Impurity removal equipment and method for battery-grade iron oxide

Abstract

The invention relates to the technical field of filtration and impurity removal of iron oxide, in particular to impurity removal equipment and method for battery-grade iron oxide, an iron oxide filter cake is ground and crushed through rotation of a crushing roller, and crushed materials slide down along two sides of a boss and are sprayed towards the two sides of the boss and the bottom end of the crushing roller through a spraying pipe; turbid liquid washed along the boss is introduced into the stirring barrel on the lower portion, large-particle agglomerates or large-particle impurities which are not fully smashed and washed are intercepted through the filter screens, meanwhile, the scraping frame rotates in a reciprocating mode and is used for scraping and sweeping the filter screens on the two sides of the boss and scattering the scraped materials to the smashing rollers, stacked materials on the filter screens are reduced, and the smashing and washing efficiency is further improved; the washing turbid liquid in the stirring drum is further stirred and sent to the next stage of filter-pressing washing operation, impurity removal of battery-grade iron oxide is completed, water pollution, solid waste pollution, heavy metal pollution and the like caused by direct discharge of solid waste iron mud are reduced, filter-pressing mother liquor is subjected to purification treatment such as efficient activated carbon, ultrafiltration and reverse osmosis, and environmental protection is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of iron oxide filtration and impurity removal, and in particular to an impurity removal device and method for battery-grade iron oxide. Background Art

[0002] The traditional DSD acid reduction process generates a large amount of solid waste iron sludge during production. The direct discharge of this iron oxide sludge causes water pollution, solid waste contamination, and heavy metal pollution, presenting challenges to business development. Therefore, there is a pressing need to utilize solid iron oxide sludge to co-produce iron oxide products. Battery-grade iron oxide does not require a specific color; instead, it primarily requires control of impurity elements, particle size, and specific surface area. Impurities (such as Si, Al, Ca, Mg, Na, K, S, P, Cl, and heavy metals such as Cu, Zn, Cr, and Ni) can severely impact the electrochemical performance of batteries. Therefore, impurity removal is a core and critical process step, typically performed in conjunction with multiple methods. Among them, wet chemical impurity removal is a common existing treatment method, including targeted mixed acid washing / alkaline washing / water washing, followed by solid-liquid separation (acid washing separation to remove acid-soluble impurities in iron oxide, alkaline washing separation to remove alkaline-soluble impurities in iron oxide, and water washing separation to remove soluble salt impurities in iron oxide), and then multiple deionized water washing to neutrality, and then drying and calcining to obtain a high-purity battery-grade iron oxide product. Specific existing technologies, such as a wet purification method for iron oxide powder and wastewater recycling disclosed in Chinese patent document CN114655995B, often use a filter press for solid-liquid separation, and the filter mother liquor is discharged through the filter cloth, taking away soluble impurities and discharging The mother liquor from the filtration can be further purified by high-efficiency activated carbon, ultrafiltration, reverse osmosis, etc. to reduce the impact of water pollution, solid waste pollution, and heavy metal pollution, which is beneficial to environmental protection. The iron oxide filter cake obtained by filtration separation is then put into the washing tank and washed with a mixture of acid / alkali solution / deionized water. The turbid liquid after washing is then passed into the filter press for filtration, and the cycle is repeated many times until the purity specification standard is met. Among them, how to efficiently and fully mix the acid / alkali solution / deionized water to wash the iron oxide filter cake has obviously become the key to iron oxide impurity removal, which can improve the impurity removal efficiency and achieve less impurity residue requirements after a limited number of washing and separation. Therefore, further research and development optimization is still needed. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to propose a battery-grade iron oxide impurity removal device and method to solve the problem of how to more efficiently and fully wash the iron oxide filter cake with mixed acid / alkali solution / deionized water in the existing iron oxide impurity removal.

[0004] Based on the above purpose, the present invention provides a battery-grade iron oxide impurity removal device, comprising a horizontal impurity removal cylinder: The impurity removal cylinder consists of an upper grinding cylinder and a lower mixing cylinder. The inner cavity of the grinding cylinder is a horizontal cylindrical shape. A feed port is opened at the top of the grinding cylinder. Grinding rollers are rotatably connected to both sides of the upper part of the grinding cylinder. A boss is provided on the bottom wall of the grinding cylinder. The feed after being crushed by the grinding rollers slides along both sides of the boss. A spray pipe is provided in the grinding cylinder for spraying towards both sides of the boss. The inner bottom wall of the crushing cylinder is provided with discharge ports on both sides of the boss, and a filter screen is provided on the discharge ports; A scraper is provided in the pulverizing barrel, and a scraper assembly is connected to one end of the scraper. The scraper assembly includes two scraper plates connected in a V shape, and the intersection end of the two scraper plates is rotatably connected to the scraper. The two scraper plates are respectively provided with openings near their intersection ends. An extension plate is connected in parallel to one end of the scraper, one of the scraper plates is in a state parallel to the scraper, and the corresponding opening is closed by the extension plate. The other end of the scraper rotates back and forth around the axial direction in the pulverizing barrel, driving one of the scraper plates to scrape the filter screen and sprinkle the scraped material downward along the open opening onto the pulverizing roller. Until the scraper rotates to the other side of the boss, the scraper assembly is pushed by the side end of the boss to make the other scraper plate rotate parallel to the scraper.

