阅读说明：本技术 提高湿法磷酸氟收率的系统 (System for improving wet-process fluorine phosphate yield ) 是由 梅毅 何宾宾 谢德龙 朱远蹠 聂云祥 于 2021-03-08 设计创作，主要内容包括：本发明公开了一种提高湿法磷酸氟收率的系统,包括搅拌桶,浓磷酸与脱氟剂通过管道反应器进入搅拌桶中混合均匀,所述搅拌桶的出料口与筛板脱氟塔的二段浓磷酸进口相连通,空气经空气加热器后与所述筛板脱氟塔的下部的热空气进口相连通,饱和蒸汽与所述筛板脱氟塔下部的蒸汽进口相连通,所述筛板脱氟塔上侧的氟尾气出口与雾沫分离器相连通,所述雾沫分离器与氟吸收洗涤塔相连通,所述筛板脱氟塔下部的湿法磷酸出口与成品酸储槽相连通；本发明所述系统可使现有湿法磷酸生产磷铵工艺氟的收率提高20%以上,每吨P-2O-5氟硅酸量为60kg以上,且产品磷铵的氟含量显著降低,具有明显的经济效益,资源效益及环境效益。(The invention discloses a system for improving the yield of wet-process phosphoric acid fluoride, which comprises a stirring barrel, wherein concentrated phosphoric acid and a defluorinating agent enter the stirring barrel through a pipeline reactor to be uniformly mixed, a discharge port of the stirring barrel is communicated with a two-stage concentrated phosphoric acid inlet of a sieve plate defluorinating tower, air is communicated with a hot air inlet at the lower part of the sieve plate defluorinating tower after passing through an air heater, saturated steam is communicated with a steam inlet at the lower part of the sieve plate defluorinating tower, a fluorine tail gas outlet at the upper side of the sieve plate defluorinating tower is communicated with a mist separator, the mist separator is communicated with a fluorine absorption washing tower, and a wet-process phosphoric acid outlet at the lower part of the sieve plate; the system of the invention can improve the fluorine yield of the prior process for producing ammonium phosphate by wet-process phosphoric acid by more than 20 percent, and each ton of P 2 O 5 The fluosilicic acid amount is more than 60kg, and the fluorine content of the product ammonium phosphate is obviously reduced, thereby having obvious economic benefit, resource benefit and environmental benefit.)

1. A system for improving yield of wet-process fluorine phosphate is characterized in that: comprises a stirring barrel (1), concentrated phosphoric acid and defluorinating agent enter the stirring barrel (1) through a pipeline reactor to be uniformly mixed, the discharge hole of the mixing tank (1) is communicated with a two-stage concentrated phosphoric acid inlet (203) of a sieve plate defluorination tower (2), air passes through an air heater (3) and then is communicated with a hot air inlet (201) at the lower part of the sieve plate defluorination tower (2), saturated steam is communicated with a steam inlet (202) at the lower part of the sieve plate defluorination tower (2), a fluorine tail gas outlet (205) at the upper side of the sieve plate defluorination tower (2) is communicated with the mist separator (4), the mist separator (4) is communicated with the fluorine absorption washing tower (5), the fluorine tail gas is discharged after being treated by the mist separator (4) and the fluorine absorption washing tower (5) in sequence, a wet-process phosphoric acid outlet (204) at the lower part of the sieve plate defluorination tower (2) is communicated with a finished acid storage tank (6);

concentrated phosphoric acid and a defluorinating agent enter a stirring barrel (1) through a pipeline reactor to be uniformly mixed, then the mixture is introduced into a sieve plate defluorinating tower (2) from the upper part, steam is introduced into the sieve plate defluorinating tower (2) from the lower part, and the phosphoric acid and the steam are fully contacted in a countercurrent way to complete defluorination; electric heating hot air is introduced into the bottommost part of the sieve plate defluorination tower (2) to ensure that the fluorine quickly overflows; after steam enters the sieve plate defluorination tower (2), the steam is directly contacted with phosphoric acid, so that the temperature of the phosphoric acid is controlled to be 100 +/-10 ℃.

