Graphite purification system

Abstract

The utility model discloses a graphite purification system, which comprises: a first pickling unit, which comprises a first acid leaching purification device, and a first washing impurity removal device and a second washing impurity removal device for washing the pickled material; the alkali fusion unit comprises an alkali fusion treatment device for roasting a mixture of the first acid pickling material and alkali, and first washing equipment and second washing equipment for washing the material; and the second acid pickling unit comprises a second acid leaching purification device, a cleaning device for cleaning the materials and a drying device for drying the materials. According to the scheme, the first acid pickling unit provided with the first water washing impurity removal device and the second water washing impurity removal device is additionally arranged, so that materials are treated by the first acid pickling unit, acid-soluble impurities mixed in the materials can react with acid, and then washing is performed twice to remove the impurities, so that the impurities can be better removed, and the product quality is improved. The purity of the material is favorably improved, and the quality of a final product is ensured.

Description

Technical Field

[0001] The present application generally relates to the technical field of graphite purification. More specifically, the present application relates to a graphite purification system. Background Art

[0002] Graphite, due to its unique crystal structure, possesses numerous exceptional physical and chemical properties, including excellent electrical and thermal conductivity, thermal shock resistance, plasticity, lubricity, high-temperature resistance, and corrosion resistance. It is widely used in key sectors of the national economy, including refractory, environmental protection, metallurgy, machinery, chemicals, and electronics. High-purity graphite, a further processed form of graphite, has significant application value in high-end, cutting-edge fields such as composite materials, new energy batteries, the nuclear industry, and aerospace.

[0003] In the prior art, the production of high-purity graphite is mostly obtained by using hydrofluoric acid method and alkali acid method, wherein the hydrofluoric acid method purification is to utilize hydrofluoric acid to react with the impurities in graphite, thereby realizing the purification of graphite. Although this purification method is simple, fluorine has a large environmental pollution and is highly harmful to the human body, so alkali acid method is often used to prepare high-purity graphite in production. Alkali acid method purification is to first mix graphite with alkali and then roast it, and after roasting, remove impurities by washing, and then add acid to carry out acid leaching reaction, and obtain high-purity graphite product after secondary washing. Although alkali acid method is a kind of environmentally friendly chemical purification method, purification research is mostly in the laboratory stage and is not mass-produced. In addition, impurities such as silicates in graphite cannot be effectively removed by alkali acid method purification, and the graphite purity obtained is low, which is difficult to meet the production requirements of some products.

[0004] In view of this, there is an urgent need to provide a new graphite purification system so that high-purity graphite can be obtained on the basis of mass production. Utility Model Content

[0005] In order to at least solve one or more of the above-mentioned technical problems, the present application proposes a graphite purification system in multiple aspects.

[0006] The graphite purification system provided in the present application includes: a first pickling unit, which includes a first acid leaching purification device for pickling a material, and a first water washing and impurity removal device and a second water washing and impurity removal device for washing the pickled material; an alkali fusion unit, which includes an alkali fusion treatment device for roasting a mixture of the first pickled material and alkali, and a first washing device and a second washing device for washing the material treated by the alkali fusion treatment device, wherein the first pickled material is a material obtained by treatment in the first pickling unit; and a second pickling unit, which includes a second acid leaching purification device for pickling the mixture treated by the alkali fusion unit again, a washing device for washing the pickled material, and a drying device for drying the washed material.

[0007] In some embodiments, the first pickling unit further includes a first pulping device, which is used to pulp the material pickled by the first acid leaching and purification device to obtain a first pulping liquid.

[0008] In some embodiments, the first water washing and impurity removal device is used to wash the material after acid washing by the first acid leaching and purification device, and the washed material enters the first pulping device for pulping; the second water washing and impurity removal device is used to wash the first pulping liquid.

[0009] In some embodiments, the alkali melting treatment device includes a mixing device and a roasting device connected to each other, wherein the mixing device is used to mix the first pickling material with alkali to obtain a mixture, and the roasting device is used to roast the mixture.

[0010] In some embodiments, the alkali melting treatment device further includes a drying device connected to the mixing device, wherein the drying device is used to dry the first pickling material, and the dried first pickling material enters the mixing device and is mixed with alkali.

