Semi-hydrate and dihydrate mixed ardealite three-stage countercurrent washing device

Abstract

The utility model relates to the technical field of ardealite, and particularly provides a semi-hydrated and dihydrate mixed ardealite three-stage countercurrent washing device which comprises a first-stage washing tank, a second-stage washing tank and a third-stage washing tank which are sequentially arranged, the first-stage washing tank is provided with a semi-hydrated and dihydrate mixed ardealite feeding port, and the second-stage washing tank is provided with a semi-hydrated and dihydrate mixed ardealite feeding port; wherein a discharge hole of the first-stage washing tank is used for filtering through first-stage filtering equipment, a filtered solid outlet is connected to the second-stage washing tank, a discharge hole of the second-stage washing tank is used for filtering through second-stage filtering equipment, a filtered solid outlet is connected to the third-stage washing tank, a discharge hole of the third-stage washing tank is used for filtering through third-stage filtering equipment, and a filtered solid outlet is connected to a purified phosphogypsum warehouse; a filtrate outlet of the third-stage filtering equipment is connected to the second-stage washing tank, a filtrate outlet of the second-stage filtering equipment is connected to the first-stage washing tank, and a filtrate outlet of the first-stage filtering equipment is connected to the sewage treatment system. The quality of the phosphogypsum prepared by the device meets the requirements, and zero sewage discharge can be realized in the washing process.

Description

TECHNICAL FIELD

[0001] The utility model belongs to phosphogypsum technical field relates to a kind of semi-water two water mixed phosphogypsum three-stage countercurrent washing device. BACKGROUND

[0002] Phosphogypsum is the byproduct of wet-process phosphoric acid (P2O5), about 5-5.5 tons of phosphogypsum is produced per ton of wet-process phosphoric acid (P2O5). Direct stockpiling of phosphogypsum is harmful to the environment.

[0003] Fresh phosphogypsum has a pH below 3, its main contaminant is phosphorus, with a content of 0.6%-0.8% (mass percentage, dry basis, calculated as P2O5), followed by alkali metal salts, silicon, iron, aluminum, magnesium and other impurities, the alkali metal exists in the form of soluble salts such as sulfates, phosphates and fluorides, with a content of 0.05%-0.3% (mass percentage, dry basis, calculated as sodium equivalent), in addition, it contains SiO2 mainly in the form of quartz, accounting for about 1.5%-5% (mass percentage, dry basis). The presence of these impurities seriously affects the implementation of large-scale comprehensive utilization of phosphogypsum. After purification, phosphogypsum is a good resource, which can be widely used in cement retarder, paper-faced gypsum board, organic material, nutrient soil, sulfuric acid production, earthwork balance and many other fields, and reasonable utilization not only can reduce its impact on the environment, but also can create certain economic benefits.

[0004] Saning Company has a set of high-phosphorus and fluorine wastewater treatment device, two sets of dihydrate wet-process phosphoric acid: 130,000 tons / year dihydrate wet-process phosphoric acid (25% P2O5), 350,000 tons / year dihydrate wet-process phosphoric acid (25% P2O5, 45% P2O5), and one set of 200,000 tons / year hemihydrate wet-process phosphoric acid (40% P2O5). The produced hemihydrate gypsum and dihydrate gypsum are different in characteristics, the dihydrate gypsum is relatively soft, while the hemihydrate gypsum is relatively hard. The solubility of dihydrate gypsum is relatively low, while it will quickly coagulate and harden during the drying process. In contrast, the solubility of hemihydrate gypsum is relatively high, but it will gradually lose plasticity in water and eventually coagulate and harden into a solid with certain strength. In order to fully utilize the advantages of hemihydrate gypsum and dihydrate gypsum. SUMMARY

[0005] The utility model provides a kind of semi-water two water mixed phosphogypsum three-stage countercurrent washing device, after purification, hemihydrate gypsum and dihydrate gypsum are mixed, which can have good solubility and good strength, improve the quality of products, and the washing process can realize zero sewage discharge.

