Acid mixer for phosphoric acid production based on wet process

Abstract

The utility model belongs to the technical field of wet-process phosphoric acid production equipment, and discloses an acid mixer based on wet-process phosphoric acid production, which comprises a mother pipe and an extraction tank body, the lower end part of the mother pipe is fixedly connected with a son pipe through a flange bolt, the son pipe is sleeved with a sleeve II, the sleeve II is sleeved with a sleeve I, and the sleeve I is sleeved with a sleeve II. The upper end part of the sleeve II is fixedly connected with the upper end part of the sleeve I through a flange bolt, the sleeve I is arranged on the extraction tank body in a penetrating manner, and the sleeve I is fixedly connected with the extraction tank body; the main pipe is located above the extraction tank body, an ore pulp pipe communicated with the main pipe is arranged on the outer side of the main pipe, and the lower ends of the sub pipe and the second sleeve pipe extend into the extraction tank body. According to the scheme, a unique structural design is adopted, so that sulfuric acid is output in a spraying manner and is quickly dispersed in phosphoric ore pulp, the phenomenon of local over-concentration is avoided, centralized release of heat is effectively reduced, the local overheating risk of the device is reduced, the service life is prolonged, and the operation stability is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the wet process phosphoric acid production equipment technical field more specifically, relate to the mixed acid ware based on the production of wet process phosphoric acid. BACKGROUND

[0002] Phosphoric acid extraction reaction tank is the key equipment in the production of wet process phosphoric acid, its process involves the complex chemical reaction of phosphorite slurry and sulfuric acid, dilute phosphoric acid and other substances in the tank, generating phosphoric acid and calcium sulfate dihydrate (CaSO4.2H2O) crystallization. The reaction process has a crucial influence on the production efficiency of phosphoric acid, product quality and production cost etc.

[0003] The common phosphoric acid extraction reaction tank process includes the following steps (taking the two water wet process phosphoric acid extraction as an example): phosphorite slurry and sulfuric acid are set flow according to certain proportion, sulfuric acid enters the mixed acid ware and the outlet pipe of axial flow pump after metering, and pre-mixes with the slurry from the filtered dilute phosphoric acid and the outlet pipe of axial flow pump, and is added to the first chamber, the second chamber and the third chamber of the reaction tank to carry out sufficient reaction. The reaction slurry is circulated and flashed by the low-position flash cooling circulating pump in the sixth chamber of the reaction tank, and the cooled slurry returns to the first chamber of the reaction tank from the low-position flash cooler by gravity.

[0004] Its total reaction is as follows:

[0005] Ca5F (PO4) 3 + 5H2SO4 + 10H2O = 3H3PO4 + 5CaSO4·2H2O + HF↑

[0006] In actual production, the reaction is carried out in two steps:

[0007] 1) Phosphorite particles are first decomposed by dilute phosphoric acid to generate calcium monophosphate

[0008] Ca5F (PO4) 3 + 10H3PO4 = 3H3PO4 + 5Ca (H2PO4) 2 + HF↑;

[0009] 2) Calcium monophosphate continues to react with sulfuric acid to generate phosphoric acid and calcium sulfate dihydrate crystals

[0010] 5Ca (H2PO4) 2 + 5H2SO4 + 10H2O = 10H3PO4 + 5CaSO4·2H2O↓.

[0011] Reaction rate influencing factors: the reaction process of phosphorite decomposition by sulfuric acid is a liquid-solid phase reaction, and its reaction rate is mainly related to reaction temperature, hydrogen ion concentration, effective surface area of mineral particles and diffusion of liquid film, etc.

[0012] Side reaction problem: in the process of ore slurry reaction, especially when the grade of ore slurry is low and the content of impurities is high, the side reaction is more intense.

