An apparatus for purifying phosphoric acid using a continuous ion exchange method

Abstract

This utility model discloses an apparatus for purifying phosphoric acid by continuous ion exchange. The apparatus includes several functional areas connected end to end, each functional area having a resin tank: a primary feeding area, including a raw material tank and an intermediate buffer tank, wherein the raw material is pumped into the resin tank by a pump and then enters the intermediate buffer tank; a washing area, including a washing water transfer tank, a washing water tank and a first compressed air tank, wherein the compressed air tank is used to pressurize the residual material from the first resin tank in the primary feeding area into the intermediate buffer tank, and the washing water tank is pumped into the remaining resin tanks in the washing area by a pump and then enters the washing water tank.

Description

Technical Field

[0001] This utility model relates to the field of fluid separation, and in particular to an apparatus for purifying phosphoric acid by continuous ion exchange. Background Technology

[0002] Phosphoric acid (H3PO4) is a colorless, transparent solid crystal at room temperature with a melting point of 42°C. When the temperature exceeds its melting point, it becomes a colorless, transparent, viscous liquid. In industry and laboratories, phosphoric acid is often found as an 85% aqueous solution. This solution is a colorless, odorless, non-volatile, viscous liquid and is an important chemical reagent. It is a moderately strong tribasic acid; phosphoric acid releases three protons stepwise to form H2PO4. - HPO4 2- and PO4 3- Three different protonation forms. This property makes it remarkably diverse in chemical reactions.

[0003] Phosphoric acid has wide applications in industry, serving as a crucial raw material for the production of fertilizers, detergents, and food additives. Furthermore, phosphate plays a vital role in nature and within organisms, particularly in cellular energy conversion (such as ATP production and utilization) and bone formation. In addition, the buffering properties of phosphates make them indispensable in laboratory research and pharmaceutical preparation, widely used to maintain pH stability in solutions. This property provides significant support for scientific research and medical applications.

[0004] Traditional chemical precipitation methods are mainly used for metal ions (such as Fe) in phosphoric acid. 3+ Al 3+ Mg 2+ Ca 2+ ), fluoride (F - ), sulfate (SO4 2- Arsenic (As), etc. Commonly used processes include neutralization precipitation, sulfide precipitation, fluoride precipitation, and gypsum process.

[0005] Neutralization precipitation method: Lime, ammonia and sodium carbonate are used to adjust the pH of the feed solution to cause metal ions to form hydroxide or phosphate precipitates; however, this method may lead to phosphate loss if too much precipitant is added (such as in the production of calcium phosphate), and the pH of the feed solution needs to be precisely controlled.

[0006] Sulfide precipitation method: Using sodium sulfide and hydrogen sulfide, this method can selectively remove heavy metals (such as As, Pb, Cd); however, this method generates toxic hydrogen sulfide gas during production, and if excessive sulfur is added... 2- There is a possibility of product contamination.

[0007] Fluoride precipitation method: Sodium silicate or sodium chloride is used to remove fluoride impurities by producing sodium fluorosilicate (Na2SiF6) precipitate; however, the sodium fluorosilicate produced by this method has low solubility, and the use of excessive sodium silicate will also increase costs.

[0008] Gypsum method: calcium salts are used to remove sulfate ions, causing calcium sulfate to precipitate; however, the calcium sulfate produced by this method may encapsulate phosphoric acid, resulting in the loss of phosphorus pentoxide (P2O5). Utility Model Content

[0009] The purpose of this invention is to solve the above-mentioned problems by providing an apparatus for purifying phosphoric acid by continuous ion exchange.

[0010] The technical solution of this utility model is implemented as follows:

[0011] This invention provides an apparatus for purifying phosphoric acid using a continuous ion exchange method. The apparatus comprises several interconnected functional zones, each containing a resin tank:

[0012] The primary feeding area includes a raw material tank and an intermediate buffer tank. The raw material is pumped into the resin tank by a pump and then enters the intermediate buffer tank.