[0005] Preferably, the crushing roller is arranged parallel to the crushing drum, and the spray pipe is arranged parallel to and adjacent to the lower portion of the crushing roller.

[0006] Preferably, a plurality of spray heads are spaced apart along the outer circumference of the spray pipe for spraying toward the side ends of the boss and the bottom end of the crushing roller.

[0007] Preferably, the length direction of the boss is parallel to the axial direction of the pulverizing cylinder, and the cross section of the boss is fan-shaped.

[0008] Preferably, the impurity removal device is arranged at the bottom of the filter press, a stirring shaft is provided in the stirring drum, a liquid outlet pipe is connected to one side of the stirring drum, and one end of the liquid outlet pipe leads to the adjacent filter press.

[0009] Preferably, a transfer part is rotatably connected at the center position of one side wall of the crushing cylinder, and the scraper includes a connecting rod in the crushing cylinder close to the transfer part. The length direction of the connecting rod is parallel to the radial direction inside the crushing cylinder, one end of the connecting rod is connected to a U-shaped connecting frame, and the other end is connected to the transfer part. The intersection end of the two scraper plates is fixedly connected to a rotating shaft, and shaft holes rotatably connected to the rotating shaft are provided at both side ends of the connecting frame, and one end of the extension plate is fixedly connected to the inner side of the connecting frame.

[0010] Preferably, strip-shaped through grooves are provided on both sides of the through opening of the scraper plate, and the side ends of the extension plates are elastically connected to the limit strips, and the side ends of the limit strips along the length direction are designed with inclined end faces. When one of the scraper plates is in a state parallel to the scraper frame, the limit strip pops outward along the corresponding strip-shaped through groove until the scraper frame rotates to the side end of the boss, and the scraper assembly is pushed by the side end of the boss. The limit strip is pushed by the inner end of the strip-shaped through groove and elastically contracts inward, so that the scraper assembly rotates until the scraper frame is against the side end of the boss, and the other scraper plate rotates to be parallel to the scraper frame.

[0011] Preferably, when the scraper plate rotates to abut against the side end of the boss, the outer end of the scraper plate is designed with an inclined end face facing away from the boss. As the scraper plate scrapes the filter screen, the scraping material gradually decreases, and the scraping material accumulates between the inclined end face of the scraper plate and the inner wall of the crushing barrel until the scraper frame starts to rotate downward, and the scraping material slides down along the inclined end face of the scraper plate.

[0012] The present invention also provides a method for removing impurities from battery-grade iron oxide, comprising the following steps: The iron oxide filter cake falls into the grinding drum from the feed port and is crushed by the grinding roller. The crushed material slides down along the two side ends of the boss and is sprayed toward the two side ends of the boss and the bottom end of the grinding roller through the spray pipe. The turbid liquid after washing along the boss is passed into the lower mixing drum through the discharge port, and the large particles or large particles of impurities that are not fully crushed and washed are intercepted by the filter screen. At the same time, the scraper rotates back and forth around the axial direction of the grinding drum, driving one of the scraper plates to scrape the filter screen, and the scraped material is sprinkled downward along the open through-port onto the grinding roller until it is When the scraper rotates to the other side of the boss, the scraper assembly is pushed by the side end of the boss to make the other scraper rotate parallel to the scraper. The scraper parallel to the scraper scrapes the filter screen on the other side of the boss, and the scraping material is sprinkled downward along the open opening onto the crushing roller, thereby reducing the pile of material on the filter screen and further improving the crushing and washing efficiency. The washing turbid liquid in the mixing drum is stirred by the stirring shaft, further crushed and washed, and then sent to the next level of filter press washing operation. The iron oxide filter cake obtained by multi-stage filter press separation can remove impurities from battery-grade iron oxide.

