A purification and recovery system for a copper-containing catalyst

Abstract

The utility model provides a kind of purification recovery system of copper-containing catalyst, and the purpose is to solve the technical problem of lower purity of copper chloride product recovered by existing process.The device comprises: synthetic furnace, hydrolysis tank, silicon slag processing unit, first reaction tank, filter, second reaction tank and drying unit, the hydrolysis tank is connected with the residue outlet of synthetic furnace;The import of silicon slag processing unit is connected with the bottom outlet of hydrolysis tank, and the liquid outlet is connected with the import of first reaction tank;The bottom outlet of first reaction tank is connected with second reaction tank through filter;Drying unit is connected with second reaction tank.Waste silicon powder is first hydrolyzed by hydrolysis tank, then dried by pressure filtration, and the filtrate enters the first reaction tank to react to generate copper hydroxide precipitate, and the mixture after reaction is separated by filtration, and the precipitate enters the second reaction tank again to react, so that the copper hydroxide is converted again into relatively pure copper chloride containing water of combination, the impurity content of product is extremely low, and the catalyst purity is significantly improved.

Description

Technical Field

[0001] This utility model relates to the field of polycrystalline silicon production technology, and in particular to a purification and recovery system for copper-containing catalysts. Background Technology

[0002] In the cold hydrogenation process of Siemens polysilicon production, the fluidized bed reactor continuously consumes copper chloride as a catalyst. To ensure reaction efficiency, the silicon powder containing accumulated impurities needs to be periodically removed from the bed. This process results in the discharge of a large amount of undeactivated copper chloride catalyst. Current technology typically involves dissolving the copper chloride-containing waste silicon powder in demineralized water, performing preliminary solid-liquid separation, and then directly recovering the copper chloride from the resulting clear liquid through evaporation, concentration, and drying. While this method achieves preliminary catalyst recovery, it is essentially a physical concentration process and cannot separate other soluble metal chloride impurities (such as calcium chloride and ferric chloride) dissolved in the clear liquid. These impurities are concentrated simultaneously with the target product, copper chloride, during evaporation, ultimately leading to a low purity of the recovered copper chloride product. Summary of the Invention

[0003] In view of the above situation and to overcome the defects of the prior art, the purpose of this utility model is to provide a purification and recovery system for copper-containing catalysts, which solves the technical problem of low purity of copper chloride products recovered by existing processes.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A purification and recovery system for a copper-containing catalyst includes: a synthesis furnace; a hydrolysis tank, the inlet of which is connected to the slag outlet of the synthesis furnace; a silicon slag treatment unit, the inlet of which is connected to the bottom outlet of the hydrolysis tank; a first reaction tank, the inlet of which is connected to the liquid outlet of the silicon slag treatment unit; a filter, the inlet of which is connected to the bottom outlet of the first reaction tank; a second reaction tank, the inlet of which is connected to the bottom outlet of the filter; and a drying unit, the inlet of which is connected to the bottom outlet of the second reaction tank.

[0006] In use, this invention involves first hydrolyzing waste silicon powder in a hydrolysis tank, then drying it by pressure filtration in a silicon slag treatment unit. The filtrate obtained from the pressure filtration then enters the first reaction tank to react and generate copper hydroxide precipitate. The resulting mixture is then filtered and separated, and the precipitate re-enters the second reaction tank for further reaction, thereby converting the copper hydroxide back into relatively pure copper chloride containing bound water. This product has extremely low impurity content, significantly improving catalyst purity and activity. Simultaneously, because the recovered catalyst has extremely high purity, it avoids the accumulation of impurities in the fluidized bed reactor, significantly extending the reactor's continuous operating cycle and reducing the frequency of shutdowns for cleaning due to excessive impurities, thus lowering maintenance costs and operating energy consumption.

[0007] Optionally, the top inlet of the hydrolysis tank is connected to the slag outlet of the synthesis furnace via a first pipeline, and the bottom slag outlet is connected to the inlet of the silicon slag treatment unit via a second pipeline; the liquid outlet of the silicon slag treatment unit is connected to the inlet of the first reaction tank via a third pipeline; the first reaction tank and the filter are connected via a fourth pipeline; the second reaction tank and the filter are connected via a fifth pipeline; the second reaction tank and the drying unit are connected via a sixth pipeline; and pumps are installed on the second and fourth pipelines.

[0008] Optionally, a stirring device is provided in the hydrolysis tank and / or the first reaction tank and / or the second reaction tank.

[0009] Optionally, the upper end of the hydrolysis tank is connected to a seventh pipeline for discharging waste gas to the waste gas treatment system.

