Apparatus for preparing silver oxalate and method for preparing silver oxalate

Abstract

The application relates to the field of silver oxalate, and discloses a device for preparing silver oxalate and a preparation method of silver oxalate. The device for preparing silver oxalate comprises a silver nitrate dissolving unit, an oxalic acid dissolving unit, a reaction and synthesis unit, a centrifugal separation unit and a storage and recycling unit, wherein the silver nitrate dissolving unit and the oxalic acid dissolving unit are connected with the reaction and synthesis unit respectively; the reaction and synthesis unit is connected with the centrifugal separation unit; the centrifugal separation unit comprises a feeding port and a discharging port; and the storage and recycling unit is used for recycling washing liquid obtained by the centrifugal separation unit. According to the application, a silver oxalate synthesis device and a preparation method of silver oxalate are provided; the device can be used to prepare silver oxalate, the preparation steps can be simplified, and the washing water consumption can be significantly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of silver oxalate, in particular to a device for preparing silver oxalate and a preparation method of silver oxalate. BACKGROUND

[0002] Silver oxalate is an important silver salt, as a raw material for preparing nano-silver and silver catalyst, it has important application value in the fields of photosensitive chemistry and catalyst synthesis,

[0003] The existing preparation method of silver oxalate is to use silver nitrate and oxalic acid / sodium oxalate / ammonium oxalate solution containing oxalate compound to prepare, because the solubility of oxalic acid is low, the solubility at room temperature is only about 9.52g, in order to remove the impurities in silver oxalate, the silver oxalate obtained by reaction needs to be washed with a large amount of water, the water consumption in the preparation process is large, and the production cost per unit product is high. How to improve the production capacity, reduce the water consumption per unit product and reduce the production cost is an important technical problem. SUMMARY

[0004] The purpose of the present application is to overcome the above-mentioned problems existing in the prior art, to provide a silver oxalate synthesis device and a preparation method of silver oxalate, which can simplify the preparation steps and significantly reduce the amount of washing water when using the device to prepare silver oxalate.

[0005] In order to achieve the above-mentioned purpose, the present application provides a device for preparing silver oxalate, which comprises a silver nitrate dissolving unit, an oxalic acid dissolving unit, a reaction synthesis unit, a centrifugal separation unit and a storage and recycling unit,

[0006] The silver nitrate dissolving unit and the oxalic acid dissolving unit are respectively connected with the reaction synthesis unit, so that the silver nitrate solution in the silver nitrate dissolving unit and the solution containing oxalate in the oxalic acid dissolving unit enter the reaction synthesis unit to react;

[0007] The reaction synthesis unit is connected with the centrifugal separation unit, so that the reaction product in the reaction synthesis unit enters the centrifugal separation unit for solid-liquid separation and then is washed to obtain a washing liquid and a filter cake;

[0008] The centrifugal separation unit comprises a feeding port and a discharging port;

[0009] The storage and recycling unit is used for recycling the washing liquid obtained by the centrifugal separation unit, the storage and recycling unit comprises a liquid inlet and a liquid outlet, the liquid inlet is connected with the discharging port of the centrifugal separation unit, the liquid outlet is connected with the feeding port of the centrifugal separation unit, and the recycled washing liquid enters the centrifugal separation unit for washing through the liquid outlet.

[0010] Preferably, a pump is provided between the liquid outlet of the storage reuse unit and the feed inlet of the centrifugal separation unit, through which the liquid in the storage reuse unit is fed into the centrifugal separation unit for washing.

[0011] Preferably, the storage reuse unit comprises a liquid discharge port for discharging the washing liquid with a pH lower than 1, so that the pH of the washing liquid in the storage reuse unit is 1 or higher.

[0012] Preferably, the centrifugal separation unit is a centrifugal filter.

[0013] Preferably, the silver nitrate dissolving unit and the oxalic acid dissolving unit each comprise a heating unit and a first stirring unit.