2. The system for increasing wet process fluorine phosphate yield of claim 1, wherein: the sieve plate defluorination tower (2) is made of an outer carbon steel lining fluorine material.

3. The system for increasing wet process fluorine phosphate yield of claim 1, wherein: the concentration of the concentrated phosphoric acid is 40-55%.

4. The system for increasing wet process fluorine phosphate yield of claim 1, wherein: the steam pressure is 0.1-0.3 MPa, and the temperature of hot air is higher than 100 ℃.

5. The system for increasing wet process fluorine phosphate yield of claim 1, wherein: the ratio of air to phosphoric acid is 0.001-0.01 m³/m³。

6. The system for increasing wet process fluorine phosphate yield of claim 1, wherein: the defluorinating agent is a byproduct of producing hydrofluoric acid by fluosilicic acid, wherein active SiO is₂60-80%, F is less than 10%, and the dosage of defluorinating agent is one ton of P₂O₅Less than 10 kg.

Technical Field

The invention relates to the technical field of wet-process phosphoric acid production, in particular to a system capable of improving the yield of wet-process phosphoric acid fluorine.

Background

After more than 60 years of development, the phosphorus chemical industry in ChinaThe method goes through a development path from imported products to exported products, realizes the historical leap from imported major countries to manufacturing major countries, becomes a world major phosphate fertilizer production country, and the total phosphate fertilizer yield of China is P by the end of 2019₂O₅2240 ten thousand t and the yield is 1610.2 ten thousand t, and the achievement which attracts attention of the world is obtained. The phosphorus fertilizers are more in variety, ammonium phosphate is a main product, the yield of the ammonium phosphate in 2019 is 1359.3 ten thousand, and accounts for 84.4 percent of the total yield of the phosphorus fertilizers, the ammonium phosphate is a high-concentration compound fertilizer containing two nutrient elements of nitrogen and phosphorus and is prepared by reacting ammonia and wet-process phosphoric acid, and the wet-process phosphoric acid is tribasic acid and is generally used for decomposing phosphorus ores by using sulfuric acid.

In nature, fluorine exists mainly in 2 forms: one is found in fluorite (calcium fluoride), which is a small storage in the world, with a current proven storage of about 2.7 million tons of fluorite mineral, but only 6500 million tons of mineral are available for mining, and are concentrated in a few countries. China has already proved that the basic reserve of fluorite minerals is about 0.45 hundred million t in 2018. Except fluorite, fluorine is associated with phosphate ore in another existing form in the nature, and although the content of fluorine in the phosphate ore is very low and is 2-5 percent of fluorine, the fluorine-containing phosphate ore is mainly fluorapatite Ca₅(PO₄)₃F exists in the form of small amount of calcium fluosilicate (CaSiF)₆) Exist in the form of (1). However, the global storage of phosphorite is 690 hundred million tons, and the fluorine resource amount is 20.8 hundred million tons according to the average fluorine content of 3 percent; in 2018 years, the exploitation amount of phosphorite is 0.5 million tons, the amount of fluorine resources is 150 million tons, and is close to the domestic hydrofluoric acid production amount (158.8 million tons) in 2018 years, so the recovery of associated fluorine in the phosphorus industry has great significance. In the wet phosphoric acid production process for producing raw materials for ammonium phosphate production, the fluorine recovery point is mainly in the extraction process and the phosphoric acid concentration process, but the fluorine yield is low, and each ton of P is low₂O₅The recovered fluosilicic acid is basically 50kg H₂SiF₆Within (percent), the recovery rate is lower than 50 percent, and the rest fluorine is reserved in concentrated phosphoric acid, enters an ammonium phosphate product, and finally enters soil, water and the like to cause certain damage to the natural environment. Therefore, the yield of wet-process fluorine phosphate is improved, and the fluorine is reduced to enter into an ammonium phosphate product. At present, the technology of wet-process phosphoric acid fluorine yield of ammonium phosphate is not reported. But the feed phosphoric acid defluorination technologyIn the related reports, CN 104176719A reports a defluorination method for tower-type air-stripping feed phosphoric acid, feed-grade low-fluorine phosphoric acid is heated to 90-105 ℃ and is introduced into a defluorination empty tower from the upper part, and air is introduced into the bottom of the tower to complete defluorination; CN 112174104A reports a high-temperature stripping defluorination method and device for wet-process phosphoric acid, which is to uniformly mix defluorination agent and heavy-weight-removing clarified concentrated phosphoric acid, heat the mixture to 70-90 ℃, and then keep the phosphoric acid in a liquid storage tank at the lower part of a coil pipe or a shell and tube defluorination tower in a boiling state. The patent has the advantages of high energy consumption, serious corrosion of a coil pipe or a tube type under a high-temperature condition, short phosphoric acid retention time and low defluorination efficiency. CN 110467167A discloses a wet phosphoric acid defluorination method by coupling precipitation pre-defluorination and stripping defluorination, phosphoric acid after precipitation defluorination passes through a multistage defluorination tower, the air temperature is 20-30 ℃, the patent has the defects of low air temperature, the phosphoric acid temperature is lowered after entering the defluorination tower, the defluorination is not beneficial to the defluorination, the defluorination process is long, and the cost is high.

