CN116534818A - Method for inhibiting scale by micro-bubbles in wet-process phosphoric acid production process - Google Patents

Abstract

The invention provides a method for using micro-bubble scale inhibition in the production process of wet-process phosphoric acid. By introducing micro-bubbles during the pulp transportation process, a layer of micro-bubble "protective film" can be adsorbed and gathered on the pipe wall or the surface of the scale to avoid Scaling-prone substances deposit or continue to scale on the tube wall. At the same time, the surface of the microbubbles is negatively charged, which can enrich the impurity ions in the liquid phase on the surface of the microbubbles, avoiding the formation of insoluble precipitates and causing scaling; in addition, the slurry and The multiphase fluid formed by the uniform mixing of microbubbles can strip off solids deposited on the pipe wall, pipe elbow or variable diameter, so as to realize the descaling of the pipe during the production process of wet-process phosphoric acid and avoid pipe blockage.

Description

A method of micro-bubble scale inhibition in the production process of wet-process phosphoric acid

technical field

The invention belongs to the technical field of wet-process phosphoric acid, and in particular relates to a method for using microbubbles to prevent scale in the production process of wet-process phosphoric acid.

Background technique

During the production process of wet-process phosphoric acid, collophosphine reacts with sulfuric acid to generate phosphoric acid and phosphogypsum continuously. Phosphogypsum crystals continue to crystallize and grow, and are easy to crystallize, grow and scale on pipe walls, pipe elbows or variable diameters. Affect the normal fluid transport of the pipeline; in addition, collophosite contains a large amount of impurities such as carbon, silicon, aluminum, iron, magnesium, etc., which are dissolved and released into phosphoric acid during the acidolysis process, and are easily mixed with calcium ions, potassium ions, sodium ions or fluorine Combined with ions, etc., it may co-precipitate with phosphogypsum to form insoluble solids, which will scale inside the pipeline or reactor, affecting the normal transportation of pipelines or the normal operation of the reactor.

CN106882776A discloses a wet-process phosphoric acid production system and a wet-process phosphoric acid production method. The wet-process phosphoric acid production system includes sequentially connected mineral material conveying equipment, a pulp storage tank, a pulp thickening tank, a pulp high level tank, an extraction tank, a slurry thickening tank, a phosphoric acid clarification tank and a phosphoric acid storage tank. By connecting the thick slurry outlet of the slurry thickening tank to the feed port of the thick slurry dilution tank, the filter cleaning equipment does not participate in the filtration of the phosphoric acid stock solution, and only filters the diluted slurry separated by the slurry thickener to solve the filter and related problems. The problem of pipe fouling and blockage. The above-mentioned wet-process phosphoric acid production system has a poor effect on pipeline scaling, frequent maintenance of filters, and high production costs.

CN210973888U discloses a kind of wet-process phosphoric acid production system, adopts phosphoric acid backwater as the washing water of the three washing areas, adopts clean and high-temperature condensed water as the filter cloth regenerated water in the filter cloth regeneration area, by adding concentrated sulfuric acid in the three washing liquid storage tanks , can settle the easy-to-scale substances and then quickly wash them down in the third washing area. Adding sulfuric acid can improve the washing effect. The structure of the above-mentioned production system is complicated, and the production cost of phosphoric acid is relatively high.

Therefore, it is necessary to provide a method that is simple, low in phosphoric acid production cost, and can effectively avoid the crystallization and growth of phosphogypsum and easily scaling substances in the wet process phosphoric acid process, and avoid pipeline descaling and blockage. The method of anti-scaling of air bubbles.

Contents of the invention

The purpose of the present invention is to provide a method for using micro-bubbles in the production process of wet-process phosphoric acid. By introducing micro-bubbles in the slurry transportation process, it is possible to avoid the deposition of easily scaling substances on the pipe wall or continuous scaling, and at the same time, micro-bubbles are used The negative charge on the surface enriches the impurity ions in the liquid phase, avoids the formation of insoluble precipitates and causes scaling, realizes descaling of pipelines, and avoids pipeline blockage.