[0013] The beneficial effects of the present invention are as follows: the iron oxide filter cake falls into the grinding drum from the feed port, is crushed by the grinding roller, and the ground material slides down along the two side ends of the boss, and is sprayed toward the two side ends of the boss and the bottom end of the grinding roller through the spray pipe. The turbid liquid after washing along the boss is passed into the lower mixing drum through the discharge port, and the large particles or large particles of impurities that are not fully crushed and washed are intercepted by the filter screen. At the same time, the scraper rotates back and forth around the axial direction of the grinding drum to scrape the filter screens on both sides of the boss, and the scraped material is sent along the open The outlet is spread downward onto the crushing roller, thereby reducing the pile of materials on the filter screen and further improving the crushing and washing efficiency. The washing turbid liquid in the mixing drum is stirred by the stirring shaft, further crushed and washed, and then sent to the next level of filter press washing operation. The iron oxide filter cake obtained by multi-stage filter press separation can remove impurities of battery-grade iron oxide, thereby realizing the co-production of solid waste iron sludge, reducing water pollution, solid waste pollution, heavy metal pollution, etc. caused by direct discharge, and the filter press mother liquor can be further purified by high-efficiency activated carbon, ultrafiltration, reverse osmosis, etc., which is beneficial to environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or 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 for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 This is a structural diagram of the scraper of the present invention when it is against one side of the boss; Figure 3 It is a structural schematic diagram of the adapter portion of the present invention; Figure 4 It is a side structural schematic diagram of the scraper assembly of the present invention; Figure 5 It is a front view structural schematic diagram of a single scraper plate of the present invention; Figure 6 This is a side view of the structure of a scraper frame of the present invention in which an extension plate is connected to one end; Figure 7 This is a front view of the structure of a scraper frame of the present invention in which an extension plate is connected to one end; Figure 8 It is a front view structural diagram of the extension plate and the limiting strip of the present invention; Figure 9 This is a side structural schematic diagram of a scraper assembly connected to one end of the scraper frame of the present invention; Figure 10 This is a schematic structural diagram of the scraper of the present invention rotating clockwise around the grinding cylinder; Figure 11 This is a schematic structural diagram of the present invention when the scraper plate rotates clockwise to the upper part of the crushing roller; Figure 12 For the present invention Figure 11 A magnified schematic diagram of point A in the middle; Figure 13 It is a structural schematic diagram of the scraper of the present invention when it is rotated to the other side of the boss; Figure 14 This is a schematic structural diagram of the present invention when the other side end of the boss pushes against the scraper assembly; Figure 15 For the present invention Figure 14 A magnified schematic diagram of point B in the middle; Figure 16 This is a structural diagram of the scraper of the present invention when it is against the other side of the boss; Figure 17 For the present invention Figure 16 The enlarged schematic diagram of point C in the middle; Figure 18 This is a schematic structural diagram of the present invention when the scraper plate rotates counterclockwise to the upper part of the crushing roller; Figure 19 This is a schematic structural diagram of the present invention when the scraping material is accumulated between the inclined end surface of the scraping plate and the inner wall of the crushing cylinder; Figure 20 For the present invention Figure 19 The enlarged schematic diagram of point D in the middle; Figure 21 It is a schematic top view of the extension plate and the limiting strip of the present invention.

[0016] The following are marked in the figure: 100. De-impurity drum; 101. Crushing drum; 102. Mixing drum; 103. Mixing shaft; 104. Liquid outlet pipe; 105. Liquid inlet pipe; 200. Filter press; 2. Feed inlet; 3. Crushing roller; 31. Crushing teeth; 4. Boss; 5. Spray pipe; 51. Spray head; 6. Discharge port; 7. Scraper; 71. Connecting rod; 72. Connecting frame; 73. Shaft hole; 8. Scraper plate; 80. Through port; 81. Rotating shaft; 82. Strip through groove; 9. Extension plate; 91. Limiting strip; 10. Adapter. DETAILED DESCRIPTION

[0017] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0018] It should be noted that, unless otherwise defined, the technical or scientific terms used in the present invention should have the usual meanings understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0019] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 As shown, a battery-grade iron oxide impurity removal equipment includes a horizontal impurity removal drum 100, which includes an upper crushing drum 101 and a lower stirring drum 102. The inner cavity of the crushing drum 101 is a horizontal cylindrical shape. A feed port 2 is provided at the top of the crushing drum 101. Crushing rollers 3 are rotatably connected to both sides of the upper part of the crushing drum 101. A boss 4 is provided on the inner bottom wall of the crushing drum 101. The feed crushed by the crushing roller 3 slides along both sides of the boss 4. A spray pipe 5 is provided in the crushing drum 101 for spraying toward both sides of the boss 4. A discharge port 6 is provided on the inner bottom wall of the crushing drum 101 at both sides of the boss 4. A filter screen is provided on the discharge port 6. A scraper 7 is provided in the crushing drum 101. One end of the scraper 7 is connected to A scraper assembly is connected, which includes two scraper plates 8 connected in a V shape. The intersection end of the two scraper plates 8 is rotatably connected to the scraper 7. The two scraper plates 8 are respectively provided with openings 80 near their intersection ends. One end of the scraper 7 is connected in parallel with an extension plate 9. One of the scraper plates 8 is in a state parallel to the scraper 7, and the corresponding opening 80 is closed by the extension plate 9. The other end of the scraper 7 reciprocates in the axial direction of the crushing cylinder 101, driving one of the scraper plates 8 to scrape the filter screen and sprinkle the scraping material downward along the open opening 80 onto the crushing roller 3, until the scraper 7 rotates to the other side of the boss 4, and the scraper assembly is pushed by the side end of the boss 4 to make the other scraper plate 8 rotate parallel to the scraper 7.