[0014] Preferably, the heating unit is one or more of an electric heater, a steam heating jacket, and a steam heating coil.

[0015] Preferably, the heating unit is provided outside the silver nitrate dissolving unit and the oxalic acid dissolving unit.

[0016] Preferably, the first stirring unit is one or more of an electric paddle type and a propeller type agitator.

[0017] Preferably, the reaction synthesis unit comprises a cooling unit and a second stirring unit.

[0018] Preferably, the cooling unit is a cooling jacket.

[0019] Preferably, the cooling unit is provided outside the reaction synthesis unit.

[0020] Preferably, the second stirring unit is one or more of an electric paddle type and a propeller type agitator.

[0021] The second aspect of the present application provides a method for preparing silver oxalate, which is prepared in the device for preparing silver oxalate described in the present application, comprising the following steps:

[0022] 1) a step of preparing a silver nitrate solution in the silver nitrate dissolving unit and preparing an oxalate-containing compound solution in the oxalic acid dissolving unit;

[0023] 2) a step of passing the silver nitrate solution and the oxalate-containing compound solution obtained in step 1) into the reaction synthesis unit to allow them to react;

[0024] 3) a step of passing the reaction product obtained in step 2) into the centrifugal separation unit for centrifugal separation and washing to obtain a washing liquid and a filter cake;

[0025] 4) passing the washing liquid obtained in step 3) into the storage and recycling unit for recycling,

[0026] wherein the method further comprises passing the washing liquid recycled by the storage and recycling unit into the centrifugal separation unit for recycling.

[0027] Preferably, the silver nitrate solution has a concentration of 2-85% by mass, and the oxalate-containing compound solution has a concentration of 4-33% by mass.

[0028] Preferably, the silver nitrate solution has a concentration of 10-50% by mass, and the oxalate-containing compound solution has a concentration of 9-30% by mass.

[0029] Preferably, in step 2), the reaction conditions include a reaction temperature of 5-30°C and a reaction time of 10-600 min.

[0030] Preferably, in step 2), the molar ratio of oxalate in the oxalate-containing compound to silver nitrate in the silver nitrate solution passed into the reaction and synthesis unit is 1:1.25-2, preferably 1:1.4-2, and more preferably 1:1.5-1.9.

[0031] Preferably, the washing conditions include washing with the recycled washing liquid first and then washing with water, and the water washing is such that the pH of the water after washing is greater than 5.

[0032] By the above technical solution, the device for preparing silver oxalate of the present application simplifies the preparation steps and significantly reduces the amount of washing water used in the preparation of silver oxalate. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a schematic diagram of the device for preparing silver oxalate of the present application,

[0034] REFERENCE NUMERALS

[0035] 1: silver nitrate dissolving unit; 2: oxalic acid dissolving unit;

[0036] 3: reaction and synthesis unit; 4: centrifugal separation unit;

[0037] 5: storage and recycling unit; 6: pump; DETAILED DESCRIPTION

[0038] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are provided as approximate descriptions of the ranges and values. The ranges and values should be construed as having a range of values including the values provided. For values that are less than one, one unit is considered to be 0.1, i.e., one unit is approximately 0.1.

[0039] The following description is made with reference to the drawings Figure 1 The device for preparing silver oxalate provided by the present application will be described in detail below, and the embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, but cannot be understood as a limitation of the present application.

[0040] As Figure 1 shown, the device for preparing silver oxalate provided by the present application comprises a silver nitrate dissolving unit 1, an oxalic acid dissolving unit 2, a reaction synthesis unit 3, a centrifugal separation unit 4 and a storage and recycling unit 5,

[0041] The silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are each connected to the reaction synthesis unit 3, so that the silver nitrate solution in the silver nitrate dissolving unit 1 and the solution containing oxalate in the oxalic acid dissolving unit 2 enter the reaction synthesis unit 3 to react;

[0042] The reaction synthesis unit 3 is connected to the centrifugal separation unit 4, so that the reaction product reacted in the reaction synthesis unit 3 enters the centrifugal separation unit 4 to be separated into solid and liquid, and then is washed to obtain a washing liquid and a filter cake;