To achieve this purpose of the invention, the present invention adopts the following technical solutions:

The object of the present invention is to provide a method for using micro-bubbles in the production process of wet-process phosphoric acid, the method comprising: introducing micro-bubbles into the slurry pipeline used for wet-process phosphoric acid production to obtain the pulp containing micro-bubbles, Realize anti-scaling.

In the production process of wet-process phosphoric acid provided by the present invention, the method of micro-bubble scale inhibition is adopted, and the micro-bubbles are introduced into the slurry transportation process, and the micro-bubbles can be adsorbed and gathered on the pipe wall or the surface of the scale, thereby forming a layer of "protective film". Avoid the deposition or continuous scaling of substances that are prone to scaling on the tube wall; at the same time, the surface of the microbubbles has a negative charge, which can adsorb impurity ions such as calcium, potassium, sodium, aluminum, iron and magnesium in the liquid phase, making them on the surface of the microbubbles Enrichment, reducing the concentration in the liquid phase, thereby avoiding the formation of insoluble precipitates and scaling; in addition, the uniform mixing of pulp and microbubbles can form a multiphase fluid with strong shear force, which is conducive to deposition on pipe walls and pipe elbows Or the solid peeling off at the variable diameter can realize the descaling of the pipeline and avoid the clogging of the pipeline. The method of the invention is simple to operate, has good descaling effect on pipelines, and is suitable for popularization and application in a wide range.

The present invention cannot use millimeter-scale large bubbles to descale pipelines, because millimeter-scale large bubbles are easily aggregated in the pipeline to form a large-scale air mass, that is, a continuous phase of gas is formed in the pulp, and it is difficult to form a strong shear force The multiphase fluid is not conducive to the stable transportation of the fluid, and will cause serious cavitation to the delivery pump.

Preferably, the method of introducing micro-bubbles is to insert a bubble gun into the slurry conveying pipeline, and the micro-bubbles are ejected from the bubble gun.

Preferably, the bubbling gun includes a high-pressure gas microporous bubbling gun or a high-pressure gas membrane-type bubbling gun.

Preferably, the pressure of the high-pressure gas microporous bubbling gun and the high-pressure gas membrane bubbling gun is 0.4-0.8MPa, for example, it can be 0.4MPa, 0.45MPa, 0.5MPa, 0.6MPa, 0.7MPa or 0.8MPa, etc. .

Preferably, the time from where the microbubbles are inserted into the bubbling gun to the fouling-prone pipe section of the slurry delivery pipeline is 0.5s to 15s, for example, it can be 0.5s, 1s, 3s, 5s, 10s, 13s or 15s, etc. .

Preferably, the position where the bubble gun releases microbubbles is at the top of the bubble gun.

Preferably, the tip of the bubbling gun is evenly distributed in a circular shape in the slurry pipeline, which can realize the absorption and accumulation of microbubbles on the pipe wall, avoiding the deposition or continuous scaling of easily scaling substances on the pipe wall, and It can effectively adsorb the impurity ions in the liquid phase in the pipeline, and the micro-bubbles sprayed into the uniformly distributed ring-shaped gun head mix more evenly with the ore slurry, which is conducive to deposition on the pipe wall, pipe elbow or variable diameter. Exfoliation of solids for efficient descaling of pipes.

Preferably, the distance between the nozzles distributed on the outer ring and the central point of the slurry pipeline is 3/4 to 2/3 of the radius of the slurry pipeline, for example, it can be 3/4, 37/50, 7/10, 17/25 or 2/3 etc.

In the present invention, the distance between the tip of the nozzle distributed on the outer ring and the center point of the slurry pipeline is preferably 3/4 to 2/3 of the radius of the slurry pipeline, which can not only reduce the deposition of easily scaling substances on the pipe wall, but also reduce the contamination of the pipeline. The impurity ions in the liquid phase are effectively adsorbed, thereby reducing the thickness of the solid finally deposited on the wall of the slurry pipeline.

