阅读说明：本技术 高纯磷酸的生产系统以及生产方法 (Production system and production method of high-purity phosphoric acid ) 是由 高麟 吴志强 于 2020-06-30 设计创作，主要内容包括：本发明公开了高纯磷酸的生产系统以及生产方法。该高纯磷酸的生产系统包括：电炉,使包含磷矿的原料发生还原反应并输出含有磷蒸气和粉尘的第一气体；加热单元,对所述第一气体进行加热并输出温度≥190℃的第二气体；第一过滤单元,对所述第二气体中的粉尘进行拦截并输出第三气体；氧化单元,所述氧化单元将所述第三气体氧化为含有五氧化二磷蒸气的第四气体；吸收单元,利用吸收剂吸收五氧化二磷并输出磷酸。通过第一过滤单元对第二气体中的粉尘进行物理拦截,使第二气体中的磷蒸气全部通过,从而可以获得高浓度和高纯度的磷蒸气；然后,高浓度和高纯度的磷蒸气再进行氧化反应,具有明显高于窑法磷酸中的氧化效率。(The invention discloses a production system and a production method of high-purity phosphoric acid. The production system of the high-purity phosphoric acid comprises: an electric furnace for reducing a raw material containing phosphate ore and outputting a first gas containing phosphorus vapor and dust; the heating unit is used for heating the first gas and outputting a second gas with the temperature being more than or equal to 190 ℃; the first filtering unit intercepts dust in the second gas and outputs a third gas; an oxidation unit that oxidizes the third gas into a fourth gas containing phosphorus pentoxide vapor; and the absorption unit absorbs the phosphorus pentoxide by using the absorbent and outputs the phosphoric acid. The first filtering unit is used for physically intercepting dust in the second gas, so that phosphorus vapor in the second gas can completely pass through the first filtering unit, and high-concentration and high-purity phosphorus vapor can be obtained; then, the phosphorus vapor with high concentration and high purity is subjected to oxidation reaction, and the oxidation efficiency is obviously higher than that in the kiln method phosphoric acid.)

1. A production system for high-purity phosphoric acid, characterized by comprising:

an electric furnace (100), the electric furnace (100) causing a reduction reaction of a raw material containing phosphorus ore and outputting a first gas containing phosphorus vapor and dust;

the heating unit (200) heats the first gas and outputs a second gas with the temperature being more than or equal to 190 ℃;

a first filtering unit (300), the first filtering unit (300) intercepting dust in the second gas and outputting a third gas;

an oxidation unit (400), the oxidation unit (400) oxidizing the third gas to a fourth gas containing phosphorus pentoxide vapor;

an absorption unit that absorbs phosphorus pentoxide with an absorbent and outputs phosphoric acid.

2. The system for producing highly pure phosphoric acid according to claim 1, wherein: also comprises

A condensing unit (610), the condensing unit (610) condensing the fourth gas into a fifth gas containing phosphorus pentoxide solids;

the second filtering unit (620) intercepts particulate matters in the fifth gas to obtain phosphorus pentoxide solid;

the absorption unit absorbs the phosphorus pentoxide solid by using an absorbent and outputs phosphoric acid.

3. The system for producing highly pure phosphoric acid according to claim 2, wherein: the condensing unit (610) outputs a fifth gas with the temperature of 100-140 ℃.

4. The production system of high purity phosphoric acid according to claim 1 or 2, characterized in that: the system also comprises a tail gas treatment unit (700) for treating the tail gas.

5. The production system of high purity phosphoric acid according to claim 4, characterized in that: the tail gas treatment unit (700) comprises a caustic wash tower.

6. The production system of high purity phosphoric acid according to claim 1 or 2, characterized in that: and the gas traction unit is used for enabling the gas to flow step by step.

7. The system for producing highly pure phosphoric acid according to claim 6, wherein: the gas pulling unit comprises a first fan (810) arranged in front of the oxidation unit (400) and a second fan (820) arranged behind the oxidation unit (400).

8. The production system of high purity phosphoric acid according to claim 1 or 2, characterized in that: the heating unit (200) heats the first gas and outputs a second gas with the temperature of 200-280 ℃.

9. The production system of high purity phosphoric acid according to claim 1 or 2, characterized in that: the first filtering unit (300) intercepts dust in the second gas and outputs dust content less than or equal to 10mg/Nm³A third gas of (2); the filter medium of the first filter unit (300) is metal ceramic, metal mesh, metal porous membrane or metal fiber felt.

