Purifying device for wet-process phosphoric acid

Abstract

The utility model discloses a wet-process phosphoric acid purification device and belongs to the technical field of phosphorus chemical industry. Comprising a wet-process phosphoric acid storage tank, a desulfurization reaction tank, a settling tank, a finished acid storage tank and a vertical flow settler, wherein the desulfurization reaction tank is connected with the wet-process phosphoric acid storage tank; the heights of the desulfurization reaction tank, the vertical flow settler, the settling tank and the finished acid storage tank are sequentially reduced, the desulfurization reaction tank is connected with the vertical flow settler, the vertical flow settler is connected with the settling tank, an overflow port of the settling tank is connected with the finished acid storage tank through a chute, a cover plate capable of being opened is arranged at the top of the chute, and a solid-liquid separation tank is arranged at the tail end of the chute. And a vertical flow settler is arranged to improve the settling effect. The finished product acid storage tank is connected with the vertical flow settler through the chute, and the chute is cleaned regularly, so that solid substances adhered to the chute are prevented from entering the finished product acid storage tank. And the solid-liquid separation tank is used for separating solid impurities when the chute is cleaned, so that the impurities are prevented from entering the finished acid storage tank. And the solid content of phosphoric acid can be ensured to be below 0.7% all the time.

Description

TECHNICAL FIELD

[0001] The utility model belongs to phosphorus chemical technology field, especially related to a purification device of wet-process phosphoric acid. BACKGROUND

[0002] Wet-process phosphoric acid (H3PO4) can be used as raw material for compound fertilizer production. In the prior art, the content of sulfate ion (SO4 2- ) in wet-process phosphoric acid is usually high (can reach about 3.50%), which will result in low concentration of phosphorus pentoxide (P2O5) (about 21.5%). Wet-process phosphoric acid with the above characteristics (high content of sulfate ion and low content of phosphorus pentoxide) will result in low effective component of compound fertilizer. In order to ensure the quality of phosphate fertilizer, desulfurization treatment is needed for wet-process phosphoric acid with high content of sulfate ion.

[0003] For example, the patent with application number CN201520918660.8 discloses a wet-process phosphoric acid desulfurization device, which comprises a wet-process phosphoric acid metering pump and a phosphate ore slurry metering pump. The wet-process phosphoric acid metering pump and the phosphate ore slurry metering pump are connected to a desulfurization reaction tank. The desulfurization reaction tank is connected to a settling tank through a slurry pump. The settling tank is connected to a desulfurized acid storage tank. The desulfurization reaction tank is provided with stirring blades. The bottom of the settling tank is provided with a slag discharge port.

[0004] For example, the patent with application number CN201921611271.5 discloses a phosphoric acid fine desulfurization system, which comprises a desulfurizer adding device, a fine desulfurization reaction tank and a fine desulfurization settling tank connected in sequence through pipelines. The fine desulfurization reaction tank is provided with a phosphoric acid feeding port. The fine desulfurization settling tank is provided with a reflux pipe and a discharge pipe. The reflux pipe is in communication with the fine desulfurization reaction tank. The discharge pipe is arranged at the bottom of the fine desulfurization settling tank.

[0005] That is, in the prior art, desulfurization is carried out in the desulfurization reaction tank by using a desulfurizer, and then settling is carried out in the settling tank. The clear liquid is sent to a finished product acid storage tank for storage. The applicant found that the settling effect of the existing settling tank (usually a settling tank) is not good. The solidification content of phosphoric acid is occasionally greater than 1%. High solid content will also affect the content of effective components in compound fertilizer. SUMMARY

[0006] In order to solve the foregoing problems, the utility model embodiment provides a purification device of wet-process phosphoric acid, which can ensure that the solid content of phosphoric acid is always below 0.7% and ensure the quality of phosphoric acid. The technical solution is as follows:

[0007] The utility model discloses a kind of purification devices of wet-process phosphoric acid, the device includes wet-process phosphoric acid storage tank, desulfurization reaction tank, settling tank 1 and finished product acid storage tank 2, the desulfurization reaction tank is connected with wet-process phosphoric acid storage tank by pipeline with pump;The device further includes vertical flow settler, the height of the desulfurization reaction tank, vertical flow settler, settling tank 1 and finished product acid storage tank 2 is sequentially reduced, the overflow port of the desulfurization reaction tank is connected with the center tube 7 of vertical flow settler by pipeline, the overflow weir 6 of vertical flow settler is connected with settling tank 1 by pipeline, the overflow port of settling tank 1 is connected with finished product acid storage tank 2 by inclined downward chute 3, the top of chute 3 is equipped with openable cover plate 32 and its end is equipped with solid-liquid separation tank 4.

