Defluorination system for nitrophosphate fertilizer

Abstract

The utility model relates to the technical field of nitrophosphate fertilizers, in particular to a defluorination system for a nitrophosphate fertilizer. The nitrophosphate defluorination system comprises a mother liquor tank, a defluorination agent storage tank, a primary desiliconization reaction tank, a secondary desiliconization reaction tank and a desiliconization filter press, the mother liquor tank is connected to the primary desiliconization reaction tank, the fluorine removal agent storage tank is connected to the primary desiliconization reaction tank, the primary desiliconization reaction tank is connected to the secondary desiliconization reaction tank, and the secondary desiliconization reaction tank is connected to the desiliconization filter press. According to the defluorination system for the nitrophosphate fertilizer disclosed by the utility model, defluorination treatment can be carried out on decalcification mother liquor, and solid-liquid separation is carried out by using the desiliconization filter press, so that the defluorination effect is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of nitrophosphate fertilizers, in particular to a nitrophosphate fertilizer defluorination system. Background Art

[0002] The current production process of nitrophosphate fertilizer includes:

[0003] Phosphate rock acid hydrolysis: using nitric acid as an acid hydrolysis agent to convert P2O5 in phosphate rock into a form that can be absorbed by crops;

[0004] Freezing crystallization and filtration: The acid solution after acid hydrolysis contains Ca(NO3)2. By cooling, Ca(NO3)2 is crystallized in the form of Ca(NO3)2·4H2O and suspended in the acid solution, which is then filtered to obtain a frozen mother liquor.

[0005] Decalcification treatment: The frozen mother liquor is decalcified to obtain a decalcified mother liquor.

[0006] It has been discovered that the fluorine content in the decalcification mother liquor is relatively high. If the next step of treatment is carried out, the fluorine will be brought into the final product, causing the fluorine content in nitrophosphate fertilizer to exceed the standard. In addition, during the post-treatment of the decalcification mother liquor, as fluorine is enriched, it will seriously corrode the equipment, posing a potential safety hazard to production.

[0007] Therefore, it is necessary to propose a nitrophosphate fertilizer defluorination system. Utility Model Content

[0008] In order to overcome the shortcomings of the prior art, the utility model provides a nitrophosphate fertilizer defluorination system, which can defluorinate the decalcified mother liquor and use a desiliconizing filter press to separate the solid and liquid to achieve the defluorination effect.

[0009] The technical solution adopted by the utility model to solve its technical problems is:

[0010] A nitrophosphate fertilizer defluorination system, comprising a mother liquor tank, a defluorination agent storage tank, a primary desiliconization reaction tank, a secondary desiliconization reaction tank, and a desiliconization filter press;

[0011] The mother liquor tank is connected to the primary desiliconization reaction tank, the defluorination agent storage tank is connected to the primary desiliconization reaction tank, the primary desiliconization reaction tank is connected to the secondary desiliconization reaction tank, and the secondary desiliconization reaction tank is connected to the desiliconization filter press.

[0012] As a preferred solution, the reaction temperature of the primary desiliconization reaction tank is 35-45°C, and the reaction temperature of the secondary desiliconization reaction tank is 45-55°C.

[0013] As a preferred solution, the secondary desiliconization reaction tank is connected to a desiliconization filter press feed tank, and the desiliconization filter press feed tank is connected to a desiliconization filter press.

[0014] As a more preferred solution, the liquid outlet of the desiliconization filter press is connected to the desiliconization clear liquid tank, and the material outlet of the desiliconization filter press is connected to the acid insoluble matter re-slurry tank.

[0015] As a more preferred solution, the acid insoluble matter reslurry tank is connected to the acid insoluble matter filter press.

[0016] As a more preferred solution, the liquid outlet of the acid-insoluble filter press is connected to a waste liquid tank.

[0017] As a more preferred solution, the discharge port of the acid-insoluble filter press is connected to a waste tank.

[0018] As a preferred solution, the feed inlet of the primary desiliconization reaction tank is connected to a sulfuric acid tank.

[0019] As a preferred solution, the defluorinating agent in the defluorinating agent storage tank is sodium sulfate.

[0020] As a preferred solution, the mother liquor in the mother liquor tank is decalcified mother liquor.