[0011] In some embodiments, the alkali melting unit further includes a second pulping device connected to the roasting device and the first washing device, the second pulping device is used to pulp the roasted mixture to obtain a second pulping liquid, and the first washing device is used to wash the second pulping liquid.

[0012] In some embodiments, the alkali melting unit further includes a third pulping device connected to the first washing equipment and the second washing equipment, the third pulping device being used to pulp the second pulping liquid washed by the first washing equipment again to obtain a third pulping liquid, and the second washing equipment being used to wash the third pulping liquid.

[0013] In some embodiments, the first water washing and impurity removal device and the first washing equipment are both filter presses, and the second water washing and impurity removal device, the second washing equipment and the cleaning device are all centrifuges.

[0014] In some embodiments, the first acid leaching purification device and the second acid leaching purification device are both reactors.

[0015] In some embodiments, the drying device and the drying device are both dryers.

[0016] The graphite purification system provided above, in embodiments of the present application, incorporates a first acid wash unit prior to the alkali melting unit. This first acid wash unit removes some acid-soluble impurities from the material. This step not only removes impurities more thoroughly but also helps reduce the amount of alkali used in the subsequent roasting step. Furthermore, in some embodiments, the roasted mixture is washed twice with water to further remove insoluble silicate impurities and metaaluminates. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the exemplary embodiments of the present application will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0018] Figure 1 A schematic diagram of a graphite purification system according to an embodiment of the present application is shown;

[0019] Figure 2 The experimental data measured in two embodiments of the present application are shown.

[0020] In the figure: 100, first pickling unit; 200, alkali melting unit; 300, second pickling unit;

[0021] 101. First reactor; 102. First filter press; 103. First pulping tank; 104. First centrifuge;

[0022] 201, first dryer; 202, high-efficiency mixer; 203, rotary kiln; 204, second pulping tank; 205, second filter press; 206, third pulping tank; 207, second centrifuge;

[0023] 301. Second reactor; 302. Third centrifuge; 303. Second dryer. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0025] It should be understood that the terms "include" and "comprising" used in the description and claims of this application indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0026] It should also be understood that the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this specification and claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" as used in this specification and claims refers to any and all possible combinations of one or more of the associated listed items, including and including these combinations.

[0027] As used in this specification and claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0028] The specific implementation of the present application will be described in detail below with reference to the accompanying drawings.

[0029] The solution of the present application provides a graphite purification system, which includes a first pickling unit 100, an alkali melting unit 200 and a second pickling unit 300 connected in sequence. When in use, the material with impurities first enters the first pickling unit 100 for pickling treatment, thereby removing some acid-soluble impurities in the material, and then obtaining a first pickled material. The first pickled material enters the alkali melting unit 200, where it is mixed with alkali and then roasted. During the roasting process, impurities such as Si and Al in the first pickled material react with the alkali to generate impurities such as silicate and metaaluminate, which are then removed by washing with water. The mixed material treated by the alkali melting unit 200 is then put into the second pickling unit 300 for a second pickling treatment to obtain a high-purity material.

[0030] It is worth noting that the material in the solution of this application refers to graphite, which can be spherical graphite or graphite of other shapes. The graphite mixed with impurities is processed by the graphite purification system of this application to obtain high-purity graphite. The first pickling unit 100, alkali melting unit 200, and second pickling unit 300 in the purification system are described in detail below.

[0031] The first pickling unit 100 in this application includes a first acid leaching and purification device, a water washing and impurity removal device, and a first pulping device. Specifically, the water washing and impurity removal device includes a first water washing and impurity removal device and a second water washing and impurity removal device. The first acid leaching and purification device is connected to the first water washing and impurity removal device, which is connected to the first pulping device, which is connected to the second water washing and impurity removal device.

[0032] In one embodiment, the first acid leaching and purification device is a first reactor 101, the first water washing and impurity removal device is a first filter press 102, the first pulping device is a first pulping tank 103, and the second water washing and impurity removal device is a first centrifuge 104. Specifically, the discharge port of the first reactor 101 is connected to the feed port of the first filter press 102 via a pipeline, the discharge port of the first filter press 102 is connected to the feed port of the first pulping tank 103, and the discharge port of the first pulping tank 103 is connected to the feed port channel pipeline of the first centrifuge 104.

