Mixed reaction clarification device for producing monopotassium phosphate through organic extraction of crude phosphoric acid

Abstract

The utility model discloses a mixed reaction clarification device for producing monopotassium phosphate by organically extracting crude phosphoric acid. The mixed reaction clarification device comprises a primary extraction reaction tank (19), a secondary extraction reaction tank (3), a clarification tank (9) and a water-phase precipitate collecting tank (23) which are sequentially arranged from top to bottom, an extraction phase inlet and a potassium chloride solution inlet are formed in the top of the primary extraction reaction tank; the bottom end of the secondary extraction reaction tank is provided with a discharge port externally connected with a discharge pipe, and the top of the secondary extraction reaction tank is provided with an extractant liquid inlet guide pipe and a primary extraction reaction tank liquid inlet guide pipe connected to the bottom of the primary extraction reaction tank; the upper part of the clarifying tank is provided with an overflow weir, an organic phase outlet and a central cylinder, the outer side of the clarifying tank is provided with a water phase liquid level control barrel communicated with the clarifying tank, the water phase liquid level control barrel is provided with at least three water phase outlets, and the bottom of the water phase liquid level control barrel is provided with a water phase precipitate discharge port. The monopotassium phosphate produced by the monopotassium phosphate production equipment is low in chloride ion content, the equipment is not easy to block in the production process, and the production stability is high.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of potassium dihydrogen phosphate production equipment, and specifically relates to a novel mixed reaction clarifying device suitable for producing potassium dihydrohydrogen phosphate through extraction method. BACKGROUND

[0002] Potassium dihydrogen phosphate is a high-quality phosphorus-potassium fertilizer, and is widely applied in the food processing, pharmaceutical industry, medical treatment, fire fighting, water treatment, metal surface treatment and other industries.

[0003] The traditional potassium dihydrogen phosphate is mostly produced by neutralization method, that is, purified phosphoric acid and potassium hydroxide are reacted to obtain potassium dihydrogen phosphate, but the production cost is extremely high.

[0004] The production of potassium dihydrogen phosphate by using crude phosphoric acid and potassium chloride extraction method has a lower cost, and is a current research hotspot in the industry.

[0005] The existing potassium dihydrogen phosphate production equipment is often blocked due to the accumulation of precipitates, which causes frequent shutdown for cleaning, affects the continuity of production, and has a small production capacity, and none of the equipment realizes large-scale production.

[0006] Therefore, it is urgent to develop a set of potassium dihydrogen phosphate production equipment matched with the extraction method process. SUMMARY

[0007] The utility model discloses a kind of mixed clarifying devices for producing potassium dihydrogen phosphate by crude phosphoric acid organic extraction, to solve the deficiencies of prior art, the product chloride ion content of production is lower, equipment is not easy to block, production stability is higher, and the mixed clarifying device can be scaled production.

[0008] To achieve the above object, the technical scheme adopted by the utility model is as follows:

[0009] A kind of mixed reaction clarifying device for producing potassium dihydrogen phosphate by crude phosphoric acid organic extraction, including the sequence setting from top to bottom of primary extraction reaction tank, secondary extraction reaction tank, clarifying tank, water phase precipitate collection tank;

[0010] Extraction phase inlet and potassium chloride solution inlet are arranged at the top of the primary extraction reaction tank;

[0011] The secondary extraction reaction tank is a cylinder with a conical bottom, a discharge port with a discharge pipe connected to the bottom end and a flow control valve, an extractant inlet conduit at the top and a primary extraction reaction tank inlet conduit connected to the bottom of the primary extraction reaction tank through a pipeline, the extractant inlet conduit being connected to an extractant overflow port through a pipeline, and a first stirring mechanism being arranged in the secondary extraction reaction tank, with a stirring shaft of the first stirring mechanism extending out of the top of the secondary extraction reaction tank and being connected to a first stirring motor;