[0043] The centrifugal separation unit 4 comprises a feeding port and a discharging port;

[0044] The storage and recycling unit 5 is used to recycle the washing liquid obtained by the centrifugal separation unit 4, and the storage and recycling unit 5 comprises a liquid inlet and a liquid outlet, the liquid inlet is connected to the discharging port of the centrifugal separation unit 4, the liquid outlet is connected to the feeding port of the centrifugal separation unit 4, and the recycled washing liquid enters the centrifugal separation unit 4 for washing through the liquid outlet.

[0045] According to the present application, in order to facilitate the addition and discharge of materials, the feeding port is preferably located above the centrifugal separation unit 4, the discharging port is located below the centrifugal separation unit 4, the liquid inlet is located above the storage and recycling unit 5, and the liquid outlet is located below the storage and recycling unit 5.

[0046] According to the present application, in order to facilitate the recycling of the washing liquid, preferably, a pump 6 is arranged between the liquid outlet of the storage and recycling unit 5 and the feeding port of the centrifugal separation unit 4, and the liquid in the storage and recycling unit 5 is sent into the centrifugal separation unit 4 for washing by the pump 6. As the pump 6, various acid-resistant pumps commonly used in the chemical industry can be used.

[0047] According to the present application, in order to facilitate the disposal of the washing solution with pH too low to be used for the next washing, preferably, the storage and reuse unit 5 comprises a liquid discharge port for discharging the washing solution with pH lower than 1, so as to make the pH of the washing solution in the storage and reuse unit 5 higher than 1.

[0048] According to the present application, as the storage and reuse unit 5 can be various containers for storing liquid commonly used in the art, for example, can be a liquid storage tank, preferably a plastic liquid storage tank.

[0049] According to the present application, as the centrifugal separation unit 4 is preferably a centrifugal filter, as the centrifugal filter, the existing centrifugal filter for solid-liquid separation in the chemical industry can be used.

[0050] According to the present application, the silver nitrate dissolving unit 1 and the oxalate dissolving unit 2 are used for preparing silver nitrate solution and oxalate compound solution, in order to accelerate the dissolution speed, save time and improve efficiency, preferably, the silver nitrate dissolving unit 1 and the oxalate dissolving unit 2 each comprises a heating unit and a first stirring unit.

[0051] As the heating unit is not particularly limited, can be a heating device commonly used in the chemical industry, preferably, the heating unit is one or more of an electric heater, a steam heating jacket, and a steam heating coil; more preferably, the heating unit is an electric heater and / or a steam heating jacket.

[0052] In order to facilitate heating, preferably, the heating unit is arranged outside the silver nitrate dissolving unit 1 and the oxalate dissolving unit 2.

[0053] As the first stirring unit is not particularly limited, can be a stirring device commonly used in the chemical industry, preferably, the first stirring unit is one or more of an electric paddle type and a propeller type. Specifically, a frame stirrer can be used.

[0054] According to the present application, the reaction and synthesis unit 3 is used for reacting silver nitrate solution and oxalate compound solution to generate silver oxalate, in order to fully react, and after the reaction is completed, to reduce the temperature so that the silver oxalate is fully precipitated, the reaction and synthesis unit 3 comprises a cooling unit and a second stirring unit.

[0055] Preferably, the cooling unit is one or more of a cooling jacket, a cooling coil, or natural cooling without insulation; more preferably, the cooling unit is a cooling jacket.

[0056] As the arrangement position of the cooling unit is not particularly limited, as long as cooling can be achieved. Preferably, the cooling unit is arranged outside the reaction and synthesis unit 3, for example, can be arranged in the form of a jacket.

[0057] Preferably, the second stirring unit is one or more of an electric paddle type and a propeller type agitator. Specifically, a frame type agitator can be used.