[0013] The washing area includes a washing water transfer tank, a washing water tank, and a first compressed air tank. The compressed air tank is used to press the residual material from the first resin tank in the first feeding area into the intermediate buffer tank. The washing water tank pumps the washing water into the remaining resin tanks in the washing area and into the washing water tank.

[0014] The pre-regeneration zone includes a second compressed air tank and a wash water tank, wherein the second compressed air pumps the wash water from the resin tank into the wash water tank;

[0015] The regeneration zone includes a dilute acid tank and a refill acid tank. The dilute acid is pumped into the resin tank by a pump and then into the refill acid tank.

[0016] The acid washing area includes a return water tank, which pumps liquid into the resin tank via a pump, and the liquid in the resin tank flows back into the jacketed acid tank.

[0017] The secondary feeding area includes a product liquid tank for collecting product liquid from the resin tank in the primary feeding area into the product liquid tank;

[0018] The top material area includes a return water tank. The resin tank in the top material area is connected to the product liquid tank. The product liquid tank pumps a portion of the product liquid into the resin tank, which then flows into the return water tank.

[0019] The advantages or beneficial effects of the above technical solutions include at least the following:

[0020] 1. Reduce various errors caused by manual operation.

[0021] 2. Continuous operation and continuous material output.

[0022] 3. Reduced consumption of acids, alkalis, and water.

[0023] 4. The advantages of using continuous ion exchange technology also include the following:

[0024] 1) Because the equipment operates continuously, the product composition and concentration remain stable, which facilitates the stable operation of subsequent processes.

[0025] 2) Due to the increased production efficiency, the resin columns, storage tanks and their supporting facilities are small in scale, compact in design, and easy to install in any location.

[0026] 3) The rotation cycle can be adjusted according to the quality changes of the incoming raw material liquid as needed in the production process.

[0027] 4) Depending on the convenience of the production process, the flow direction of the raw material liquid can be connected in a counter-current or parallel flow manner.

[0028] 5) Because multiple resin columns are used, the production process can be flexibly changed. Attached Figure Description

[0029] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0030] Figure 1 A schematic diagram of a continuous ion exchange system according to an embodiment of the present invention is shown;

[0031] Figure 2 A schematic diagram showing the correspondence between functional areas and valve positions in an embodiment of this utility model is provided.

[0032] Reference numerals: 11, First compressed air tank; 12, Second compressed air tank; 21, First liquid valve; 22, Second liquid valve; 23, Third liquid valve; 24, Fourth liquid valve; 25, Fifth liquid valve; 26, Sixth liquid valve; 31, First conductivity meter; 32, Second conductivity meter; 33, Third conductivity meter. Detailed Implementation

[0033] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0034] It should be noted that, where there is no conflict, the embodiments and features described in these embodiments can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] It should be understood that the term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0036] It should be noted that the terms "one" and "multiple" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0037] The names of the messages or information exchanged between the multiple devices in this embodiment of the invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0038] An apparatus for purifying phosphoric acid using a continuous ion exchange method, comprising several interconnected functional zones, each containing a resin tank:

[0039] The primary feeding area has three resin tanks, including a raw material tank and an intermediate buffer tank. The raw material is pumped into the resin tank by a pump and then enters the intermediate buffer tank.

[0040] The washing area has four resin tanks, including a washing water transfer tank, a washing water tank, and a first compressed air tank 11. The compressed air tank is used to press the residual material from the first resin tank in the first feeding area into the intermediate buffer tank. The washing water tank pumps the washing water into the remaining resin tanks in the washing area and into the washing water tank.

[0041] The pre-regeneration zone has a resin tank, including a second compressed air tank 12 and a wash water tank, wherein the second compressed air pumps the wash water in the resin tank into the wash water tank;

[0042] The regeneration area has two resin tanks, including a dilute acid tank and a backup acid tank. The dilute acid is pumped into the resin tank by a pump and then into the backup acid tank.

[0043] The acid washing area has three resin tanks, including a return water tank. The return water tank pumps liquid into the resin tank via a pump, and the liquid in the resin tank flows back into the acid tank.