[0012] The clarification tank is a cylinder with a conical bottom, an overflow weir arranged in an annular manner on the inner wall of the cylinder and a central cylinder arranged in the center of the cylinder, an organic phase outlet being arranged on the cylinder wall at the position of the overflow weir, a water phase liquid level control barrel being arranged outside the clarification tank and being in communication with the clarification tank, at least three water phase outlets being arranged on the water phase liquid level control barrel from top to bottom, a 1# water phase sediment discharge outlet being arranged at the bottom end of the conical bottom, a 2# water phase sediment discharge outlet being arranged on the conical bottom, a 3# water phase sediment discharge outlet being arranged at the bottom of the water phase liquid level control barrel, valves being arranged on the 1# water phase sediment discharge outlet, the 2# water phase sediment discharge outlet and the 3# water phase sediment discharge outlet, and the discharge pipe connected to the bottom end of the secondary extraction reaction tank being inserted into the central cylinder;

[0013] A second stirring mechanism is arranged in the water phase sediment collection tank, with a stirring shaft of the second stirring mechanism extending out of the top of the water phase sediment collection tank and being connected to a second stirring motor, and the 2# water phase sediment discharge outlet of the clarification tank and the 3# water phase sediment discharge outlet of the water phase liquid level control barrel being connected to the water phase sediment collection tank through pipelines.

[0014] Further, baffles are uniformly distributed on the inner wall of the secondary extraction reaction tank.

[0015] Further, a 1# water phase outlet, a 2# water phase outlet and a 3# water phase outlet with valves are arranged on the water phase liquid level control barrel from top to bottom.

[0016] The utility model has the following beneficial effects:

[0017] The utility model discloses a primary extraction reaction tank, secondary extraction reaction tank, clarification tank, water phase sediment collection tank are set from top to bottom, and the reaction tank and the clarification tank are not at the same horizontal plane, and it is convenient to separate and timely remove the more precipitate separated in the extraction process, and it is not easy to cause the blockage of equipment, reduces the influence of process fluctuation on equipment, and greatly improves the stability of equipment operation and production. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structural schematic diagram of the utility model.

[0019] Figure 2 The baffle plate 5 in the secondary extraction reaction tank of the utility model is shown in a layout diagram. DETAILED DESCRIPTION

[0020] The content of the utility model is further described below in combination with the drawings and examples.

[0021] As Figure 1 shown, a mixed reaction clarifying device for producing potassium dihydrogen phosphate from crude phosphoric acid organic extraction includes a primary extraction reaction tank 19, a secondary extraction reaction tank 3, a clarifying tank 9, and a water phase precipitation collection tank 23 arranged in sequence from top to bottom at different height positions.

[0022] An extraction phase inlet 20 and a potassium chloride solution inlet 21 are arranged at the top of the primary extraction reaction tank 19.

[0023] The secondary extraction reaction tank 3 is a cylinder with a conical bottom, and a discharge port for connecting a discharge pipe is arranged at the bottom end of the cylinder, and a flow control valve 6 is arranged on the discharge pipe. An extractant inlet conduit 2 is arranged at the top of the cylinder, and a primary extraction reaction tank inlet conduit 18 connected to the bottom of the primary extraction reaction tank 19 by a pipeline. The extractant inlet conduit 2 is connected to the extractant overflow port 1 by a pipeline. A first stirring mechanism 4 is arranged in the secondary extraction reaction tank 3, and the stirring shaft of the first stirring mechanism penetrates the top of the secondary extraction reaction tank and is connected to a first stirring motor 22. The baffle plate 5 is uniformly distributed on the inner wall of the secondary extraction reaction tank 3, Figure 2 As shown in the figure, the baffle plate 5 is arranged in the secondary extraction reaction tank. The baffle plate changes the flow direction of the liquid, increases the degree of turbulence, and thus improves the extraction mass transfer efficiency.

[0024] The clarifying tank 9 is a cylinder with a conical bottom, and an overflow weir 17 arranged in a ring on the inner wall of the cylinder and a central cylinder 8 arranged in the center of the cylinder are arranged at the upper part of the cylinder, and an organic phase outlet 7 is arranged on the cylinder wall at the position of the overflow weir 17. The arrangement of the central cylinder 8 can prolong the phase separation time of the mixed phase formed in the secondary extraction reaction tank 3, reduce entrainment, and facilitate more thorough phase separation, thereby improving product quality.

