Device for recycling anhydrous hydrogen fluoride by-product

Abstract

The utility model discloses a device for recycling anhydrous hydrogen fluoride by-products. A hydrogen fluoride reaction tower is connected with a stock bin through a filter, the stock bin is connected with a repulping tank through a pipeline, the repulping tank is connected with a phosphoric acid reaction tower through a repulping pump, and the phosphoric acid reaction tower is connected with the hydrogen fluoride reaction tower through a pipeline; and the re-pulping tank is connected with a phosphoric acid storage tank through a phosphoric acid aging tank. According to the device disclosed by the utility model, the fluorine element in the fluorine-containing silicon slag, which is a byproduct of anhydrous hydrogen fluoride, is recycled, and the recycled fluorine element can be used for producing the anhydrous hydrogen fluoride again, so that the utilization efficiency of resources is improved, the yield of the anhydrous hydrogen fluoride is increased, and meanwhile, the influence on the environment is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of anhydrous hydrogen fluoride production, and particularly relates to a device for recycling by-products of anhydrous hydrogen fluoride. Background Art

[0002] During the industrial production of wet-process phosphoric acid, a large amount of fluorosilicic acid is by-produced in the phosphoric acid concentration section. When anhydrous hydrogen fluoride is produced by the concentrated sulfuric acid method using fluorosilicic acid as a raw material, a large amount of fluorine-containing silicon slag is by-produced, in which fluorine (including free fluorine and lattice fluorine) exists in the form of fluorosilicic acid and silicon exists in the form of silicon dioxide. The silicon dioxide in the fluorine-containing silicon slag has poor activity and contains fluorine, and cannot be directly used as a filler in rubber or other fields. Therefore, it is generally treated by stacking, which not only wastes land but also easily causes environmental pollution and resource waste. The existing idea is to remix the fluorine-containing silicon slag with phosphogypsum after re-slurrying, but there are problems such as difficult control of the water balance, difficult operation of the slag yard filter, and impact on the dry discharge of phosphogypsum. In addition, after the fluorine-containing silicon slag is mixed and stacked with phosphogypsum, the fluorine element contained will be wasted. Therefore, how to make good use of the fluorine and silicon resources in the fluorine-containing silicon slag is a major issue in clean production and comprehensive utilization of resources, and has important practical significance for the normal production of enterprises.

[0003] Chinese Patent CN116443885B discloses a method and system for resource utilization of fluorine-containing silicon slag. The method includes a fluorine-containing silicon slag treatment step and a wastewater treatment step, and the system includes a defluorination reaction device, a waste liquid collection device, a dispersion device, a shear pump, a modification reaction device, a drying device, a re-slurry water storage device, a waste liquid treatment device, and an MVR concentration system. It harmlessizes and fully utilizes the fluorine-containing silicon slag, and the produced nano-active silicon dioxide has good performance. During the production process, water resources are recycled and there is no wastewater discharge, and the environmental benefits and technical and economic benefits are remarkable.

[0004] Chinese Patent CN104803366A discloses a method for recycling fluorine-containing silicon slag to increase the recovery amount of fluorine resources in phosphoric acid. Fluorine-containing silicon slag is added to dilute sulfuric acid, then concentrated, and fluorine is blown out by passing air and then filtered to obtain defluorinated concentrated phosphoric acid. The fluorine-containing gas blown out by air is recovered to form fluorosilicic acid, which is then used to prepare anhydrous hydrogen fluoride and by-product fluorine-containing silicon slag.

[0005] Although the resource utilization of fluorine-containing silicon slag can be achieved in the prior art, the fluorine element in it cannot be well recovered and utilized, and there is still a waste of fluorine resources. In addition, there are problems of blockage during the transportation of fluorine-containing silicon slag and scaling in the transportation pipeline of phosphoric acid, which have not been solved. Therefore, it is necessary to develop a device that can solve the problems of pipeline scaling and blockage while recycling fluorine-containing silicon slag. Summary of the Invention

[0006] In view of the above technical problems, the utility model provides a device for recycling by-products of anhydrous hydrogen fluoride, which realizes the recycling of fluorine elements in fluorosilicate slag, a by-product of anhydrous hydrogen fluoride. The recycled fluorine elements can be used again in the production of anhydrous hydrogen fluoride, improving the utilization efficiency of resources, increasing the output of anhydrous hydrogen fluoride, and reducing the impact on the environment at the same time.