[0058] The second aspect of the present application provides a method for preparing silver oxalate, which is prepared in the device for preparing silver oxalate of the present application, comprising the following steps:

[0059] 1) a step of preparing a silver nitrate solution in the silver nitrate dissolving unit 1 and preparing a solution containing an oxalate compound in the oxalic acid dissolving unit 2;

[0060] 2) a step of passing the silver nitrate solution and the solution containing the oxalate compound obtained in step 1) into the reaction and synthesis unit 3 to make them react;

[0061] 3) a step of passing the reaction product obtained in step 2) into the centrifugal separation unit 4 to centrifugally separate it to obtain a washing liquid and a filter cake;

[0062] 4) a step of passing the washing liquid obtained in step 3) into the storage and recycling unit 5 to recycle it,

[0063] wherein the method further comprises passing the washing liquid recycled by the storage and recycling unit 5 into the centrifugal separation unit 4 for recycling.

[0064] According to the present application, preferably, the concentration of the silver nitrate solution is 2-85% by mass and the concentration of the solution containing the oxalate compound is 4-33% by mass from the perspective of saving water and facilitating solid-liquid separation; more preferably, the concentration of the silver nitrate solution is 10-50% by mass and the concentration of the solution containing the oxalate compound is 9-30% by mass.

[0065] In the present application, the oxalate compound can be one or more of oxalic acid, sodium oxalate and ammonium oxalate, and is preferably oxalic acid.

[0066] According to the present application, preferably, in step 2), the reaction conditions include a reaction temperature of 5-30℃ and a reaction time of 10-600 min; more preferably, the reaction conditions include a reaction temperature of 10-30℃ and a reaction time of 60-300 min.

[0067] According to the present application, when the ratio of oxalate in the oxalate-containing compound to silver nitrate in the silver nitrate solution is a specific value, the reaction is more complete, preferably, in step 2), the molar ratio of oxalate in the oxalate-containing compound introduced into the reaction synthesis unit 3 to silver nitrate in the silver nitrate solution is 0.5-0.8; more preferably, in step 2), the molar ratio of oxalate in the oxalate-containing compound introduced into the reaction synthesis unit 3 to silver nitrate in the silver nitrate solution is 1:1.25-2.5, preferably 1:1.25-2, more preferably 1:1.4-2, further preferably 1:1.5-1.9.

[0068] According to the present application, after the reaction product obtained in step 2) is introduced into the centrifugal separation unit 4 for centrifugal separation, washing is performed to obtain a washing liquid and a filter cake. The washing can be performed while introducing a washing liquid and performing centrifugation.

[0069] In addition, the rotation speed for centrifugal separation and the rotation speed for centrifugal washing can be the same or different, for example, can be 900-100 rpm.

[0070] According to the present application, from the perspective of saving washing water, preferably, the conditions for the washing include: first washing using the recovered washing liquid and then washing using water, and the water washing is such that the pH of the water after washing is greater than 5.

[0071] The present application will be described in detail below through examples, but the present application is not limited to the following examples.

[0072] Example 1 below is prepared using the device for preparing silver oxalate as shown in Figure 1 The device includes a silver nitrate dissolving unit 1, an oxalic acid dissolving unit 2, a reaction synthesis unit 3, a centrifugal separation unit 4, and a storage and recycling unit 5, the silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are each a reaction kettle with an electric heating device and a frame stirrer, the reaction synthesis unit 3 is a reaction kettle with a jacket cooling device and a frame stirrer, the centrifugal separation unit 4 is a centrifugal filter with a feed inlet and a discharge outlet, and the storage and recycling unit 5 is a liquid storage tank with a liquid inlet, a liquid outlet, and a liquid discharge port.

