System for preparing basic chromium sulfate powder by taking electroplating chromium wastewater as raw material
By designing a system that includes impurity removal, reduction, enrichment, adjustment and powder making steps, the problem of chromium resources in electroplating chromium wastewater cannot be effectively utilized, and a high-purity and uniform particle size alkaline chromium sulfate powder was successfully prepared, achieving efficient utilization of resources.
Patent Information
- Application Number
- CN202421894908.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-08-07
AI Technical Summary
It is difficult for the prior art to effectively utilize the chromium resources contained in electroplating wastewater to prepare alkaline chromium sulfate powders with high purity and uniform particle size.
A system is designed, including a decomposition removal device, a reduction device, an enrichment device, an adjustment device and a powder making device. Through continuous decomposition removal, reduction, enrichment, adjustment and powder making processes, electroplating chromium wastewater is converted into high-purity alkaline chromium sulfate powder.
The effective utilization of chromium resources in electroplating chromium wastewater is achieved, and the alkaline chromium sulfate powder is high in purity and uniform in particle size, meeting the industry standard requirements.
Smart Images
Figure CN222922911U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electroplating chromium wastewater treatment, in particular to a system for preparing basic chromium sulfate powder by using electroplating chromium wastewater as raw material. Background Art
[0002] As a chemical raw material, basic chromium sulfate plays a very important role in chromium salt chemical industry.
[0003] In industrial production, basic chromium sulfate is widely used in the leather industry. As an important chemical for leather tanning, it is used to treat animal leather, giving the leather certain softness and durability. In addition, basic chromium sulfate also has certain uses in mordanting, ceramic glaze color and trivalent chromium electroplating.
[0004] At present, domestic basic chromium sulfate is mainly prepared by the sodium dichromate reduction method, and the reducing agents are mainly sulfur dioxide, sucrose, formaldehyde, etc. The preparation process is relatively complex, the raw material sodium dichromate is expensive, and the acidification and reduction process is not easy to control, and it is easy to produce hexavalent chromium mist to pollute the environment.
[0005] Chromium metal has good corrosion resistance, can maintain its luster for a long time, and also has properties such as wear resistance, good heat resistance, and high hardness. Therefore, chromium metal is widely used in electroplating, such as electroplating hard chromium, electroplating decorative chromium, zinc-chromium passivation, etc. During the electroplating process, due to the rinsing of the electroplated parts, the scrapping of the bath solution, the replacement and cleaning of the filter cloth and filter element of the plating solution filter, etc., a certain amount of chromium-containing wastewater will be generated. The main pollution factors in the chromium-containing wastewater are Cr 2 O 7 2 - 、Cr 3+ 、Zn 2+ 、Cu 2+ 、Fe 3+ 、Ni 2+ etc.
[0006] The conventional chromium water treatment method is the reduction-neutralization-flocculation method. First, under acidic conditions, a reducing agent is added to reduce Cr 2 O 7 2- to Cr 3+ , and then alkali is added to adjust the pH value of the wastewater, so that metal ions are all converted into corresponding hydroxide precipitates and removed. The chromium sludge obtained by this method has complex composition and low chromium content, and is not easy to be reused secondary.
[0007] As can be seen from the above, it is difficult to prepare basic chromium sulfate with sodium dichromate as raw material, and a large amount of chromium resources are contained in electroplating chromium wastewater, and the chromium resources have not been effectively utilized. How to prepare basic chromium sulfate with electroplating chromium wastewater as raw material is an urgent problem to be solved at present. Content of the Utility Model
[0008] The purpose of the present utility model is to provide a system for preparing basic chromium sulfate powder using electroplating chromium wastewater as a raw material, so as to solve the problems existing in the above-mentioned prior art. Through this system, basic chromium sulfate powder can be prepared using electroplating chromium wastewater as a raw material, effectively utilizing waste chromium resources. The obtained basic chromium sulfate powder has high purity and uniform particle size, meeting the requirements of industry standards.