Preferably, the distance between the nozzles distributed in the inner ring and the center point of the slurry pipeline is 1/3 to 1/2 of the radius of the slurry pipeline, for example, it can be 1/3, 7/20, 19/50, 2/5 or 3/4 etc.

Preferably, the gun tips of the outer ring and the gun tips of the inner ring are distributed alternately, which is conducive to more uniform mixing of the microbubbles and the pulp.

Preferably, the ratio of the total gas flow required by the microbubbles to the volume flow of the pulp is 1:(12-80), for example, it can be 1:12, 1:20, 1:30, 1:50, 1 :70 or 1:80 etc.

In the present invention, the ratio of the total gas flow rate required by the microbubbles to the volume flow rate of the pulp is preferably 1: (12-80), which can greatly reduce the thickness of solids finally deposited on the pipe wall of the pulp delivery pipeline. When the ratio of the total gas flow required by the microbubbles to the volume flow rate of the ore pulp is small, that is, the amount of microbubbles is small, the microbubble "protective film" cannot be well formed on the pipe wall or the surface of the scale, and After the microbubbles are mixed with the pulp, they cannot form a multi-phase fluid with strong shear force, and cannot effectively peel off the solids deposited on the pipe wall, pipe elbow or variable diameter; when the total gas flow required by the microbubbles is different from the pulp The volume flow ratio is large, that is, the amount of microbubbles is large, and the multiphase fluid with strong shear force cannot be formed after the microbubbles are mixed with the pulp, and the removal effect of solids deposited on the pipe wall, pipe elbow or variable diameter is poor .

Preferably, the microbubbles have a diameter of 1-500 μm, such as 1 μm, 10 μm, 50 μm, 100 μm, 300 μm, 400 μm or 500 μm.

Preferably, the gas in the microbubbles includes any one or a combination of at least two of air, nitrogen, helium or argon, wherein a typical but non-limiting combination includes a combination of air and nitrogen, helium and Argon or Nitrogen and Helium.

The numerical ranges described in the present invention not only include the above-mentioned point values, but also include any point values between the above-mentioned numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention will not exhaustively list the above-mentioned point values. Specific point values covered by the stated ranges.

As a preferred technical solution of the present invention, the method includes: inserting a high-pressure gas microporous bubbling gun or a high-pressure gas membrane bubbling gun with a pressure of 0.4 to 0.8 MPa into the pipeline for transporting the pulp during the production process of wet-process phosphoric acid, Introduce micro-bubbles with a diameter of 1-500 μm to obtain a slurry containing micro-bubbles to achieve scale inhibition;

The time from the position where the microbubbles are inserted into the bubbling gun to the easy-fouling pipe section of the slurry delivery pipeline is 0.5s to 15s; the position where the microbubbles are released from the bubbling gun is at the top, and the The nozzles are evenly distributed in a circular shape in the slurry pipeline; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 3/4~2/3 of the radius of the slurry pipeline; the nozzles distributed in the inner ring and The distance between the central point of the slurry pipeline is 1/3~1/2 of the radius of the slurry pipeline; the nozzles of the outer ring and the nozzles of the inner ring are distributed alternately; the total gas flow required by the microbubbles is related to the volume of the slurry The flow ratio is 1:(12-80); the gas in the microbubbles includes any one or a combination of at least two of air, nitrogen, helium or argon.

Compared with the prior art, the present invention has the following beneficial effects:

The invention adopts micro-bubbles to strengthen the descaling of the slurry pipeline in the production process of wet-process phosphoric acid, and introduces micro-bubbles in the slurry transportation process to avoid the deposition or scaling of the pipe wall, and strengthen the stripping of solids deposited on the pipe wall, pipe elbow or variable diameter, Realize pipeline descaling and scale inhibition, and avoid pipeline blockage.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a pipeline for transporting ore pulp inserted into a bubbling gun in the present invention.

In the figure: 1-slurry conveying pipeline; 2-bubbling gun; 3-the gun head of the inner ring bubbling gun; 4-the gun head of the outer ring bubbling gun.