[0020] The present invention is based on the existing iron oxide wet impurity removal process and equipment, including a horizontal impurity removal drum 100 for wet washing, the impurity removal drum 100 includes an upper crushing drum 101 and a lower stirring drum 102, and the turbid liquid after washing is passed into an existing conventional high-efficiency filtering device such as a filter press 200 for solid-liquid separation. Therefore, the impurity removal equipment of the present invention can be set separately, and can also be set at the bottom of a device such as a filter press 200. The iron oxide filter cake obtained by pressure filtration separation falls into the impurity removal drum 100, and the corresponding acid solution / alkali solution / deionized water is passed into the impurity removal drum 100 as a washing liquid, first crushed by the upper crushing drum 101, and then mixed and stirred by the lower stirring drum 102. A stirring shaft 103 can be provided in parallel in the stirring drum 102, and a liquid outlet pipe 104 is externally connected to one side of the stirring drum 102. A stirring blade is provided on the periphery of the stirring shaft 103, and one end of the liquid outlet pipe 104 can lead to an adjacent filter press 200. For example, three filter presses 200 can be arranged in parallel to form a filter press unit. The bottom ends of the first two filter presses 200 are provided with impurity removal cylinders 100, which are rotated by a stirring shaft 103 to fully mix, stir and wash the crushed material of the iron oxide filter cake with the washing liquid. The turbid liquid after washing is pushed to the liquid outlet pipe 104 and led to the next adjacent filter press 200 by the liquid outlet pipe 104 for secondary filter pressing and washing. The turbid liquid after the secondary filter pressing and washing is then led to the next adjacent filter press 200 for tertiary filter pressing. The mother liquor of the filter pressing is discharged through the filter cloth and recycled or discharged. The iron oxide filter cake obtained by each filter pressing separation is equivalent to undergoing a solid-liquid separation (acid-soluble impurities in the iron oxide are removed after acid washing, alkali-soluble impurities in the iron oxide are removed after alkali washing, and soluble salt impurities in the iron oxide are removed after water washing). The iron oxide filter cake obtained by the three filter pressing separations is finally subjected to processes such as drying and calcination to obtain a high-purity battery-grade iron oxide product. Among them, the inner cavity of the grinding cylinder 101 is a horizontal cylindrical shape, and a feeding port 2 is provided at the top of the grinding cylinder 101. Grinding rollers 3 are rotatably connected on both sides of the upper part of the grinding cylinder 101. A boss 4 is provided on the inner bottom wall of the grinding cylinder 101. A spray pipe 5 is provided in the grinding cylinder 101. The inner bottom wall of the grinding cylinder 101 is provided with discharge ports 6 on both sides of the boss 4, and is connected to the lower mixing cylinder 102 through the discharge ports 6. A filter is provided on the discharge port 6, and a scraper 7 is provided in the grinding cylinder 101. One end of the scraper 7 is connected to a scraper assembly. Specifically, the grinding roller 3 is arranged parallel to the grinding cylinder 101, and the side of the grinding cylinder 101 away from the liquid outlet pipe 104 is externally connected to an existing conventional power device such as a drive motor, which drives the grinding rollers 3 on both sides to rotate relative to each other, for example Figure 1 、 Figure 2As shown, the outer periphery of the grinding roller 3 is provided with grinding teeth 31, and the grinding teeth 31 on the grinding rollers 3 on both sides are staggered. The grinding roller 3 on the left side rotates clockwise, and the grinding roller 3 on the right side rotates counterclockwise. The length direction of the boss 4 is parallel to the axial direction of the grinding cylinder 101, and the cross section of the boss 4 is fan-shaped. The tip of the boss 4 is located below the middle of the grinding rollers 3 on both sides. The spray pipe 5 is arranged parallel to the adjacent lower part of the grinding roller 3. The grinding cylinder 101 is away from the liquid outlet pipe 104. The liquid inlet pipe 105 is connected to the outside of the grinding cylinder 101. The liquid inlet pipe 105 passes through the grinding cylinder 101 and is connected to the spray pipe 5 for passing the washing liquid. A plurality of spray heads 51 are arranged at intervals along the outer periphery of the spray pipe 5. The spray heads 