[0010] Optionally, an eighth pipeline connects the first reaction vessel to the seventh pipeline.

[0011] Optionally, the first reaction vessel is connected to a sodium hydroxide pipeline for introducing sodium hydroxide solution.

[0012] Optionally, the second reaction vessel is connected to a hydrogen chloride pipeline for introducing hydrogen chloride.

[0013] Optionally, the filter is connected to a drain pipe for discharging waste liquid and a nitrogen pipe for introducing nitrogen gas; the discharge end of the drying unit is connected to a product pipe.

[0014] Optionally, the silica slag treatment unit includes a filter press and a drying device.

[0015] Optionally, the drying unit includes: a vibrating fluidized bed; a hot air intake system, including a hot air duct connected to the vibrating fluidized bed, a heat exchanger and a hot air blower connected to the hot air duct, and a steam inlet pipe and a steam outlet pipe connected to the heat exchanger; and a cold air intake system, including a cold air duct connected to the vibrating fluidized bed.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] In use, this invention involves first hydrolyzing waste silicon powder in a hydrolysis tank, then drying it by pressure filtration in a silicon slag treatment unit. The filtrate obtained from the pressure filtration then enters the first reaction tank to react and generate copper hydroxide precipitate. The resulting mixture is then filtered and separated, and the precipitate re-enters the second reaction tank for further reaction, thereby converting the copper hydroxide back into relatively pure copper chloride containing bound water. This product has extremely low impurity content, significantly improving catalyst purity and activity. Simultaneously, because the recovered catalyst has extremely high purity, it avoids the accumulation of impurities in the fluidized bed reactor, significantly extending the reactor's continuous operating cycle and reducing the frequency of shutdowns for cleaning due to excessive impurities, thus lowering maintenance costs and operating energy consumption. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Reference numerals: 1. Synthesis furnace; 2. Hydrolysis tank; 3. Silicon slag treatment unit; 4. First reaction tank; 5. Filter; 6. Second reaction tank; 7. Drying unit; 71. Vibrating fluidized bed; 72. Hot air pipeline; 73. Heat exchanger; 74. Cold air pipeline; 8. Pump body; 11. First pipeline; 12. Second pipeline; 13. Third pipeline; 14. Fourth pipeline; 15. Fifth pipeline; 16. Sixth pipeline; 17. Seventh pipeline; 18. Eighth pipeline; 19. Sodium hydroxide pipeline; 20. Drainage pipeline; 21. Nitrogen pipeline; 22. Hydrogen chloride pipeline; 23. Product pipeline. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this utility model application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0022] In the description of the embodiments of this utility model application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side" etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, are only for the convenience of describing the embodiments of this utility model application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this utility model application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this utility model application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In the embodiments of this utility model application, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model application according to the specific circumstances.

[0025] In the embodiments of this utility model application, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0026] The following disclosure provides many different implementations or examples for carrying out different structures of the embodiments of this utility model application. To simplify the disclosure of the embodiments of this utility model application, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the embodiments of this utility model application. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of this utility model application; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various implementations and / or arrangements discussed.

[0027] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0028] like Figure 1 As shown in the figure, the present invention provides a purification and recovery system for a copper-containing catalyst, comprising: a synthesis furnace 1, a hydrolysis tank 2, a silicon slag treatment unit 3, a first reaction tank 4, a filter 5, a second reaction tank 6, and a drying unit 7.

[0029] Synthesis furnace 1 is used to generate waste silicon powder containing copper chloride. The inlet of hydrolysis tank 2 is connected to the slag outlet of synthesis furnace 1. The inlet of silicon slag treatment unit 3 is connected to the bottom outlet of hydrolysis tank 2. The inlet of first reaction tank 4 is connected to the liquid outlet of silicon slag treatment unit 3. The inlet of filter 5 is connected to the bottom outlet of first reaction tank 4. The inlet of second reaction tank 6 is connected to the bottom outlet of filter 5. The inlet of drying unit 7 is connected to the bottom outlet of second reaction tank 6.

[0030] In use, the waste silicon powder from the copper chloride discharged from the synthesis furnace 1 enters the hydrolysis tank 2, where the copper chloride is hydrolyzed. After hydrolysis, it enters the silicon slag treatment unit 3 for pressure filtration and drying. The waste slag containing silicon powder can be recycled or sold after discharge. The filtrate obtained from the pressure filtration enters the first reaction tank 4 to generate copper hydroxide precipitate. The mixture after the reaction is filtered and separated by the filter 5. The soluble filtrate enters the wastewater treatment system, and the precipitate enters the second reaction tank 6 for reaction, which converts the copper hydroxide back into relatively pure copper chloride containing bound water. Finally, it is processed by the drying unit 7 to obtain anhydrous copper chloride. The final anhydrous copper chloride can be recycled, reducing the need for external procurement.