[0073] The silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are respectively connected with the reaction and synthesis unit 3, the reaction and synthesis unit 3 is connected with the feeding port of the centrifugal separation unit 4, the discharging port of the centrifugal separation unit 4 is connected with the liquid inlet of the storage and recycling unit 5 for recycling the washing liquid obtained from the centrifugal separation unit 4, the storage and recycling unit 5 comprises a liquid inlet and a liquid outlet, the liquid inlet is connected with the discharging port of the centrifugal separation unit 4, the liquid outlet is connected with the feeding port of the centrifugal separation unit 4 and the recycled washing liquid is pumped into the centrifugal separation unit 4 by the pump 6, and the recycled washing liquid enters the centrifugal separation unit 4 through the liquid outlet to wash the filter cake.

[0074] Example 1

[0075] (1) The silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are heated to 65℃, and 165kg of silver nitrate solution with a concentration of 40% by mass and 130kg of oxalic acid solution with a concentration of 16% by mass are respectively prepared under stirring at 20rpm.

[0076] (2) The above silver nitrate and oxalic acid solutions are passed into the reaction and synthesis unit 3 in a mass flow ratio of 127:100 in parallel flow, the solution temperature in the reaction and synthesis unit 3 is cooled to 25℃, and reaction is carried out for 3h.

[0077] (3) The stirrer (20rpm) of the reaction and synthesis unit 3 is started, the solution in the reaction and synthesis unit 3 is passed into the centrifugal separation unit 4, and centrifugal separation is carried out at 950rpm for 40min until the solid and liquid are completely separated, and the acid liquid obtained by centrifugal separation is discharged; then the filter cake is washed with water while centrifugal separation is carried out at 950rpm until the pH of the water after washing is 6, and a total of 331kg of water is used.

[0078] (4) The washing liquid obtained by washing with pure water in step (3) is passed into the storage and recycling unit 5 for recycling.

[0079] The silver oxalate product obtained is 67.04kg, the silver content is 62.0%, and the yield is 99.2%. The washing water consumption of the process unit product is about 4.9kg / kg-silver oxalate, the total water consumption is 7.9kg / kg-silver oxalate, and the waste acid liquid discharged in the process is about 3.4kg / kg-silver oxalate.

[0080] Example 2

[0081] (1) The silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are heated to 65℃, and 165kg of silver nitrate solution with a concentration of 40% by mass and 130kg of oxalic acid solution with a concentration of 16% by mass are respectively prepared under stirring at 25rpm.

[0082] (2) The silver nitrate and oxalic acid solutions described above are passed into the reaction synthesis unit 3 in a mass flow ratio of 127:100 in a concurrent manner, the solution temperature in the reaction synthesis unit 3 is cooled to 25°C, and reaction is carried out for 3h.

[0083] (3) The stirrer (25rpm) of the reaction synthesis unit 3 is started, the solution in the reaction synthesis unit 3 is passed into the centrifugal separation unit 4, and centrifugation is carried out at 950rpm for 40min until the solid and liquid are completely separated,

[0084] (4) After centrifugation at 950rpm, the obtained filter cake is first washed with the recovered washing liquid of Example 1, and the washing liquid is directly discharged; then the obtained filter cake is washed with deionized water until the pH of the water after washing is 6, a total of 235kg of water is used, and the washing liquid is passed into the recovery unit 5 for recovery. The silver oxalate product obtained is 66.8kg, the silver content is 62.2%, and the yield is 99.1%; the water consumption per unit product in the process is 6.5kg / kg-silver oxalate, and the amount of acid liquid discharged is 8.4kg / kg-silver oxalate.

[0085] Example 3

[0086] (1) The silver nitrate dissolving unit 1 and the oxalic acid dissolving unit 2 are heated to 65°C, and 190kg of silver nitrate solution with a concentration of 35% by mass and 139kg of oxalic acid solution with a concentration of 15% by mass are respectively prepared under stirring at 20rpm.

[0087] (2) The silver nitrate and oxalic acid solutions described above are passed into the reaction synthesis unit 3 in a mass flow ratio of 137:100 in a concurrent manner, the solution temperature in the reaction synthesis unit 3 is cooled to 20°C, and reaction is carried out for 4h.

