阅读说明：本技术 一种百分之三十二离子膜烧碱的工艺流程 (Technological process of thirty-two percent ion membrane caustic soda ) 是由 洪建新 于 2020-05-20 设计创作，主要内容包括：本发明公开了一种百分之三十二离子膜烧碱的工艺流程,包括以下步骤：将卤水库卤水和脱硝处理过的低芒盐水经化盐工序去除天然有机物杂质；去除杂质的化工品自流经过马槽过程中投放精制剂去除一些杂质离子后送至DrM过滤器；过滤后的精盐水送至离子膜工段,经离子交换膜电槽电解产生32％成品烧碱、氢气、氯气和淡盐水；淡盐水经过脱氯塔进行脱氯反应,脱出氯气后再进入脱硝塔反应生成芒硝和低芒盐水,对电解后残存的淡盐水进行脱氯脱硝后生成低芒盐水可以再次用于化盐工步。本发明可以对离子膜电槽电解后产生的废料再利用,提高对盐泥的利用率,且采用盐泥制作生态水泥,有效提高利用率。(The invention discloses a technological process of thirty-two percent ion membrane caustic soda, which comprises the following steps: removing natural organic matter impurities from brine water in a brine storage and denitrated low-mango brine through a salt dissolving process; feeding a refining agent to remove some impurity ions in the process that the chemical products with the impurities removed automatically flow through the manger and then are sent to a DrM filter; delivering the filtered refined brine to an ion exchange membrane working section, and electrolyzing by an ion exchange membrane electric tank to generate 32% finished caustic soda, hydrogen, chlorine and light brine; and (3) the light brine is subjected to dechlorination reaction in a dechlorinating tower, after chlorine is removed, the light brine enters a denitration tower to react to generate mirabilite and low-awn brine, and the residual light brine after electrolysis is subjected to dechlorination and denitration to generate low-awn brine which can be used in the salt dissolving step again. The invention can recycle the waste generated after the electrolysis of the ion membrane electric cell, improves the utilization rate of the salt mud, and effectively improves the utilization rate by adopting the salt mud to prepare the ecological cement.)

1. A technological process of thirty-two percent ion membrane caustic soda comprises the following steps:

the method comprises the following steps: removing natural organic matter impurities from brine water in a brine storage and denitrated low-mango brine through a salt dissolving process;

step two: feeding a refining agent to remove some impurity ions in the process that the chemical products with the impurities removed automatically flow through the manger, then sending the chemical products to a DrM filter, and filtering out salt mud;

step three: delivering the filtered refined brine to an ion exchange membrane working section, and electrolyzing by an ion exchange membrane electric tank to generate 32% finished caustic soda, hydrogen, chlorine and light brine;

step four: the light brine is subjected to dechlorination reaction in a dechlorination tower, after chlorine is removed, the light brine enters a denitration tower to react to generate mirabilite and low-awn brine, and the residual light brine after electrolysis is subjected to dechlorination and denitration to generate low-awn brine which can be used in the salt dissolving step again;

step five: chlorine gas is sent to a liquid chlorine working procedure for liquefaction after being dried and compressed to produce liquid chlorine;

step six: the hydrogen is dried, compressed and stored in a gas tank and is sent to a hydrogen department for use.

2. The process of thirty-two percent ionic membrane caustic soda as claimed in claim 1, wherein: the ion exchange membrane electrobath in the third step adopts a multi-pole type electrobath, the total voltage of the electrobath is the sum of the voltages of all unit electrobaths, all the electrobaths in the circuit are connected in parallel to generate an electrolytic reaction, and the electrolytic reaction formula is as follows:

2NaCl+2H₂O＝2NaOH+H₂↑+Cl₂↑

the H + is directly discharged on the cathode to generate hydrogen. In the electrolysis process, adding a proper amount of high-purity hydrochloric acid into the anode chamber to neutralize the returned OH < - >, adding required pure water into the cathode chamber, and adjusting the temperature of the electrolytic cell to be less than 88 ℃; the power consumption of the caustic soda is less than 2300 KWh; the header hydrogen pressure is less than 2.7mH 2O; the pressure of the chlorine in the header pipe is less than 2.3mH2O, and the bipolar ion exchange membrane electric tank is closed in time after the use, so that the service life of the machine is effectively prolonged.

3. The process of thirty-two percent ionic membrane caustic soda as claimed in claim 1, wherein: the main indexes of 32 percent of finished product alkali in the third step are as follows: sodium hydroxide is more than or equal to 32 percent, sodium chloride is less than or equal to 0.004 percent, and the generated 32 percent of finished product alkali can be directly used as a liquid alkali product or further decocted to be concentrated to prepare a solid caustic soda finished product.