[0009] To achieve the above purpose, the present utility model provides the following solution:
[0010] The present utility model provides a system for preparing basic chromium sulfate powder using electroplating chromium wastewater as a raw material, which includes an impurity removal device, a reduction device, an enrichment device, an adjustment device, and a powder making device connected in sequence; the inlet of the impurity removal device is used to introduce electroplating chromium wastewater, and the impurity removal device is used to remove impurity metal ions in the electroplating chromium wastewater; the reduction device is used to reduce hexavalent chromium ions in the electroplated chromium wastewater after impurity removal to trivalent chromium ions to form a reduced solution; the enrichment device includes an enrichment and transformation ion exchange column, on which a reduced solution inlet, a sodium sulfate solution inlet, and a chromium sulfate desorption solution outlet are provided. The reduced solution inlet is connected to the outlet of the reduction device. The enrichment and transformation ion exchange column is used to adsorb chromium ions in the reduced solution. The sodium sulfate solution inlet is used to introduce sodium sulfate solution to desorb the enrichment and transformation ion exchange column to form a chromium sulfate desorption solution, and the chromium sulfate desorption solution outlet is connected to the inlet of the adjustment device; the adjustment device is used to adjust the pH value of the chromium sulfate desorption solution and adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption solution; the powder making device is used to concentrate, dry, and crush the adjusted chromium sulfate desorption solution to form basic chromium sulfate powder.
[0011] Preferably, the impurity removal device includes a wastewater adjustment tank, a wastewater lift pump, and a multi-media filter connected in sequence. The inlet of the wastewater adjustment tank is used to introduce the electroplating chromium wastewater, and the multi-media filter is used to remove impurity particles in the electroplating chromium wastewater; the impurity removal device further includes an impurity removal ion exchange column, on which a wastewater inlet, a dilute acid inlet, and an impurity-removed solution outlet are provided. The wastewater inlet is connected to the outlet of the multi-media filter. The impurity removal ion exchange column is used to adsorb impurity metal ions in the electroplating chromium wastewater to form an impurity-removed solution, and the impurity-removed solution outlet is connected to the inlet of the reduction device.
[0012] Preferably, the impurity removal device further includes a dilute acid preparation tank and a dilute acid lift pump. The ion exchange column for impurity removal is further provided with a dilute acid inlet and a dilute acid desorbing solution outlet. The outlet of the dilute acid preparation tank is communicated with the dilute acid inlet of the ion exchange column for impurity removal through the dilute acid lift pump. The dilute acid inlet is used for introducing dilute acid to desorb the ion exchange column for impurity removal to form a dilute acid desorbing solution, and the dilute acid desorbing solution outlet is used for discharging the dilute acid desorbing solution.
[0013] Preferably, the reduction device includes a reduction reaction tank and a post-reduction liquid pump. The reduction reaction tank is provided with an inlet for the liquid after impurity removal, a reduction liquid inlet, and a post-reduction liquid outlet. The inlet for the liquid after impurity removal is communicated with the outlet of the ion exchange column for impurity removal. The reduction liquid inlet is used for introducing reduction liquid. The reduction reaction tank is used for reacting the liquid after impurity removal with the reduction liquid to reduce hexavalent chromium ions in the liquid after impurity removal to trivalent chromium ions to form the post-reduction liquid. The post-reduction liquid outlet is communicated with the inlet of the enrichment and transformation ion exchange column through the post-reduction liquid pump.
[0014] Preferably, a stirrer is arranged in the reduction reaction tank.
[0015] Preferably, the reduction device further includes a reduction liquid preparation tank and a reduction liquid lift pump. The outlet of the reduction liquid preparation tank is communicated with the reduction liquid inlet of the reduction reaction tank through the reduction liquid lift pump.
[0016] Preferably, the enrichment device further includes a sodium sulfate solution preparation tank and a sodium sulfate solution lift pump. The outlet of the sodium sulfate solution preparation tank is communicated with the sodium sulfate solution inlet of the enrichment and transformation ion exchange column through the sodium sulfate solution lift pump.
[0017] Preferably, the adjustment device includes a chromium sulfate component adjustment tank and an adjusted liquid lift pump. The chromium sulfate component adjustment tank is provided with a chromium sulfate desorbing solution inlet, a dilute alkali inlet, an anhydrous sodium sulfate inlet, and an adjusted liquid outlet. The chromium sulfate desorbing solution inlet is communicated with the chromium sulfate desorbing solution outlet of the enrichment and transformation ion exchange column. The dilute alkali inlet is used for introducing dilute alkali to adjust the pH value of the chromium sulfate desorbing solution to 3.0 - 3.5, and the anhydrous sodium sulfate inlet is used for introducing anhydrous sodium sulfate to adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorbing solution to 0.8 - 0.9 to form the adjusted liquid. The adjusted liquid outlet is communicated with the inlet of the powder making device through the adjusted liquid lift pump.