[0031] Specifically, the top inlet of the hydrolysis tank 2 is connected to the slag outlet of the synthesis furnace 1 via the first pipe 11, and the bottom slag outlet is connected to the inlet of the silicon slag treatment unit 3 via the second pipe 12. The silicon slag treatment unit 3 has a silicon slag outlet at its bottom, and a third pipe 13 is connected to one of its liquid outlets. The other end of the third pipe 13 is connected to the top inlet of the first reaction tank 4. The bottom outlet of the first reaction tank 4 is connected to the input end of the filter 5 via the fourth pipe 14. The bottom outlet of the filter 5 is connected to the top inlet of the second reaction tank 6 via the fifth pipe 15, and the bottom outlet of the second reaction tank 6 is connected to the top inlet of the drying unit 7 via the sixth pipe 16. Pumps 8 are installed on both the second pipe 12 and the fourth pipe 14.

[0032] Optionally, the upper end of the hydrolysis tank 2 is connected to a seventh pipeline 17 for discharging waste gas to the waste gas treatment system.

[0033] Optionally, an eighth pipeline 18 is connected between the first reaction vessel 4 and the seventh pipeline 17.

[0034] Optionally, the first reaction vessel 4 is connected to a sodium hydroxide pipeline 19 for introducing sodium hydroxide solution. In use, a 30% sodium hydroxide solution can be introduced into the first reaction vessel 4 through the sodium hydroxide pipeline 19 for stirring and reaction to generate copper hydroxide precipitate.

[0035] Optionally, a stirring device may be provided in the hydrolysis tank 2 and / or the first reaction tank 4 and / or the second reaction tank 6.

[0036] Optionally, the filter 5 is connected to a drain pipe 20 for discharging waste liquid and a nitrogen pipe 21 for introducing nitrogen gas.

[0037] Optionally, the second reaction vessel 6 is connected to a hydrogen chloride pipeline 22 for introducing hydrogen chloride. When the copper hydroxide enters the second reaction vessel 6, the reaction is carried out by continuously introducing hydrogen chloride, which can convert the copper hydroxide back into relatively pure copper chloride containing bound water.

[0038] Optionally, the discharge end of the drying unit 7 is connected to a product pipeline 23. In use, the product pipeline 23 can be used to transport the product copper chloride to the synthesis furnace / fluidized bed.

[0039] As an implementation scenario, in this scenario, the silicon slag treatment unit 3 includes a filter press and a drying device. After the silicon slag discharged from the hydrolysis tank 2 is filtered and dried by the silicon slag treatment unit 3, this part of the waste residue containing silicon powder is discharged from the bottom outlet for recycling or sale, while the filtrate obtained from the filter press flows to the first reaction tank 4 through the third pipeline 13 on one side.

[0040] As an implementation scenario, in this scenario, the drying unit 7 includes a vibrating fluidized bed 71 and a hot air intake system and a cold air intake system connected and communicating with the vibrating fluidized bed.

[0041] Optionally, the hot air intake system includes a hot air duct 72, on which a heat exchanger 73 and a hot air blower are connected. A steam inlet pipe and a steam outlet pipe are connected to the heat exchanger. One end of the hot air duct 72 is connected to the bottom of the vibrating fluidized bed 71 via multiple branch pipes. In use, live steam is introduced into the heat exchanger 73 through the steam inlet pipe and discharged from the steam outlet pipe after heat exchange. Under the action of the hot air blower, ambient temperature air is heated by the heat exchanger 73 and then enters the vibrating fluidized bed 71.

[0042] Optionally, the cold air intake system includes a cold air duct 74, which connects to the bottom right side of the vibrating fluidized bed 71. Specifically, the outlet of the vibrating fluidized bed 71 is located at the right end, with multiple branch pipes arranged sequentially from left to right. The cold air duct 74 is located between the right-side branch pipe and the outlet of the vibrating fluidized bed 71. In use, under the action of the cold air fan, cold air enters the vibrating fluidized bed 71 through the cold air duct 74. The dual-path intake of hot and cold air and steam heat exchange help improve drying efficiency.