[0013] For example, carbonate in ore slurry is easily decomposed by sulfuric acid to produce sulfate, decomposed by phosphoric acid to produce phosphate, and release CO2:

[0014] CaCO3+H2SO4+H2O=CaSO4.2HO2+CO2

[0015] MgCO3+H2SO4=MgSO4+CO2+H2O

[0016] MgCO3+H3PO4=Mg(H2PO4)2+CO2+H2O+CO2

[0017] Disadvantages of traditional mixed acid method:

[0018] 1. Inadequate mixing: in the sulfuric acid addition area of the reaction tank, it is necessary to make sulfuric acid disperse rapidly in the slurry, but the traditional ordinary acid mixer only combines the mother pipe and the sub-pipe at the outlet to realize the mixing function. This way can not guarantee the sufficient mixing of sulfuric acid and phosphate ore slurry, and local over-concentration phenomenon is easy to occur, which affects the uniformity and efficiency of the reaction.

[0019] 2. Large heat release: the ordinary acid mixer releases a large amount of heat during the mixing process due to the simultaneous combination of flow and area, which has multiple effects on the device, such as causing local overheating of the device, affecting the service life and running stability of the equipment, and increasing energy consumption.

[0020] 3. Foam problem: the rapid dilution of sulfuric acid by the slurry releases a large amount of heat, which increases the volume ratio of foam in the circulating slurry, thins the foam wall, and reduces the stability. Defoaming agent needs to be added to eliminate the foam, which not only increases the production cost, but also may have certain impact on the product quality.

[0021] 4. Pipe blockage: inadequate mixing and large heat release may also cause pipe blockage, affecting the normal operation of the device, increasing maintenance cost and downtime, and reducing production efficiency. Practical new type content

[0022] The purpose of the present application is to solve the problems existing in the prior art, and to provide an acid mixer for wet-process phosphoric acid production.

[0023] To solve the above problems, the present application adopts the following technical scheme:

[0024] The utility model provides a mixed acid ware based on the production of wet method phosphoric acid, including the parent tube and the extraction tank body, the parent tube lower end is connected with the sub tube through the flange bolt fixed connection, the sub tube is equipped with the sleeve pipe two, the sleeve pipe two is equipped with the sleeve pipe one, the upper end of sleeve pipe two and the upper end of sleeve pipe one are connected through the flange bolt fixed connection, the sleeve pipe one is set up on the extraction tank body, and the sleeve pipe one is fixedly connected with the extraction tank body;

[0025] The parent tube is located above the extraction tank body, and a mineral slurry pipe is arranged on the outer side of the parent tube and communicates with the parent tube.

[0026] The parent tube is provided with a spray pipe, the upper end of the spray pipe is fixedly connected with the parent tube through the flange bolt, the bottom end of the spray pipe extends into the sub tube, and the bottom end of the spray pipe is provided with a spraying structure close to the lower end of the sub tube.

[0027] As a further scheme of the utility model, the spraying structure comprises a transition joint connected with the lower end of the spray pipe, a spray head is connected to the lower end of the transition joint, and the pipe wall of the spray head is uniformly provided with spray holes.

[0028] As a further scheme of the utility model, the distance between the lower end of the sleeve pipe two and the bottom of the top plate of the extraction tank body is 1500mm, and the distance between the lower end of the sub tube and the bottom of the top plate of the extraction tank body is 3000mm.

[0029] As a further scheme of the utility model, the size specification of the spray pipe is ∅133*12mm, and the size specification of the sleeve pipe two is ∅426*8mm.

[0030] As a further scheme of the utility model, the size specification of the mineral slurry pipe is ∅219*6mm.

[0031] As a further scheme of the utility model, the size specification of the parent tube is ∅325*6mm, and the size specification of the sub tube is ∅325*20mm.

[0032] Compared with the prior art, the utility model has the advantages that:

[0033] The unique structure design of the scheme makes sulfuric acid output in the form of spraying to rapidly disperse in the phosphate ore slurry, avoids the phenomenon of local over-concentration, effectively reduces the concentrated heat release, reduces the risk of local overheating of the device, prolongs the service life, and improves the operation stability. At the same time, the spraying pipe is extended to the slurry liquid to play the role of secondary sulfuric acid addition, which not only reduces the overflow of fluorine-containing gas, is beneficial to environmental protection, but also improves the speed and efficiency of reaction crystallization. In addition, the flange bolt connection mode is convenient for disassembly, installation and fixation, facilitates the maintenance and repair of the equipment, and has significant economic and environmental benefits. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a structural schematic view of the utility model.