[0018] Preferably, the adjustment device further includes a dilute alkali preparation tank, a dilute alkali lift pump, and an anhydrous sodium sulfate storage tank. The outlet of the dilute alkali preparation tank is connected to the dilute alkali inlet of the chromium sulfate composition adjustment tank through the dilute alkali lift pump; the outlet of the anhydrous sodium sulfate storage tank is connected to the anhydrous sodium sulfate inlet of the chromium sulfate composition adjustment tank.
[0019] Preferably, the powder making device includes an evaporation and concentration mechanism, a drying mechanism, and a crushing mechanism that are connected in sequence. The inlet of the evaporation and concentration mechanism is connected to the outlet of the adjusted liquid lift pump. The evaporation and concentration mechanism is used to evaporate and concentrate the adjusted liquid so that the concentration specific gravity of the adjusted liquid reaches 1.4 g / cm 3 -1.5 g / cm 3 , and the outlet of the crushing mechanism is used to discharge the basic chromium sulfate powder.
[0020] The utility model has achieved the following technical effects compared with the prior art:
[0021] The system for preparing basic chromium sulfate powder from electroplating chromium wastewater provided by the utility model includes an impurity removal device, a reduction device, an enrichment device, an adjustment device, and a powder making device that are connected in sequence. Among them, the enrichment device includes an enrichment and transformation ion exchange column. When in use, first, the electroplating chromium wastewater is introduced into the impurity removal device, and the impurity metal ions in the electroplating chromium wastewater are removed through the impurity removal device; the electroplating chromium wastewater after impurity removal enters the reduction device, and the hexavalent chromium ions in the electroplating chromium wastewater after impurity removal are reduced to trivalent chromium ions through the reduction device to form a reduced liquid; the reduced liquid enters the enrichment and transformation ion exchange column, and the chromium ions in the reduced liquid are adsorbed through the enrichment and transformation ion exchange column. After the resin in the enrichment and transformation ion exchange column is saturated with adsorption, a sodium sulfate solution is introduced into the enrichment and transformation ion exchange column for desorption to form a chromium sulfate desorption solution; the chromium sulfate desorption solution enters the adjustment device, and the pH value of the chromium sulfate desorption solution is adjusted through the adjustment device, and the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption solution is adjusted; the adjusted chromium sulfate desorption solution enters the powder making device for concentration, drying, and crushing to form basic chromium sulfate powder. The obtained basic chromium sulfate powder has high purity and uniform particle size, meeting the requirements of industry standards. Description of the Drawings
[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0023] Figure 1Schematic diagram of a system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material provided by an embodiment of the present utility model.
[0024] In the figure: 11 - wastewater conditioning tank, 12 - wastewater lift pump, 13 - multi - medium filter, 14 - ion exchange column for impurity removal, 15 - dilute acid preparation tank, 16 - dilute acid lift pump, 21 - reduction reaction tank, 22 - post - reduction liquid pump, 23 - reduction liquid preparation tank, 24 - reduction liquid lift pump, 31 - enrichment and transformation ion exchange column, 32 - sodium sulfate solution preparation tank, 33 - sodium sulfate solution lift pump, 41 - chromium sulfate composition adjustment tank, 42 - adjusted liquid lift pump, 43 - dilute alkali preparation tank, 44 - dilute alkali lift pump, 45 - anhydrous sodium sulfate storage tank, 51 - evaporation and concentration mechanism, 52 - drying mechanism, 53 - crushing mechanism, 61 - sewage treatment system. Specific implementation manners
[0025] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.
[0026] The purpose of the present utility model is to provide a system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material, so as to solve the problems existing in the prior art. Through this system, basic chromium sulfate powder can be prepared using electroplating chromium wastewater as raw material, effectively utilizing the waste chromium resources. The obtained basic chromium sulfate powder has high purity and uniform particle size, meeting the requirements of industry standards.