[0006] The utility model discloses a technical scheme, provide a kind of semi-water two water mixed phosphogypsum three-stage countercurrent washing device, including sequentially arranged first washing tank, second washing tank and third washing tank, first washing tank is equipped with semi-water two water mixed phosphogypsum adding port, wherein first washing tank discharge port is filtered by first filter equipment, filter solid outlet is connected to second washing tank, second washing tank discharge port is filtered by second filter equipment, filter solid outlet is connected to third washing tank, third washing tank discharge port is filtered by third filter equipment, filter solid outlet is connected to purified phosphogypsum storehouse;The filtrate outlet of third filter equipment is connected to second washing tank, the filtrate outlet of second filter equipment is connected to first washing tank, the filtrate outlet of first filter equipment is connected to sewage treatment system.

[0007] Further, the first filter equipment, the second filter equipment and the third filter equipment are all plate-and-frame filter presses.

[0008] Further, the washing water inlet of the third washing tank is connected to an external washing water pipeline.

[0009] Further, the sewage treatment system comprises a plurality of sewage reaction tanks and sewage sedimentation tanks arranged in sequence.

[0010] Further, the sewage treatment system is provided with two-stage sewage reaction tanks and sewage sedimentation tanks, wherein a first-stage sewage reaction tank is connected to a first-stage sewage sedimentation tank, and the first-stage sewage sedimentation tank is further connected to a second-stage sewage reaction tank and a second-stage sewage sedimentation tank.

[0011] Further, the sewage reaction tank is provided with a defluorination agent adding port, and the residue of the sewage sedimentation tank is delivered to a fluorine recovery system.

[0012] Further, the clear liquid of the last-stage sewage sedimentation tank is delivered to the first washing tank.

[0013] The utility model has the following beneficial effects:

[0014] The semi-hemihydrate gypsum and the dihydrate gypsum are mixed and then purified, the soluble impurities are removed through multi-stage washing, and the phosphogypsum after three-stage washing meets the relevant standards for comprehensive utilization of phosphogypsum. The water after washing is reused gradually, and the first-stage washing sewage can also be reused for washing of phosphogypsum after further purification, and no sewage is discharged in the whole process. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The structure of the utility model is shown in the figure. In the figure, the first washing tank 1, the second washing tank 2, the third washing tank 3, the first filter equipment 4, the second filter equipment 5, the third filter equipment 6, the first-stage sewage reaction tank 7, the first-stage sewage sedimentation tank 8, the second-stage sewage reaction tank 9, and the second-stage sewage sedimentation tank 10. DETAILED DESCRIPTION

[0016] The embodiments of the present application will be described in detail below with reference to the embodiments and drawings, but those skilled in the art will understand that the following embodiments are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application.

[0017] As shown in Figure 1 The utility model provides a kind of semi-water two water mixed phosphogypsum three-stage countercurrent washing device, including sequentially arranged first washing tank 1, second washing tank 2 and third washing tank 3, and the first washing tank is provided with semi-water two water mixed phosphogypsum inlet, wherein the first washing tank 1 discharge port is filtered by first filter equipment 4, and the filter solid outlet is connected to the second washing tank 2, the second washing tank 2 discharge port is filtered by second filter equipment 5, and the filter solid outlet is connected to the third washing tank 3, and the third washing tank 3 discharge port is filtered by third filter equipment 6, and the filter liquid outlet of third filter equipment 6 is connected to the second washing tank 2, the filter liquid outlet of second filter equipment 5 is connected to the first washing tank 1, and the filter liquid outlet of first filter equipment 4 is connected to sewage treatment system.

[0018] In the utility model, semi-water phosphogypsum and two water phosphogypsum are mixed and then purified, and the mixed phosphogypsum can fully exert the advantages of semi-water phosphogypsum and two water phosphogypsum, the strength of two water phosphogypsum prepared by washing and then purifying two water phosphogypsum alone is not as good as that of semi-water phosphogypsum, and the solubility of semi-water phosphogypsum washed alone is not as good as that of two water phosphogypsum, after mixing the two, the solubility and the strength are both good, which facilitates efficient operation of the device and quality of subsequent products.

[0019] In some embodiments, the first filter equipment, the second filter equipment and the third filter equipment are all plate-and-frame filter presses.

[0020] In some embodiments, the washing water inlet of the third washing tank is connected to an external washing water pipeline.

[0021] In some embodiments, the sewage treatment system comprises a plurality of sewage reaction tanks and sewage sedimentation tanks arranged in sequence.