Disclosure of Invention

The invention aims to provide a system capable of improving defluorination efficiency and greatly improving the yield of ammonium phosphate and phosphoric acid fluoride.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a system for improving yield of wet-process fluorine phosphate is characterized in that: the device comprises a stirring barrel, concentrated phosphoric acid and a defluorinating agent enter the stirring barrel through a pipeline reactor to be uniformly mixed, a discharge port of the stirring barrel is communicated with a two-stage concentrated phosphoric acid inlet of a sieve plate defluorinating tower, air passes through an air heater and then is communicated with a hot air inlet at the lower part of the sieve plate defluorinating tower, saturated steam is communicated with a steam inlet at the lower part of the sieve plate defluorinating tower, a fluorine tail gas outlet at the upper side of the sieve plate defluorinating tower is communicated with a mist separator, the mist separator is communicated with a fluorine absorption washing tower, fluorine tail gas is treated by the mist separator and the fluorine absorption washing tower in sequence and then is discharged, and a wet-process phosphoric acid outlet at the lower part of the;

concentrated phosphoric acid and a defluorinating agent enter a stirring barrel through a pipeline reactor to be uniformly mixed, then the mixture is introduced into a sieve plate defluorinating tower from the upper part, steam is introduced into the sieve plate defluorinating tower from the lower part, and phosphoric acid and the steam are in full countercurrent contact to complete defluorination; electrically heated hot air is introduced into the bottommost part of the sieve plate defluorination tower, so that the fluorine quickly overflows; after steam enters a sieve plate defluorination tower, the steam is directly contacted with phosphoric acid, and the temperature of the phosphoric acid is controlled to be 100 +/-10 ℃.

Preferably, the sieve plate defluorination tower is made of an outer carbon steel lining fluorine material.

Preferably, the concentration of the concentrated phosphoric acid is 40-55%.

Preferably, the steam pressure is 0.1-0.3 MPa, and the temperature of the hot air is higher than 100 ℃.

Preferably, the ratio of the air to the phosphoric acid is 0.001-0.01 m³/m³。

Preferably, the defluorinating agent is a byproduct of fluosilicic acid production of hydrofluoric acid, wherein the active SiO is₂60-80%, F is less than 10%, and the dosage of defluorinating agent is one ton of P₂O₅Less than 10 kg.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: this application the in-process of system using passes through pipeline reactor earlier concentrated phosphoric acid and defluorinating agent and gets into the agitator in the misce bene, then lets in the sieve defluorinating tower from upper portion, increases the dwell time of phosphoric acid, and during steam introduced the sieve defluorinating tower from the lower part, hot-air entered the overflow of accelerating fluorine from the lower part simultaneously. Phosphoric acid is fully contacted with steam in a countercurrent manner to complete defluorination, defluorinated phosphoric acid is used for producing an ammonium phosphate product, and the temperature of the phosphoric acid is controlled to be 100 +/-10 ℃; the fluorine-containing steam is discharged from the tower top, and enters a washing tower after being defoamed by a mist separator.