[0035] Mark explanation in the drawing:

[0036] 1, sleeve one; 2, mother pipe; 3, spraying pipe; 4, ore slurry pipe; 5, extraction tank body; 6, sleeve two; 7, transition joint; 8, spray head; 9, sub-pipe. DETAILED DESCRIPTION

[0037] The technical scheme in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model; Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments; Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0038] Please refer to Figure 1 , the mixed acid device for wet-process phosphoric acid production, including mother pipe 2 and extraction tank body 5, the lower end of mother pipe 2 is fixedly connected with sub-pipe 9 through flange bolt, sub-pipe 9 is sleeved with sleeve two 6, sleeve two 6 is sleeved with sleeve one 1, the upper end of sleeve two 6 is fixedly connected with the upper end of sleeve one 1 through flange bolt, sleeve one 1 is inserted in extraction tank body 5, and sleeve one 1 is fixedly connected with extraction tank body 5; Mother pipe 2 is located above extraction tank body 5, the outer side of mother pipe 2 is provided with ore slurry pipe 4 in communication therewith, ore slurry pipe 4 is used for conveying phosphate ore slurry into mother pipe, and the lower end of sub-pipe 9 and sleeve two 6 extends to the inside of extraction tank body 5. The setting of sleeve one 1 and sleeve two 6 not only plays a protection role on the internal sub-pipe 9 and other components, but also helps to maintain the stability of the reaction system to a certain extent. Sleeve two 6 is sleeved on sub-pipe 9, and then connected with sleeve one 1, forming a relatively stable structure system, which can withstand the pressure and impact force in the reaction process, and ensure the structural integrity of the whole mixed acid device.

[0039] The spray pipe 3 is arranged in the mother pipe 2 and used for inputting concentrated sulfuric acid. The upper end of the spray pipe 3 is fixedly connected with the mother pipe 2 through flange bolts. The bottom end of the spray pipe 3 extends into the sub-pipe 9. The bottom end of the spray pipe 3 is provided with a spraying structure which is close to the lower end of the sub-pipe 9 and outputs sulfuric acid from the bottom.

[0040] In the working process of the mixed acid device, the mother pipe 2 is located above the tank body 5 of the extraction tank, the sub-pipe 9 is located in the tank body 5 of the extraction tank, the ore pulp pipe 4 is used for conveying phosphate ore pulp into the mother pipe 2, and the sub-pipe 9 is used for conveying into the tank body 5 of the extraction tank. At the same time, the spray pipe 3 is used for conveying concentrated sulfuric acid, and the spray pipe 3 and the spraying structure form a dispersion device for sulfuric acid. The spraying structure sprays the sulfuric acid at the bottom of the sub-pipe 9, so that the sulfuric acid is rapidly dispersed in the phosphate ore pulp, fully mixed, and the phenomenon of local over-concentration is avoided, the consistency of the sulfuric acid and the phosphate ore pulp at each point of the reaction tank is ensured, the mixing is more sufficient, and the production efficiency and quality of the phosphoric acid are improved. In addition, the spraying mixing mode gradually mixes the sulfuric acid and the phosphate ore pulp. After the concentrated sulfuric acid and the ore pulp react, the temperature of the liquid phase is about 90°C, the temperature of the slurry is about 80°C, and the temperature of the gas phase is about 75°C. Compared with the traditional mixing mode, the heat is effectively reduced, the risk of local overheating of the device is reduced, the service life of the device is prolonged, and the operation stability of the device is improved. The heat generation is reduced, thereby reducing the generation of foam. The reduction of the amount of foam generated reduces the amount of defoaming solvent used, reduces the production cost, reduces the pipeline blockage problem caused by foam, prolongs the operation cycle of the device, and improves the production efficiency of the device.