[0008] Among them, the chute 3 in the utility model embodiment includes U-shaped groove body 31 and the multiple cover plates 32 at the top thereof, and the multiple cover plates 32 are arranged side by side and adjacent along the direction in which the U-shaped groove body 31 is located.

[0009] Among them, the vertical flow settler in the utility model embodiment includes a first bracket, a first cylinder 5 vertically arranged on the first bracket, an overflow weir 6 outside the top of the first cylinder 5, a center tube 7 in the upper part of the first cylinder 5, and a first conical bottom 8 at the bottom of the first cylinder 5.

[0010] Specifically, the height of the first cylinder 5 in the utility model embodiment is 5-9 m, and the diameter thereof is 5-9 m; the height of the first conical bottom 8 is 4-6.5 m, and the cone angle thereof is 50-70°.

[0011] Among them, the settling tank 1 in the utility model embodiment is a circular tank structure, and a feed inlet is arranged at the center of the top thereof, a slurry outlet is arranged at the center of the bottom thereof, an overflow port is arranged at the upper part thereof, and the height thereof is greater than or equal to 8 m; a valve is arranged on the overflow port.

[0012] Further, the purification device in the utility model embodiment further includes a slurry tank, the slurry tank is lower than the vertical flow settler and the settling tank 1, and the slurry outlet and the bottom end of the first conical bottom 8 are both connected with the slurry tank by pipelines provided with valves.

[0013] Wherein, the solid-liquid separation tank 4 in the utility model embodiment includes the second support, the second support and the vertical second cylinder 41, the second conical bottom 42 of the second cylinder 41 bottom, the valve of the second conical bottom 42 bottom end, the feed inlet 43 of the second cylinder 41 upper portion one side, the discharge outlet 44 of the second cylinder 41 upper portion other side and the material receiving trolley of the second cylinder 41 directly below;The feed inlet 43 and the discharge outlet 44 are tangent to the second cylinder 41, and are respectively located on the opposite sides of the second cylinder 41, and are connected with the chute 3 of the corresponding side.

[0014] Wherein, the diameter of the second cylinder 41 in the utility model embodiment is 800-1200mm, and the height is 1100-1500mm;The height of the second conical bottom 42 is 1100-1500mm, and the cone angle is 25-50°.

[0015] Further, the upper of the chute 3 in the utility model embodiment is provided with a spray cleaning pipe;The spray cleaning pipe is parallel to the chute 3, and the valve is arranged on it, and the spray head is arranged on the lower side of it and faces the chute 3.

[0016] The technical scheme provided by the utility model embodiment has the beneficial effects that: the utility model embodiment provides a kind of purification device of wet-process phosphoric acid, vertical flow settler is arranged between desulfurization reaction tank and settling tank (the height of vertical flow settler is usually higher than settling tank), to improve the settling effect, only need to set desulfurization reaction tank in high position (such as set on hillside), without pump.In finished acid storage tank and vertical flow settler are connected by chute easy to clean, clean chute regularly, avoid the solid material adhered on chute into finished acid storage tank, guarantee the solid content of phosphoric acid stable.Set solid-liquid separation tank for separating solid impurities when cleaning chute, avoid impurities into finished acid storage tank.In short, the solid content of phosphoric acid in finished acid storage tank can be guaranteed to be below 0.7% by the patent. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the principle block diagram of the purification device of wet-process phosphoric acid in the utility model embodiment;

[0018] Figure 2 It is the structure schematic view of the settling tank, finished acid storage tank, chute and solid-liquid separation tank in the utility model embodiment in the utility model embodiment;

[0019] Figure 3 It is the structure schematic view of vertical flow settler;

[0020] Figure 4 It is the structure schematic view of chute;

[0021] Figure 5 It is the structure schematic view of solid-liquid separation tank.

