Production system of defluorinated TCP

Abstract

The utility model discloses a production system of a defluorination TCP (Transmission Control Protocol), which solves the technical problems in the prior art that the consumption of washing liquid is higher, the particulate matter content of tail gas is difficult to reach the standard, and the resource recovery difficulty of circulating absorption neutralization liquid is high. The production system of the defluorinated TCP comprises a raw material pretreatment unit used for pretreating mixed powder of ground phosphate rock, phosphoric acid and sodium salt and outputting particles to be sintered; the first heat exchange unit is used for recovering heat of the high-temperature defluorinated flue gas and outputting first cooled flue gas; the high-temperature dust removal unit is used for recovering impurity particles of the first cooled flue gas and outputting low-dust gas and dust; the second heat exchange unit is used for recovering heat of the low-dust gas and outputting second cooled flue gas; the deacidification unit is used for recovering acidic gas of the second cooled flue gas and outputting a sodium salt solution and clean tail gas; and the crystallization unit is used for recovering sodium salt in the sodium salt solution and outputting sodium salt powder.

Description

Technical Field

[0001] This utility model relates to the technical field of defluorinated TCP, and more specifically, to a production system for defluorinated TCP. Background Technology

[0002] Tricalcium phosphate (TCP) is a common inorganic compound with the chemical formula Ca3(PO4)2. TCP exists in nature as a mineral (such as in natural phosphate rock), usually accompanied by a certain amount of fluoride. In some applications, such as food additives or pharmaceuticals, a low fluoride content in TCP is required, necessitating defluorination treatment. The production of defluorinated TCP through calcination involves volatilizing the fluoride in the mineral under high-temperature conditions, thereby reducing the fluoride content in tricalcium phosphate.

[0003] The calcination method for producing defluorinated TCP products involves mixing phosphate rock powder, phosphate, and sodium salt in a specific ratio, granulating the mixture, and then feeding it into a rotary kiln where coal tar is used as heat energy for high-temperature sintering and defluorination at 1200–1300℃. Currently, the treatment of the high-temperature defluorination flue gas discharged from calcination involves recovering waste heat in a waste heat boiler and then sending it to a scrubbing tower. In the scrubbing tower, a circulating pump sprays the absorbent liquid Ca(OH)2 around to scrub the flue gas to remove particulate matter and acidic gases. The scrubbed gas is then discharged after meeting the standards. However, because the flue gas entering the scrubbing tower still contains a large amount of particulate impurities, the consumption of scrubbing liquid is high, the particulate matter content of the exhaust gas is difficult to meet the standards, and the resource recovery of the circulating absorption and neutralization liquid is difficult because it needs to be filtered before resource recovery, resulting in low resource utilization. Utility Model Content

[0004] The main purpose of this invention is to provide a production system for defluorinated TCP, in order to solve the technical problems in the prior art, such as high consumption of washing liquid, difficulty in meeting the particulate matter content of tail gas, and high difficulty in resource recovery of circulating absorption and neutralization liquid.

[0005] To achieve the above objectives, this utility model provides a production system for defluorinated TCP, the technical solution of which is as follows:

[0006] The defluorination TCP production system includes a rotary kiln and also includes:

[0007] A raw material pretreatment unit is used to pretreat a mixed powder including phosphate rock powder, phosphate and sodium salt and output granules to be sintered; the raw material pretreatment unit includes a granulation device, the discharge port of which is connected to the raw material inlet of a rotary kiln; the rotary kiln processes the granules to be sintered and outputs defluorinated TCP and high-temperature defluorinated flue gas;

[0008] The first heat exchange unit is used to recover the heat of the high-temperature defluorination flue gas and output the first cooled flue gas; the first heat exchange unit includes a first waste heat boiler, the air inlet of the first waste heat boiler is connected to the high-temperature defluorination flue gas outlet of the rotary kiln.

[0009] A high-temperature dust removal unit is used to recover impurities and particulate matter from the first cooled flue gas and output low-dust gas and dust. The high-temperature dust removal unit includes a metal filter element, and the raw gas inlet of the metal filter element is connected to the first cooled flue gas outlet of the first heat exchange unit.

[0010] The second heat exchange unit is used to recover the heat of the low-dust gas and output the second cooled flue gas; the second heat exchange unit includes a second waste heat boiler, the air inlet of the second waste heat boiler is connected to the low-dust gas outlet of the high-temperature dust removal unit.

