improve energy utilization efficiency, achieve mechanical energy saving, and make the actual output power of the motor closer to the "effective grinding power".

[0035] Third embodiment: See also Figure 10 and Figure 11 , further comprising an auxiliary mechanism 7; The auxiliary mechanism 7 includes a first gear 71, a movable frame 72 and a mounting cover 74. The first gear 71 is keyed to the output shaft at the top of the grinding motor 44. A top plate 43 is mounted on the top of the mounting frame 41 by bolts. The movable frame 72 is mounted above the top plate 43. The mounting cover 74 is fixed to the upper surface of the movable frame 72. A slide plate 73 is fixed to the lower surface of the movable frame 72. A limit plate 75 is fixed to the upper surface of the carrier frame 8 and located on one side of the mounting frame 41. A sliding rod 76 is slidably connected to the inner surface of the limit plate 75. A connecting plate 78 is fixed to the outer end of the sliding rod 76. An adjusting screw 77 is rotatably connected to the outer wall of the connecting plate 78. The upper surface of the movable frame 72 is rotatably connected to the fourth gear 714 located inside the mounting cover 74. The axis of the fourth gear 714 is connected to a rotating shaft 715 via a keyway. The top keyway of the rotating shaft 715 is connected to the third gear 713. A fixed frame 79 is fixed on the upper surface of the movable frame 72, and a feeding barrel 710 is fixed inside the fixed frame 79. A feeding screw 716 is rotatably connected inside the feeding barrel 710, and a second gear 712 is connected to the keyway at the outer end of the feeding screw 716. Two hoses 711 are installed above the feeding barrel 710.

[0036] See also Figure 10 : During the operation of the first embodiment, when the grinding motor 44 rotates clockwise, the ratchet 45 will not affect the rotation of the swivel 46, so the rotating mechanism 5 will not rotate. Therefore, the clockwise rotation of the grinding motor 44 will control the first gear 71 to rotate on the top plate 43.

[0037] The working principle of this embodiment is as follows: S1: Open the grinding jar 611, start the grinding motor 44 to control the first gear 71 to rotate slowly clockwise, and the user rotates the adjusting screw 77, which drives the connecting plate 78 to move horizontally to the left along the limit plate 75. During the movement, the connecting plate 78 pushes the movable frame 72 to move horizontally along the top plate 43; S2: When moving, the fourth gear 714 stably contacts the slowly rotating first gear 71. At this time, the first gear 71 and the fourth gear 714 form an engagement to control the fourth gear 714 to complete the driving rotation. At the same time, when the movable frame 72 moves, the outlet position of the feeding barrel 710 is synchronously moved to above the grinding jar 611. S3: At this time, when the fourth gear 714 is driven to rotate, it will drive the third gear 713 to engage and control the rotation of the second gear 712 through the rotating shaft 715. When the second gear 712 rotates, it can drive the feeding screw 716 to rotate to mix the graphite and urea lowered by the hose 711 and transport them to the grinding tank 611, ultimately realizing automatic assisted unloading.

[0038] The slide plate 73 and the top plate 43 are connected in a sliding manner, the connecting plate 78 and the movable frame 72 are fixedly connected, and the adjusting screw 77 and the limiting plate 75 are threadedly connected. The outer wall of the rotating shaft 715 is rotatably connected to the axis of the mounting cover 74 , the second gear 712 and the third gear 713 are meshed with each other, and the first gear 71 and the fourth gear 714 are adapted to each other.

[0039] See also Figure 10 and Figure 11 : The sliding rod 76 is used to slide the upper and lower positions, so that the movement of the connecting plate 78 can be more stable; Secondly, before the user pushes the movable frame 72 , the movable frame 72 is away from the grinding jar 611 , so as to ensure greater safety during the rotation of the grinding jar 611 .