51 are arranged in multiple rows at intervals along the length direction of the spray pipe 5, and in multiple rows at intervals along the circumferential direction of the spray pipe 5, so that the iron oxide filter cake falls into the grinding cylinder 101 from the feed port 2 and passes through the powder The crushing roller 3 rotates and crushes, and the crushed material slides down along the side ends of the boss 4. At the same time, it is sprayed toward the side ends of the boss 4 and the bottom end of the crushing roller 3 through multiple spray heads 51. On the one hand, the crushed material is efficiently dispersed when sliding along the two sides of the boss 4, and is not easy to pile up. It is sprayed and mixed with the washing liquid to achieve a sufficient and efficient washing effect. On the other hand, the crushed material adhering to the bottom end of the crushing roller 3 is sprayed and washed. The adhering crushed material is blown to the tip of the boss 4 and slides down, achieving a sufficient and efficient washing effect. The turbid liquid after washing along the boss 4 is passed into the lower mixing drum 102 through the discharge port 6, and the large particles or large particles of impurities that are not fully crushed and washed are intercepted by the filter screen. The washing turbid liquid in the mixing drum 102 is stirred by the stirring shaft 103, and the small particles that are not fully crushed and washed are further crushed and washed, and then sent to the next level of filter press washing operation through the liquid outlet pipe 104; The scraper assembly includes two scraper plates 8 connected in a V shape, and the intersection ends of the two scraper plates 8 are rotatably connected to the scraper frame 7. The two scraper plates 8 are respectively provided with openings 80 near their intersection ends. One end of the scraper frame 7 is connected in parallel with an extension plate 9. One of the scraper plates 8 is in a state parallel to the scraper frame 7 and the corresponding opening 80 is closed by the extension plate 9. The other end of the scraper frame 7 reciprocates around the axial direction of the crushing cylinder 101. The scraper frame 7 can start to rotate when the iron oxide filter cake starts to fall, or it can start to rotate in the middle and later stages of the iron oxide filter cake falling (at this time, piles are easily formed at the filter screen). For example Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9As shown, the scraper 7 is against one side of the boss 4, and one of the scraper plates 8 is in a state parallel to the scraper 7. The opening 80 of the scraper plate 8 is closed by the extension plate 9. The other scraper plate 8 is opened in a V-shape and tilted outward. The opening 80 of the scraper plate 8 is naturally in an open state. As the scraper 7 rotates clockwise around the crushing cylinder 101, it drives one of the scraper plates 8 to scrape the filter screen. Figure 10 As shown, the large particles or impurities that are not fully crushed and washed on the filter screen are scraped by the scraper plate 8, and the scraper rotates upward with the scraper plate 8 until it reaches the upper part of the crushing roller 3, as shown in FIG. Figure 11 、 Figure 12 As shown, the scraping material is sprinkled downward along the open through-port 80 onto the crushing roller 3. Even if part of the scraping material falls onto the upper end of the crushing roller 3, the crushing roller 3 can be rotated and brought to the middle of the crushing rollers 3 on both sides for further crushing and washing, thereby avoiding the accumulation of material on the filter screen affecting the washing and discharge of the material, until the scraper 7 rotates to the other side of the boss 4. Figure 13 、 Figure 14 、 Figure 15 As shown, the scraper assembly is pushed by the side end of the boss 4 until the scraper frame 7 is pressed against the other side of the boss 4, as shown in FIG. Figure 16 、 Figure 17 As shown, the other scraper plate 8 is rotated to be parallel to the scraper frame 7. At this time, the scraper plate 8 rotates counterclockwise again, relying on the scraper plate 8 parallel to the scraper frame 7 to scrape the filter screen on the other side of the boss 4 until the scraper frame 7 is rotated to the upper part of the crushing roller 3, as shown. Figure 18 As shown, the scraping material is also scattered downward along the open through-port 80 onto the crushing roller 3. As a result, the scraper 7 reciprocates. After the iron oxide filter cake falls off, the scraper 7 still keeps reciprocating for a period of time until the material piled on the filter screen is consumed, thereby further improving the crushing and washing efficiency.