[0011] A deacidification unit is used to recover acidic gases from the second cooled flue gas and output sodium salt solution and clean tail gas; the deacidification unit includes a deacidification tower, the inlet of which is connected to the outlet of the second cooled flue gas of the second heat exchange unit.

[0012] A crystallization unit is used to recover sodium salt from the sodium salt solution and output sodium salt powder; the crystallization unit includes a crystallization device, the inlet of which is connected to the sodium salt solution outlet of the deacidification unit, and the outlet of which is connected to the mixed powder inlet of the raw material pretreatment unit.

[0013] The advantages of this defluorination TCP production system are as follows: First, a high-temperature-resistant metal filter is used to recover particulate matter before washing, facilitating the recycling of intercepted dust, improving the deacidification efficiency and effect of the deacidification unit, and reducing deacidification costs. Because the sodium salt solution (circulating absorption and neutralization liquid) contains few particulate impurities, it facilitates resource recycling. Second, filtration at a higher temperature prevents phase changes in substances in the high-temperature defluorination flue gas from clogging the filter element, thus improving system stability. Furthermore, the deacidification unit uses sodium hydroxide as an absorbent, outputting a sodium salt solution, and the sodium salt is recovered through a crystallization unit and reused as reaction raw material in the rotary kiln, significantly improving resource utilization and reducing material input costs.

[0014] As a further improvement to the aforementioned defluorination TCP production system, the raw material pretreatment unit also includes a dust densification device. The inlet of the densification device is connected to the dust outlet of the metal filter cartridge, and the outlet of the densification device is connected to the mixing powder inlet of the granulation equipment. This allows for the deep recovery and utilization of valuable resources in the dust, saving material input costs.

[0015] As a further improvement to the aforementioned defluorination TCP production system, the first heat exchange unit further includes an economizer and / or an air cooler.

[0016] As a further improvement to the aforementioned defluorination TCP production system, the high-temperature dust removal unit also includes an electric heater for heating the backflush gas, the outlet of which is connected to the backflush gas inlet of the metal filter element.

[0017] As a further improvement to the aforementioned defluorination TCP production system, the deacidification unit also includes a sodium hydroxide storage tank, a circulating pump for feeding sodium hydroxide into the deacidification tower, and a sodium salt solution storage tank. The sodium hydroxide storage tank is equipped with a level gauge, and the sodium salt solution storage tank is equipped with both a level gauge and a pH meter. Therefore, feeding and discharging can be based on the level gauge readings, and the circulation process of the neutralization solution can be controlled using the pH meter readings, thus improving system stability.

[0018] As a further improvement to the aforementioned defluorination TCP production system, the crystallization unit further includes a reverse osmosis device for concentrating the sodium salt solution. The feed inlet of the reverse osmosis device is connected to the sodium salt solution outlet of the deacidification unit, and the concentrate outlet of the reverse osmosis device is connected to the inlet of the crystallization device. Therefore, by concentrating the sodium salt solution using the reverse osmosis device, the liquid throughput of the crystallization device can be significantly reduced, thereby significantly reducing heat consumption and improving crystallization efficiency.

[0019] As a further improvement to the aforementioned defluorination TCP production system: the heat source inlet of the crystallization equipment is connected to the outlet of the first waste heat boiler, the condensate outlet of the crystallization equipment is connected to the feed inlet of the reverse osmosis equipment, and the clarified liquid outlet of the reverse osmosis equipment is connected to the inlet of the first waste heat boiler. This allows for the deep recovery of valuable resources from the sodium salt solution, significantly saving on the amount of water purchased.

[0020] It is evident that the defluorination TCP production system of this utility model has a simple structure, low equipment investment and operating costs, can achieve deep utilization of resources, significantly reduce raw material costs, and makes it easy for exhaust gas to meet emission standards. It effectively solves the technical problems of high consumption of washing liquid, difficulty in meeting the particulate matter content of exhaust gas standards, and high difficulty in resource recovery of circulating absorption and neutralization liquid in the prior art, and has strong practicality.

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. Attached Figure Description

[0022] The accompanying drawings, which form part of this utility model, are used to aid in understanding this utility model. The contents provided in the drawings and their related descriptions in this utility model can be used to explain this utility model, but do not constitute an improper limitation of this utility model.

[0023] In the attached diagram:

[0024] Figure 1 This is a schematic diagram of the defluorination TCP production system of Embodiment 1 of this utility model.

[0025] Figure 2 This is a schematic diagram of the defluorination TCP production system of Embodiment 2 of this utility model.