Detailed ways

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

The present invention will be further described in detail below. However, the following examples are only simple examples of the present invention, and do not represent or limit the protection scope of the present invention, and the protection scope of the present invention shall be determined by the claims.

As shown in Figure 1, the present invention provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. Specifically, the method includes: during the production process of wet-process phosphoric acid, a high-pressure A gas microporous bubbling gun or a high-pressure gas membrane bubbling gun is inserted into the slurry delivery pipeline to introduce microbubbles with a diameter of 1 to 500 μm to obtain a slurry containing microbubbles to achieve scale inhibition;

The time from the position where the microbubbles are inserted into the bubbling gun to the easy-fouling pipe section of the slurry delivery pipeline is 0.5s to 15s; the position where the microbubbles are released from the bubbling gun is at the top, and the The nozzles are evenly distributed in a circular shape in the slurry pipeline; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 3/4~2/3 of the radius of the slurry pipeline; the nozzles distributed in the inner ring and The distance between the central point of the slurry pipeline is 1/3~1/2 of the radius of the slurry pipeline; the nozzles of the outer ring and the nozzles of the inner ring are distributed alternately; the total gas flow required by the microbubbles is related to the volume of the slurry The flow ratio is 1:(12-80); the gas in the microbubbles includes any one or a combination of at least two of air, nitrogen, helium or argon.

Example 1

This embodiment provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. The method includes: using a high-pressure gas microporous bubbling gun or high-pressure gas membrane The type bubbling gun is inserted into the pipeline for transporting ore slurry, and micro-bubbles with a diameter of 1-200 μm are introduced to obtain a slurry containing micro-bubbles to achieve scale inhibition;

The time from the position where the microbubbles are inserted into the bubbling gun to the easy-fouling pipe section of the slurry delivery pipeline is 6s; The slurry pipeline is evenly distributed in a ring shape; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 3/4 of the radius of the slurry pipeline; the distance between the nozzles distributed in the inner ring and the center point of the slurry pipeline It is 1/2 of the radius of the pipeline for transporting the pulp; the gun heads of the outer ring and the gun heads of the inner ring are distributed alternately; the ratio of the total gas flow required by the microbubbles to the volume flow rate of the pulp is 1:30; the described The gas inside the microbubbles is air.

Example 2

This embodiment provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. The method includes: using a high-pressure gas microporous bubbling gun or high-pressure gas membrane The type bubbling gun is inserted into the slurry pipeline, and micro-bubbles with a diameter of 1-500 μm are introduced to obtain a slurry containing micro-bubbles to achieve scale inhibition;

The time from the position where the microbubbles are inserted into the bubbling gun to the easy-fouling pipe section of the slurry delivery pipeline is 0.5s; It is evenly distributed in a ring shape in the slurry pipeline; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 2/3 of the radius of the slurry pipeline; the distance between the nozzles distributed in the inner ring and the center point of the slurry pipeline The distance is 1/3 of the radius of the slurry pipeline; the nozzles of the outer ring and the nozzles of the inner ring are distributed alternately; the ratio of the total gas flow required by the microbubbles to the volume flow rate of the slurry is 1:12; The gas inside the microbubbles is nitrogen.

Example 3

This embodiment provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. The method includes: using a high-pressure gas microporous bubbling gun or high-pressure gas membrane The type bubbling gun is inserted into the slurry conveying pipeline, and micro-bubbles with a diameter of 1-300 μm are introduced to obtain a slurry containing micro-bubbles to achieve scale inhibition;

The time from the position where the microbubbles are inserted into the bubble gun to the easy-to-foul pipe section of the slurry delivery pipeline is 15s; The slurry pipeline is evenly distributed in a ring shape; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 3/4 of the radius of the slurry pipeline; the distance between the nozzles distributed in the inner ring and the center point of the slurry pipeline It is 1/3 of the radius of the pipeline for transporting the pulp; the gun heads of the outer ring and the gun heads of the inner ring are distributed alternately; the ratio of the total gas flow required by the microbubbles to the volume flow rate of the pulp is 1:80; the described The gas inside the microbubbles is a mixture of 50% helium and 50% argon.