10. The production method of the high-purity phosphoric acid is characterized by comprising the following steps: a production system of high purity phosphoric acid using any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of phosphorus pentoxide, and particularly relates to a production system and a production method of high-purity phosphoric acid.

Background

Wet process for preparing phosphoric acid by decomposing phosphate ore with sulfuric acid to obtain diluted phosphoric acid and CaSO₄·nH₂And (3) concentrating the dilute phosphoric acid to obtain wet-process phosphoric acid containing about 54 percent of phosphoric acid by using solid waste residue (phosphogypsum for short) taking O as a main body. The main drawbacks of this process: firstly, a large amount of sulfuric acid is consumed; secondly, the waste residue phosphogypsum can not be effectively utilized, and the entrained sulfuric acid, phosphoric acid and solubility thereofThe fluoride is dissolved in water, and is washed by rainwater after being naturally stacked, so that the environment is easily seriously polluted; thirdly, the impurity content of the product phosphoric acid is high, and the product phosphoric acid is generally only used for producing fertilizers; fourthly, in order to ensure the economical efficiency of the product, high-grade phosphorite must be used.

Because of the problems of the wet-process phosphoric acid preparation process, the currently mainly used phosphoric acid preparation method is a thermal-process phosphoric acid preparation process and a kiln-process phosphoric acid preparation process, and the two processes both use phosphorite, silica and a carbonaceous reducing agent as raw materials.

The thermal method phosphoric acid preparation process comprises the steps of firstly reducing phosphorus in phosphate ore in an electric furnace in the form of simple substance phosphorus vapor and converting a carbonaceous reducing agent into CO, then washing and cooling gas which is discharged out of the electric furnace and mainly comprises the simple substance phosphorus vapor and the CO, so that the simple substance phosphorus vapor is cooled into solid and gas phase to be separated, obtaining product yellow phosphorus, heating the product yellow phosphorus into liquid phase, and then carrying out oxidation combustion reaction with introduced air in a hydration tower to obtain phosphoric anhydride P ₂O₅And then the phosphoric acid is obtained by water absorption.

The kiln phosphoric acid is also called KPA method, the method is carried out in a rotary kiln, firstly, the phosphorus in the phosphate ore is reduced and volatilized in the form of simple substance phosphorus steam, then the simple substance phosphorus steam is oxidized into phosphorus pentoxide by the introduced air in the middle space of the kiln, finally, kiln gas containing the phosphorus pentoxide is obtained, and the kiln gas is absorbed into the phosphoric acid after being washed and dedusted.

Although the hot method phosphoric acid making process can not generate a large amount of waste residues, the gas discharged by the electric furnace contains a large amount of dust, the condensation temperature of phosphorus vapor is low, and the washing and cooling can cause the condensed simple substance phosphorus vapor to be integrated with the dust, thereby seriously affecting the quality of yellow phosphorus. Although the kiln phosphoric acid process saves a large amount of electric energy, a large amount of dust exists in the rotary kiln, the dust seriously affects the oxidation reaction of phosphorus vapor, and although the condensation temperature of the phosphorus pentoxide vapor is higher, the kiln gas is washed, cooled and dedusted, so that part of the phosphorus pentoxide vapor is condensed, the washing and dedusting effect is poor, the washed gas still has more dust, and high-purity phosphoric acid cannot be obtained. It is found that it is very difficult to obtain phosphoric acid having a high concentration and a high purity by the conventional phosphoric acid production method.

Disclosure of Invention

The invention aims to provide a production system and a production method of high-purity phosphoric acid, which have simple process and can obtain high-purity phosphoric acid.

In order to achieve the above object, according to one aspect of the present invention, there is provided a production system of high purity phosphoric acid. The production system of the high-purity phosphoric acid comprises:

an electric furnace that causes a reduction reaction of a raw material containing phosphate ore and outputs a first gas containing phosphorus vapor and dust;

the heating unit heats the first gas and outputs a second gas with the temperature being more than or equal to 190 ℃;

the first filtering unit intercepts dust in the second gas and outputs a third gas;

an oxidation unit that oxidizes the third gas into a fourth gas containing phosphorus pentoxide vapor;

an absorption unit that absorbs phosphorus pentoxide with an absorbent and outputs phosphoric acid.