[0021] Among them, for multi-stage filter press washing, considering that the soluble impurities in the iron oxide filter cake decrease step by step, the washing flow of the spray pipe 5 can be adaptively designed to decrease step by step. More preferably, in the same stage of filter press washing, in the latter part of the iron oxide filter cake dropping and after the dropping, as the material piled on the filter screen is gradually consumed, the washing flow of the spray pipe 5 can also be adaptively reduced step by step.

[0022] In an embodiment of the present invention, optionally, Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9As shown, a connecting portion 10 is rotatably connected at the center position of the side wall of one side of the pulverizing cylinder 101. The connecting portion 10 is located on the same side of the liquid outlet pipe 104. Specifically, a component such as a turntable can be used. The scraper 7 includes a connecting rod 71 on the side of the pulverizing cylinder 101 close to the connecting portion 10. The length direction of the connecting rod 71 is parallel to the radial direction of the pulverizing cylinder 101. One end of the connecting rod 71 is connected to a U-shaped connecting frame 72, and the other end is connected to the inner side of the connecting portion 10. Specifically, the connecting rod 71 is connected to one side of the U-shaped connecting frame 72, that is, the side close to the connecting portion 10. Since the pulverizing roller 3 and the spray pipe 5 are both connected to the side of the pulverizing cylinder 101 away from the connecting portion 10, that is, there is a gap with the side of the pulverizing cylinder 101 close to the connecting portion 10, thereby connecting The rod 71 rotates in the gap near the adapter 10 on one side of the crushing cylinder 101, and will not interfere with the crushing roller 3 and the spray pipe 5. Specifically, the outer side of the crushing cylinder 101 can be provided with one of the existing conventional power equipment designs such as a servo motor plus a motion controller, or a stepper motor plus a stepper driver, or a swing cylinder plus a solenoid valve, which is used to drive the adapter 10 to rotate axially. The intersection end of the two scraper plates 8 is fixedly connected with a rotating shaft 81. The length direction of the scraper plate 8 is parallel to the length direction inside the crushing cylinder 101. The two sides of the U-shaped connecting frame 72 are respectively connected to the two sides of the length direction of the scraper plate 8. Specifically, the side ends of the connecting frame 72 are provided with shaft holes 73 rotatably connected to the rotating shaft 81, and one end of the extension plate 9 is fixedly connected to the inner side of the connecting frame 72.

[0023] The two side edges of the U-shaped connecting frame 72 can be designed to be as short as possible to prevent the scraping material from falling along the U-shaped space of the connecting frame 72 .

[0024] Among them, optionally, a support wheel can be provided in the top middle section of the boss 4 or the top middle section of the spray pipe 5, and the support wheel is used to abut against the bottom end of the crushing roller 3 and rotate synchronously with the crushing roller 3. It is used to firmly support the rotation of the crushing roller 3 without affecting the scraping movement of the scraper frame 7 and the scraper assembly.

[0025] In an embodiment of the present invention, optionally, Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 21 As shown, the scraper plate 8 is provided with strip-shaped through grooves 82 on both sides of its opening 80, and the strip-shaped through grooves 82 are connected to the corresponding opening 80. The side ends of the extension plate 9 are elastically connected to the limit strips 91, as shown in FIG. Figure 8 、 Figure 21As shown, the limiting strip 91 is designed with an inclined end surface along the side end in the length direction. When one of the scraper plates 8 is in a state parallel to the scraper frame 7, the limiting strip 91 pops outward along the corresponding strip-shaped through groove 82. Since the scraper material is light in weight, the scraper material weight and the friction between the outer end of the scraper plate 8 and the inner wall of the crushing cylinder 101 are not enough to overcome the elastic force of the limiting strip 91. Therefore, the limiting effect of the limiting strip 91 is utilized to keep one of the scraper plates 8 parallel to the scraper frame 7 until the scraper frame 7 rotates to the side end of the boss 4. Figure 13 、 Figure 14 、 Figure 15 As shown, the scraper assembly is pushed against the side end of the boss 4. At this time, the limit strip 91 is pushed against the inner side end of the strip groove 82 and elastically contracts inward. The limit strip 91 moves away from the strip groove 82, and the scraper assembly starts to rotate until the scraper frame 7 is against the side end of the boss 4. Figure 16 、 Figure 17 As shown, the other scraper plate 8 rotates to be parallel to the scraper frame 7, that is, the limiting strip 91 pops outward and extends into the strip-shaped through groove 82 of the other scraper plate 8 to play a limiting role.

[0026] In an embodiment of the present invention, optionally, Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 、 Figure 16 、 Figure 17 、 Figure 18 As shown, when the scraper plate 8 rotates to abut against the side end of the boss 4, the outer end of the scraper plate 8 is designed with an inclined end face away from the boss 4. On the one hand, the sharper outer end design of the scraper plate 8 is conducive to more efficient scraping of the filter screen and reducing the friction between the outer end and the inner wall of the crushing cylinder 101. On the other hand, in the initial stage of scraping by the scraper plate 8, due to the large amount of scraping material, part of the scraping material may fall downward along the open passage 80 before the scraper plate 8 rotates to the upper part of the crushing roller 3, and thus is not taken to the crushing roller 3 for re-crushing and washing, that is, only part of the scraping material will be taken in for re-crushing and washing, and the scraping material obtained by the scraper plate 8 scraping the filter screen gradually decreases, and the scraping material is accumulated between the inclined end face of the scraper plate 8 and the inner wall of the crushing cylinder 101, as shown in FIG. Figure 19 、 Figure 20As shown, until the scraper 7 starts to rotate downward, the scraped material slides down along the inclined end surface of the scraper plate 8 and falls between the crushing rollers 3 on both sides to be crushed and washed again, thereby achieving the effect of further improving the crushing and washing efficiency.

