阅读说明：本技术 一种氢氧化钠生产中盐水的控钾工艺及精制系统 (Potassium control process and refining system for brine in sodium hydroxide production ) 是由 何文明 程蓉 雷杉杉 史波 于 2021-07-20 设计创作，主要内容包括：本发明提供了一种氢氧化钠生产中盐水的控钾工艺及精制系统,涉及氢氧化钠生产技术领域。控钾工艺包括在盐水中加入除钾试剂,除钾试剂与盐水中的钾反应产生沉淀,除钾试剂的加入量不超过盐水中钾质量的30倍,除钾试剂与盐水搅拌反应0.5小时,并对盐水中的钾含量进行监测。精制系统包括按照盐水的输送方向顺次连通的第一折流槽、化盐桶、第二折流槽、前反应槽、文丘里混合器、预处理器、后反应槽及膜过滤器,第一折流槽进行PH调节和除铵,化盐桶将盐水制成饱和粗盐水,第二折流槽进行除有机物和除镁离子,前、后反应槽除钙,文丘里混合器内盐水与絮凝剂反应,预处理器内对沉淀进行沉降,在前反应槽、预处理器及后反应槽中至少一处实施控钾工艺。(The invention provides a potassium control process and a refining system for brine in sodium hydroxide production, and relates to the technical field of sodium hydroxide production. The potassium control process comprises the steps of adding a potassium removal reagent into saline water, enabling the potassium removal reagent to react with potassium in the saline water to generate precipitates, enabling the addition amount of the potassium removal reagent to be not more than 30 times of the mass of the potassium in the saline water, enabling the potassium removal reagent to react with the saline water in a stirring mode for 0.5 hour, and monitoring the content of the potassium in the saline water. The refined system includes the first baffling groove that communicates in order according to the direction of delivery of salt solution, change the salt bucket, the second baffling groove, preceding reaction tank, the venturi mixer, preprocessor, back reaction tank and membrane filter, first baffling groove carries out PH and adjusts and removes ammonium, it makes the salt solution into saturated coarse salt water to change the salt bucket, the second baffling groove removes organic matter and removes the magnesium ion, it is preceding, back reaction tank removes calcium, salt solution and flocculating agent reaction in the venturi mixer, subside the sediment in the preprocessor, in the preceding reaction tank, at least one department implements the accuse potassium technology in preprocessor and the back reaction tank.)

1. A process for controlling potassium in brine in sodium hydroxide production is characterized in that a potassium removal reagent is added into the brine, the potassium removal reagent reacts with potassium in the brine to generate precipitates, the addition amount of the potassium removal reagent is not more than 30 times of the mass of the potassium in the brine, the potassium removal reagent and the brine are stirred and react for 0.5 hour, and the potassium content in the brine is monitored.

2. The process for controlling potassium in brine in sodium hydroxide production according to claim 1, wherein the pH value is 5-8 and the temperature is 25-65 ℃ in the environment of reaction of the potassium removal reagent and the brine.

3. The process of claim 1, wherein the potassium removing agent is sodium tetraphenylborate.

4. A system for refining brine in the production of sodium hydroxide, comprising:

the first baffling groove, the salt melting barrel, the second baffling groove, the front reaction groove, the Venturi mixer, the pre-processor, the rear reaction groove and the membrane filter are communicated in sequence according to the conveying direction of the salt water;

wherein, first baffling groove carries out PH to the brine that gets into and adjusts and remove ammonium, it makes saturated coarse brine with the brine to change the salt bucket, second baffling groove removes organic matter and removes the magnesium ion to brine, preceding reaction tank removes calcium to brine, salt water and flocculating agent reaction messenger brine in the venturi mixer, the deposit in the brine is in subside in the preprocessor, back reaction tank removes calcium, in preceding reaction tank, preprocessor and back reaction tank in at least one implement according to any one of claim 1 ~ 3 the accuse potassium technology of brine in the sodium hydroxide production.

5. The system for refining brine in the production of sodium hydroxide as claimed in claim 4, wherein the first baffling tank and the salt dissolving barrel are sequentially communicated with an ammonia removal reaction tank and an ammonia removal tower according to the conveying direction of brine.

6. A refining system for brine in sodium hydroxide production according to claim 4, characterized in that the system further comprises a third flow cell in communication with the membrane filter, the brine passing through the membrane filter and entering the third flow cell, the third flow cell being fed with sodium sulfite for free chlorine removal.

7. A refining system for brine in sodium hydroxide production according to claim 4, wherein a pressurized dissolved air tank is communicated between the Venturi mixer and the front reaction tank, and ferric chloride is added into the Venturi mixer as a flocculating agent.

8. The system of claim 4, wherein the first baffling tank is filled with sodium hydroxide and sodium hypochlorite to adjust the pH of the brine and remove ammonium, the second baffling tank is filled with sodium hydroxide and sodium hypochlorite to remove magnesium and organic substances, and the front reaction tank and the rear reaction tank are filled with calcium carbonate to remove calcium.