[0088] (3) The stirrer (20rpm) of the reaction synthesis unit 3 is started, the slurry in the reaction synthesis unit 3 is passed into the centrifugal separation unit 4, and centrifugation is carried out at 950rpm for 50min until the solid and liquid are completely separated, then the obtained filter cake is washed with the recovered washing liquid 215kg of Example 2 while centrifugation at 950rpm, the filtrate is directly discharged; finally, the obtained filter cake is washed with deionized water until the pH of the water after washing is greater than 5, a total of 198kg of water is used. The silver oxalate product obtained is 68.5kg, the silver content is 61.0%, the yield is 99.0%, the water consumption per unit product in the process is 6.3kg / kg-silver oxalate, and the amount of acid liquid discharged is 6.7kg / kg-silver oxalate.

[0089] In the initial stage of washing the silver oxalate filter cake with deionized water, the centrifugal filtrate with a pH less than 1 can be directly discharged, and only the filtrate with a higher pH is reused.

[0090] Comparative Example 1

[0091] (1) Dissolve silver nitrate and oxalic acid at room temperature, and prepare 0.825 kg of silver nitrate solution with a concentration of 40% by mass and 1.312 kg of oxalic acid solution with a concentration of 8.0% by mass, respectively.

[0092] (2) Under continuous stirring, the above silver nitrate and oxalic acid solutions are added in a mass flow ratio of 63:100 in parallel into a 3000 ml glass beaker. After the reaction is completed, it is naturally cooled to room temperature (25°C) in 4 hours.

[0093] (3) The slurry is filtered under suction using a Buchner funnel, and the filter cake is washed with distilled water, with each time of distilled water being 300 ml. The filter cake is washed until the pH value of the washing water is greater than 5, and a total of 1800 ml of water is used, and the washing liquid is discharged. 0.332 kg of silver oxalate filter cake is obtained, with a silver content of 62.5% by mass and a yield of 99.0%, and the total water consumption in the process is 10.4 kg / kg-silver oxalate, and the total amount of waste acid generated is about 10.9 kg / kg-silver oxalate.

[0094] The water consumption and waste acid generation in the preparation process of the above examples and comparative examples are analyzed and compared, and the results are shown in Table 1. It can be seen that, by using the process and method of the present application, the water consumption per unit product and the waste acid generation in the preparation process are greatly reduced, the process can be continuously operated, the process is greatly simplified, and it is friendly to the environment.

[0095] Table 1

[0096]

[0097] Note: The water saving amount is calculated based on Comparative Example 1

[0098] The above describes the preferred embodiments of the present application in detail, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. An apparatus for preparing silver oxalate, characterized by, The device comprises a silver nitrate dissolving unit (1), an oxalic acid dissolving unit (2), a reaction synthesis unit (3), a centrifugal separation unit (4) and a storage and recycling unit (5), The silver nitrate dissolving unit (1) and the oxalic acid dissolving unit (2) are respectively connected with the reaction synthesis unit (3), so that the silver nitrate solution in the silver nitrate dissolving unit (1) and the oxalic acid solution in the oxalic acid dissolving unit (2) enter the reaction synthesis unit (3) to react; The reaction synthesis unit (3) is connected with the centrifugal separation unit (4), so that the reaction product in the reaction synthesis unit (3) enters the centrifugal separation unit (4) to be separated and then washed to obtain a washing liquid and a filter cake; The centrifugal separation unit (4) comprises a feeding port and a discharging port; The storage and recycling unit (5) is used for recycling the washing liquid obtained by the centrifugal separation unit (4), and the storage and recycling unit (5) comprises a liquid inlet and a liquid outlet, the liquid inlet is connected with the discharging port of the centrifugal separation unit (4), the liquid outlet is connected with the feeding port of the centrifugal separation unit (4), and the recycled washing liquid enters the centrifugal separation unit (4) for washing through the liquid outlet.