[0007] To achieve the above object, the utility model provides a device for recycling by-products of anhydrous hydrogen fluoride. The hydrogen fluoride reaction tower is connected to the silo through a filter, the silo is connected to the re-slurry tank through a pipeline, the re-slurry tank is connected to the phosphoric acid reaction tower through a re-slurry pump, and the phosphoric acid reaction tower is connected to the hydrogen fluoride reaction tower through a pipeline.

[0008] Preferably, the filter is composed of a first filter, a second filter and a third filter; the silo is composed of a first silo, a second silo and a third silo.

[0009] More preferably, the first filter is connected to the first silo through a pipeline, the second filter is connected to the second silo through a pipeline; the third filter is connected to the third silo through a pipeline.

[0010] Preferably, a silicon slag regulating valve and a first flowmeter are provided on the pipeline connecting the silo and the re-slurry tank.

[0011] Preferably, the re-slurry tank is connected to the phosphoric acid storage tank through a phosphoric acid aging tank.

[0012] More preferably, a phosphoric acid regulating valve and a second flowmeter are provided on the pipeline connecting the phosphoric acid aging tank and the re-slurry tank.

[0013] Preferably, a stirring device is provided in the re-slurry tank, and the stirring device is connected to a motor.

[0014] Preferably, the re-slurry tank is connected to the silo through a re-slurry circulation pump.

[0015] Preferably, the re-slurry tank is connected to the concentration reaction tower through a re-slurry pump.

[0016] Preferably, the filter is connected to the filtrate storage tank through a pipeline.

[0017] The beneficial effects of the utility model are as follows:

[0018] 1. Recycle the by-product of hydrogen fluoride - fluorosilicate slag, mix it with dilute phosphoric acid to release fluorine elements, and then react to obtain fluosilicic acid for use in the production of hydrogen fluoride again, improving the utilization rate of fluorine elements, reducing resource waste, increasing the production capacity of hydrogen fluoride, facilitating large-scale industrial production, and reducing raw material costs at the same time.

[0019] 2. The dilute phosphoric acid used in the reaction process is also a by-product of wet-process phosphoric acid, which reduces the treatment pressure of the by-product and avoids waste of resources at the same time. The phosphoric acid after the reaction is treated in a concentration reaction tower, temporarily stored and then used for the next process or directly discharged and stored in a heap.

[0020] 3. After the fluorine element in the fluorosilicate slag is recycled, the remaining mixed solution containing silicon dioxide can be used for pipeline dredging when transported in the pipeline, especially to help solve the scaling problem existing in the wet-process phosphoric acid transportation pipeline. Brief Description of the Drawings

[0021] Figure 1 is a schematic diagram of the overall structure of the present invention. 1 is a hydrogen fluoride reaction tower, 2 is a first filter, 3 is a second filter, 4 is a third filter, 5 is a first bin, 6 is a phosphoric acid regulating valve, 7 is a silicon slag regulating valve, 8 is a first flowmeter, 9 is a second flowmeter, 10 is a phosphoric acid aging tank, 11 is a phosphoric acid storage tank, 12 is an electric motor, 13 is a re-slurry tank, 14 is a stirring device, 15 is a second bin, 16 is a third bin, 17 is a filtrate storage tank, 18 is a re-slurry pump, 19 is a concentration reaction tower, 20 is a phosphoric acid reaction tower, 21 is a re-slurry circulation pump. Detailed Embodiments

[0022] The technical solutions of the present invention will be further explained and illustrated below in conjunction with the drawings and specific embodiments. It should be noted that the following embodiments are only the preferred embodiments of the present invention and should not be construed as a limitation of the present invention. The protection scope of the present invention should be based on the content recorded in the claims. Modifications and substitutions made by those skilled in the art to the technical solutions of the present invention without creative efforts all fall within the protection scope of the present invention.

[0023] Embodiment 1

[0024] A device for recycling by-products of anhydrous hydrogen fluoride. The hydrogen fluoride reaction tower 1 is connected to a bin through a filter, and the bin is connected to the re-slurry tank 13 through a pipeline to preliminarily separate the fluorosilicate slag and the reaction liquid generated in the hydrogen fluoride production process, and then perform re-slurrying to release fluorine elements. The re-slurry tank 13 is connected to the phosphoric acid reaction tower 20 through a re-slurry pump 18 to react the fluorine elements released from the re-slurry tank 13 with phosphoric acid to generate fluosilicic acid. The phosphoric acid reaction tower 20 is connected to the hydrogen fluoride reaction tower 1 through a pipeline to transport the generated fluosilicic acid to the hydrogen fluoride reaction tower 1 for recycling, produce hydrogen fluoride, improve the utilization efficiency of fluorine elements and the output of hydrogen fluoride, save resources and reduce the impact on the environment.