9. A refining system of brine in sodium hydroxide production according to claim 4, wherein the pore size of the filter membrane in the membrane filter is 0.1-0.5 um.

10. A refining system for brine in sodium hydroxide production according to claim 4, characterized in that ICP is used to monitor the potassium content of brine.

Technical Field

The invention relates to the technical field of sodium hydroxide production, in particular to a potassium control process and a refining system for brine in sodium hydroxide production.

Background

The existing caustic soda production process is to refine brine by adding sodium hydroxide and sodium carbonate to remove calcium and magnesium impurities to obtain refined brine, deeply remove metal impurities by chelating resin to obtain secondary brine (entering-tank brine), and produce a caustic soda (sodium hydroxide) product by electrolysis in an electrolytic tank after meeting the indexes of the entering-tank brine.

In the process, the potassium content in brine, refined brine and secondary brine (entering a tank) is not controlled, so that the potassium content in caustic soda (sodium hydroxide) is not controlled, and the potassium content in the product cannot meet the part of customers with requirements on the potassium content in the product.

Disclosure of Invention

The invention aims to develop a potassium control process and a refining system for brine in sodium hydroxide production, which can control the potassium content in the sodium hydroxide production process.

The invention is realized by the following technical scheme:

a potassium removal reagent is added into brine, the potassium removal reagent reacts with potassium in the brine to generate precipitates, the addition amount of the potassium removal reagent is not more than 30 times of the mass of the potassium in the brine, the potassium removal reagent and the brine are stirred and react for 0.5 hour, and the potassium content in the brine is monitored.

Optionally, in an environment where the potassium removal reagent reacts with the saline water, the pH value is 5-8, and the temperature is 25-65 ℃.

Optionally, the potassium removal reagent is sodium tetraphenylborate.

A system for refining brine in sodium hydroxide production, comprising:

first baffling groove, salt changing bucket, second baffling groove, preceding reaction tank, venturi mixer, preprocessor, back reaction tank, the membrane filter that communicate in order according to the direction of delivery of salt water, first baffling groove carries out PH to the brine that gets into and adjusts and remove ammonium, it makes saturated coarse brine with salt water to change the salt bucket, the second baffling groove removes organic matter and removes magnesium ion to salt water, preceding reaction tank removes calcium to salt water, salt water and flocculating agent reaction make salt water flocculation in the venturi mixer, the sediment in the salt water is in subside in the preprocessor, the back reaction tank removes calcium, and the accuse potassium technology of salt water in the sodium hydroxide production is implemented in at least one department in preceding reaction tank, preprocessor and the back reaction tank.

Optionally, the first diversion groove and the salt melting barrel are sequentially communicated with an ammonia removal reaction groove and an ammonia removal tower according to the conveying direction of the salt water.

Optionally, this system still includes the third launder that communicates with the membrane filter, and salt solution process get into in the third launder behind the membrane filter, add sodium sulfite in the third launder and carry out free chlorine and get rid of.

Optionally, a pressurizing dissolved air tank is communicated between the venturi mixer and the front reaction tank, and ferric chloride is added into the venturi mixer to serve as a flocculating agent.

Optionally, add sodium hydroxide and sodium hypochlorite in the first baffling groove and carry out PH regulation and remove ammonium to brine, add sodium hydroxide and sodium hypochlorite in the second baffling groove and remove magnesium and remove the organic matter, add calcium carbonate in preceding reaction tank and the back reaction tank and remove calcium.

Optionally, the aperture of the filter membrane in the membrane filter is 0.1 um-0.5 um.

Optionally, ICP is used to monitor the potassium content of the brine.

The invention has the beneficial effects that:

the invention adds the potassium removing reagent to react with potassium to generate precipitate, and filters the precipitate by a membrane filter, thereby reducing the potassium content in the brine or the refined brine, wherein the potassium content in the brine can be reduced to about 90 percent at most, controlling the potassium content in the brine entering a tank, reducing the potassium content in the produced caustic soda and improving the quality of the caustic soda.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art can appreciate, the described embodiments may be modified in various different ways, without departing from the spirit or scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the invention "a plurality" means two or more unless specifically limited otherwise.

In the creation of the present invention, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise the first and second features being in direct contact, or may comprise the first and second features being in contact, not directly, but via another feature in between. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in figure 1, the invention discloses a process for controlling potassium in brine in sodium hydroxide production and a refining system, wherein the brine sequentially passes through a first diversion groove, an ammonia removal reaction groove, an ammonia removal tower, a salt melting barrel, a second diversion groove, a front reaction groove, a pressurized dissolved air tank, a Venturi mixer, a preprocessor, a rear reaction groove, a membrane filter and a third diversion groove to prepare refined brine.

In first baffling groove, the sodium hydroxide and the sodium hypochlorite of adding mix with brine, and the PH of brine is used for adjusting to the sodium hydroxide, and the sodium hypochlorite of adding is used for removing ammonium to brine.