[0021] The beneficial effects of the utility model are:

[0022] The present application discloses a nitric phosphate fertilizer defluorination system, which comprises the following steps: adding the defluorination agent in the defluorination agent storage tank into the primary desiliconization reaction tank, and performing defluorination reaction in the primary desiliconization reaction tank and the secondary desiliconization reaction tank; performing filter press treatment on the reaction liquid in the desiliconization filter press feed tank to obtain acid insoluble matter, and performing re-slurry treatment on the acid insoluble matter to obtain fluoride salt insoluble matter. It can be seen that the present system can defluorinate the decalcified mother liquor, and perform solid-liquid separation by the desiliconization filter press to achieve the defluorination effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic structural diagram of a nitrophosphate fertilizer defluorination system described in this application;

[0025] Figure 2 This is a schematic diagram of a nitrophosphate fertilizer defluorination system in operation according to the present application;

[0026] Among them: 1. Mother liquor tank; 2. Defluorination agent storage tank; 3. Primary desiliconization reaction tank; 4. Secondary desiliconization reaction tank; 5. Desiliconization filter press; 6. Desiliconization filter press feed tank; 7. Desiliconization clear liquid tank; 8. Acid insoluble matter re-slurry tank; 9. Acid insoluble matter filter press; 10. Waste liquid tank; 11. Waste material tank; 12. Sulfuric acid tank. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0028] As used herein, "and / or" includes any and all combinations of one or more associated listed items. The terms used herein are only used to describe specific embodiments and are not intended to limit the present invention. As used herein, the singular forms "a", "an", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It is further understood that "including", when used in this specification, specifies the stated features, integers, steps, operations, elements and / or compositions, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, compositions and / or combinations thereof.

[0029] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by ordinary technicians in the technical field to which the utility model belongs. It is further understood that terms, such as defined in commonly used dictionaries, are interpreted in accordance with their meanings in the context of the relevant field, and are not idealized or overly formal meanings, unless explicitly defined as such herein.

[0030] The exemplary utility model described herein may appropriately lack any one or more element limitations that are not specifically disclosed herein. Therefore, the terms "comprise", "include", "contain", etc. should be understood broadly and non-restrictively. In addition, the terminology used herein is used as a description, not a limitation, and it is unintentional to use these terminology expressions that do not include any equivalent characteristics, but only describe some of their characteristics, but various modifications are possible within the scope of the utility model according to the rights. Therefore, although the utility model has been specifically disclosed through preferred embodiments and optional features, the modifications disclosed herein to embody the changes of the utility model may be recorded by those skilled in the art, and such modifications and changes will be considered to be within the scope of the utility model.

[0031] In order to solve the problem that the fluorine content in nitrophosphate fertilizer products exceeds the standard and the equipment will be corroded when the fluorine content is too high during the production process, the present application provides the following Figure 1-2 As shown, a nitrophosphate fertilizer defluorination system comprises a mother liquor tank 1, a defluorination agent storage tank 2, a primary desiliconization reaction tank 3, a secondary desiliconization reaction tank 4, and a desiliconization filter press 5;

[0032] The mother liquor tank 1 is connected to the primary desiliconization reaction tank 3 , the defluorination agent storage tank 2 is connected to the primary desiliconization reaction tank 3 , the primary desiliconization reaction tank 3 is connected to the secondary desiliconization reaction tank 4 , and the secondary desiliconization reaction tank 4 is connected to the desiliconization filter press 5 .

[0033] Therefore, in the above technical solution, the discharge port connected to the mother liquor tank 1 is connected to the feed port of the primary desiliconization reaction tank 3, the discharge port of the defluorination agent storage tank 2 is connected to the feed port of the primary desiliconization reaction tank 3, the discharge port of the primary desiliconization reaction tank 3 is connected to the feed port of the secondary desiliconization reaction tank 4, and the discharge port of the secondary desiliconization reaction tank 4 is connected to the feed port of the desiliconization filter press 5. Through the above technical solution, the defluorination agent storage tank can be introduced into the primary desiliconization reaction tank, and the mother liquor in the mother liquor tank can be introduced into the primary desiliconization reaction tank. The mother liquor can react with the defluorination agent in the primary desiliconization reaction tank and the secondary desiliconization reaction tank to convert fluoride ions into acid-insoluble substances, and the acid-insoluble substances are then removed by the desiliconization filter press.