[0025] The secondary extraction reaction tank 3 and the clarifying tank 9 are connected in an up-down manner, so that a large amount of precipitate generated in the secondary extraction reaction tank can enter the clarifying tank by relying on its own gravity, preventing the secondary extraction reaction tank from being blocked, and prolonging the cleaning cycle of the equipment. The flow control valve 6 is arranged between the secondary extraction reaction tank and the clarifying tank, and when the production is increased, the opening degree of the flow control valve can be increased, and when the production is reduced, the opening degree of the flow control valve can be reduced.

[0026] A water phase liquid level control barrel 15 is arranged outside the clarifying tank 9 and communicates with the clarifying tank, a 1# water phase outlet 16a, a 2# water phase outlet 16b and a 3# water phase outlet 16c are arranged on the water phase liquid level control barrel from top to bottom, respectively, and valves are arranged on the 1# water phase outlet 16a, the 2# water phase outlet 16b and the 3# water phase outlet 16c.

[0027] A second stirring mechanism 24 is arranged in the water phase precipitation collection tank 23, a stirring shaft of the second stirring mechanism penetrates through the top of the water phase precipitation collection tank and is connected with the second stirring motor 13.

[0028] The utility model sets up primary extraction reaction tank 19 and secondary extraction reaction tank 3 and carries out twice chloride ion extraction, can further improve chloride ion extraction rate, reduces the chloride ion content of the potassium dihydrogen phosphate product obtained finally, and significantly improves product quality. Figure 1 The utility model shows single equipment, and in actual production, multiple equipment can be used jointly to realize scale production.

[0029] The working principle and operation process of the utility model are as follows:

[0030] Firstly, close the valves of the 1st water phase sediment discharge outlet 11, the 2nd water phase sediment discharge outlet 12 and the 3rd water phase sediment discharge outlet 14, and close the valves of the 1st water phase outlet 16a, the 2nd water phase outlet 16b and the 3rd water phase outlet 16c. Then, add the extraction phase into the primary extraction reaction tank 19 through the extraction phase inlet 20, and add the potassium chloride solution into the primary extraction reaction tank 19 through the potassium chloride solution inlet 21. The extraction phase is the associated compound formed by the purified phosphoric acid with low impurities and the extraction agent after the crude phosphoric acid and the extraction agent are mixed and separated. The extraction agent is the organic compound that is immiscible with the water phase, and the mixture of kerosene, decanol and trioctylamine is used in the embodiment. The extraction agent can form the associated compound with the phosphoric acid and is not associated with the impurities in the crude phosphoric acid. When the liquid level in the primary extraction reaction tank 19 reaches 1 / 2, the mixing device of the primary extraction reaction tank is started, the extraction phase and the potassium chloride solution are mixed, and the primary extraction chloride ion reaction occurs. In the primary extraction reaction tank 19, the extraction agent extracts the chloride ion from the mixed solution of the crude phosphoric acid and the potassium chloride for the first time. The first stirring mechanism 4 is driven to move by the first stirring motor 22, the extraction agent material from the extraction agent overflow port 1 and the reaction material in the primary extraction reaction tank 19 are put into the secondary extraction reaction tank 3. In the secondary extraction reaction tank, the extraction agent extracts the chloride ion from the mixed solution of the phosphoric acid and the potassium chloride for the second time, the secondary extraction chloride ion reaction occurs by using the strong alkalinity and extraction property of the extraction agent, and the potassium phosphate dihydrogen water phase impurities are precipitated in the secondary extraction reaction tank 3. During the production operation, the extraction agent inlet pipe 2 and the primary extraction reaction tank inlet pipe 18 are inserted into the liquid surface by 400-500 mm to prevent the flammable and explosive extraction agent from generating static electricity by rubbing with the air. The material after the secondary extraction reaction falls into the clarification tank 9 through the central cylinder 8, and the mixture is gradually separated during the flowing process. The continuous feeding is performed, the organic phase with low density of the enriched chloride ion flows upward after the clarification tank is filled with the material, enters the overflow weir 17, flows out from the organic phase outlet 7 and enters the subsequent treatment process. The potassium phosphate dihydrogen water phase with high density flows downward into the water phase control barrel 15 and is discharged from the water phase outlets at different heights such as the 1st water phase outlet 16a, the 2nd water phase outlet 16b and the 3rd water phase outlet 16c, and high-quality potassium phosphate dihydrogen products are obtained through concentration and crystallization. The 1st water phase sediment discharge outlet 11, the 2nd water phase sediment discharge outlet 12 and the 3rd water phase sediment discharge outlet 14 are opened regularly to discharge the sediments to prevent the blockage. The potassium phosphate dihydrogen water phase discharged from the water phase outlet can continue to enter the next stage of the mixing extraction tank to extract the chloride ion again, and the chloride ion content of the potassium phosphate dihydrogen water solution can be further reduced after multiple extractions to meet the higher quality requirements.