4. The process of thirty-two percent ionic membrane caustic soda as claimed in claim 1, wherein: and in the step five, the chlorine gas is dried by adopting concentrated sulfuric acid with the concentration of 82%, and after the sulfuric acid is contacted with the wet chlorine gas, the water in the chlorine gas is absorbed by the concentrated sulfuric acid with the concentration of 82%.

5. The process of thirty-two percent ionic membrane caustic soda as claimed in claim 4, wherein: the drying in the sixth step adopts calcium oxide, and the reaction formula is as follows:

CaO+H2O＝Ca(OH)2。

6. the process of thirty-two percent ionic membrane caustic soda as claimed in claim 1, wherein: in the fourth step, the dechlorination is carried out efficiently by adopting a chemical method and a physical method, the solubility of chlorine in the acidic brine is reduced along with the reduction of the pH value, so the light brine needs to be treated by adding acid before dechlorination, and the reaction formula is as follows:

Cl2+H2＝＝HCl+HclO；

since free chlorine in the dilute brine has strong oxidizing property, it can be subjected to redox reaction with reducing substances such as sodium sulfite and the like under alkaline conditions to remove chlorine, and the reaction formula is:

Cl2+NaSO3+2NaOH＝＝NaSO4+2NaCl+H2O。

7. the process of thirty-two percent ionic membrane caustic soda as claimed in claim 1, wherein: and D, putting the salt slurry obtained in the step II into a filter press for filter pressing, further filtering out partial salt water after filter pressing, putting the salt water into a salt dissolving process for reuse, improving the utilization rate of the salt slurry, and putting the filtered salt slurry into calcium chloride for producing ecological cement for relevant departments to use.

8. The process of thirty-two percent ionic membrane caustic soda as claimed in claim 6, wherein: the physical method specifically adopts an air blowing method, wherein the air blowing method is to utilize an air blower to introduce a large amount of air into the fresh brine, and the air is fully mixed and contacted with the fresh brine to destroy the equilibrium concentration of a gas-liquid interface, so that chlorine dissolved in a liquid phase is transferred to a gas phase and is taken away by the air, and the dechlorination effect is achieved.

Technical Field

The invention relates to the technical field of caustic soda preparation, in particular to a technological process of thirty-two percent ionic membrane caustic soda.

Background

Along with the rapid development of social economy, people have more and more extensive use of caustic soda, the demand for caustic soda is large, sodium hydroxide has a chemical formula of NaOH, is commonly called caustic soda, caustic soda and caustic soda, is strong caustic soda with strong corrosiveness, is generally in a sheet or block shape, is easy to dissolve in water (release heat when dissolved in water) and form an alkaline solution, has deliquescence, is easy to absorb water vapor (deliquescence) and carbon dioxide (deterioration) in air, can be added with hydrochloric acid to check whether deterioration occurs, and has a diaphragm electrolysis method and an ion exchange membrane method in the preparation process, wherein the ion membrane exchange method is to refine brine by a traditional method after primary refined brine is filtered by a sintered carbon tubular filter and then secondarily refined by a chelating ion exchange resin tower to reduce the content of calcium and magnesium in the brine to be below 0.002 percent and electrolyzes the secondary refined brine, chlorine is generated in the anode chamber, Na + in the brine in the anode chamber enters the cathode chamber and OH in the cathode chamber through the ionic membrane to generate sodium hydroxide.

However, the existing ionic membrane caustic soda preparation process is not sufficient for the weak brine after refined salt reaction; thus, the existing requirements are not met, and a process flow of thirty-two percent ion membrane caustic soda is provided for the requirements.

Disclosure of Invention

The invention aims to provide a process flow of thirty-two percent ionic membrane caustic soda, which aims to solve the problems that the conventional ionic membrane caustic soda preparation process in the background art is insufficient in the use of light salt water after refined salt reaction and the like.

In order to achieve the purpose, the invention provides the following technical scheme: a technological process of thirty-two percent ion membrane caustic soda comprises the following steps:

the method comprises the following steps: removing natural organic matter impurities from brine water in a brine storage and denitrated low-mango brine through a salt dissolving process;

step two: feeding a refining agent to remove some impurity ions in the process that the chemical products with the impurities removed automatically flow through the manger, then sending the chemical products to a DrM filter, and filtering out salt mud;

step three: delivering the filtered refined brine to an ion exchange membrane working section, and electrolyzing by an ion exchange membrane electric tank to generate 32% finished caustic soda, hydrogen, chlorine and light brine;

step four: the light brine is subjected to dechlorination reaction in a dechlorination tower, after chlorine is removed, the light brine enters a denitration tower to react to generate mirabilite and low-awn brine, and the residual light brine after electrolysis is subjected to dechlorination and denitration to generate low-awn brine which can be used in the salt dissolving step again;

step five: chlorine gas is sent to a liquid chlorine working procedure for liquefaction after being dried and compressed to produce liquid chlorine;

step six: the hydrogen is dried, compressed and stored in a gas tank and is sent to a hydrogen department for use.