[0027] To make the above - mentioned objects, features, and advantages of the present utility model more obvious and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.
[0028] As Figure 1 shown, this embodiment provides a system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material, including an impurity removal device, a reduction device, an enrichment device, an adjustment device, and a powder - making device connected in sequence.
[0029] In this embodiment, the inlet of the impurity removal device is used to introduce electroplating chromium wastewater, and the impurity removal device is used to remove impurity metal ions from the electroplating chromium wastewater; specifically, the impurity removal device includes a wastewater conditioning tank 11, a wastewater lift pump 12, and a multi-media filter 13 that are connected in sequence. The inlet of the wastewater conditioning tank 11 is used to introduce electroplating chromium wastewater, and the multi-media filter 13 is used to remove impurity particles from the electroplating chromium wastewater; the impurity removal device further includes an ion exchange column 14 for impurity removal. The ion exchange column 14 for impurity removal is provided with a wastewater inlet, a dilute acid inlet, and a post-impurity removal liquid outlet. The wastewater inlet is connected to the outlet of the multi-media filter 13. The ion exchange column 14 for impurity removal is used to adsorb impurity metal ions in the electroplating chromium wastewater to form a post-impurity removal liquid, and the post-impurity removal liquid outlet is connected to the inlet of the reduction device.
[0030] Further, when the resin in the ion exchange column 14 for impurity removal is saturated with adsorption, desorption regeneration is carried out using dilute acid; specifically, the impurity removal device further includes a dilute acid preparation tank 15 and a dilute acid lift pump 16. The ion exchange column 14 for impurity removal is further provided with a dilute acid inlet and a dilute acid desorption liquid outlet. The outlet of the dilute acid preparation tank 15 is connected to the dilute acid inlet of the ion exchange column 14 for impurity removal through the dilute acid lift pump 16. The dilute acid inlet is used to introduce dilute acid to carry out desorption on the ion exchange column 14 for impurity removal to form a dilute acid desorption liquid, and the dilute acid desorption liquid outlet is used to discharge the dilute acid desorption liquid.
[0031] In this embodiment, the reduction device is used to reduce hexavalent chromium ions in the electroplating chromium wastewater after impurity removal to trivalent chromium ions to form a post-reduction liquid; specifically, the reduction device includes a reduction reaction tank 21 and a post-reduction liquid pump 22. The reduction reaction tank 21 is provided with a post-impurity removal liquid inlet, a reduction liquid inlet, and a post-reduction liquid outlet. A stirrer is provided in the reduction reaction tank 21; the post-impurity removal liquid inlet is connected to the post-impurity removal liquid outlet of the ion exchange column 14 for impurity removal. The reduction liquid inlet is used to introduce a reduction liquid. The reduction reaction tank 21 is used for the post-impurity removal liquid and the reduction liquid to react to reduce hexavalent chromium ions in the post-impurity removal liquid to trivalent chromium ions to form a post-reduction liquid. The post-reduction liquid outlet is connected to the post-reduction liquid inlet of the enrichment and transformation ion exchange column 31 through the post-reduction liquid pump 22.
[0032] Further, the reduction device further includes a reduction liquid preparation tank 23 and a reduction liquid lift pump 24. The outlet of the reduction liquid preparation tank 23 is connected to the reduction liquid inlet of the reduction reaction tank 21 through the reduction liquid lift pump 24.
[0033] It should be noted that during the impurity removal process, the impurity metal ions exchange hydrogen ions in the resin in the ion exchange column 14 for impurity removal into the post-impurity removal liquid, so that no additional acid needs to be added during the subsequent acidification and reduction process; the reduction liquid can be selected as a sodium sulfite solution.
[0034] In this embodiment, the enrichment device includes an enrichment transformation ion exchange column 31. A reduced solution inlet, a sodium sulfate solution inlet, and a chromium sulfate desorption solution outlet are provided on the enrichment transformation ion exchange column 31. The reduced solution inlet is communicated with the outlet of the reduction device. The enrichment transformation ion exchange column 31 is used to adsorb chromium ions in the reduced solution; when the resin in the enrichment transformation ion exchange column 31 is saturated with adsorption, sodium sulfate solution is used for regeneration; specifically, the sodium sulfate solution inlet is used to introduce sodium sulfate solution to desorb the enrichment transformation ion exchange column 31 to form a chromium sulfate desorption solution, and the chromium sulfate desorption solution outlet is communicated with the inlet of the adjustment device.