[0040] It should be noted that when the first gear 71 and the fourth gear 714 are engaged, the user can also control the grinding motor 44 to rotate slowly counterclockwise, so that the rotating ring 46 and the feeding screw 716 can be linked to rotate. In this state, the rotation of the feeding screw 716 is reverse rotation, and the graphite and urea in the feeding barrel 710 will move in the opposite direction inside the feeding barrel 710, and will not form a discharge, but will form compression; At this time, the rotating ring 46 controls the four grinding jars 611 to rotate and switch between different working positions of the jars. This embodiment

[0041] Compared with the traditional design, the present invention is designed to manually push the movable frame 72 so that the first gear 71 and the fourth gear 714 engage. If the gear 71 rotates clockwise during the engagement process, the grinding jar 611 under the workstation stops, and the fourth gear 714 rotates to control the feeding screw 716 to automatically mix the graphite and urea and feed them into the grinding jar 611. Therefore, this design is convenient for users to automatically unload the materials. The graphite and urea are mixed synchronously during the unloading process, ensuring that the subsequent grinding process is more convenient and quick, and can also effectively improve the grinding effect. Secondly, the user can also rotate the linkage counterclockwise to rotate the swivel 46 and the first gear 71. At this time, the feeding screw 716 rotates in the opposite direction to compress the graphite and urea, which can be used to squeeze and crush large pieces of graphite and agglomerated urea. At the same time, the grinding tank 611 rotates to automatically switch the workstation, which is more convenient for the user to unload materials and can realize automatic integrated multi-tank unloading.

[0042] Fourth embodiment: The sodium sulfate recovery method comprises the following steps: S1; Preparation of modified graphite: Commercial graphite and urea are mixed, ground evenly, and then calcined in a tube furnace under an argon atmosphere to obtain nitrogen-doped graphite. The grinding process needs to be completed in the grinding assembly 6; The mixing ratio of graphite and urea is 0.5:1-3:1, and the grinding is carried out at 500 r / min for 2 hours. The calcination temperature in the tube furnace is 300-1000°C, and the calcination time is 30-300 minutes. S2: Preparation of electrode: Disperse modified graphite in ethanol and add a binder, disperse evenly by ultrasonication, wash and dry the nickel foam, drop the graphite dispersion onto the surface of the nickel foam, dry it, and compact it using a tablet press; The dosage ratio of modified graphite to binder is 20:1-5:1, and the dispersion mass of modified graphite on the surface of nickel foam is 10-200 mg / cm 2 ; S3; Assembly of the electrolysis system: A modified graphite electrode was used as the working electrode, a calomel electrode was selected as the reference electrode, and a platinum electrode was selected as the counter electrode. A three-electrode system was assembled, and the lithium extraction solution was selected as the electrolyte. The system was connected to an electrochemical workstation. The potassium and sodium concentrations of the lithium precipitation mother solution were 9.3 g / L and 67.5 g / L, respectively. S4: Electrolysis process: After setting the working voltage, the electrolysis degree is controlled by controlling the electrolysis time, which is 5-60 minutes; S5: Sodium sulfate recovery: Collect the electrolyte after electrolysis and evaporate and crystallize to obtain high-purity sodium sulfate. This embodiment

[0043] Traditionally, lithium precipitation mother liquor is treated with no further processing after lithium extraction, with little attention paid to subsequent sodium resource recovery. Furthermore, because sodium sulfate is generally more soluble than potassium sulfate, the separated sodium sulfate often contains potassium, limiting the purity of the separation. This patent utilizes an electrochemical method to selectively separate the small amount of potassium in the post-lithium extraction liquor, making the separation of high-purity sodium sulfate much simpler.

[0044] Expanded graphite or graphene material for K + The adsorption capacity is better than that of Na + , especially when the interlayer spacing is greater than 0.4 nm, K + The embedding kinetics of Na is better and the ionic radius is smaller. + It is difficult to embed stably due to the size mismatch with the interlayer structure (higher energy barrier needs to be overcome); in addition, K + The hydration radius of Na (about 0.331 nm) is smaller than that of + (about 0.358nm), which is more easily removed from the hydration layer and embedded in the graphite interlayer under the drive of the electric field. In the electric field, by properly controlling the power supply time, the potassium ions can be completely adsorbed with almost no loss of sodium, thus achieving "sodium-potassium separation."