[0043] As a method for purifying and recovering copper-containing catalysts: First, waste silicon powder containing approximately 5% copper chloride, discharged from the synthesis of trichlorosilane, is introduced into hydrolysis tank 2. Copper chloride has a solubility of 745 g / L in water. It is first hydrolyzed using demineralized water, with continuous stirring by a stirring device to ensure that most of the copper chloride in the waste silicon powder dissolves in the water. Then, it enters the silicon slag treatment unit 3 through the second pipeline 12 for pressure filtration and drying. The waste residue is discharged from the bottom (this portion of the silicon powder-containing waste residue can be recycled or sold). The filtrate obtained from the pressure filtration enters the first reaction tank 4 through the third pipeline 13 on one side. After entering the first reaction tank 4, the filtrate is stirred and reacted by introducing a 30% sodium hydroxide solution through the sodium hydroxide pipeline 19, generating copper hydroxide precipitate. Then, the reacted mixture enters the filter 5 through the fourth pipeline 14 for filtration and separation. The soluble filtrate enters the wastewater treatment system through the drain pipeline 20, while the precipitate (mostly copper hydroxide) enters the second reaction tank 6 through the fifth pipeline 15 for further reaction. In the second reaction vessel 6, hydrogen chloride gas is introduced through hydrogen chloride pipeline 22 to react and convert copper hydroxide back into relatively pure copper chloride containing bound water. The resulting copper chloride containing bound water then enters the drying unit 7 through the sixth pipeline 16, where it undergoes drying to obtain anhydrous copper chloride. The final anhydrous copper chloride can be recycled to reduce external procurement. In actual use, control valves are installed on each pipeline for intelligent regulation.

[0044] Any aspects not described in detail in this embodiment are techniques known in the art.

[0045] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in this utility model, and these should all be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A purification recovery system of a copper-containing catalyst, characterized by, include: Synthesis furnace (1); The inlet of the hydrolysis tank (2) is connected to the slag outlet of the synthesis furnace (1); The inlet of the silicon slag treatment unit (3) is connected to the bottom outlet of the hydrolysis tank (2); The inlet of the first reaction vessel (4) is connected to the outlet of the silicon slag treatment unit (3); The filter (5) has its inlet connected to the bottom outlet of the first reaction vessel (4); The inlet of the second reaction vessel (6) is connected to the bottom outlet of the filter (5); The inlet of the drying unit (7) is connected to the bottom outlet of the second reaction vessel (6).

2. The purification and recovery system according to claim 1, characterized in that: The top inlet of the hydrolysis tank (2) is connected to the slag outlet of the synthesis furnace (1) through the first pipeline (11), and the bottom slag outlet is connected to the inlet of the silicon slag treatment unit (3) through the second pipeline (12). The outlet of the silicon slag treatment unit (3) is connected to the inlet of the first reaction tank (4) through a third pipeline (13); The first reaction vessel (4) is connected to the filter (5) via a fourth pipeline (14); The second reaction vessel (6) is connected to the filter (5) via a fifth pipeline (15); The second reaction vessel (6) is connected to the drying unit (7) via a sixth pipeline (16); Pump bodies (8) are installed on the second pipeline (12) and the fourth pipeline (14).

3. The purification recovery system of claim 1, wherein A stirring device is provided in each of the hydrolysis tank (2) and / or the first reaction tank (4) and / or the second reaction tank (6).

4. The purification recovery system of claim 1, wherein The upper end of the hydrolysis tank (2) is connected to a seventh pipeline (17) for discharging waste gas to the waste gas treatment system.

5. The purification and recovery system according to claim 4, characterized in that, An eighth pipeline (18) is connected between the first reaction vessel (4) and the seventh pipeline (17).

6. The purification and recovery system of claim 1, wherein The first reaction vessel (4) is connected to a sodium hydroxide pipeline (19) for introducing sodium hydroxide solution.

7. The purification and recovery system of claim 1, wherein The second reaction vessel (6) is connected to a hydrogen chloride pipeline (22) for introducing hydrogen chloride.

8. The purification and recovery system according to claim 1, characterized in that: And / or, the filter (5) is connected to a drain pipe (20) for discharging waste liquid and a nitrogen pipe (21) for introducing nitrogen gas. And / or, the discharge end of the drying unit (7) is connected to a product pipeline (23).

9. The purification and recovery system of claim 1, wherein The silicon slag treatment unit (3) includes a filter press and a drying device.

10. The purification and recovery system according to claim 1, characterized in that, The drying unit (7) includes: Vibrating fluidized bed (71); The hot air intake system includes a hot air duct (72) connected to the vibrating fluidized bed (71), a heat exchanger (73) and a hot air blower are connected to the hot air duct (72), and a steam inlet pipe and a steam outlet pipe are connected to the heat exchanger (73); The cold air intake system includes a cold air duct (74) connected to the vibrating fluidized bed (71).

Images