Preferably, the ion exchange membrane electrobath in the third step is a multi-pole type electrobath, the total voltage of the electrobath is the sum of the voltages of all unit electrobaths, all the electrobaths in the circuit are connected in parallel to generate an electrolytic reaction, and the electrolytic reaction formula is as follows:

2NaCl+2H₂O＝2NaOH+H₂↑+Cl₂↑

the H + is directly discharged on the cathode to generate hydrogen. In the electrolysis process, adding a proper amount of high-purity hydrochloric acid into the anode chamber to neutralize the returned OH < - >, adding required pure water into the cathode chamber, and adjusting the temperature of the electrolytic cell to be less than 88 ℃; the power consumption of the caustic soda is less than 2300 KWh; the header hydrogen pressure is less than 2.7mH 2O; the pressure of the chlorine in the header pipe is less than 2.3mH2O, and the bipolar ion exchange membrane electric tank is closed in time after the use, so that the service life of the machine is effectively prolonged.

Preferably, the main indexes of 32% finished product alkali in the third step are as follows: sodium hydroxide is more than or equal to 32 percent, sodium chloride is less than or equal to 0.004 percent, and the generated 32 percent of finished product alkali can be directly used as a liquid alkali product or further decocted to be concentrated to prepare a solid caustic soda finished product.

Preferably, the chlorine gas is dried by using concentrated sulfuric acid with a concentration of 82% in the drying in the fifth step, and after the sulfuric acid is contacted with the wet chlorine gas, the moisture in the chlorine gas is absorbed by the concentrated sulfuric acid with a concentration of 82%.

Preferably, calcium oxide is used for drying in the sixth step, and the reaction formula is as follows:

CaO+H2O＝Ca(OH)2。

preferably, the dechlorination in the fourth step is carried out by a chemical method and a physical method at the same time, the solubility of chlorine in the acidic brine is reduced along with the reduction of the pH value, so the light brine needs to be subjected to acid treatment before dechlorination, and the reaction formula is as follows:

Cl2+H2＝＝HCl+HclO；

since free chlorine in the dilute brine has strong oxidizing property, it can be subjected to redox reaction with reducing substances such as sodium sulfite and the like under alkaline conditions to remove chlorine, and the reaction formula is:

Cl2+NaSO3+2NaOH＝＝NaSO4+2NaCl+H2O。

preferably, the salt mud in the second step is put into a filter press for filter pressing, part of salt water can be further filtered out after filter pressing, the salt water is put into a salt dissolving step for reuse, the utilization rate of the salt mud is improved, and the filtered salt mud is put into calcium chloride for producing ecological cement for relevant departments to use.

Preferably, the physical method specifically adopts an air blowing method, wherein the air blowing method is to introduce a large amount of air into the fresh brine by using an air blower, and the air is fully mixed and contacted with the fresh brine to destroy the equilibrium concentration of a gas-liquid interface, so that chlorine dissolved in a liquid phase is transferred to a gas phase and is taken away by air, and the dechlorination effect is achieved.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention adopts the ion exchange membrane electric tank to electrolyze to prepare the caustic soda, the quality of the caustic soda is high, and the quality requirement of chemical fiber, pharmacy and other industries on the high-purity caustic soda can be met;

2. the energy consumption is low through the ionic membrane caustic soda method, the energy is effectively saved, and the cost is reduced;

3. the chemical method and the physical method are synchronously used when the light salt brine is dechlorinated, so that the dechlorination effect of the light salt brine is effectively improved;

4. the method comprises the steps of drying and compressing hydrogen and chlorine generated by preparing caustic soda by electrolyzing an ion exchange membrane electric tank;

5. the residual fresh brine after electrolysis is subjected to dechlorination and denitration to generate low-mango brine which can be reused in the salt dissolving step, so that the utilization rate is improved;

6. the salt slurry is subjected to filter pressing and further filtered, the salt water is put into the salt dissolving step again, and the excess salt slurry is added with calcium chloride to be used for producing ecological cement for relevant departments to use.