[0045] Using a three-electrode system and an electrochemical workstation to perform the electrolysis process can accurately control the potential or current of the reaction process and record or adjust the reaction progress in real time.

[0046] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An energy-saving graphite processing grinding device, characterized in that: It includes a base plate, a carrier frame, a driving mechanism, a rotating mechanism and a grinding assembly; The carrier is fixed on the upper surface of the base plate, and the driving mechanism includes a mounting frame, a positioning plate and a grinding motor. The mounting frame is mounted on the upper surface of the carrier frame by bolts, the positioning plate is fixed inside the mounting frame, and the grinding motor is mounted inside the positioning plate by bolts. The bottom output shaft of the grinding motor is connected to a ratchet by a keyway, and a swivel is rotatably connected inside the mounting frame and outside the ratchet. The inner wall of the swivel is rotatably connected to a spring ratchet, and the keyway at the bottom axis of the swivel is connected to a driving pulley; The rotating mechanism includes a mounting seat, a driving gear and a driven pulley, the mounting seat is fixedly arranged on the upper surface of the carrier, the driving gear is rotatably connected to the internal axis of the mounting seat, the driving gear axis is connected to the driven pulley with a keyway, the outer walls of the driven pulley and the driving pulley are sleeved with a belt, the outer wall of the driving gear is meshed and connected with four linkage gears, the axis centers of the four linkage gears are all connected with key rods with keyways, and the tops of the four key rods are rotatably connected to the main turntable; The grinding assembly includes four grinding jars, four auxiliary turntables and four positioning plates, the four auxiliary turntables are connected to the top of the four key rods by keyways, the four positioning plates are installed above the four auxiliary turntables, and the four grinding jars are placed on the upper surfaces of the four positioning plates; The grinding motor is electrically connected to a PLC, a motor controller, a bidirectional converter, a temperature measurement module and an energy storage module through wires. The temperature measurement module is electrically connected to the PLC, and the bidirectional converter is electrically connected to the energy storage module through wires.

2. The energy-saving graphite processing grinding device according to claim 1, characterized in that: The grinding motor, bidirectional converter and energy storage module are electrically connected in series, the motor controller, PLC and grinding motor are electrically connected in parallel, and the PLC, temperature measurement module and grinding motor are electrically connected in series.

3. The energy-saving graphite processing grinding device according to claim 1, characterized in that: The ratchet and the spring ratchet teeth are meshed with each other, and the axes of the driving pulley and the driven pulley are rotatably connected to the supporting frame through bearings.

4. The energy-saving graphite processing grinding device according to claim 1, characterized in that: The driving gear is rotatably connected to the axis of the mounting seat, the four linkage gears are meshed with the inner gear ring, the four linkage gears are equidistantly distributed in an annular pattern about the axis of the driving gear, and the main turntable is rotatably connected to the inner wall of the mounting seat.

5. The energy-saving graphite processing grinding device according to claim 1, characterized in that: A slide groove is provided inside the positioning plate, a positioning block is installed inside the slide groove, a fastening bolt is threadedly connected inside the positioning block, a slider is slidably connected inside the slide groove and located on one side of the positioning block, a guide wheel is rotatably connected inside the slider, and a return spring is fixed on the opposite side of the slider and the positioning block; Side plates are fixed on the upper surface of the positioning plate and located on both sides of the grinding jar, a fixing plate is installed inside the side plate, a fixing screw is threadedly connected to the middle position of the fixing plate, a nut is threadedly connected to the upper surface of the fixing plate and located on the outer wall of the fixing screw, and a clamping plate is rotatably connected to the bottom end of the fixing screw and located on the top of the grinding jar; Two guide rails are fixedly arranged on the upper surface of the bottom plate, and the tops of the two guide rails are slidably connected with shields.