[0041] Specifically, the spraying structure includes a transition joint 7 connected with the lower end of the spray pipe 3. The lower end of the transition joint 7 is connected with a spray head 8. The pipe wall of the spray head 8 is uniformly provided with spray holes. The concentrated sulfuric acid input in the spray pipe 3 is sprayed out through the spray head 8, can be mixed with the phosphate ore pulp from multiple directions, and can form better mixing contact. In addition, the flange bolt connection mode in the embodiment is convenient to disassemble and install and fix.

[0042] In addition, the distance between the lower end of the sleeve pipe two 6 and the bottom of the top plate of the extraction tank tank body 5 is 1500mm, and the distance between the lower end of the sub-pipe 9 and the bottom of the top plate of the extraction tank tank body 5 is 3000mm. This design makes the spray pipe 3 extend to the liquid surface of the slurry liquid by 200-300mm, plays a role of secondary sulfuric acid addition, so that the sulfuric acid can reach the end of the mixing, reduce the overflow of fluorine-containing gas, and improve the speed and efficiency of the reaction crystallization.

[0043] The size of the spray pipe 3 is ∅133x12mm, and the size of the sleeve pipe 2 is ∅426x8mm. The size of the ore pulp pipe 4 is ∅219x6mm. The size of the main pipe 2 is ∅325x6mm, and the size of the sub-pipe 9 is ∅325x20mm. The sizes are carefully designed and calculated, and they match each other to ensure the smooth flow of the materials in the acid mixer and avoid the blockage or uneven flow.

[0044] The above merely describes the preferred specific implementation of the present application; however, the protection scope of the present application is not limited to this. Any skilled person in the art, according to the technical scheme and the improved concept of the present application, can make equivalent replacement or change within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A mixer for use in wet-process phosphoric acid production, characterized in that: Including the mother tube (2) and the extraction tank body (5), the lower end of the mother tube (2) is fixedly connected with the daughter tube (9) through the flange bolt, the daughter tube (9) is sleeved with the sleeve two (6), the sleeve two (6) is sleeved with the sleeve one (1), the upper end of the sleeve two (6) is fixedly connected with the upper end of the sleeve one (1) through the flange bolt, the sleeve one (1) is inserted into the extraction tank body (5), and the sleeve one (1) is fixedly connected with the extraction tank body (5); The mother tube (2) is located above the extraction tank body (5), the outer side of the mother tube (2) is provided with a mineral slurry pipe (4) in communication with the mineral slurry pipe (4), the lower end of the daughter tube (9) and the sleeve two (6) extends into the inside of the extraction tank body (5); The mother tube (2) is provided with a spray pipe (3), the upper end of the spray pipe (3) is fixedly connected with the mother tube (2) through the flange bolt, the bottom end of the spray pipe (3) extends into the daughter tube (9), and the bottom end of the spray pipe (3) is provided with a spray structure, the spray structure is close to the lower end of the daughter tube (9).

2. The mixed acid device for wet-process phosphoric acid production according to claim 1, characterized by: The spray structure includes a transition joint (7) connected with the lower end of the spray pipe (3), the lower end of the transition joint (7) is connected with a spray head (8), and the pipe wall of the spray head (8) is uniformly provided with spray holes.

3. The mixed acid device for wet-process phosphoric acid production according to claim 1, characterized by: The distance between the lower end of the sleeve two (6) and the bottom of the top plate of the extraction tank body (5) is 1500mm, and the distance between the lower end of the daughter tube (9) and the bottom of the top plate of the extraction tank body (5) is 3000mm.

4. The mixed acid device for wet-process phosphoric acid production according to claim 1, characterized by: The size specification of the spray pipe (3) is ∅133x12mm, and the size specification of the sleeve two (6) is ∅426x8mm.

5. The mixed acid apparatus for wet-process phosphoric acid production according to claim 1, characterized by: The size specification of the mineral slurry pipe (4) is ∅219x6mm.

6. The mixed acid apparatus for wet-process phosphoric acid production according to claim 1, characterized by: The size specification of the mother tube (2) is ∅325x6mm, and the size specification of the daughter tube (9) is ∅325x20mm.

Images