[0033] During use, the material with impurities enters the first reactor 101 and is mixed with water and acid in a certain mass ratio for pickling. After the material is pickled, the discharge port of the first reactor 101 is opened, and the pickled material enters the first filter press 102 through a pipeline for primary water washing. After the primary water washing is completed, it enters the first pulping tank 103 through a pipeline for pulping to obtain a first pulping liquid. The first pulping liquid enters the first centrifuge 104 through a pipeline for secondary water washing. After the secondary water washing is completed, the first pickled material is obtained.

[0034] In the examples provided herein, the material is first mixed with an acid, causing some impurities in the material to react with the acid to form soluble compounds, and then the soluble compounds are removed by water washing in a filter press. The material is then pulped. The pulping process allows the material to fully dissociate from the soluble compounds and other impurities, facilitating subsequent physical separation. The first pulping liquid obtained after pulping is then washed in a centrifuge to further remove impurities from the material.

[0035] In this solution, the material can be treated by the first pickling unit 100 to remove acid-soluble impurities in the material, thereby preventing impurities in the material such as silicon (Si), aluminum (Al) and other metal ions from reacting with the alkali to form corresponding compounds, thereby reducing the amount of alkali used in subsequent steps.

[0036] In some embodiments of the present application, the alkali melting unit 200 includes a drying device, an alkali melting treatment device, a second pulping device, a first washing device, a third pulping device, and a second washing device connected in sequence. In some embodiments, the alkali melting treatment device includes a mixing device and a roasting device connected to each other, wherein the mixing device is used to mix the first acid-washed material with alkali to obtain a mixed material, and the roasting device is used to roast the mixed material.

[0037] In some embodiments, the drying device is a first dryer 201, and the mixing device is a VC mixer 202 with high mixing efficiency and adjustable speed. The VC in the VC mixer refers to the internal structure of the mixer, namely "V-shaped" and "conical." The roasting device is a rotary kiln 203, the second pulping device is a second pulping tank 204, the first washing equipment is a second filter press 205, the third pulping device is a third pulping tank 206, and the second washing equipment is a second centrifuge 207.

[0038] During use, the first pickled material obtained by the first pickling unit 100 is transported in ton bags to the first dryer 201 for drying. The dried material then enters the VC mixer through a pipeline, where it is thoroughly mixed with alkali to produce a mixed material. The mixed material is then transported to the rotary kiln 203 via a pipeline connected at one end to the discharge port of the VC mixer and at the other end to the feed port of the rotary kiln 203, where it is calcined. This calcination causes impurities such as Si and Al in the mixed material to react with the alkali, producing impurities such as silicates and metaaluminates. These impurities are then removed by water washing.

[0039] In some embodiments of the present application, in order to better remove impurities in the mixed material after roasting, two cycles of pulping-washing operations are performed on the mixed material after roasting. Specifically, the mixed material after roasting is transported to the second pulping tank 204 through a pipeline connected to the discharge port of the rotary kiln 203 at one end and the feed port of the second pulping tank at the other end, and pulping is carried out in the second pulping tank 204 to obtain a second pulping liquid. After the pulping is completed, the second pulping liquid enters the second filter press 205 through the discharge port of the second pulping tank, and is subjected to a primary water washing in the second filter press 205. After the water washing is completed, the first cycle of pulping-washing operation is completed. Most of the soluble impurities in the material can be removed by the first cycle of pulping-washing operation.

[0040] After the first cycle of pulping and washing is complete, the material flows out of the discharge port of the second filter press 205 and enters the third pulping tank 206 through its feed port, where pulping is repeated. After pulping is completed, a third pulping liquid is obtained. This third pulping liquid flows out of the discharge port of the third pulping tank 206 and enters the feed port of the second centrifuge 207 for centrifugal washing. Upon completion of the centrifugal washing, the second cycle of pulping and washing is complete. This second cycle of pulping and washing further removes silicates and metaaluminates from the material.

[0041] In some embodiments, after the roasted mixture undergoes two cycles of pulping and washing, most impurities have been removed, but a small amount of impurities still remain in the material. To further improve the purity of the material, the material obtained after the alkali melting unit 200 is then processed in the second acid washing unit 300.

[0042] The second pickling unit 300 in the present application includes a second acid leaching and purification device, a cleaning device, and a drying device connected in sequence. Specifically, the second acid leaching and purification device in the second pickling unit 300 is a second reactor 301, the cleaning device is a third centrifuge 302, and the drying device is a second dryer 303.