Example 4

This example provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. Except that the ratio of the total gas flow required by the microbubbles to the volume flow rate of the pulp is 1:5, other conditions and implementation Example 1 is the same.

Example 5

This example provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. Except that the ratio of the total gas flow required by the microbubbles to the volume flow rate of the pulp is 1:120, other conditions and implementation Example 1 is the same.

Example 6

This example provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid. In addition to deleting the nozzles distributed in the outer ring, only the nozzles distributed in the inner ring are left in the pipeline for conveying the slurry. Except that a circle is evenly distributed, other conditions are the same as in Example 1.

Example 7

This embodiment provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid, except that the distance between the nozzles distributed on the outer ring and the central point of the slurry pipeline is 3/5 of the radius of the slurry pipeline. Other conditions are the same as in Example 1.

Example 8

This embodiment provides a method for using microbubble scale inhibition in the production process of wet-process phosphoric acid, except that the distance between the nozzles distributed on the outer ring and the central point of the slurry pipeline is 9/10 of the radius of the slurry pipeline, Other conditions are the same as in Example 1.

Comparative example 1

This comparative example provides a method of using micro-bubbles for scale inhibition in the production process of wet-process phosphoric acid. The method is the same as that of Example 1 except that bubbles with a diameter of 1-50 mm are introduced in the same volume.

Table 1 lists the solid thickness results deposited on the pipe wall of the slurry transport pipeline in the above-mentioned embodiments and comparative examples.

Table 1

The following points can be seen from Table 1:

(1) From comprehensive examples 1 to 3, it can be seen that in the production process of wet-process phosphoric acid provided by the present invention, the method of microbubble scale inhibition can effectively avoid pipe wall deposition or scaling, and strengthen peeling and deposition on pipe walls and pipe elbows Or the solid at the variable diameter, the thickness of the solid finally deposited on the wall of the slurry pipeline is small;

(2) comprehensive embodiment 1 and embodiment 4～5 can find out, the ratio of the gas total flow required by embodiment 4 microbubbles and the volumetric flow rate of ore slurry is 1:5, and the amount of microbubbles is more, and microbubbles and After the slurry is mixed, it cannot form a multi-phase fluid with strong shear force, and the removal effect of the solid deposited on the pipe wall, pipe elbow or variable diameter is poor, and the thickness of the solid deposited on the pipe wall of the slurry transportation pipe is 1.55cm; Example 5 The ratio of the total gas flow required by microbubbles to the volume flow rate of the ore slurry is 1:120, the amount of microbubbles is small, and the microbubble "protective film" cannot be well formed on the pipe wall or the surface of the scale, and After the micro-bubbles are mixed with the slurry, they cannot form a multiphase fluid with strong shear force, and the solid thickness finally deposited on the wall of the slurry delivery pipeline is 1.46cm;

(3) Combining Example 1 and Examples 6 to 8, it can be seen that in Example 6, only the nozzles distributed in the inner ring are distributed uniformly in a circle in the slurry pipeline, and in Example 7, they are distributed in the outer ring The distance between the gun head and the center point of the slurry pipeline is 3/5 of the radius of the slurry pipeline, and the distance between the gun head distributed on the outer ring and the center point of the slurry pipeline in embodiment 8 is 9/10 of the radius of the slurry pipeline. The scale inhibition effect of the slurry pipeline is poor, and the thickness of the solid deposited on the wall of the slurry pipeline is relatively large;

(5) Combining Example 1 and Comparative Example 1, it can be seen that Comparative Example 1 introduces bubbles with the same air volume and a diameter of 1 to 50 mm. Because large bubbles of millimeter order are very easy to aggregate in the pipeline to form a large-scale air mass, that is, in the The continuous phase of gas is formed in the slurry, and it is difficult to form a multiphase fluid with strong shear force. The solid thickness finally deposited on the wall of the slurry pipeline is 5.66cm; and the introduction of millimeter-sized large bubbles is not conducive to the stable transportation of the fluid. It will also cause serious cavitation to the delivery pump.