[0026] Figure 3 This is a schematic diagram of the defluorination TCP production system of Embodiment 3 of this utility model.

[0027] The relevant markings in the above figures are:

[0028] 100-Rotary kiln, 110-Granulation equipment, 120-Enrichment equipment, 200-First heat exchange unit, 310-Metal filter element, 320-Electric heater, 400-Second heat exchange unit, 510-Deacidification tower, 520-Sodium hydroxide storage tank, 530-Sodium salt solution storage tank, 610-Crystallization equipment, 620-Reverse osmosis equipment. Detailed Implementation

[0029] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0030] The technical solutions and features provided in the various parts of this utility model, including the following description, can be combined with each other without conflict.

[0031] Furthermore, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, and not all of the embodiments. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the protection scope of the present invention.

[0032] Regarding the terminology and units used in this utility model: The terms "comprising," "having," and any variations thereof in the specification, claims, and related parts of this utility model are intended to cover non-exclusive inclusion.

[0033] Example 1

[0034] Figure 1 This is a schematic diagram of the defluorination TCP production system in this embodiment.

[0035] like Figure 1 The defluorination TCP production system shown includes a rotary kiln 100, a raw material pretreatment unit, a first heat exchange unit 200, a high-temperature dust removal unit, a second heat exchange unit 400, a deacidification unit, and a crystallization unit.

[0036] The raw material pretreatment unit is used to pretreat the mixed powder including phosphate rock powder, phosphate and sodium salt and output the particles to be sintered; the raw material pretreatment unit includes a granulation device 110, the discharge port of the granulation device 110 is connected to the raw material inlet of the rotary kiln 100; the rotary kiln 100 processes the particles to be sintered and outputs defluorinated TCP and high-temperature defluorinated flue gas.

[0037] The first heat exchange unit 200 is used to recover the heat of the high-temperature defluorination flue gas and output the first cooled flue gas; the first heat exchange unit 200 includes an economizer, an air cooler and a first waste heat boiler that are sequentially connected to the high-temperature defluorination flue gas outlet of the rotary kiln 100.

[0038] The high-temperature dust removal unit is used to recover impurities and particulate matter from the first cooled flue gas and output low-dust gas and dust; the high-temperature dust removal unit includes a metal filter element 310 and an electric heater 320, the raw gas inlet of the metal filter element 310 is connected to the first cooled flue gas outlet of the first heat exchange unit 200; the electric heater 320 is used to heat the backflush gas, and the gas outlet of the electric heater 320 is connected to the backflush gas inlet of the metal filter element 310.

[0039] The second heat exchange unit 400 is used to recover the heat of the low-dust gas and output the second cooled flue gas; the second heat exchange unit 400 includes a second waste heat boiler, and the air inlet of the second waste heat boiler is connected to the low-dust gas outlet of the high-temperature dust removal unit.

[0040] The deacidification unit is used to recover the acidic gas from the second cooled flue gas and output sodium salt solution and clean tail gas; the deacidification unit includes a deacidification tower 510, a sodium hydroxide storage tank 520, a circulation pump that inputs sodium hydroxide into the deacidification tower 510, and a sodium salt solution storage tank 530; the air inlet of the deacidification tower 510 is connected to the second cooled flue gas outlet of the second heat exchange unit 400; the sodium hydroxide storage tank 520 is equipped with a level gauge; the sodium salt solution storage tank 530 is equipped with a level gauge and a pH meter.

[0041] The crystallization unit is used to recover sodium salt from the sodium salt solution and output sodium salt powder; the crystallization unit includes a crystallization device 610, the inlet of the crystallization device 610 is connected to the sodium salt solution outlet of the deacidification unit, and the outlet of the crystallization device 610 is connected to the mixed powder inlet of the raw material pretreatment unit.

[0042] Example 2

[0043] Figure 2 This is a schematic diagram of the defluorination TCP production system in this embodiment.

[0044] Compared to Example 1, the difference in the defluorination TCP production system of this embodiment is that the crystallization unit further includes a reverse osmosis device 620 for concentrating the sodium salt solution. The raw solution inlet of the reverse osmosis device 620 is connected to the sodium salt solution outlet of the deacidification unit, and the concentrated solution outlet of the reverse osmosis device 620 is connected to the inlet of the crystallization device 610. The heat source inlet of the crystallization device 610 is connected to the outlet of the first waste heat boiler, the condensate outlet of the crystallization device 610 is connected to the raw solution inlet of the reverse osmosis device 620, and the clarified solution outlet of the reverse osmosis device 620 is connected to the inlet of the first waste heat boiler.