[0022] Figure 6 is a top view of the solid-liquid separation tank.

[0023] In the figure: 1 sedimentation tank, 2 finished acid storage tank, 3 chute, 4 solid-liquid separation tank, 5 first cylinder, 6 overflow weir, 7 center cylinder, 8 first conical bottom;

[0024] 31 U-shaped groove body, 32 cover plate;

[0025] 41 second cylinder, 42 second conical bottom, 43 feed inlet, 44 discharge outlet. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the utility model more clear, the utility model will be described in further detail below with reference to the drawings.

[0027] Example 1

[0028] Referring to Figures 1-6 , example 1 provides a kind of purification device of wet-process phosphoric acid, and the device includes wet-process phosphoric acid storage tank, desulfurization reaction tank, sedimentation tank 1, finished acid storage tank 2, vertical flow sedimentation device and mud tank etc.Desulfurization reaction tank is connected with wet-process phosphoric acid storage tank by pipeline with pump.Wet-process phosphoric acid storage tank is used to store wet-process phosphoric acid.Desulfurization reaction tank is used to carry out desulfurization reaction, and it is best set in high position (such as on hillside) with prior art, vertical flow sedimentation device is main sedimentation device, and it is used to separate solid impurities in phosphoric acid.Sedimentation tank 1 is used to further sediment phosphoric acid, and it is used to temporarily store phosphoric acid (such as when cleaning chute 3, not let phosphoric acid output).Among them, sedimentation tank 1 is circular tank structure, its top center is equipped with feed inlet (it is lower than overflow weir 6, it is connected with overflow weir 6 by pipeline), its bottom center is equipped with mud outlet, its upper portion is equipped with overflow port (it is connected with finished acid storage tank 2 by chute 3, it is higher than finished acid storage tank 2), its height is greater than or equal to 8 m.Overflow port is equipped with valve (can be closed when cleaning chute 3).Of course, sedimentation tank 1 can also be other structures, such as common inclined plate sedimentation tank.The height of desulfurization reaction tank, vertical flow sedimentation device, sedimentation tank 1 and finished acid storage tank 2 decreases in turn, and mud tank is lower than vertical flow sedimentation device and sedimentation tank 1.The overflow port of desulfurization reaction tank is connected with the center cylinder 7 of vertical flow sedimentation device by pipeline, the overflow weir 6 of vertical flow sedimentation device is connected with sedimentation tank 1 by pipeline, and the overflow port of sedimentation tank 1 is connected with finished acid storage tank 2 by inclined chute 3.Mud outlet and the bottom end of first conical bottom 8 are connected with mud tank by pipeline with valve for collecting mud produced by sedimentation.Chute 3 is closed structure, its material is 316L stainless steel, its top is equipped with openable cover plate 32 (open when cleaning), and its end is equipped with solid-liquid separation tank 4 to carry out solid-liquid separation (avoid solid that cleaning flows into finished acid storage tank 2).

[0029] Wherein, refer to Figure 4 The chute 3 in the embodiment of the utility model comprises a U-shaped groove body 31 and a plurality of cover plates 32 on the top of the U-shaped groove body 31. The U-shaped groove body 31 is arranged obliquely and is arranged on the corresponding support. The width of the U-shaped groove body 31 is 350-600 mm, the height is 300-500 mm, and the thickness is 2-5 mm. The plurality of cover plates 32 are arranged side by side and adjacent to each other (preferably close together) along the direction of the U-shaped groove body 31, and specifically are rectangular plates matched with the U-shaped groove body 31. One end of the cover plate 32 is hinged (specifically through a hinge) to the top of the corresponding groove side of the U-shaped groove body 31 and can be opened upward.