[0025] Preferably, the filter is composed of a first filter 2, a second filter 3 and a third filter 4; the silo is composed of a first silo 5, a second silo 15 and a third silo 16, which can empty the reaction products in the hydrogen fluoride reaction tower 1 at one time, and the three sets of filters and silos are connected in parallel for standby to avoid affecting the production efficiency due to device blockage.

[0026] Further preferably, the first filter 2 is connected to the first silo 5 by a pipeline, the second filter 3 is connected to the second silo 15 by a pipeline; the third filter 4 and the third silo 16 are connected by a pipeline.

[0027] Preferably, a silicon slag regulating valve 7 and a first flowmeter 8 are provided on the pipeline connecting the silo and the repulping tank 13 to regulate the amount of fluorine-containing silicon slag entering the repulping tank 13.

[0028] Preferably, the repulping tank 13 is connected to the phosphoric acid storage tank 11 through the phosphoric acid aging tank 10 to transport dilute phosphoric acid into the repulping tank 13 to help release the fluorine element in the fluorine-containing silicon slag. At the same time, the dilute phosphoric acid does not react with silicon dioxide, which can purify silicon dioxide, and there will be no large amount of fluorine-containing gas escaping during the repulping process, improving safety and avoiding waste of fluorine resources.

[0029] Further preferably, a phosphoric acid regulating valve 6 and a second flowmeter 9 are provided on the pipeline connecting the phosphoric acid aging tank 10 and the repulping tank 13 to control the amount of dilute phosphoric acid entering the repulping tank 13, so that the fluorine-containing silicon slag and the dilute phosphoric acid are kept in an appropriate ratio to enable the reaction to proceed quickly and without blockage.

[0030] Preferably, a stirring device 14 is provided in the repulping tank 13, and the stirring device 14 is connected to the motor 12 to help the fluorine-containing silicon slag and the dilute phosphoric acid to be quickly mixed evenly.

[0031] Preferably, the repulping tank 13 is connected to the silo through the repulping circulation pump 21.

[0032] Preferably, the repulping tank 13 is connected to the concentration reaction tower 19 by a pipeline through the repulping pump 18 to transport the mixed solution releasing the fluorine element to the concentration reaction tower 19 for use as a defluorinating agent.

[0033] Preferably, the filter is connected to the filtrate storage tank 17 by a pipeline to store the filtered solution for use in the next process.

Claims

1. An apparatus for recycling by-products of anhydrous hydrogen fluoride, characterized in that: The hydrogen fluoride reaction tower (1) is connected to the silo through a filter, the silo is connected to the re-slurry tank (13) through a pipeline, the re-slurry tank (13) is connected to the phosphoric acid reaction tower (20) through a re-slurry pump (18), and the phosphoric acid reaction tower (20) is connected to the hydrogen fluoride reaction tower (1) through a pipeline.

2. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: The filter consists of a first filter (2), a second filter (3) and a third filter (4); the silo consists of a first silo (5), a second silo (15) and a third silo (16).

3. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 2, characterized in that: The first filter (2) is connected to the first silo (5) through a pipeline, the second filter (3) is connected to the second silo (15) through a pipeline; the third filter (4) is connected to the third silo (16) through a pipeline.

4. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: A silica slag regulating valve (7) and a first flow meter (8) are provided on the pipeline connecting the silo and the re-slurry tank (13).

5. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: The re-slurry tank (13) is connected to the phosphoric acid storage tank (11) through a phosphoric acid aging tank (10).

6. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 5, characterized in that: A phosphoric acid regulating valve (6) and a second flow meter (9) are provided on the pipeline connecting the phosphoric acid aging tank (10) and the re-slurry tank (13).

7. An apparatus for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: A stirring device (14) is provided in the re-slurry tank (13), and the stirring device (14) is connected to the motor (12).

8. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: The re-slurry tank (13) is connected to the silo through a re-slurry circulation pump (21).

9. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, characterized in that: The re-slurry tank (13) is connected to the concentration reaction tower (19) through a re-slurry pump (18) through a pipeline.

10. The device for recycling by-products of anhydrous hydrogen fluoride according to claim 1, wherein: The filter is connected to the filtrate storage tank (17) through a pipeline.

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