[0044] The secondary feeding area has six resin tanks, including a product liquid tank, for collecting the product liquid from the resin tanks in the primary feeding area into the product liquid tank;

[0045] The top material area has a resin tank, including a return water tank. The resin tank in the top material area is connected to the product liquid tank. The product liquid tank pumps part of the product liquid into the resin tank through a pump, and then flows into the return water tank.

[0046] like Figure 1 As shown, the functional areas from left to right are: washing area, primary feeding area, secondary feeding area, top feeding area, water washing acid area, regeneration area and pre-regeneration area.

[0047] The device described above has 20 valve positions, each corresponding to a resin tank, wherein:

[0048] Valve positions 1 to 4 are the washing area. The resin tanks of valve positions 1 to 3 are connected in a forward parallel feeding manner, with the front end connected to the washing water tank and the rear end connected to the washing water transfer tank. The front end of the resin tank of valve position 4 is connected to the first compressed air tank 11 and the rear end is connected to the intermediate buffer tank.

[0049] Valve positions 5 to 7 are the primary feeding zone. The resin tanks at valve positions 5 to 7 are connected in a forward parallel feeding manner, with the front end connected to the raw material tank and the rear end connected to the intermediate buffer tank.

[0050] Valve positions 8 to 13 are secondary feeding areas. The resin tanks at valve positions 8 to 13 are connected in a forward parallel feeding manner. The front end of the resin tanks at valve positions 8 to 10 is connected to the intermediate buffer tank, and the rear end is connected to the front end of the resin tanks at valve positions 11 to 13. The rear end of the resin tanks at valve positions 11 to 13 is connected to the product liquid tank.

[0051] Valve position 14 is the top material area. The front end of the resin tank at valve position 14 is connected to the product liquid tank, and the rear end is connected to the return water tank.

[0052] Valve positions 15-17 are the acid washing zone. The resin tanks at valve positions 15-17 are connected in a forward series feeding manner, with the front end connected to the return water tank and the rear end connected to the auxiliary acid tank. The device further includes an acid mixing tank, which is connected to the auxiliary acid tank. The resin tank at valve position 17 is connected to the auxiliary acid tank through a first flow path and to the acid mixing tank through a second flow path. A first liquid valve 21 is installed on the first flow path, and a second liquid valve 22 is installed on the second flow path. When the first liquid valve 21 is open and the second liquid valve 22 is closed, the resin tank at valve position 17 is connected to the auxiliary acid tank.

[0053] When the second liquid valve 22 is open and the first liquid valve 21 is closed, the resin tank at valve position 17 is connected to the acid mixing tank.

[0054] Valve positions 18 and 19 are the regeneration zone. The resin tanks at valve positions 18 and 19 are connected in a forward series feeding manner, with the front end connected to the dilute acid tank and the rear end connected to the jacketed acid tank.

[0055] Valve position 20 is the pre-regeneration zone. One end of the resin tank at valve position 20 is connected to compressed air, and the other end is connected to the washing tank. The device further includes a waste liquid tank. A third flow path connects the second compressed air tank 12, the resin tank at valve position 20, and the washing water tank. A fourth flow path connects the general acid tank, the resin tank at valve position 20, and the waste liquid tank. A third liquid valve 23 and a fourth liquid valve 24 are installed on the third flow path. A fifth liquid valve 25 and a sixth liquid valve 26 are installed on the fourth flow path. When both the third liquid valve 23 and the fourth liquid valve 24 are open, and both the fifth liquid valve 25 and the sixth liquid valve 26 are closed, the second compressed air tank 12 is connected to the washing water tank via the resin tank at valve position 20. When both the fifth liquid valve 25 and the sixth liquid valve 26 are open, and both the third liquid valve 23 and the fourth liquid valve 24 are closed, the general acid tank is connected to the waste liquid tank via the resin tank at valve position 20.

[0056] The device has a drive unit for moving the resin tank of each valve position in a predetermined direction, namely, the direction from valve position 20 toward valve position 1.