Drawings

FIG. 1 is an overall process flow diagram of the present invention;

FIG. 2 is an electrolytic flow diagram of an ion exchange membrane cell of the present invention;

FIG. 3 is a flow diagram of the dechlorination of the dilute brine of the present invention;

FIG. 4 is a flow chart of the present invention for treating and recycling salty mud.

Detailed Description

The technical solutions in the embodiments of the present invention will be 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.

Referring to fig. 1-4, an embodiment of the present invention is shown: a technological process of thirty-two percent ion membrane caustic soda comprises the following steps:

the method comprises the following steps: removing natural organic matter impurities from brine water in a brine storage and denitrated low-mango brine through a salt dissolving process;

step two: feeding a refining agent to remove some impurity ions in the process that the chemical products with the impurities removed automatically flow through the manger, then sending the chemical products to a DrM filter, and filtering out salt mud;

step three: delivering the filtered refined brine to an ion exchange membrane working section, and electrolyzing by an ion exchange membrane electric tank to generate 32% finished caustic soda, hydrogen, chlorine and light brine;

step four: the light brine is subjected to dechlorination reaction in a dechlorination tower, after chlorine is removed, the light brine enters a denitration tower to react to generate mirabilite and low-awn brine, and the residual light brine after electrolysis is subjected to dechlorination and denitration to generate low-awn brine which can be used in the salt dissolving step again, so that the utilization rate is improved;

step five: chlorine gas is sent to a liquid chlorine working procedure for liquefaction after being dried and compressed to produce liquid chlorine;

step six: the hydrogen is dried, compressed and stored in a gas tank and is sent to a hydrogen department for use.

Further, the ion exchange membrane electrobath in the third step adopts a multi-pole type electrobath, the total voltage of the electrobath is the sum of the voltages of all unit electrobaths, all the electrobaths in the circuit are connected in parallel to generate an electrolytic reaction, and the electrolytic reaction formula is as follows:

2NaCl+2H₂O＝2NaOH+H₂↑+Cl₂↑

the H + is directly discharged on the cathode to generate hydrogen. In the electrolysis process, adding a proper amount of high-purity hydrochloric acid into the anode chamber to neutralize the returned OH < - >, adding required pure water into the cathode chamber, and adjusting the temperature of the electrolytic cell to be less than 88 ℃; the power consumption of the caustic soda is less than 2300 KWh; the header hydrogen pressure is less than 2.7mH 2O; the pressure of the chlorine in the header pipe is less than 2.3mH2O, and the bipolar ion exchange membrane electric tank is closed in time after the use, so that the service life of the machine is effectively prolonged.

Further, the main indexes of 32% finished product alkali in the third step are as follows: sodium hydroxide is more than or equal to 32 percent, sodium chloride is less than or equal to 0.004 percent, and the generated 32 percent of finished product alkali can be directly used as a liquid alkali product or further decocted to be concentrated to prepare a solid caustic soda finished product.

Further, in the step five, the chlorine gas is dried by using concentrated sulfuric acid with the concentration of 82%, and after the sulfuric acid is contacted with the wet chlorine gas, the water in the chlorine gas is absorbed by the concentrated sulfuric acid with the concentration of 82%.

Further, calcium oxide is adopted for drying in the sixth step, and the reaction formula is as follows:

CaO+H2O＝Ca(OH)2。

furthermore, in the fourth step, the dechlorination is carried out efficiently by adopting a chemical method and a physical method, the solubility of chlorine in the acidic brine is reduced along with the reduction of the pH value, so the light brine needs to be treated by adding acid before dechlorination, and the reaction formula is as follows:

Cl2+H2＝＝HCl+HclO；

since free chlorine in the dilute brine has strong oxidizing property, it can be subjected to redox reaction with reducing substances such as sodium sulfite and the like under alkaline conditions to remove chlorine, and the reaction formula is:

Cl2+NaSO3+2NaOH＝＝NaSO4+2NaCl+H2O。

and further, the salt mud in the step two is put into a filter press for filter pressing, partial salt water can be further filtered out after filter pressing, the salt water is put into a salt dissolving process for recycling, the utilization rate of the salt mud is improved, and the filtered salt mud is put into calcium chloride for producing ecological cement for relevant departments to use.

Further, the physical method specifically adopts an air blowing method, the air blowing method is that a large amount of air is blown into the fresh brine by an air blower and is fully mixed and contacted with the fresh brine, the equilibrium concentration of a gas-liquid interface is destroyed, and chlorine dissolved in a liquid phase is transferred to a gas phase and taken away by air, so that the dechlorination effect is achieved, and the chemical method and the physical method are synchronously used when the dechlorination is carried out on the fresh brine, so that the dechlorination effect of the fresh brine is effectively improved.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.