[0030] Wherein, refer to Figure 3 The vertical flow settler in the embodiment of the utility model comprises a first support (not shown in the figure), a first cylinder 5 arranged vertically on the first support, an overflow weir 6 on the outside of the top of the first cylinder 5, a central cylinder 7 in the upper part of the first cylinder 5, and a first conical bottom 8 (specifically a circular cone with a large upper part and a small lower part, which is coaxially arranged with the first cylinder 5) at the bottom of the first cylinder 5. The central cylinder 7 is coaxially arranged with the first cylinder 5 and the upper end thereof protrudes out of the first cylinder 5, and the overflow weir 6 is higher than the settling tank 1. Specifically, the height of the first cylinder 5 is 5-9 m, and the diameter is 5-9 m. The height of the first conical bottom 8 is 4-6 m, and the cone angle is 50-70°. The diameter of the central cylinder 7 is 700-1000 mm, the lower end thereof is located 2000-2500 mm below the liquid surface, and the length is 2700-3500 mm.

[0031] Wherein, refer to Figures 5-6 The solid-liquid separation tank 4 in the embodiment of the utility model comprises a second support (not shown in the figure), a second cylinder 41 arranged vertically on the second support, a second conical bottom 42 (specifically a circular cone with a large upper part and a small lower part, which is coaxially arranged with the second cylinder 41) at the bottom of the second cylinder 41, a valve at the bottom end of the second conical bottom 42 (which is opened as required), a feed inlet 43 on one side of the upper part of the second cylinder 41, a discharge outlet 44 on the other side of the upper part of the second cylinder 41, and a material receiving trolley (not shown in the figure, which is used to receive the material discharged from the second cylinder 41) directly below the second cylinder 41. The top of the second cylinder 41 is closed. The feed inlet 43 and the discharge outlet 44 are tangent to the second cylinder 41 and are located on the opposite sides of the second cylinder 41, and are connected with the corresponding chute 3. Specifically, the feed inlet 43 is arranged on the left side of the front of the second cylinder 41, and the discharge outlet 44 is arranged on the right side of the rear of the second cylinder 41. Specifically, the diameter of the second cylinder 41 is 800-1200 mm, and the height is 1100-1500 mm. The height of the second conical bottom 42 is 1100-1500 mm, and the cone angle is 25-50°.

[0032] Embodiment 2

[0033] The embodiment 2 provides a purification device for wet-process phosphoric acid, which has substantially the same structure as the device in the embodiment 1, except that the size of the settling tank 1 in the embodiment 2 is as follows: the diameter is 18.2 m, and the height is 14.2 m. The U-shaped groove body 31 has a width of 400 mm, a height of 350 mm, and a thickness of 3 mm. The first cylinder body 5 has a height of 7 m and a diameter of 7 m. The first conical bottom 8 has a height of 5.9 m and a conical angle of 60°. The central cylinder 7 has a diameter of 800 mm, a lower end located 2200 mm below the liquid level, and a length of 3000 mm. The second cylinder body 41 has a diameter of 1000 mm and a height of 1250 mm. The second conical bottom 42 has a height of 1250 mm and a conical angle of 34°.

[0034] The phosphoric acid in the finished acid storage tank is detected, and the results are shown in Table 1.

[0035] Table 1

[0036]

[0037] As shown in Table 1, the solid content of the phosphoric acid is always below 0.7%.

[0038] Embodiment 3

[0039] The embodiment 3 provides a purification device for wet-process phosphoric acid, which has substantially the same structure as the device in the embodiment 1, except that a spraying cleaning pipe is arranged directly above the chute 3 in the embodiment 3. The spraying cleaning pipe is arranged parallel to the chute 3, is provided with a valve, and is provided with a nozzle on the lower side facing the chute 3. The spraying cleaning pipe is connected with a cleaning water supply structure, and the distance between the spraying cleaning pipe and the chute 3 is ensured to allow the cover plate 32 to be opened. When the chute 3 is cleaned, the cover plate 32 is opened, and the nozzle sprays water towards the chute 3.

[0040] In the embodiment, the "first" and "second" only play a distinguishing role, and have no other special meanings.