[0027] Among them, optionally, the outer end of the scraper plate 8, that is, the end facing the inner wall of the crushing cylinder 101, can be designed as an elastic telescopic structure, similar to the existing conventional elastic telescopic rod, elastic telescopic cylinder and other structures. The outer end of the scraper plate 8 can also be made of elastic wear-resistant materials such as existing conventional rubber, so that even if the outer end of the scraper plate 8 is worn due to long-term use, the outer end of the scraper plate 8 remains elastically in contact with the inner wall of the crushing cylinder 101.

[0028] Among them, optionally, an observation window can be provided on the crushing barrel 101 to facilitate observation of the crushing and washing conditions in the crushing barrel 101 and convenient maintenance of the crushing and washing components in the crushing barrel 101. The mixing barrel 102 can also be equipped with an online conductivity meter / pH meter to monitor the conductivity / pH of the washing turbid liquid online for monitoring the washing process and assisting in adaptively adjusting the spray flow and scraping frequency.

[0029] The present invention also provides a method for removing impurities from battery-grade iron oxide, comprising the following steps: The iron oxide filter cake falls into the grinding drum 101 from the feed port 2, and is crushed by the grinding roller 3. The ground material slides down along the side ends of the boss 4, and is sprayed toward the side ends of the boss 4 and the bottom end of the grinding roller 3 through multiple spray heads 51. The turbid liquid washed along the boss 4 is passed into the lower mixing drum 102 through the discharge port 6, and the large particles or large particles of impurities that are not fully crushed and washed are intercepted by the filter screen. At the same time, the scraper 7 reciprocates around the axial direction of the grinding drum 101, driving one of the scraper plates 8 to scrape the filter screen, and the scraped material is sprinkled downward along the open through-port 80 onto the grinding roller 3. Until the scraper 7 rotates to the other side of the boss 4, the scraper assembly is pushed by the side end of the boss 4 to make the other scraper plate 8 rotate parallel to the scraper 7, and the scraper plate 8 parallel to the scraper 7 scrapes the filter screen on the other side of the boss 4, and the scraping material is sprinkled downward along the open through-port 80 onto the crushing roller 3, thereby reducing the pile of material on the filter screen and further improving the crushing and washing efficiency. The washing turbid liquid in the mixing drum 102 is stirred by the stirring shaft 103, further crushed and washed, and then sent to the next level of filter press washing operation by the liquid outlet pipe 104. The iron oxide filter cake obtained by multi-stage filter press separation can remove impurities of battery-grade iron oxide.

[0030] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A battery-grade iron oxide impurity removal device, comprising a horizontally placed impurity removal drum (100), characterized in that: The impurity removal cylinder (100) comprises an upper grinding cylinder (101) and a lower mixing cylinder (102). The inner cavity of the grinding cylinder (101) is in a horizontal cylindrical shape. A feed port (2) is provided at the top of the grinding cylinder (101). Grinding rollers (3) are rotatably connected to both sides of the upper inner portion of the grinding cylinder (101). A boss (4) is provided on the inner bottom wall of the grinding cylinder (101). The feed material after being ground by the grinding rollers (3) slides down along both sides of the boss (4). A spray pipe (5) is provided in the grinding cylinder (101) for spraying toward both sides of the boss (4). The inner bottom wall of the grinding cylinder (101) is provided with discharge ports (6) on both sides of the boss (4), and a filter screen is provided on the discharge port (6); A scraper (7) is provided in the crushing cylinder (101), one end of the scraper (7) is connected to a scraper assembly, the scraper assembly includes two scraper plates (8) connected in a V shape, the intersection ends of the two scraper plates (8) are rotatably connected to the scraper (7), the two scraper plates (8) are respectively provided with openings (80) near their intersection ends, one end of the scraper (7) is connected in parallel to an extension plate (9), one of the scraper plates (8) is in a state parallel to the scraper (7), The corresponding opening (80) is closed by the extension plate (9), and the other end of the scraper (7) reciprocates around the axial direction of the crushing cylinder (101), driving one of the scraper plates (8) to scrape the filter screen and scatter the scraped material downward along the open opening (80) onto the crushing roller (3), until the scraper (7) rotates to the other side of the boss (4), and the scraper assembly is pushed by the side end of the boss (4) to make the other scraper plate (8) rotate parallel to the scraper (7).

2. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The crushing roller (3) is arranged parallel to the crushing cylinder (101), and the spray pipe (5) is arranged parallel to and adjacent to the lower portion of the crushing roller (3).

3. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The spray pipe (5) is provided with a plurality of spray heads (51) spaced apart along its outer circumference for spraying toward the side ends of the boss (4) and the bottom end of the crushing roller (3).

4. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The length direction of the boss (4) is parallel to the axial direction of the grinding cylinder (101), and the cross section of the boss (4) is fan-shaped.

5. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The impurity removal device is arranged at the bottom end of the filter press (200), a stirring shaft (103) is arranged in the stirring drum (102), a liquid outlet pipe (104) is connected to one side of the stirring drum (102), and one end of the liquid outlet pipe (104) leads to the adjacent filter press (200).

6. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The center position of one side wall of the crushing cylinder (101) is rotatably connected to a transfer portion (10); the scraper (7) comprises a connecting rod (71) located in the crushing cylinder (101) and close to the transfer portion (10); the length direction of the connecting rod (71) is parallel to the radial direction of the crushing cylinder (101); one end of the connecting rod (71) is connected to a U-shaped connecting frame (72); the other end is connected to the transfer portion (10); the intersection of the two scraping plates (8) is fixedly connected to a rotating shaft (81); the two side ends of the connecting frame (72) are provided with shaft holes (73) rotatably connected to the rotating shaft (81); one end of the extension plate (9) is fixedly connected to the inner side of the connecting frame (72).

7. The impurity removal equipment for battery-grade iron oxide according to claim 1, characterized in that: The scraper plate (8) is provided with strip-shaped through grooves (82) on both sides of its opening (80), and the side ends of the extension plate (9) are elastically connected to the limiting strips (91), and the side ends of the limiting strips (91) along the length direction thereof are designed to have inclined end faces. When one of the scraper plates (8) is in a state parallel to the scraper frame (7), the limiting strips (91) pop outward along the corresponding strip-shaped through grooves (82) until the scraper frame (7) rotates to the side end of the boss (4), and pushes the scraper assembly through the side end of the boss (4). The limiting strips (91) are pushed by the inner side ends of the strip-shaped through grooves (82) and elastically shrink inward, so that the scraper assembly rotates until the scraper frame (7) is in contact with the side end of the boss (4), and the other scraper plate (8) rotates to be parallel to the scraper frame (7).

8. The impurity removal equipment for battery-grade iron oxide according to claim 6, characterized in that: When the scraper plate (8) rotates to abut against the side end of the boss (4), the outer end of the scraper plate (8) is designed to be an inclined end face away from the boss (4). As the scraper plate (8) scrapes the filter screen, the scraped material gradually decreases and accumulates between the inclined end face of the scraper plate (8) and the inner wall of the crushing cylinder (101). When the scraper frame (7) starts to rotate downward, the scraped material slides down along the inclined end face of the scraper plate (8).

9. A method for removing impurities from battery-grade iron oxide, the method using the battery-grade iron oxide impurity removal device according to any one of claims 1 to 8 for removing impurities, characterized in that: The following steps are involved: The iron oxide filter cake falls into the grinding drum (101) from the feed port (2), and is crushed by the grinding roller (3). The crushed material slides downward along the two side ends of the boss (4), and is sprayed toward the two side ends of the boss (4) and the bottom end of the grinding roller (3) through the spray pipe (5). The turbid liquid washed along the boss (4) is passed into the lower mixing drum (102) through the discharge port (6), and the large particles of aggregates or large particles of impurities that are not fully crushed and washed are intercepted by the filter screen. At the same time, the scraper (7) reciprocates around the axial direction of the grinding drum (101), driving one of the scraper plates (8) to scrape the filter screen, and the scraped material is sprinkled downward along the open through-port (80) to the grinding roller. (3), until the scraper (7) rotates to the other side of the boss (4), the side end of the boss (4) pushes the scraper assembly to make the other scraper (8) rotate parallel to the scraper (7), and the scraper (8) parallel to the scraper (7) scrapes the filter screen on the other side of the boss (4), and the scraping material is sprinkled downward along the open through-port (80) onto the crushing roller (3), thereby reducing the pile of materials on the filter screen and further improving the crushing and washing efficiency. The washing turbid liquid in the mixing drum (102) is stirred by the stirring shaft (103), further crushed and washed, and then sent to the next level of filter pressing and washing operation. The iron oxide filter cake obtained by multi-stage filter pressing separation can remove impurities of battery-grade iron oxide.

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