The sieve plate defluorination tower in the system greatly increases the residence time of phosphoric acid and improves the defluorination efficiency. While introducing steam, introducing hot air, keeping the sieve plate defluorination tower at positive pressure, reducing the steam consumption of single ton of phosphoric acid and improving the overflow efficiency of fluorine; the yield of the ammonium phosphate fluoride is greatly improved, and the damage of fluorine to the environment is reduced while the fluorine resource is recovered; the system is simple to operate, high in processing capacity, safe, reliable and low in operating cost.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a functional block diagram of a system according to an embodiment of the present invention;

wherein: 1. a stirring barrel; 2. a sieve plate defluorination tower; 201. a hot air inlet; 202. a steam inlet; 203. a second-stage concentrated phosphoric acid inlet; 204. a wet-process phosphoric acid outlet; 205. a fluorine tail gas outlet; 3. an air heater; 4. a mist separator; 5. a fluorine absorption scrubber; 6. and a finished acid storage tank.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.

Example one

As shown in fig. 1, the embodiment of the invention discloses a system for increasing yield of wet-process phosphoric acid fluorine, which comprises a stirring barrel 1, wherein concentrated phosphoric acid and a defluorinating agent enter the stirring barrel 1 through a pipeline reactor to be uniformly mixed, a discharge port of the stirring barrel 1 is communicated with a two-stage concentrated phosphoric acid inlet 203 of a sieve plate defluorinating tower 2, air passes through an air heater 3 and then is communicated with a hot air inlet 201 at the lower part of the sieve plate defluorinating tower 2, saturated steam is communicated with a steam inlet 202 at the lower part of the sieve plate defluorinating tower 2, a fluorine tail gas outlet 205 at the upper side of the sieve plate defluorinating tower 2 is communicated with a mist separator 4, the mist separator 4 is communicated with a fluorine absorption washing tower 5, the fluorine tail gas is treated by the mist separator 4 and the fluorine absorption washing tower 5 in sequence and then is discharged, and a wet-process phosphoric acid outlet 204 at the;

in the using process of the system, concentrated phosphoric acid and a defluorinating agent enter a stirring barrel 1 through a pipeline reactor to be uniformly mixed, then the mixture is introduced into a sieve plate defluorinating tower 2 from the upper part, steam is introduced into the sieve plate defluorinating tower 2 from the lower part, and phosphoric acid and the steam are in countercurrent full contact to complete defluorination; electrically heated hot air is introduced into the bottommost part of the sieve plate defluorination tower 2 to ensure that the fluorine quickly overflows; after steam enters the sieve plate defluorination tower 2, the steam is directly contacted with phosphoric acid, and the temperature of the phosphoric acid is controlled to be 100 +/-10 ℃.

Furthermore, the sieve plate defluorination tower (2) can be made of an outer carbon steel lining fluorine material. Preferably, the concentration of the concentrated phosphoric acid is 40-55%; the steam pressure is 0.1-0.3 MPa, and the temperature of hot air is higher than 100 ℃; the ratio of air to phosphoric acid is 0.001-0.01 m³/m³(ii) a The defluorinating agent is a byproduct of producing hydrofluoric acid by fluosilicic acid, wherein active SiO is₂60-80%, F is less than 10%, and the dosage of defluorinating agent is one ton of P₂O₅Less than 10 kg.

Example two

10 million tons/year P is prepared using the system₂O₅Wherein the operating conditions are as follows:

EXAMPLE III

20 million tons/year P was prepared using the system₂O₅Wherein the operating conditions are as follows:

example four

30 million tons/year P were prepared using the system₂O₅Wherein the operating conditions are as follows:

the sieve plate defluorination tower in the system greatly increases the residence time of phosphoric acid and improves the defluorination efficiency. While introducing steam, introducing hot air, keeping the sieve plate defluorination tower at positive pressure, reducing the steam consumption of single ton of phosphoric acid and improving the overflow efficiency of fluorine; the yield of the ammonium phosphate fluoride is greatly improved, and the damage of fluorine to the environment is reduced while the fluorine resource is recovered; the system is simple to operate, high in processing capacity, safe, reliable and low in operating cost.