[0041] The above merely provides preferred embodiments of the utility model, and is not intended to limit the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A wet-process phosphoric acid purification apparatus comprising a wet-process phosphoric acid storage tank, a desulfurization reaction tank, a settling tank (1), and a finished acid storage tank (2), the desulfurization reaction tank being connected to the wet-process phosphoric acid storage tank by a pipe line with a pump; characterized in that, The device also comprises a vertical flow settler, the height of the desulfurization reaction tank, the vertical flow settler, the settling tank (1) and the finished acid storage tank (2) decreases in turn, the overflow port of the desulfurization reaction tank is connected with the central cylinder (7) of the vertical flow settler through a pipeline, the overflow weir (6) of the vertical flow settler is connected with the settling tank (1) through a pipeline, the overflow port of the settling tank (1) is connected with the finished acid storage tank (2) through a downward inclined chute (3), the top of the chute (3) is provided with an openable cover plate (32) and the end thereof is provided with a solid-liquid separation tank (4).

2. The wet-process phosphoric acid purification plant according to claim 1, characterized in that, The chute (3) comprises a U-shaped groove body (31) and a plurality of cover plates (32) at the top of the U-shaped groove body (31), the plurality of cover plates (32) are arranged side by side and adjacent along the direction in which the U-shaped groove body (31) is located; one end of the cover plate (32) is hinged to the top of the corresponding groove side of the U-shaped groove body (31) and it can be opened upward.

3. The wet-process phosphoric acid purification apparatus according to claim 1, characterized by The vertical flow settler comprises a first support, a first cylinder (5) vertically arranged on the first support, an overflow weir (6) at the top outer side of the first cylinder (5), a central cylinder (7) in the upper part of the first cylinder (5) and a first conical bottom (8) at the bottom of the first cylinder (5), the central cylinder (7) is coaxially arranged with the first cylinder (5) and the upper end thereof protrudes out of the first cylinder (5), the overflow weir (6) is higher than the settling tank (1).

4. The wet-process phosphoric acid purification plant according to claim 3, characterized in that, The height of the first cylinder (5) is 5-9m and the diameter thereof is 5-9m; the height of the first conical bottom (8) is 4-6.5m and the cone angle thereof is 50-70°.

5. The wet-process phosphoric acid purification apparatus according to claim 1, characterized by The settling tank (1) is a circular tank structure, a feed inlet is arranged at the center of the top thereof, a slurry outlet is arranged at the center of the bottom thereof, an overflow port is arranged at the upper part thereof and the height thereof is greater than or equal to 8m; a valve is arranged on the overflow port.

6. The wet-process phosphoric acid purification plant according to claim 5, characterized in that, The device also comprises a slurry tank, the slurry tank is lower than the vertical flow settler and the settling tank (1), the slurry outlet and the bottom end of the first conical bottom (8) are connected with the slurry tank through pipelines provided with valves.

7. The wet-process phosphoric acid purification plant according to claim 1, characterized in that, The solid-liquid separation tank (4) comprises a second support, a second cylinder (41) vertically arranged on the second support, a second conical bottom (42) at the bottom of the second cylinder (41), a valve at the bottom end of the second conical bottom (42), a feed inlet (43) at one side of the upper part of the second cylinder (41), a discharge outlet (44) at the other side of the upper part of the second cylinder (41) and a receiving trolley directly below the second cylinder (41); the feed inlet (43) and the discharge outlet (44) are tangent to the second cylinder (41) and are respectively arranged on the opposite sides of the second cylinder (41) and are connected with the chute (3) on the corresponding side.

8. The wet-process phosphoric acid purification plant according to claim 7, characterized in that, The diameter of the second cylinder (41) is 800-1200mm and the height thereof is 1100-1500mm; the height of the second conical bottom (42) is 1100-1500mm and the cone angle thereof is 25-50°.

9. The wet-process phosphoric acid purification plant according to claim 1, characterized in that, A spray cleaning pipe is arranged directly above the chute (3); the spray cleaning pipe is arranged parallel to the chute (3), a valve is arranged on the spray cleaning pipe and a spray head is arranged on the lower side of the spray cleaning pipe and faces the chute (3).

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