[0022] In some embodiments, the sewage treatment system is provided with two-stage sewage reaction tanks and sewage sedimentation tanks, wherein the first-stage sewage reaction tank 7 is connected to the first-stage sewage sedimentation tank 8, and the first-stage sewage sedimentation tank is further connected to the second-stage sewage reaction tank 9 and the second-stage sewage sedimentation tank 10.

[0023] In some embodiments, the sewage reaction tank is provided with a defluorination agent inlet, and the agent can be a calcium agent, so that soluble fluorine is converted into calcium fluoride precipitate, and the residue separated in the sewage sedimentation tank is transported to a fluorine recovery system for recycling fluorine therein.

[0024] In some embodiments, the supernatant of the last stage sewage sedimentation tank is transported to the first washing tank, and the supernatant after defluorination can be used for the initial washing of the semi-hydrated and dihydrated mixed phosphogypsum.

[0025] In specific operation, the mixture of semi-hydrated gypsum and dihydrated gypsum is washed with the supernatant after the secondary precipitation of sewage in the first washing tank 1, and then is subjected to pressure filtration in the first plate and frame filter. After the filtration solid is washed in the second washing tank and subjected to pressure filtration in the second plate and frame filter, the filtration solid is washed in the third washing tank and subjected to pressure filtration in the third plate and frame filter. After the semi-hydrated and dihydrated mixed phosphogypsum is subjected to three-stage countercurrent washing, purified phosphogypsum is obtained. After detection, the purified phosphogypsum meets the Yichang local phosphogypsum and its comprehensive utilization product quality standard (DB4205 / T063-2023) first-grade product. The filtrate of the first plate and frame filter is subjected to treatment in the sewage first reaction tank 7, the sewage first sedimentation tank 8, the sewage second reaction tank 9, and the sewage second sedimentation tank 10, and then is recycled to wash the phosphogypsum. The filtrate of the second plate and frame filter is subjected to washing in the first washing tank 1 to realize recycling. The filtrate of the third plate and frame filter is subjected to washing in the second washing tank 2 to realize recycling. The phosphogypsum washing water is subjected to countercurrent washing and is connected with the sewage treatment system to realize recycling of the washing water, and no sewage is discharged.

[0026] The above embodiments describe the preferred embodiments of the present application, 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 solution of the present application, including the combination of various technical features in any other manner. These simple modifications and combinations should also be considered as disclosed by the present application, and all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A device for tertiary countercurrent washing of hemihydrate-dihydrate mixed ardealite, characterized in that it comprises: The device comprises a first-stage washing tank, a second-stage washing tank and a third-stage washing tank arranged in sequence, the first-stage washing tank is provided with a semi-hydrated and two-hydrated mixed phosphogypsum adding port, a first-stage filtering device is arranged at an outlet of the first-stage washing tank, a filter solid outlet is connected to the second-stage washing tank, a second-stage filtering device is arranged at an outlet of the second-stage washing tank, a filter solid outlet is connected to the third-stage washing tank, a third-stage filtering device is arranged at an outlet of the third-stage washing tank, a filter solid outlet is connected to a purified phosphogypsum storage, a filtrate outlet of the third-stage filtering device is connected to the second-stage washing tank, a filtrate outlet of the second-stage filtering device is connected to the first-stage washing tank, and a filtrate outlet of the first-stage filtering device is connected to a sewage treatment system.

2. The apparatus of claim 1, wherein: The first-stage filtering device, the second-stage filtering device and the third-stage filtering device are all plate-and-frame filter presses.

3. The apparatus of claim 1, wherein: A washing water inlet of the third-stage washing tank is connected to an external washing water pipeline.

4. The apparatus of any one of claims 1-3, wherein: The sewage treatment system comprises a plurality of sewage reaction tanks and sewage sedimentation tanks arranged in sequence.

5. The apparatus of claim 4, wherein: The sewage treatment system comprises two-stage sewage reaction tanks and sewage sedimentation tanks, wherein a first-stage sewage reaction tank is connected to a first-stage sewage sedimentation tank, the first-stage sewage sedimentation tank is connected to a second-stage sewage reaction tank and a second-stage sewage sedimentation tank.

6. The apparatus of claim 5, wherein: The sewage reaction tank is provided with a defluorination agent adding port, and residue of the sewage sedimentation tank is transported to a fluorine recovery system.

7. The apparatus of claim 4, wherein: The clear liquid of the last-stage sewage sedimentation tank is transported to the first-stage washing tank.

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