[0057] The device further includes: a first conductivity meter 31, installed between the flow paths of valve position 1 and valve position 2; a second conductivity meter 32, installed between valve position 14 and the return water tank; and a third conductivity meter 33, installed between the flow paths of valve position 15 and valve position 16. The conductivity meters are used to detect the acid concentration in the flow paths.

[0058] The operation process of the device is as follows: the raw materials are stored in the raw material tank in the primary feeding area. The raw materials are pumped to the resin tank at valve positions 5 to 7 for reaction to form secondary product liquid. Then, it enters the intermediate buffer tank. The intermediate buffer tank pumps the secondary product liquid to the secondary feeding area, that is, the resin tank at valve positions 8 to 13, through a mechanical pump to form product liquid. Finally, it flows into the product liquid tank to obtain the product.

[0059] Subsequently, a portion of the product liquid is drawn from the product liquid tank and flows through the resin tank at valve position 14 to the return water tank. The return water tank uses a mechanical pump to pump the liquid to the resin tanks at valve positions 15-17 for cleaning, removing the acid from valve positions 15-17 and transferring it to the acid tank. If the third conductivity meter 33 detects that the acid concentration is too low, the second liquid valve 22 is opened and the first liquid valve 21 is closed, allowing the liquid to flow into the acid mixing tank for acid replenishment. If no low acid concentration is detected, the first liquid valve 21 is opened and the second liquid valve 22 is closed, allowing the liquid flowing from the resin tank at valve position 17 to enter the acid tank. The acid is stored in the resin tank at valve positions 18 and 19 via a mechanical pump, and then flows into the recycled acid tank. At valve position 20, the third liquid valve 23 and the fourth liquid valve 24 are opened first, and the fifth liquid valve 25 and the sixth liquid valve 26 are closed. The second compressed air tank 12 pumps high-pressure air into the resin tank at valve position 20 to pump the residual liquid into the washing water tank for cleaning. Then, the fifth liquid valve 25 and the sixth liquid valve 26 are opened again, and the third liquid valve 23 and the fourth liquid valve 24 are closed. The recycled acid tank pumps the acid into the resin tank at valve position 20 via a liquid pump. Excess acid will flow into the waste liquid tank.

[0060] In valve positions 1 to 4, the first compressed air tank 11 will perform an initial cleaning with high-pressure air, and then the washing water tank will pour the cleaning water from the resin tank in valve position 1 into the resin tanks in valve positions 2 and 3 in sequence for a second cleaning.

[0061] It should be noted that the above process for each valve position is performed synchronously. After each process, the drive device drives the resin tank of each valve position to move one valve position distance in a predetermined direction, which is the direction from valve position 20 to valve position 1.

[0062] The first conductivity meter is used to detect the acidity cleaning status of valve positions 1 to 3 and to detect whether the washing material meets the standard. The second conductivity meter is used to detect whether the top material is completed. The third conductivity meter is used to detect whether the acid washing meets the standard.

[0063] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0064] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present invention and are not intended to limit the scope of the present invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. An apparatus for purifying phosphoric acid using a continuous ion exchange method, characterized in that: The device includes several interconnected functional areas, each containing a resin tank: The primary feeding area includes a raw material tank and an intermediate buffer tank. The raw material is pumped into the resin tank by a pump and then enters the intermediate buffer tank. The washing area includes a washing water transfer tank, a washing water tank and a first compressed air tank (11). The compressed air tank is used to press the residual material from the first resin tank in the first feeding area into the intermediate buffer tank. The washing water tank pumps the washing water into the remaining resin tanks in the washing area and into the washing water tank. The pre-regeneration zone includes a second compressed air tank (12) and a wash water tank, wherein the second compressed air pumps the wash water in the resin tank into the wash water tank; The regeneration zone includes a dilute acid tank and a refill acid tank. The dilute acid is pumped into the resin tank by a pump and then into the refill acid tank. The acid washing area includes a return water tank, which pumps liquid into the resin tank via a pump, and the liquid in the resin tank flows back into the jacketed acid tank. The secondary feeding area includes a product liquid tank for collecting product liquid from the resin tank in the primary feeding area into the product liquid tank; The top material area includes a return water tank. The resin tank in the top material area is connected to the product liquid tank. The product liquid tank pumps a portion of the product liquid into the resin tank, which then flows into the return water tank.