Brine enters a salt dissolving barrel after passing through an ammonia removal reaction tank and an ammonia removal tower, and light brine and solid salt added into the salt dissolving barrel are prepared into saturated crude brine.

The salt solution gets into the second baffling groove behind the salt dissolving bucket, adds sodium hydroxide and sodium hypochlorite and salt solution mixture in the second baffling groove, and the organic matter in sodium hydroxide is used for the magnesium in the demineralized water, sodium hypochlorite demineralized water.

And the brine enters the front reaction tank after passing through the second diversion tank, and sodium carbonate is added into the front reaction tank to carry out coarse decalcification on the brine.

After passing through the front reaction tank, the saline water passes through a pressurized dissolved air tank and a Venturi mixer in sequence, ferric trichloride is added into the Venturi mixer to serve as a flocculating agent, and the saline water enters a preprocessor and is subjected to preprocessing sedimentation to remove most of precipitates.

The brine enters a rear reaction tank after passing through a preprocessor, sodium carbonate is added into the rear reaction tank for calcium removal and brine is filtered through a membrane filter, the brine after passing through the membrane filter enters a third flow groove, and sodium sulfite is added into the third flow groove to remove free chlorine in the brine to prepare refined brine.

Adding a potassium removing reagent at least one of the front reaction tank, the preprocessor and the rear reaction tank, wherein the potassium removing reagent reacts with potassium in the brine to generate precipitate, and after the precipitate passes through the membrane filter, the potassium content in the brine is reduced to about 90 percent at most, so that the potassium content in the refined brine is controlled, and the quality of a caustic soda product is improved.

In general, the potassium removing reagent is mainly added into a preprocessor, a small amount of potassium removing reagent is added into a front reaction tank and a rear reaction tank, the potassium removing reagent in the front reaction tank performs a pre-reaction, and the potassium removing reagent in the rear reaction tank can ensure the potassium removing efficiency.

The mass of the added potassium removal reagent is not more than 30 times of the mass of potassium in the brine, and the potassium removal reagent is stirred with the brine to react for 0.5 hour, wherein the potassium removal reagent is sodium tetraphenylborate.

In the membrane filter, the aperture of the filter membrane is 0.1 um-0.5 um.

In the environment of reaction of the potassium removal reagent and saline water, the pH value is 5-8, and the temperature is 25-65 ℃.

ICP (inductively coupled plasma emission spectrometer) is arranged on the brine or a brine processing device or a brine transmission line for potassium content monitoring.

A potassium removal reagent was added to the preconditioner and 5 sets of potassium removal experiments were performed, with 5 sets of experimental data as follows:

1. the potassium content in the brine is 74mg/L, a potassium removal reagent (28 times of the potassium content) is added, the mixture is stirred and reacts for 0.5 hour, the potassium content in the brine is reduced to 5mg/L after the mixture is filtered by a 0.1-0.5um filter membrane, and the potassium removal efficiency is 93.24 percent.

2. The potassium content in the brine is 45mg/L, a potassium removal reagent (16 times of the potassium content) is added, the mixture is stirred and reacts for 0.5 hour, the potassium content in the brine is reduced to 16mg/L after the mixture is filtered by a 0.1-0.5um filter membrane, and the potassium removal efficiency is 64.44%.

3. The potassium content in the brine is 45mg/L, a potassium removal reagent (8 times of the potassium content) is added, the mixture is stirred and reacts for 0.5 hour, the potassium content in the brine is reduced to 35mg/L after the mixture is filtered by a 0.1-0.5um filter membrane, and the potassium removal efficiency is 22.22 percent.

4. The potassium content in the brine is 33mg/L, a potassium removal reagent (4 times of the potassium content) is added, the mixture is stirred and reacts for 0.5 hour, the potassium content in the brine is reduced to 28mg/L after the mixture is filtered by a 0.1-0.5um filter membrane, and the potassium removal efficiency is 15.15 percent.

5. The potassium content in the brine is 66mg/L, a potassium removal reagent (2 times of the potassium content) is added, the mixture is stirred and reacts for 0.5 hour, the potassium content in the brine is reduced to 62mg/L after the mixture is filtered by a 0.1-0.5um filter membrane, and the potassium removal efficiency is 6.06 percent.

According to experimental data, the potassium removal efficiency is higher when the adding amount of the potassium removal reagent is larger.

The invention adds the potassium removing reagent to react with potassium to generate precipitate, and filters the precipitate by a membrane filter, thereby reducing the potassium content in refined brine, controlling the potassium content in the brine entering a tank, reducing the potassium content in the produced caustic soda and improving the quality of the caustic soda, wherein the potassium content in the brine can be reduced to about 90%.

The above embodiments are only preferred embodiments of the present invention, and are not intended to limit the technical solutions of the present invention, so long as the technical solutions can be realized on the basis of the above embodiments without creative efforts, which should be considered to fall within the protection scope of the patent of the present invention.