[0031] The potassium phosphate dihydrogen production device can realize the continuous and large-scale production of potassium phosphate dihydrogen, the device runs stably, the production efficiency is high, and the quality of the produced products is better.

[0032] The above-described embodiments are merely preferred modes of the present application, and are not intended to limit the scope of the present application, and various modifications and improvements to the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A mixed reaction clarification apparatus for the organic extraction of crude phosphoric acid to produce potassium dihydrogen phosphate, characterized in that, It includes a primary extraction reaction tank (19), a secondary extraction reaction tank (3), a clarification tank (9), and an aqueous phase sedimentation collection tank (23) arranged sequentially from top to bottom; An extraction phase inlet (20) and a potassium chloride solution inlet (21) are provided at the top of the primary extraction reaction tank (19); The secondary extraction reaction tank (3) is a cylindrical body with a conical bottom. It has an external discharge pipe and a discharge port with a flow control valve (6) at the bottom end. The top is provided with an extractant inlet pipe (2) and a primary extraction reaction tank inlet pipe (18) connected to the bottom of the primary extraction reaction tank (19) through a pipe. The extractant inlet pipe (2) is connected to the extractant overflow port (1) through a pipe. A first stirring mechanism (4) is provided in the secondary extraction reaction tank (3). The stirring shaft of the first stirring mechanism passes through the top of the secondary extraction reaction tank and is connected to the first stirring motor (22). The clarification tank (9) is a cylindrical body with a conical bottom. An overflow weir (17) arranged in a ring on the inner wall of the cylinder and a central cylinder (8) set in the center of the cylinder are provided on the upper part. An organic phase outlet (7) is opened on the cylinder wall at the position of the overflow weir (17). An aqueous phase level control tank (15) communicating with the inside of the clarification tank is provided on the outside of the clarification tank (9). At least three aqueous phase outlets are provided on the aqueous phase level control tank from top to bottom. A No. 1 aqueous phase sedimentation outlet (11) is provided at the bottom of the conical bottom. A No. 2 aqueous phase sedimentation outlet (12) is provided on the conical bottom. A No. 3 aqueous phase sedimentation outlet (14) is provided at the bottom of the aqueous phase level control tank (15). Valves are provided for the No. 1 aqueous phase sedimentation outlet (11), the No. 2 aqueous phase sedimentation outlet (12) and the No. 3 aqueous phase sedimentation outlet (14). The discharge pipe connected to the bottom of the secondary extraction reaction tank (3) is inserted into the central cylinder (8). A second stirring mechanism (24) is provided in the aqueous sedimentation collection tank (23). The stirring shaft of the second stirring mechanism passes through the top of the aqueous sedimentation collection tank and is connected to the second stirring motor (13). The No. 2 aqueous sedimentation outlet (12) of the clarification tank (9) and the No. 3 aqueous sedimentation outlet (14) of the aqueous level control tank (15) are respectively connected to the aqueous sedimentation collection tank (23) through pipelines.

2. The mixed reaction clarification apparatus for producing potassium dihydrogen phosphate by organic extraction of crude phosphoric acid according to claim 1, characterized in that, Baffles (5) are evenly distributed on the inner wall of the secondary extraction reaction tank (3).

3. A mixed reaction clarification apparatus for producing potassium dihydrogen phosphate by organic extraction of crude phosphoric acid according to claim 1 or 2, characterized in that, The aqueous phase level control tank is equipped with valves at the following outlets: No. 1 (16a), No. 2 (16b), and No. 3 (16c).

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