A fluorine-containing acid wastewater resource recycling system

Abstract

The utility model belongs to photovoltaic wastewater treatment technical field especially, and a kind of fluorine-containing acid wastewater resource recovery system.The utility model includes the pretreatment agitator tank, primary regulating pool, secondary regulating pool, tertiary regulating pool, flocculator and sedimentation tank connected in proper order, and the sludge outlet of sedimentation tank is connected with the import of pretreatment agitator tank by sludge backflow pipeline, and the sludge outlet of sedimentation tank is also connected with the import of sludge storage pool by shunt pipe, and sludge storage pool is connected with filter press by sludge pump, and the liquid outlet of filter press is connected with primary regulating pool by filter liquor recovery pipe.The utility model not only obtains high-purity calcium fluoride, but also realizes resource recycling, turns waste into treasure, and successfully realizes the recycling of fluorine.

Description

Technical Field

[0001] This utility model belongs to the field of photovoltaic wastewater treatment technology, and in particular relates to a resource recovery system for fluoride-containing acidic wastewater. Background Technology

[0002] The production of photovoltaic panels generates a large amount of acidic wastewater containing fluoride, with fluoride as the main pollutant. Currently, the primary treatment method involves mixing it with alkaline wastewater and repeatedly adjusting the pH by adding lime, calcium chloride, sulfuric acid, and sodium hydroxide. However, the resulting sludge, due to the presence of silicate ions in the alkaline wastewater and the addition of sulfuric acid, has very low purity calcium fluoride, making it unrecoverable and requiring disposal as waste. This not only increases the difficulty and operating costs for enterprises but also wastes a significant amount of fluoride resources. Given the current scarcity of fluorite ore in my country, a novel treatment method is needed to address these issues. Utility Model Content

[0003] To overcome the shortcomings of the prior art, this invention provides a system for the resource recovery of fluoride-containing acidic wastewater. This invention can obtain high-purity calcium fluoride.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A system for the resource recovery of fluoride-containing acidic wastewater includes a pretreatment mixing tank, a primary equalization tank, a secondary equalization tank, a tertiary equalization tank, a flocculation tank, and a sedimentation tank connected in sequence. The inlet of the pretreatment mixing tank is connected to a fluoride-containing acidic wastewater pipe. The sludge outlet of the sedimentation tank is connected to the inlet of the pretreatment mixing tank through a sludge return pipe. The sludge outlet of the sedimentation tank is also connected to the inlet of a sludge storage tank through a diversion pipe. The sludge storage tank is connected to a filter press through a sludge pump.

[0006] Preferably, the pretreatment mixing tank, the primary equalization tank, the secondary equalization tank, and the tertiary equalization tank are all connected to the lime slurry dosing tank. The pretreatment mixing tank is also connected to the calcium chloride dosing tank, and the flocculation tank is connected to the flocculant dosing tank.

[0007] Preferably, pH meters are installed on the pretreatment mixing tank, the primary equalization tank, the secondary equalization tank, and the tertiary equalization tank.

[0008] Preferably, the outlet of the primary equalization tank is higher than the inlet of the secondary equalization tank, the outlet of the secondary equalization tank is higher than the inlet of the tertiary equalization tank, the outlet of the tertiary equalization tank is higher than the inlet of the flocculation tank, and the outlet of the flocculation tank is higher than the inlet of the sedimentation tank; this allows wastewater in the equalization tank at a higher position to flow by gravity into the equalization tank or flocculation tank at a lower position, effectively reducing costs.

[0009] Preferably, the sludge storage tank is equipped with a stirring device, and the stirring method is mechanical stirring or aeration stirring.

[0010] Preferably, the filter press is connected to the primary equalization tank via a filtrate recovery pipe.

[0011] Preferably, the filter press is a plate diaphragm filter press.

[0012] The advantages of this utility model are:

[0013] (1) This invention utilizes a pretreatment mixing tank, a primary equalization tank, a secondary equalization tank, a tertiary equalization tank, a flocculation tank, and a sedimentation tank to convert fluoride ions in the fluorescent acidic wastewater generated during the production of solar panels in the photovoltaic industry into high-purity calcium fluoride. After filtration by a filter press, the fluoride is reused as a chemical raw material. This not only yields high-purity calcium fluoride but also achieves resource recycling, turning waste into treasure and successfully realizing the recycling of fluoride. This invention uses a gradient to control the pH value of the wastewater, resulting in a more complete reaction of the reagents and higher purity of the calcium fluoride.

[0014] (2) This utility model returns a portion of the sludge in the sedimentation tank to the pretreatment reaction tank, which provides a core for crystal adhesion, so that the newly generated calcium fluoride in the pretreatment reaction tank gradually adheres to the sludge, forming a larger carrier, which is convenient for subsequent pressure filtration. It also avoids calcium fluoride adhering to the lime milk added later, which helps crystal growth and thus improves the purity of calcium fluoride. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the present invention.