Firstly, by arranging the heating unit, the phosphorus vapor in the first gas can be effectively prevented from condensing, and the fluidity and phosphorus simple substance concentration of the first gas are ensured; secondly, physically intercepting dust in the second gas through the first filtering unit, so that phosphorus vapor in the second gas completely passes through the first filtering unit, and high-concentration and high-purity phosphorus vapor can be obtained; then, the phosphorus vapor with high concentration and high purity is subjected to oxidation reaction, and the oxidation efficiency is obviously higher than that in the kiln method phosphoric acid. Therefore, the production system of the high-purity phosphoric acid is obviously different from the thermal phosphoric acid preparation process and the kiln phosphoric acid preparation process, and has the advantages of simple and easily controlled process, low energy consumption and capability of obtaining the high-purity phosphoric acid. Since there is a possibility that the gas inside the yellow phosphorus electric furnace increases drastically due to the occurrence of the slump in the electric furnace, the heating unit preferably employs an electric heating device for rapid and stable heating.

Further, also includes

A condensing unit that condenses the fourth gas into a fifth gas containing phosphorus pentoxide solids;

the second filtering unit intercepts particulate matters in the fifth gas to obtain phosphorus pentoxide solid;

the absorption unit absorbs the phosphorus pentoxide solid by using an absorbent and outputs phosphoric acid.

Thus, the phosphorus pentoxide vapor can be separated from other non-condensable gases (such as hydrogen fluoride) in a condensing manner by the condensing unit and filtered to obtain high-purity phosphorus pentoxide solid, and the high-purity and high-concentration phosphoric acid can be obtained by hydrating and absorbing the phosphorus pentoxide solid.

Furthermore, the condensing unit outputs a fifth gas with the temperature of 100-140 ℃.

Further, the device also comprises a tail gas treatment unit for treating the tail gas.

Further, the tail gas treatment unit comprises a caustic tower. Therefore, gases such as hydrogen fluoride and the like can be prevented from being discharged into the atmosphere, and the environment is protected.

Further, the device also comprises a gas traction unit which enables the gas to flow in a stepwise manner.

Further, the gas traction unit comprises a first fan arranged in front of the oxidation unit and a second fan arranged behind the oxidation unit. Therefore, the operation of the whole system is more stable.

Further, the heating unit heats the first gas and outputs a second gas with a temperature of 200-280 ℃. Therefore, the condensation of the phosphorus vapor can be prevented, and the excessive energy consumption is avoided.

Further, the first filtering unit intercepts dust in the second gas and outputs dust content less than or equal to 10mg/Nm³A third gas of (2); therefore, the filter has low filtering pressure and can ensure higher product quality.

Further, the filter medium of the first filter unit is metal ceramic, metal mesh, metal porous membrane or metal fiber felt. Thus, the distance has high temperature resistance and corrosion resistance.

In order to achieve the above object, according to another aspect of the present invention, there is also provided a method for producing high purity phosphoric acid. The production method of the high-purity phosphoric acid adopts the production system of the high-purity phosphoric acid.

Therefore, compared with the existing processes for preparing phosphoric acid by a hot method and a kiln method, the production system and the production method of the high-purity phosphoric acid can obtain phosphoric acid with higher concentration and purity, and have higher economic benefit.

The invention is further described with reference to the following figures and detailed description. Additional aspects and advantages of the 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 invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to assist in understanding the invention, and are included to explain the invention and their equivalents and not limit it unduly. In the drawings:

FIG. 1 is a schematic configuration diagram of a production system of high purity phosphoric acid according to example 1 of the present invention.

FIG. 2 is a schematic configuration diagram of a production system of high purity phosphoric acid according to example 2 of the present invention.

The relevant references in the above figures are:

100-an electric furnace, 200-a heating unit, 300-a first filtering unit, 400-an oxidation unit, 510-a vapor absorption unit, 520-a solid absorption unit, 610-a condensation unit, 620-a second filtering unit, 700-a tail gas treatment unit, 810-a first fan and 820-a second fan.

Detailed Description

The invention will be described more fully hereinafter with reference to the accompanying drawings. Those skilled in the art will be able to implement the invention based on these teachings. Before the present invention is described in detail with reference to the accompanying drawings, it is to be noted that:

the technical solutions and features provided in the present invention in the respective sections including the following description may be combined with each other without conflict.

Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

With respect to terms and units in the present invention. The terms "comprising," "having," and any variations thereof in the description and claims of this invention and the related sections are intended to cover non-exclusive inclusions.