[0035] Furthermore, the enrichment device further includes a sodium sulfate solution preparation tank 32 and a sodium sulfate solution lift pump 33. The outlet of the sodium sulfate solution preparation tank 32 is communicated with the sodium sulfate solution inlet of the enrichment transformation ion exchange column 31 through the sodium sulfate solution lift pump 33.
[0036] In this embodiment, the adjustment device is used to adjust the pH value of the chromium sulfate desorption solution and adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption solution; specifically, the adjustment device includes a chromium sulfate component adjustment tank 41 and an adjusted solution lift pump 42. A chromium sulfate desorption solution inlet, a dilute alkali inlet, an anhydrous sodium sulfate inlet, and an adjusted solution outlet are provided on the chromium sulfate component adjustment tank 41. The chromium sulfate desorption solution inlet is communicated with the chromium sulfate desorption solution outlet of the enrichment transformation ion exchange column 31. The dilute alkali inlet is used to introduce dilute alkali to adjust the pH value of the chromium sulfate desorption solution to 3.0 - 3.5, and the anhydrous sodium sulfate inlet is used to introduce anhydrous sodium sulfate to adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption solution to 0.8 - 0.9 to form an adjusted solution. The adjusted solution outlet is communicated with the inlet of the powder making device through the adjusted solution lift pump 42.
[0037] Furthermore, the adjustment device further includes a dilute alkali preparation tank 43, a dilute alkali lift pump 44, and an anhydrous sodium sulfate storage tank 45. The outlet of the dilute alkali preparation tank 43 is communicated with the dilute alkali inlet of the chromium sulfate component adjustment tank 41 through the dilute alkali lift pump 44; the outlet of the anhydrous sodium sulfate storage tank 45 is communicated with the anhydrous sodium sulfate inlet of the chromium sulfate component adjustment tank 41.
[0038] In this embodiment, the powder making device is used to concentrate, dry, and crush the adjusted chromium sulfate desorption solution to form basic chromium sulfate powder; the powder making device includes an evaporation concentration mechanism 51, a drying mechanism 52, and a crushing mechanism 53 that are connected in sequence. The inlet of the evaporation concentration mechanism 51 is communicated with the outlet of the adjusted solution lift pump 42. The evaporation concentration mechanism 51 is used to evaporate and concentrate the adjusted solution to make the concentration ratio of the adjusted solution reach 1.4 g / cm 3 -1.5 g / cm 3 , and the outlet of the crushing mechanism 53 is used to discharge the basic chromium sulfate powder.
[0039] It should be noted that an adsorbed liquid outlet is also provided on the enrichment and transformation ion exchange column 31 in this embodiment. After the chromium ions in the reduced liquid are exchanged onto the resin by using the selective separation characteristics of the resin in the enrichment and transformation ion exchange column 31, an adsorbed liquid is formed, and the adsorbed liquid outlet is used to discharge the adsorbed liquid. Further, in this embodiment, the adsorbed liquid outlet of the enrichment and transformation ion exchange column 31 and the dilute acid desorption liquid outlet of the impurity removal ion exchange column 14 are both connected to the sewage treatment system 61, so that the adsorbed liquid and the dilute acid desorption liquid enter the sewage treatment system 61 for further treatment.