To sum up, the microbubble antiscaling method provided by the present invention in the production process of wet-process phosphoric acid introduces microbubbles in the slurry transportation process to avoid pipe wall deposition or scaling, and strengthens peeling and deposition on pipe walls, pipe elbows or The solid at the variable diameter can realize the descaling and antiscaling of the pipeline and avoid the clogging of the pipeline, which is suitable for large-scale promotion and application.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and those skilled in the art should understand that any person skilled in the art should be aware of any disclosure in the present invention Within the technical scope, easily conceivable changes or substitutions all fall within the scope of protection and disclosure of the present invention.

Claims (10)

1. A method for using microbubbles in the production process of wet-process phosphoric acid, characterized in that, the method comprises: introducing microbubbles in the slurry pipeline for wet-process phosphoric acid production to obtain the ore pulp containing microbubbles, Realize anti-scaling. 2. The method according to claim 1, characterized in that, the described way of introducing microbubbles is to insert a bubbling gun into the pipeline for transporting ore slurry, and the microbubbles are ejected from the bubbling gun; Preferably, the bubbling gun comprises a high-pressure gas microporous bubbling gun or a high-pressure gas membrane-type bubbling gun; Preferably, the pressure of the high-pressure gas microporous bubbling gun and the high-pressure gas membrane bubbling gun is 0.4-0.8 MPa. 3. The method according to claim 1 or 2, characterized in that the time from the position where the microbubbles are inserted into the bubbling gun to the pipe section prone to fouling of the slurry pipeline is 0.5s to 15s. 4. The method according to any one of claims 1-3, characterized in that, the position where the bubble gun releases microbubbles is at the top of the bubble gun. 5. The method according to any one of claims 1-4, characterized in that, the tips of the bubbling guns are uniformly distributed in a ring shape in the slurry transport pipeline. 6. The method according to any one of claims 1 to 5, characterized in that the distance between the nozzles distributed on the outer ring and the central point of the slurry pipeline is 3/4 to 2/3 of the radius of the slurry pipeline; Preferably, the distance between the nozzles distributed in the inner ring and the central point of the slurry delivery pipeline is 1/3-1/2 of the radius of the slurry delivery pipeline. 7. The method according to any one of claims 1-6, characterized in that the tips of the outer ring and the tips of the inner ring are distributed alternately. 8. The method according to any one of claims 1 to 7, characterized in that the ratio of the total gas flow required by the microbubbles to the volume flow of the pulp is 1: (12 to 80); Preferably, the microbubbles have a diameter of 1-500 μm. 9. The method according to any one of claims 1-8, wherein the gas in the microbubbles comprises any one or a combination of at least two of air, nitrogen, helium or argon. 10. The method according to any one of claims 1 to 9, characterized in that the method comprises: during the production process of wet-process phosphoric acid, using a high-pressure gas microporous bubbling gun with a pressure of 0.4-0.8 MPa or a high-pressure The gas membrane bubbling gun is inserted into the slurry pipeline to introduce micro-bubbles with a diameter of 1-500 μm to obtain a slurry containing micro-bubbles to achieve scale inhibition; The time from the position where the microbubbles are inserted into the bubbling gun to the easy-fouling pipe section of the slurry delivery pipeline is 0.5s to 15s; the position where the microbubbles are released from the bubbling gun is at the top, and the The nozzles are evenly distributed in a circular shape in the slurry pipeline; the distance between the nozzles distributed in the outer ring and the center point of the slurry pipeline is 3/4~2/3 of the radius of the slurry pipeline; the nozzles distributed in the inner ring and The distance between the central point of the slurry pipeline is 1/3~1/2 of the radius of the slurry pipeline; the nozzles of the outer ring and the nozzles of the inner ring are distributed alternately; the total gas flow required by the microbubbles is related to the volume of the slurry The flow ratio is 1:(12-80); the gas in the microbubbles includes any one or a combination of at least two of air, nitrogen, helium or argon.