[0043] During use, the mixed material treated by the alkali melting unit 200 is transported from the second centrifuge 207 through a pipeline to the second reactor 301, where it is mixed with water and acid and subjected to secondary pickling. After the pickling, the material enters the third centrifuge 302 through a pipeline for washing. After washing, it is transported to the second dryer 303 in a ton bag for drying. After drying, a high-purity material can be obtained.

[0044] The graphite purification system of the present application, by adding a first pickling unit 100 before the alkali melting unit 200, can effectively reduce the amount of alkali used in the alkali melting unit 200 and reduce the subsequent alkaline wastewater treatment costs. In addition, in some embodiments of the present application, the first pickling unit 100 and the alkali melting unit 200 both use a filter press and a centrifuge combined water washing method to wash the material, which has a better impurity removal effect. Specifically, the filter press is used as a primary water washing method. On the basis of deacidification and dealkali, it can also remove most impurities with good solubility. However, due to the uneven water washing of the filter press and the blocky material, the removal effect of impurities with poor solubility such as silicates and metaaluminates is poor. Therefore, after the primary water washing of the filter press, a centrifuge is used to perform a secondary water washing on the material. The centrifuge has the characteristics of good water washing uniformity, which can effectively remove poorly soluble impurities, which is beneficial to the acid leaching treatment of the second pickling unit. Therefore, the material purity obtained by adopting this solution is high.

[0045] Those skilled in the art will appreciate that the various devices in the graphite purification system are illustrative and non-restrictive. For example, the first acid leaching purification unit may not utilize a reactor, but may instead utilize an immersion tank as the vessel for acid washing the material. Other devices in the purification system may also be replaced with devices with equivalent functions. Furthermore, the devices with equivalent functions in the three processing units of the graphite purification system may be the same or different. For example, the first acid leaching purification unit and the second acid leaching purification unit may both be reactors, or the first acid leaching purification unit may be a reactor and the second acid leaching purification unit may be an immersion tank.

[0046] The above embodiments describe in detail the various devices and connection relationships in the graphite purification system. Next, taking graphite from different regions as an example, how the graphite purification system purifies graphite and the purification effect will be described in detail.

[0047] Example 1

[0048] 1000 kg of spherical graphite from area A is taken and then treated using the device in the first pickling unit 100. The 1000 kg of spherical graphite is first pickled in four batches, that is, the spherical graphite is respectively pumped into the first reactor 101 with hydrochloric acid and water (mass ratio is 1:0.3:1) through a pipeline for reaction, and the reaction duration is 8 hours. Through pickling, the content of acid-soluble impurities such as Fe, Cu, Ca, and Mg in the spherical graphite is greatly reduced. The material after pickling is pumped into the first filter press 102 through a pipeline using a vacuum pump for primary water washing. The material after water washing is sent to the first pulping tank 103 through a pipeline for pulping to obtain a first pulping liquid. After pulping, the first pulping liquid is transported to the first centrifuge 104 by a vacuum pump for secondary water washing. After the secondary water washing, the first pickled material is obtained.

[0049] Next, the first pickled material is processed using the various devices in the alkali melting unit 200. Specifically, the first pickled material is transported in ton bags to the first dryer 201 for drying. The dried material is then piped to a VC mixer, where it is mixed with alkali to form a mixture. The mass ratio of the first pickled material to the alkali is 1:0.2, and the mixing time is 20 minutes. After mixing, the mixture is piped to a continuous rotary kiln 203. Calcination in the rotary kiln 203 causes insoluble impurities such as Si and Al in the mixture to react with the alkali to form soluble silicates and metaaluminates. The mixed material with soluble impurities then enters the second pulping tank 204 through a pipeline connected to the rotary kiln 203 for pulping operation to obtain a second pulping liquid. After pulping, the second pulping liquid is pumped into the second filter press 205 through a vacuum pump. The second filter press 205 performs a primary water washing on the second pulping liquid. The primary water washing not only can dealkalize the second pulping liquid, but also can remove most of the soluble impurities. The washed material is pumped into the third pulping tank 206 for pulping operation to obtain a third pulping liquid. The third pulping liquid is then pumped into the second centrifuge 207 through a transfer pump for secondary water washing. The secondary water washing is performed by the centrifuge water washing to deeply wash the impurities in the spherical graphite, further removing the impurities in the spherical graphite.