[0045] Example 3

[0046] Figure 3 This is a schematic diagram of the defluorination TCP production system in this embodiment.

[0047] Compared with Example 2, the difference in the defluorination TCP production system of this example is that the raw material pretreatment unit further includes a encryption device 120 for encrypting dust. The inlet of the encryption device 120 is connected to the dust outlet of the metal filter element 310, and the outlet of the encryption device 120 is connected to the mixed powder inlet of the granulation device 110.

[0048] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the above description of this utility model without inventive effort should fall within the protection scope of this utility model.

Claims

1. A defluorination TCP production system, comprising a rotary kiln (100), characterized in that: Also includes: The raw material pretreatment unit is used to pretreat mixed powders including phosphate rock powder, phosphate and sodium salt and output particles to be sintered. The raw material pretreatment unit includes a granulation device (110), the discharge port of which is connected to the raw material inlet of a rotary kiln (100); the rotary kiln (100) processes the granules to be sintered and outputs defluorinated TCP and high-temperature defluorinated flue gas. The first heat exchange unit (200) is used to recover the heat of the high-temperature defluorination flue gas and output the first cooled flue gas; the first heat exchange unit (200) includes a first waste heat boiler, the air inlet of the first waste heat boiler is connected to the high-temperature defluorination flue gas outlet of the rotary kiln (100). A high-temperature dust removal unit is used to recover impurities and particulate matter from the first cooled flue gas and output low-dust gas and dust; the high-temperature dust removal unit includes a metal filter element (310), the raw gas inlet of the metal filter element (310) is connected to the first cooled flue gas outlet of the first heat exchange unit (200); The second heat exchange unit (400) is used to recover the heat of the low-dust gas and output the second cooled flue gas; the second heat exchange unit (400) includes a second waste heat boiler, the air inlet of the second waste heat boiler is connected to the low-dust gas outlet of the high-temperature dust removal unit. A deacidification unit is used to recover the acidic gas from the second cooled flue gas and output sodium salt solution and clean tail gas; the deacidification unit includes a deacidification tower (510), the inlet of which is connected to the second cooled flue gas outlet of the second heat exchange unit (400); A crystallization unit is used to recover sodium salt from the sodium salt solution and output sodium salt powder; the crystallization unit includes a crystallization device (610), the inlet of the crystallization device (610) is connected to the sodium salt solution outlet of the deacidification unit, and the outlet of the crystallization device (610) is connected to the mixed powder inlet of the raw material pretreatment unit.

2. The defluorination TCP production system as described in claim 1, characterized in that: The raw material pretreatment unit also includes a densification device (120) for densifying dust. The inlet of the densification device (120) is connected to the dust outlet of the metal filter cartridge (310), and the outlet of the densification device (120) is connected to the mixed powder inlet of the granulation device (110).

3. The defluorination TCP production system as described in claim 1, characterized in that: The first heat exchange unit (200) also includes an economizer and / or an air cooler.

4. The defluorination TCP production system as described in claim 1, characterized in that: The high-temperature dust removal unit also includes an electric heater (320) for heating the backflush air, and the outlet of the electric heater (320) is connected to the backflush air inlet of the metal filter element (310).

5. The defluorination TCP production system as described in claim 1, characterized in that: The deacidification unit also includes a sodium hydroxide storage tank (520), a circulation pump that feeds sodium hydroxide into the deacidification tower (510), and a sodium salt solution storage tank (530). The sodium hydroxide storage tank (520) is equipped with a level gauge, and the sodium salt solution storage tank (530) is equipped with a level gauge and a pH meter.

6. The defluorination TCP production system as described in claim 1, characterized in that: The crystallization unit also includes a reverse osmosis device (620) for concentrating the sodium salt solution. The raw liquid inlet of the reverse osmosis device (620) is connected to the sodium salt solution outlet of the deacidification unit, and the concentrated liquid outlet of the reverse osmosis device (620) is connected to the liquid inlet of the crystallization device (610).

7. The defluorination TCP production system as described in claim 6, characterized in that: The heat source inlet of the crystallization device (610) is connected to the outlet of the first waste heat boiler, the condensate outlet of the crystallization device (610) is connected to the raw liquid inlet of the reverse osmosis device (620), and the clear liquid outlet of the reverse osmosis device (620) is connected to the inlet of the first waste heat boiler.

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