6. The energy-saving graphite processing grinding device according to claim 5, characterized in that: The outer wall of the guide wheel fits into the outer wall of the grinding jar, the bottom end of the fastening bolt extends to the bottom of the slide groove, and the cross-section of the slider is a "T"-shaped structure.

7. The energy-saving graphite processing grinding device according to claim 1, characterized in that: It also includes auxiliary agencies; The auxiliary mechanism includes a first gear, a movable frame and a mounting cover, the first gear keyway is connected to the top output shaft of the grinding motor, the top of the mounting frame is installed with a top plate by bolts, the movable frame is installed above the top plate, the mounting cover is fixedly provided on the upper surface of the movable frame, the lower surface of the movable frame is fixedly provided with a slide plate, the upper surface of the carrier frame and located on one side of the mounting frame are fixedly provided with a limit plate, the interior of the limit plate is slidably connected to a sliding rod, the outer end of the sliding rod is fixedly provided with a connecting plate, and the outer wall of the connecting plate is rotatably connected to an adjusting screw; The upper surface of the movable frame is rotatably connected to the fourth gear located inside the mounting cover, the axis of the fourth gear is connected to a rotating shaft via a keyway, and the top keyway of the rotating shaft is connected to the third gear; A fixed frame is fixed on the upper surface of the movable frame, a feeding barrel is fixed inside the fixed frame, a feeding screw is rotatably connected inside the feeding barrel, a second gear is connected to the keyway at the outer end of the feeding screw, and two hoses are installed above the feeding barrel.

8. The energy-saving graphite processing grinding device according to claim 7, characterized in that: The slide plate and the top plate are connected in a sliding manner, the connecting plate and the movable frame are fixedly connected, and the adjusting screw and the limit plate are connected in a threaded manner; The outer wall of the rotating shaft is rotatably connected to the axis of the mounting cover, the second gear and the third gear are meshed with each other, and the first gear and the fourth gear are adapted to each other.

9. A method for recovering sodium sulfate, characterized in that: The sodium sulfate recovery method is used in an energy-saving graphite processing grinding device according to any one of claims 1 to 8, comprising the following steps: S1; Preparation of modified graphite: Commercial graphite and urea are mixed, ground evenly, and then calcined in a tube furnace under an argon atmosphere to obtain nitrogen-doped graphite. The grinding process needs to be completed in the grinding assembly 6; The mixing ratio of graphite and urea is 0.5:1-3:1, and the grinding is carried out at 500 r / min for 2 hours. The calcination temperature in the tube furnace is 300-1000°C, and the calcination time is 30-300 minutes; S2: Preparation of electrode: Disperse modified graphite in ethanol and add a binder, disperse evenly by ultrasonication, wash and dry the nickel foam, drop the graphite dispersion onto the surface of the nickel foam, dry it, and compact it using a tablet press; The dosage ratio of modified graphite to binder is 20:1-5:1, and the dispersion mass of modified graphite on the surface of nickel foam is 10-200 mg / cm 2 ; S3; Assembly of the electrolysis system: A modified graphite electrode was used as the working electrode, a calomel electrode was selected as the reference electrode, and a platinum electrode was selected as the counter electrode. A three-electrode system was assembled, and the lithium extraction solution was selected as the electrolyte. The system was connected to an electrochemical workstation. The potassium and sodium concentrations of the lithium precipitation mother solution were 9.3 g / L and 67.5 g / L, respectively. S4: Electrolysis process: After setting the working voltage, the electrolysis degree is controlled by controlling the electrolysis time, which is 5-60 minutes; S5: Sodium sulfate recovery: Collect the electrolyte after electrolysis and evaporate and crystallize to obtain high-purity sodium sulfate.

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