[0050] Next, the material obtained by the alkali melting unit 200 is processed using the various devices in the second pickling unit 300. That is, the spherical graphite after water washing is transported to the second reactor through a pipeline for secondary pickling, wherein the mass ratio of spherical graphite to hydrochloric acid is 1:0.5, and the reaction time is 8 hours. After the reaction is completed, the spherical graphite is transported to the third centrifuge 302 via a vacuum pump for deacidification and water washing. After the water washing, the spherical graphite is transported to the second dryer 303 in a ton bag for drying. After drying, high-purity graphite is obtained.

[0051] like Figure 2 As shown, the fixed carbon content in the high-purity graphite obtained by this embodiment is 99.95%. The purified spherical graphite is tested by inductively coupled plasma (ICP) testing method, wherein the content of Fe is 13.60 mg / kg, the content of Cu is 0.30 mg / kg, the content of Al is 1.10 mg / kg, the content of Cr is 1.30 mg / kg, the content of Zn is 0.02 mg / kg, the content of Na is 13.20 mg / kg, the content of Si is 3.30 mg / kg, the content of S is 4.93 mg / kg, and the content of Ti is 0.03 mg / kg. In addition, after testing the main impurity elements Fe, Al, Si, and Na in the high-purity graphite obtained in this embodiment are all less than 20 mg / kg, which meets the requirements for preparing lithium-ion battery negative electrode materials.

[0052] Example 2

[0053] Get the spherical graphite 900kg in B area, then utilize the device in the first pickling unit 100 to process the spherical graphite of this 900kg.First this 900kg spherical graphite is pickled in three batches, namely by pipeline respectively spherical graphite and hydrochloric acid, nitric acid and water are squeezed into the first reactor 101 (the mass ratio of graphite and hydrochloric acid is 1:0.3, and the mass ratio of graphite and nitric acid is 1:0.1), the duration of reaction is 12 hours.By pickling, the acid-soluble impurity contents such as Fe, Cu, Ca, Mg in spherical graphite are greatly reduced, the material after pickling is completed is squeezed into the first filter press 102 by pipeline with vacuum pump and carried out one-level washing, the material after washing is completed is sent into the first pulping tank 103 by pipeline and carries out pulping and then obtains the first pulping liquid, after pulping is completed, the first pulping liquid is transported to the first centrifuge 104 by vacuum pump and carries out secondary washing, after secondary washing is completed, obtain the first pickling material.

[0054] Next, the first pickled material is processed using the various devices in the alkali melting unit 200. Specifically, the first pickled material is transported in ton bags to the first dryer 201 for drying. The dried material is then piped to a VC mixer, where it is mixed with alkali to form a mixture. The mass ratio of the first pickled material to the alkali is 1:0.25, and the mixing time is 20 minutes. After mixing, the mixture is piped to a continuous rotary kiln 203. Calcination in the rotary kiln 203 causes insoluble impurities such as Si and Al in the mixture to react with the alkali to form soluble silicates and metaaluminates. The mixed material with soluble impurities then enters the second pulping tank 204 through a pipeline connected to the rotary kiln 203 for pulping operation to obtain a second pulping liquid. After pulping, the second pulping liquid is pumped into the second filter press 205 through a vacuum pump. The second filter press 205 performs a primary water washing on the second pulping liquid. The primary water washing not only can dealkalize the second pulping liquid, but also can remove most of the soluble impurities. The washed material is pumped into the third pulping tank 206 for pulping operation to obtain a third pulping liquid. The third pulping liquid is then pumped into the second centrifuge 207 through a transfer pump for secondary water washing. The secondary water washing is performed by the centrifuge water washing to deeply wash the impurities in the spherical graphite, further removing the impurities in the spherical graphite.

[0055] Next, the material obtained by the alkali melting unit 200 is processed using the various devices in the second pickling unit 300. That is, the spherical graphite after water washing is transported through a pipeline to the second reactor for secondary pickling, wherein the mass ratio of spherical graphite to hydrochloric acid is 1:0.5, and the reaction time is 8 hours. After the reaction is completed, the spherical graphite is transported to the third centrifuge 302 via a vacuum pump for deacidification and water washing. After the water washing, the spherical graphite is transported to the second dryer 303 in a ton bag for drying. After drying, high-purity graphite is obtained.