2. The device for preparing silver oxalate according to claim 1, wherein, The liquid outlet of the storage and recycling unit (5) and the feeding port of the centrifugal separation unit (4) are provided with a pump (6), and the liquid in the storage and recycling unit (5) is sent into the centrifugal separation unit (4) for washing through the pump (6).

3. The apparatus for preparing silver oxalate according to claim 1, wherein, The storage and recycling unit (5) comprises a liquid discharge port, which is used for discharging the washing liquid with a pH lower than 1, so that the pH of the washing liquid in the storage and recycling unit (5) is higher than or equal to 1.

4. The apparatus for preparing silver oxalate according to claim 1, wherein, The centrifugal separation unit (4) is a centrifugal filter.

5. The apparatus for preparing silver oxalate according to claim 1, wherein, The silver nitrate dissolving unit (1) and the oxalic acid dissolving unit (2) each comprise a heating unit and a first stirring unit.

6. The device for preparing silver oxalate according to claim 5, wherein, The heating unit is one or more of an electric heater, a steam heating jacket and a steam heating coil.

7. The device for preparing silver oxalate according to claim 5, wherein, The heating unit is arranged outside the silver nitrate dissolving unit (1) and the oxalic acid dissolving unit (2).

8. The apparatus for preparing silver oxalate according to claim 5, wherein, The first stirring unit is one or more of an electric paddle and a propeller stirrer.

9. The apparatus for preparing silver oxalate according to claim 1, wherein, The reaction synthesis unit (3) comprises a cooling unit and a second stirring unit.

10. The device for preparing silver oxalate according to claim 9, wherein, The cooling unit is a cooling jacket.

11. The device for preparing silver oxalate according to claim 9, wherein, The cooling unit is arranged outside the reaction synthesis unit (3).

12. The apparatus for preparing silver oxalate according to claim 9, wherein, The second stirring unit is one or more of an electric paddle and a propeller stirrer.

13. A method for preparing silver oxalate, characterized by, The device for preparing silver oxalate in any one of claims 1-12 is prepared, comprising the following steps: 1) preparing a silver nitrate solution in the silver nitrate dissolving unit (1) and preparing an oxalate compound solution in the oxalic acid dissolving unit (2); 2) passing the silver nitrate solution and the oxalate compound solution obtained in step 1) into the reaction synthesis unit (3) to react; 3) passing the reaction product obtained in step 2) into the centrifugal separation unit (4) to centrifugally separate and then wash to obtain a washing liquid and a filter cake; 4) the step of passing the washing solution obtained in step 3) into the storage and recycling unit (5) for recycling, wherein the method further comprises the step of passing the washing solution recycled by the storage and recycling unit (5) into the centrifugal separation unit (4) for recycling.

14. The production method according to claim 13, wherein The silver nitrate solution has a concentration of 2-85% by mass, and the oxalate-containing compound solution has a concentration of 4-33% by mass.

15. The method of manufacturing according to claim 14, wherein, The silver nitrate solution has a concentration of 10-50% by mass, and the oxalate-containing compound solution has a concentration of 9-30% by mass.

16. The method of making according to claim 13, wherein, In step 2), the reaction conditions include a reaction temperature of 5-30℃ and a reaction time of 10-600 min.

17. The method of making according to claim 13, wherein, In step 2), the molar ratio of oxalate in the oxalate-containing compound to silver nitrate in the silver nitrate solution passed into the reaction and synthesis unit (3) is 1:1.25-2.

18. The method of making according to claim 17, wherein, In step 2), the molar ratio of oxalate in the oxalate-containing compound to silver nitrate in the silver nitrate solution passed into the reaction and synthesis unit (3) is 1:1.4-2.

19. The method of making according to claim 18, wherein, In step 2), the molar ratio of oxalate in the oxalate-containing compound to silver nitrate in the silver nitrate solution passed into the reaction and synthesis unit (3) is 1:1.5-1.

9.

20. The method of manufacturing according to claim 13, wherein, The washing conditions include washing with the recycled washing solution first and then washing with water, and the water washing is such that the pH of the water after washing is greater than 5.

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