[0016] The meanings of the symbols marked in the figure are as follows:

[0017] 1-Pretreatment mixing tank, 2-Primary equalization tank, 3-Secondary equalization tank, 4-Tertiary equalization tank, 5-Flocculation tank, 6-Sedimentation tank, 7-Sludge storage tank, 8-Mixing device. Detailed Implementation

[0018] like Figure 1 As shown, a fluoride-containing acidic wastewater resource recovery system includes a pretreatment mixing tank 1, a primary equalization tank 2, a secondary equalization tank 3, a tertiary equalization tank 4, a flocculation tank 5, a sedimentation tank 6, a sludge storage tank 7, and a plate diaphragm filter press.

[0019] Specifically, the inlet of the pretreatment mixing tank 1 is connected to the pipeline for receiving the fluoride-containing concentrated acid wastewater. The pretreatment mixing tank 1 is also connected to a lime slurry dosing tank and a calcium chloride dosing tank for pretreatment of the fluoride-containing concentrated acid wastewater. The pretreatment mixing tank 1 is intermittently fed. The wastewater treated by the pretreatment mixing tank 1 is sequentially piped into a primary equalization tank 2, a secondary equalization tank 3, a tertiary equalization tank 4, a flocculation tank 5, and a sedimentation tank 6. The lime slurry dosing tank is connected to the primary equalization tank 2, the secondary equalization tank 3, and the tertiary equalization tank 4, respectively. pH meters are installed on the pretreatment mixing tank 1, the primary equalization tank 2, the secondary equalization tank 3, and the tertiary equalization tank 4 to gradually adjust the pH value of the wastewater, ensuring a more complete reaction of the reagents and higher purity of the calcium fluoride. The outlet of the primary equalization tank 2 is higher than the inlet of the secondary equalization tank 3, the outlet of the secondary equalization tank 3 is higher than the inlet of the tertiary equalization tank 4, and the outlet of the tertiary equalization tank 4 is higher than the inlet of the flocculation tank 5; this allows wastewater in the equalization tanks located at higher levels to flow by gravity into the equalization tanks or flocculation tanks 5 located at lower levels, effectively reducing costs.

[0020] Furthermore, the wastewater treated in the tertiary equalization tank 4 flows into the flocculation tank 5 through a pipeline. The flocculation tank 5 is connected to the flocculant dosing tank, which causes impurities in the wastewater to flocculate, facilitating sedimentation and separation in the sedimentation tank 6. The outlet of the flocculation tank 5 is connected to the inlet of the sedimentation tank 6. The flocculated fluoride-containing concentrated acid wastewater is separated by sedimentation in the sedimentation tank 6, and the wastewater that meets the standards can be discharged and recycled.

[0021] Furthermore, the sludge outlet of sedimentation tank 6 is connected to the inlet of pretreatment mixing tank 1 via a sludge return pipe. The sludge outlet of sedimentation tank 6 is also connected to the inlet of sludge storage tank 7 via a diversion pipe. Sludge storage tank 7 is connected to a filter press via a sludge pump to obtain high-purity calcium fluoride. The outlet of the filter press is connected to the primary equalization tank 2 via a filter press liquid recovery pipe. Residual calcium ions in the filter press liquid, residual fluoride ions under saturation conditions, and fine-particle calcium fluoride from the filtered liquid are recycled back into the system for reuse, further reducing chemical costs and improving the recovery rate. Sludge storage tank 7 is equipped with a stirring device 8, which uses either mechanical stirring or aeration stirring.

[0022] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A system for the resource recovery of fluoride-containing acidic wastewater, characterized in that, The system includes a pretreatment mixing tank (1), a primary equalization tank (2), a secondary equalization tank (3), a tertiary equalization tank (4), a flocculation tank (5), and a sedimentation tank (6) connected in sequence. The inlet of the pretreatment mixing tank (1) is connected to a pipe containing fluoride acidic wastewater. The sludge outlet of the sedimentation tank (6) is connected to the inlet of the pretreatment mixing tank (1) through a sludge return pipe. The sludge outlet of the sedimentation tank (6) is also connected to the inlet of a sludge storage tank (7) through a diversion pipe. The sludge storage tank (7) is connected to a filter press through a sludge pump.

2. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: The pretreatment mixing tank (1), the primary regulating tank (2), the secondary regulating tank (3) and the tertiary regulating tank (4) are all connected to the lime slurry dosing tank. The pretreatment mixing tank (1) is also connected to the calcium chloride dosing tank. The flocculation tank (5) is connected to the flocculant dosing tank.

3. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: pH meters are installed on the pretreatment mixing tank (1), the primary regulating tank (2), the secondary regulating tank (3), and the tertiary regulating tank (4).

4. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: The outlet of the primary regulating tank (2) is higher than the inlet of the secondary regulating tank (3), the outlet of the secondary regulating tank (3) is higher than the inlet of the tertiary regulating tank (4), the outlet of the tertiary regulating tank (4) is higher than the inlet of the flocculation tank (5), and the outlet of the flocculation tank (5) is higher than the inlet of the sedimentation tank (6).

5. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: The sludge storage tank (7) is equipped with a stirring device (8).

6. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: The filter press is connected to the primary equalization tank (2) via a filtrate recovery pipe.

7. The fluoride-containing acidic wastewater resource recovery system according to claim 1, characterized in that: The outlet of the filter press is connected to the primary equalization tank (2) through a filter press liquid recovery pipe.

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