[0056] like Figure 2 As shown, the fixed carbon content in the high-purity graphite obtained by this embodiment is 99.965%. The purified spherical graphite was tested by inductively coupled plasma (ICP) testing method, wherein the content of Fe was 4.67 mg / kg, the content of Cu was 0.10 mg / kg, the content of Al was 1.30 mg / kg, the content of Cr was 0.60 mg / kg, the content of Zn was 0.001 mg / kg, the content of Na was 7.60 mg / kg, the content of Si was 5.80 mg / kg, the content of S was 4.18 mg / kg, and the content of Ti was 0.10 mg / kg. In addition, after testing the main impurity elements Fe and Al impurity content in the high-purity graphite obtained by this embodiment is less than 10 mg / kg, and the content of Si and Na impurity elements is less than 20 mg / kg, which meets the requirements for preparing lithium ion battery negative electrode materials.

[0057] In the present application, since both Example 1 and Example 2 use this system to purify graphite, and the purity of the obtained graphite can meet the requirements for preparing lithium-ion battery negative electrode materials, the purification effect of the graphite purification system in the present application is good and the obtained graphite is of high purity.

[0058] Although multiple embodiments of the present application have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art can conceive of many changes, modifications, and alternatives without departing from the thought and spirit of the present application. It should be understood that in the process of practicing the present application, various alternatives to the embodiments of the present application described herein can be adopted. The accompanying claims are intended to define the scope of protection of the present application and therefore cover equivalents or alternatives within the scope of these claims.

Claims

1. A graphite purification system, characterized in that: include: A first pickling unit, comprising a first acid leaching and purification device for pickling the material, and a first water washing and impurity removal device and a second water washing and impurity removal device for washing the pickled material; an alkali melting unit comprising an alkali melting treatment device for roasting a mixture of a first pickling material and an alkali, and a first washing device and a second washing device for washing the material treated by the alkali melting treatment device, wherein the first pickling material is the material treated by the first pickling unit; as well as The second pickling unit comprises a second acid leaching and purification device for pickling the mixed material treated by the alkali fusion unit again, a cleaning device for cleaning the pickled material, and a drying device for drying the cleaned material.

2. The purification system according to claim 1, characterized in that The first pickling unit further includes a first pulping device, which is used to pulp the material pickled by the first acid leaching and purification device to obtain a first pulping liquid.

3. The purification system according to claim 2, characterized in that The first water washing and impurity removal device is used to wash the material after being pickled by the first acid leaching and purification device, and the washed material enters the first pulping device for pulping; the second water washing and impurity removal device is used to wash the first pulping liquid.

4. The purification system according to any one of claims 1 to 3, characterized in that: The alkali melting treatment device includes a mixing device and a roasting device connected to each other, wherein the mixing device is used to mix the first pickling material with alkali to obtain a mixture, and the roasting device is used to roast the mixture.

5. The purification system according to claim 4, characterized in that The alkali melting treatment device further comprises a drying device connected to the mixing device, wherein the drying device is used to dry the first pickling material, and the dried first pickling material enters the mixing device and is mixed with alkali.

6. The purification system according to claim 5, characterized in that The alkali melting unit further includes a second pulping device connected to the roasting device and the first washing device, the second pulping device is used to pulp the roasted mixture to obtain a second pulping liquid, and the first washing device is used to wash the second pulping liquid.

7. The purification system according to claim 6, characterized in that The alkali melting unit also includes a third pulping device connected to the first washing equipment and the second washing equipment. The third pulping device is used to pulp the second pulping liquid washed by the first washing equipment again to obtain a third pulping liquid. The second washing equipment is used to wash the third pulping liquid.

8. The purification system according to claim 7, characterized in that The first water washing and impurity removal device and the first washing equipment are both filter presses, and the second water washing and impurity removal device, the second washing equipment and the cleaning device are all centrifuges.

9. The purification system according to claim 1, characterized in that The first acid leaching and purification device and the second acid leaching and purification device are both reaction kettles.

10. The purification system according to claim 5, characterized in that The drying device and the drying device are both dryers.

Images