[0034] In one embodiment, the reaction temperature of the primary desiliconization reaction tank 3 is 35-45°C, and the reaction temperature of the secondary desiliconization reaction tank 4 is 45-55°C. Specifically, the reaction temperature of the primary desiliconization reaction tank is controlled at 35-45°C, and the reaction temperature of the secondary desiliconization reaction tank is controlled at 45-55°C. Such temperature setting is to ensure that the defluorinating agent (such as Glauber's salt) can effectively react with the fluoride ions in the decalcified mother liquor to achieve the precipitation of fluoride ions. The setting of different temperatures of the primary desiliconization reaction tank and the secondary desiliconization reaction tank is to optimize the reaction conditions and improve the defluorination efficiency. Specifically, the defluorinating agent in the defluorinating agent storage tank 2 is Glauber's salt, and the mother liquor in the mother liquor tank 1 is the decalcified mother liquor.

[0035] In one embodiment, the secondary desiliconization reaction tank 4 is connected to a desiliconization filter press feed tank 6 , and the desiliconization filter press feed tank 6 is connected to a desiliconization filter press 5 .

[0036] Specifically, the discharge port of the secondary desiliconization reaction tank 4 is connected to the feed port of the desiliconization filter press feed tank 6, and the discharge port of the desiliconization filter press feed tank 6 is connected to the feed port of the desiliconization filter press 5; through the above technical scheme, after the defluorination reaction, the solid matter (such as fluoride precipitate) generated by the reaction needs to be separated from the liquid, and the desiliconization filter press feed tank serves as an intermediate buffer to ensure the continuous and stable operation of the filter press, and the desiliconization filter press is responsible for solid-liquid separation to achieve the separation effect of acid insoluble matter and liquid.

[0037] In one embodiment, the liquid outlet of the desiliconization filter press 5 is connected to the desiliconization clear liquid tank 7, the material outlet of the desiliconization filter press 5 is connected to the acid insoluble matter re-slurry tank 8, and the acid insoluble matter re-slurry tank 8 is connected to the acid insoluble matter filter press 9. Specifically, the liquid outlet of the desiliconization filter press 5 is connected to the feed port of the desiliconization clear liquid tank 7, the material outlet of the desiliconization filter press 5 is connected to the feed port of the acid insoluble matter re-slurry tank 8, and the material outlet of the acid insoluble matter re-slurry tank 8 is connected to the feed port of the acid insoluble matter filter press 9.

[0038] In the above technical solution, the liquid outlet of the desiliconization filter press is connected to the desiliconization clear liquid tank, which can collect the clear liquid after the filter pressing treatment; and the material outlet of the desiliconization filter press is connected to the acid insoluble re-slurry tank, which collects and treats the fluorine-containing solid waste generated during the filter pressing process; the clear liquid treated by the desiliconization filter press has removed most of the fluorine and solid impurities, and can be collected in the desiliconization clear liquid tank for subsequent use or treatment. The fluorine-containing solid waste is pumped into the acid insoluble re-slurry tank for further treatment, such as pumping into clean water for re-slurry (beating), washing, etc., so as to better recycle or treat these wastes.

[0039] In one embodiment, the liquid outlet of the acid insoluble filter press 9 is connected to the waste liquid tank 10, and the material outlet of the acid insoluble filter press 9 is connected to the waste tank 11. The purpose of connecting the material outlet of the acid insoluble filter press to the waste tank is to collect and process the fluorine-containing solid waste after the filter press treatment. The fluorine-containing solid waste after the acid insoluble filter press treatment has been effectively dehydrated and can be conveniently collected in the waste tank for subsequent treatment or disposal.

[0040] In one embodiment, the feed port of the primary desiliconization reaction tank 3 is connected to the sulfuric acid tank 12. Therefore, the sulfuric acid in the sulfuric acid tank can be transported to the primary desiliconization reaction tank, and an appropriate amount of sulfuric acid can be added to the reaction system of the primary desiliconization reaction tank to adjust the pH of the reaction solution and promote the defluorination reaction. The addition of sulfuric acid helps the precipitation or conversion of fluoride ions into a removable form.