[0040] The process flow of the system for preparing basic chromium sulfate powder from electroplating chromium wastewater provided in this embodiment is as follows:
[0041] The electroplating chromium wastewater is introduced into the wastewater adjustment tank 11, and the electroplating chromium wastewater is pumped into the multi-media filter 13 by the wastewater lift pump 12 to remove the impurity particles in the electroplating chromium wastewater. The electroplating chromium wastewater coming out of the multi-media filter 13 enters the impurity removal ion exchange column 14 to remove the impurity metal ions (Cr 3+ 、Zn 2+ 、Cu 2+ 、Fe 3+ 、Ni 2+ etc.) to form a post-impurity removal liquid, and the qualified post-impurity removal liquid enters the reduction reaction tank 21; the stirrer of the reduction reaction tank 21 is turned on, and the reduction liquid is added as needed. The reduction liquid is pumped from the reduction liquid preparation tank 23 into the reduction reaction tank 21 by the reduction liquid lift pump 24 for reaction to reduce the hexavalent chromium ions in the post-impurity removal liquid to trivalent chromium ions to form a reduced liquid. After the reaction is completed, the reduced liquid is pumped into the enrichment and transformation ion exchange column 31 by the reduced liquid pump 22; after the reduced liquid passes through the enrichment and transformation ion exchange column 31, the chromium ions are exchanged onto the resin by using the selective separation characteristics of the resin in the enrichment and transformation ion exchange column 31. When the resin in the enrichment and transformation ion exchange column 31 is saturated with adsorption, a sodium sulfate solution is used for desorption and regeneration. The sodium sulfate solution is pumped from the sodium sulfate solution preparation tank 32 into the enrichment and transformation ion exchange column 31 by the sodium sulfate solution lift pump 33 for desorption to form a chromium sulfate desorption liquid, and the chromium sulfate desorption liquid enters the chromium sulfate composition adjustment tank 41; the dilute alkali is pumped from the dilute alkali preparation tank 43 into the chromium sulfate composition adjustment tank 41 by the dilute alkali lift pump 44 to adjust the pH value of the chromium sulfate desorption liquid to 3.0 - 3.5, and the chromium oxide content in the chromium sulfate desorption liquid is analyzed by sampling. An appropriate amount of anhydrous sodium sulfate from the anhydrous sodium sulfate storage tank 45 is added to the chromium sulfate composition adjustment tank 41 to adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption liquid to 0.8 - 0.9 to form an adjusted liquid, and the adjusted liquid is pumped into the evaporation and concentration mechanism 51 by the adjusted liquid lift pump 42; the adjusted liquid is concentrated in the evaporation and concentration mechanism 51 to a specific gravity of 1.4 g / cm 3 -1.5 g / cm 3, and then enter the drying mechanism 52 for drying (drum drying or spray drying). The obtained product enters the crushing mechanism 53 to be crushed into fine powder, and the finally obtained basic chromium sulfate powder has high purity and uniform particle size, meeting the requirements of industry standards.
[0042] In the present utility model, specific examples are used to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.
Claims
1. A system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material, characterized in that: It comprises a de-impurity device, a reduction device, an enrichment device, an adjustment device and a powder making device which are connected in sequence; the inlet of the de-impurity device is used to introduce electroplating chromium wastewater, and the de-impurity device is used to remove impurity metal ions in the electroplating chromium wastewater; the reduction device is used to reduce hexavalent chromium ions in the electroplating chromium wastewater after de-impurity to trivalent chromium ions to form a reduced liquid; The enrichment device comprises an enrichment transition ion exchange column, the enrichment transition ion exchange column is provided with a reduced liquid inlet, a sodium sulfate solution inlet and a chromium sulfate desorption liquid outlet, the reduced liquid inlet is connected with the outlet of the reduction device, the enrichment transition ion exchange column is used to adsorb chromium ions in the reduced liquid, the sodium sulfate solution inlet is used to introduce sodium sulfate solution to desorb the enrichment transition ion exchange column to form a chromium sulfate desorption liquid, and the chromium sulfate desorption liquid outlet is connected with the inlet of the adjustment device; the adjustment device is used to adjust the pH value of the chromium sulfate desorption liquid and adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption liquid; the powder making device is used to concentrate, dry and crush the adjusted chromium sulfate desorption liquid to form basic chromium sulfate powder.
2. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 1, characterized in that: The impurity removal device includes a wastewater regulating tank, a wastewater lifting pump and a multi-media filter which are connected in sequence. The inlet of the wastewater regulating tank is used to introduce the electrochromium plating wastewater, and the multi-media filter is used to remove impurity particles in the electrochromium plating wastewater. The impurity removal device also includes an ion exchange column for impurity removal, and the ion exchange column for impurity removal is provided with a wastewater inlet, a dilute acid inlet and a post-impurity removal liquid outlet. The wastewater inlet is connected to the outlet of the multi-media filter. The ion exchange column for impurity removal is used to adsorb impurity metal ions in the electrochromium plating wastewater to form a post-impurity removal liquid, and the post-impurity removal liquid outlet is connected to the inlet of the reduction device.
3. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 2, characterized in that: The impurity removal device also includes a dilute acid preparation tank and a dilute acid lifting pump. The impurity removal ion exchange column is also provided with a dilute acid inlet and a dilute acid desorption liquid outlet. The outlet of the dilute acid preparation tank is connected to the dilute acid inlet of the impurity removal ion exchange column through the dilute acid lifting pump. The dilute acid inlet is used to pass dilute acid to desorb the impurity removal ion exchange column to form a dilute acid desorption liquid. The dilute acid desorption liquid outlet is used to pass the dilute acid desorption liquid.
4. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 2, characterized in that: The reduction device comprises a reduction reaction tank and a reduced liquid pump. The reduction reaction tank is provided with a de-impurity liquid inlet, a reduced liquid inlet and a reduced liquid outlet. The de-impurity liquid inlet is communicated with the de-impurity liquid outlet of the de-impurity ion exchange column. The reduced liquid inlet is used to introduce reduced liquid. The reduction reaction tank is used for the de-impurity liquid to react with the reduced liquid to reduce the hexavalent chromium ions in the de-impurity liquid to trivalent chromium ions to form the reduced liquid. The reduced liquid outlet is communicated with the reduced liquid inlet of the enrichment transformation ion exchange column through the reduced liquid pump.
5. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 4, characterized in that: A stirrer is arranged in the reduction reaction tank.
6. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 4, characterized in that: The reduction device further comprises a reducing liquid preparation tank and a reducing liquid lifting pump, and the outlet of the reducing liquid preparation tank is connected to the reducing liquid inlet of the reducing reaction tank through the reducing liquid lifting pump.
7. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 1, characterized in that: The enrichment device also includes a sodium sulfate solution preparation tank and a sodium sulfate solution lifting pump, and the outlet of the sodium sulfate solution preparation tank is connected to the sodium sulfate solution inlet of the enrichment transformation ion exchange column through the sodium sulfate solution lifting pump.
8. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 1, characterized in that: The adjustment device includes a chromium sulfate component adjustment tank and an adjusted liquid lifting pump. The chromium sulfate component adjustment tank is provided with a chromium sulfate desorption liquid inlet, a diluted alkali inlet, an anhydrous sodium sulfate inlet and an adjusted liquid outlet. The chromium sulfate desorption liquid inlet is connected with the chromium sulfate desorption liquid outlet of the enrichment transformation ion exchange column. The diluted alkali inlet is used to introduce diluted alkali to adjust the pH value of the chromium sulfate desorption liquid to 3.0-3.5, and the anhydrous sodium sulfate inlet is used to introduce anhydrous sodium sulfate to adjust the mass ratio of chromium oxide to sodium sulfate in the chromium sulfate desorption liquid to 0.8-0.9 to form an adjusted liquid. The adjusted liquid outlet is connected with the inlet of the powder making device through the adjusted liquid lifting pump.
9. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 8, characterized in that: The adjustment device also includes a dilute alkali preparation tank, a dilute alkali lifting pump and an anhydrous sodium sulfate storage tank. The outlet of the dilute alkali preparation tank is connected to the dilute alkali inlet of the chromium sulfate component adjustment tank through the dilute alkali lifting pump; the outlet of the anhydrous sodium sulfate storage tank is connected to the anhydrous sodium sulfate inlet of the chromium sulfate component adjustment tank.
10. The system for preparing basic chromium sulfate powder using electroplating chromium wastewater as raw material according to claim 8, characterized in that: The powder making device comprises an evaporation and concentration mechanism, a drying mechanism and a crushing mechanism which are connected in sequence. The inlet of the evaporation and concentration mechanism is connected with the outlet of the adjusted liquid lifting pump. The evaporation and concentration mechanism is used to evaporate and concentrate the adjusted liquid so that the concentrated specific gravity of the adjusted liquid reaches 1.4 g / cm 3 -1.5g / cm 3 The outlet of the crushing mechanism is used to pass out the basic chromium sulfate powder.