2. The apparatus for purifying phosphoric acid by continuous ion exchange according to claim 1, characterized in that: The device has 20 valve positions, each corresponding to one of the resin tanks, wherein: Valve positions 1 to 4 are the washing area. The resin tanks of valve positions 1 to 3 are connected in a forward series manner, with the front end connected to the washing water tank and the rear end connected to the washing water transfer tank. The front end of the resin tank of valve position 4 is connected to the first compressed air tank (11) and the rear end is connected to the intermediate buffer tank. Valve positions 5 to 7 are the primary feeding zone. The resin tanks at valve positions 5 to 7 are connected in a forward parallel manner, with the front end connected to the raw material tank and the rear end connected to the intermediate buffer tank. Valve positions 8 to 13 are secondary feeding areas. The resin tanks at valve positions 8 to 13 are connected in a forward parallel manner. The front end of the resin tanks at valve positions 8 to 10 is connected to the intermediate buffer tank, and the rear end is connected to the front end of the resin tanks at valve positions 11 to 13. The rear end of the resin tanks at valve positions 11 to 13 is connected to the product liquid tank. Valve position 14 is the top material area. The front end of the resin tank at valve position 14 is connected to the product liquid tank, and the rear end is connected to the return water tank. Valve positions 15 to 17 are the water washing acid zone. The resin tanks at valve positions 15 to 17 are connected in a forward series manner, with the front end connected to the return water tank and the rear end connected to the jacketed acid tank. Valve positions 18 and 19 are the regeneration zone. The resin tanks at valve positions 18 and 19 are connected in a forward series connection, with the front end connected to the dilute acid tank and the rear end connected to the jacketed acid tank. Valve position 20 is the pre-regeneration zone. One end of the resin tank at valve position 20 is connected to the compressed air, and the other end is connected to the dewatering tank. The device has a drive mechanism for moving the resin tank at each valve position in a predetermined direction, wherein the predetermined direction is from valve position 20 toward valve position 1.

3. The apparatus for purifying phosphoric acid by continuous ion exchange according to claim 1, characterized in that: The device further includes an acid mixing tank, which is connected to the jacketed acid tank; The resin tank at valve position 17 is connected to the acid tank via a first flow path and to the acid mixing tank via a second flow path. A first liquid valve (21) is installed on the first flow path, and a second liquid valve (22) is installed on the second flow path; When the first liquid valve (21) is open and the second liquid valve (22) is closed, the resin tank at valve position 17 is connected to the acid tank. When the second liquid valve (22) is open and the first liquid valve (21) is closed, the resin tank at valve position 17 is connected to the acid mixing tank.

4. The apparatus for purifying phosphoric acid by continuous ion exchange according to claim 1, characterized in that: The device further includes a waste liquid tank; The third flow path is used to connect the second compressed air tank (12), the resin tank at valve position 20, and the washing water tank; The fourth flow path is used to connect the general acid tank, the resin tank at valve position 20, and the waste liquid tank; A third liquid valve (23) and a fourth liquid valve (24) are installed on the third flow path; A fifth liquid valve (25) and a sixth liquid valve (26) are installed on the fourth flow path; When the third liquid valve (23) and the fourth liquid valve (24) are both open, and the fifth liquid valve (25) and the sixth liquid valve (26) are both closed, the second compressed air tank (12) is connected to the washing water tank through the resin tank at valve position 20. When the fifth liquid valve (25) and the sixth liquid valve (26) are both open, and the third liquid valve (23) and the fourth liquid valve (24) are both closed, the acid tank is connected to the resin tank via valve position 20.

5. The apparatus for purifying phosphoric acid by continuous ion exchange according to claim 1, characterized in that: The device further includes: The first conductivity meter (31) is installed between the flow paths of valve position 1 and valve position 2; The second conductivity meter (32) is installed between valve position 14 and the return water tank; The third conductivity meter (33) is installed between the flow paths of valve positions 15 and 16.

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