[0041] The specific operation process of a nitrophosphate fertilizer defluorination system of the present application is as follows:

[0042] Mother liquor preparation: The decalcified mother liquor obtained from the production process of nitrophosphate fertilizer is stored in the mother liquor tank;

[0043] Preparation of defluoridation agent: prepare defluoridation agent (glauber's salt) in the defluoridation agent storage tank;

[0044] Sulfuric acid preparation: Prepare the sulphuric acid in the sulphuric acid tank;

[0045] Primary desiliconization reaction: decalcification mother liquor is transported from the mother liquor tank to the primary desiliconization reaction tank through pipelines, sulfuric acid is transported from the sulfuric acid tank to the primary desiliconization reaction tank through pipelines, and defluorination agent is transported from the defluorination agent storage tank to the primary desiliconization reaction tank through pipelines. After the feeding is completed, the temperature of the reaction tank is controlled at 35-45°C;

[0046] Secondary desiliconization reaction: After the primary desiliconization reaction, the liquid is transported to the secondary desiliconization reaction tank, where the defluorination reaction continues. The reaction temperature of the secondary desiliconization reaction tank is controlled at 45-55°C to further optimize the defluorination effect;

[0047] Desiliconization filter press feed: The feed liquid of the secondary desiliconization reaction is transported to the desiliconization filter press feed tank, which can be used to adjust the flow rate of the feed liquid entering the desiliconization filter press;

[0048] Solid-liquid separation: Desiliconization filter press, which separates the feed liquid in the desiliconization filter press feed tank into solid and liquid, wherein the solid part (including fluoride precipitation) is collected and the liquid part (clear liquid) is discharged through the liquid outlet;

[0049] Solid waste treatment: The solid waste discharged from the outlet of the desiliconization filter press is sent to the acid insoluble reslurry tank for further treatment;

[0050] Reslurry and secondary filter pressing: After the solid waste in the acid insoluble reslurry tank is reslurried, it is transported to the acid insoluble filter press for secondary filtration to further reduce the moisture content of the solid waste.

[0051] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A nitrophosphate fertilizer defluorination system, characterized in that: It comprises a mother liquor tank (1), a defluorination agent storage tank (2), a primary desiliconization reaction tank (3), a secondary desiliconization reaction tank (4), and a desiliconization filter press (5); The mother liquor tank (1) is connected to the primary desiliconization reaction tank (3), the defluorination agent storage tank (2) is connected to the primary desiliconization reaction tank (3), the primary desiliconization reaction tank (3) is connected to the secondary desiliconization reaction tank (4), and the secondary desiliconization reaction tank (4) is connected to a desiliconization filter press (5).

2. A nitrophosphate fertilizer defluorination system according to claim 1, characterized in that: The reaction temperature of the primary desiliconization reaction tank (3) is 35-45°C, and the reaction temperature of the secondary desiliconization reaction tank (4) is 45-55°C.

3. A nitrophosphate fertilizer defluorination system according to claim 1, characterized in that: The secondary desiliconization reaction tank (4) is connected to a desiliconization filter press feed tank (6), and the desiliconization filter press feed tank (6) is connected to a desiliconization filter press (5).

4. A nitrophosphate fertilizer defluorination system according to claim 3, characterized in that: The liquid outlet of the desiliconization filter press (5) is connected to the desiliconization clear liquid tank (7), and the material outlet of the desiliconization filter press (5) is connected to the acid insoluble matter reslurry tank (8).

5. A nitrophosphate fertilizer defluorination system according to claim 4, characterized in that: The acid insoluble matter reslurry tank (8) is connected to the acid insoluble matter filter press (9).

6. A nitrophosphate fertilizer defluorination system according to claim 5, characterized in that: The liquid outlet of the acid-insoluble filter press (9) is connected to the waste liquid tank (10).

7. A nitrophosphate fertilizer defluorination system according to claim 5, characterized in that: The discharge port of the acid-insoluble filter press (9) is connected to the waste tank (11).

8. A nitrophosphate fertilizer defluorination system according to claim 1, characterized in that: The feed inlet of the primary desiliconization reaction tank (3) is connected to the sulfuric acid tank (12).

9. A nitrophosphate fertilizer defluorination system according to claim 1, characterized in that: The defluorinating agent in the defluorinating agent storage tank (2) is sodium sulfate.

10. A nitrophosphate fertilizer defluorination system according to claim 1, characterized in that: The mother liquor in the mother liquor tank (1) is a decalcified mother liquor.

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