阅读说明：本技术 一种生产氟化铵溶液联产白炭黑的方法 (Method for producing ammonium fluoride solution and co-producing white carbon black ) 是由 李世江 李富斌 薛峰峰 刘海霞 孙永明 薛旭金 王建萍 张亚 施翠莲 李倩慧 于 2019-11-22 设计创作，主要内容包括：本发明涉及一种生产氟化铵溶液联产白炭黑的方法,属于化工产品制备技术领域。本发明的生产氟化铵溶液联产白炭黑的方法,包括以下步骤：1)向管状反应器内处于流动状态的混合液中加入氨水进行第一次氨化反应；第一次氨化反应至终点后混合液pH为6～7；加入氨水前的混合液为氨水和氟硅酸溶液的混合物,pH为1～2；2)向pH为6～7的混合液中加入氨水进行第二次氨化反应；第二次氨化反应至终点后混合液pH为8～9；3)将pH为8～9的混合液进行固液分离,分别得到氟化铵溶液和白炭黑。本发明的方法,采用管状反应器进行连续生产,减少了工艺流程、提高了自动化程度和反应效率,可以稳定、连续生产,提高了生产效率。(The invention relates to a method for producing ammonium fluoride solution and co-producing white carbon black, belonging to the technical field of chemical product preparation. The method for producing ammonium fluoride solution and co-producing white carbon black comprises the following steps: 1) adding ammonia water into the mixed solution in a flowing state in the tubular reactor to carry out a first ammoniation reaction; after the primary ammoniation reaction reaches the end point, the pH value of the mixed solution is 6-7; the mixed solution before adding the ammonia water is a mixture of the ammonia water and the fluorosilicic acid solution, and the pH value is 1-2; 2) adding ammonia water into the mixed solution with the pH value of 6-7 to perform a second ammoniation reaction; after the second ammoniation reaction reaches the end point, the pH value of the mixed solution is 8-9; 3) and carrying out solid-liquid separation on the mixed solution with the pH value of 8-9 to respectively obtain an ammonium fluoride solution and white carbon black. The method of the invention adopts the tubular reactor to carry out continuous production, reduces the process flow, improves the automation degree and the reaction efficiency, can carry out stable and continuous production and improves the production efficiency.)

1. A method for producing ammonium fluoride solution and co-producing white carbon black is characterized by comprising the following steps: the method comprises the following steps:

1) adding ammonia water into the mixed solution in a flowing state in the tubular reactor to carry out a first ammoniation reaction; after the primary ammoniation reaction reaches the end point, the pH value of the mixed solution is 6-7; the mixed solution before adding the ammonia water is a mixture of the ammonia water and the fluorosilicic acid solution, and the pH value is 1-2;

2) adding ammonia water into the mixed solution with the pH value of 6-7 to perform a second ammoniation reaction; after the second ammoniation reaction reaches the end point, the pH value of the mixed solution is 8-9;

3) and carrying out solid-liquid separation on the mixed solution with the pH value of 8-9 to respectively obtain an ammonium fluoride solution and white carbon black.

2. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: the tubular reactor is a plug flow reactor.

3. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: in the step 1), the method for obtaining the mixed liquid with the pH value of 1-2 comprises the following steps:

mixing ammonia water and fluorosilicic acid solution, introducing the mixture into a tubular reactor, and reacting in a flowing state until the end point pH is 1-2 to obtain the fluorine-containing silicon dioxide-fluorine composite material;

or introducing the fluorosilicic acid solution into a tubular reactor, and adding ammonia water to react under a flowing state until the end point pH is 1-2 to obtain the fluorosilicic acid.

4. The method for producing ammonium fluoride solution and co-producing white carbon black according to any one of claims 1 to 3, characterized in that: the concentration of the fluorosilicic acid solution is 15-22%.

5. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: further comprising the steps of: washing the obtained white carbon black; the number of washing treatments is at least one.

6. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 5, which is characterized by comprising the following steps of: the fluorosilicic acid solution is obtained by diluting a high-concentration fluorosilicic acid solution with diluent; the diluent is primary washing water generated by carrying out primary washing treatment on the white carbon black; the concentration of the high-concentration fluorosilicic acid solution is 35-45%.

7. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: the concentration of ammonia water adopted in the first ammoniation reaction and the second ammoniation reaction is independently selected to be 9-10 mol/L.

8. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: in the step 1), the temperature is controlled to be less than or equal to 50 ℃ in the first ammoniation reaction process.

9. The method for producing ammonium fluoride solution and coproducing white carbon black according to claim 1, which is characterized by comprising the following steps of: in the step 2), the temperature is controlled to be less than or equal to 45 ℃ in the second ammonification reaction process.

Technical Field

The invention relates to a method for producing ammonium fluoride solution and co-producing white carbon black, belonging to the technical field of chemical product preparation.

Background

Fluosilicic acid is taken as a byproduct in the production process of phosphorus chemical industry and is mainly used for producing sodium fluosilicate at present, but the sodium fluosilicate has poor economic benefit and insufficient utilization of fluorine and silicon resources. Ammonium fluoride and white carbon black with higher economic value can be prepared by ammoniating fluosilicic acid, and the ammoniation process mainly relates to the following chemical reactions:

H₂SiF₆+2NH₄OH→(NH₄)₂SiF₆+2H₂O；

(NH₄)₂SiF₆+4NH₄OH+nH₂O→6NH₄F+SiO₂·nH₂O+2H₂O。

and (3) carrying out solid-liquid separation on the fluosilicic acid ammoniated product to respectively obtain an ammonium fluoride solution and a white carbon black solid. At present, ammonium fluoride and white carbon black prepared by ammoniating fluosilicic acid are mostly produced discontinuously, for example, a method for producing ammonium fluoride and co-producing white carbon black is disclosed in a Chinese patent with an authorization publication number of CN10577567C, fluosilicic acid or ammonium fluosilicate and ammonia water are used as raw materials in the method, the ammonia water and the fluosilicic acid or ammonium fluosilicate are rapidly reacted to prepare white carbon black crystal seeds, the time is within 20s, and the pH of a reaction end point is between 6.5 and 7.5; adding water, fluosilicic acid or ammonium fluosilicate and ammonia water for reaction on the basis of prepared white carbon black and crystal seeds, controlling the pH value of the reaction end point to be between 8 and 9, preparing slurry of white carbon black precipitate and ammonium fluoride solution, wherein the addition amount of the crystal seeds is 20 to 40 percent of the total weight of the white carbon black generated by the reaction, filtering and washing the white carbon black slurry to obtain white carbon black ointment and ammonium fluoride solution, and concentrating, crystallizing and drying the ammonium fluoride solution to obtain the ammonium fluoride product. The method can effectively utilize byproducts in the production process of the phosphate fertilizer, changes waste into valuable, and has small production scale, low automation degree and low production efficiency.

Disclosure of Invention

The invention aims to provide a method for producing ammonium fluoride solution and white carbon black, which can improve the production efficiency of producing ammonium fluoride solution and white carbon black.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a method for producing ammonium fluoride solution and co-producing white carbon black comprises the following steps:

1) adding ammonia water into the mixed solution in a flowing state in the tubular reactor to carry out a first ammoniation reaction; after the primary ammoniation reaction reaches the end point, the pH value of the mixed solution is 6-7; the mixed solution before adding the ammonia water is a mixture of the ammonia water and the fluorosilicic acid solution, and the pH value is 1-2;

2) adding ammonia water into the mixed solution with the pH value of 6-7 to perform a second ammoniation reaction; after the second ammoniation reaction reaches the end point, the pH value of the mixed solution is 8-9;

3) and carrying out solid-liquid separation on the mixed solution with the pH value of 8-9 to respectively obtain an ammonium fluoride solution and white carbon black.

The method for producing ammonium fluoride solution and co-producing white carbon black can avoid the next reaction from occurring in advance due to overlarge concentration of local ammonia water, ensure the concentration of local seed crystals, avoid the increase of the number of large particles in the finally generated white carbon black, improve the quality of the white carbon black product, and ensure that the specific surface area of the prepared white carbon black is 237m²More than g, oil absorption value of 2.86cm³More than 93 percent of purity. Hair brushIn the method, a mixed solution of ammonia water with the pH value of 1-2 and a silicon fluoride solution is in a clear and transparent state, the mixed solution with the pH value of 1-2 is in a jelly shape when the ammonia water is added in a flowing state to react until the reaction end point of the pH value of 6-7, and then the mixed solution with the jelly pH value of 6-7 is added in the flowing state to react until the reaction end point of the pH value of 8-9, the mixed solution is in a slurry shape. According to the method for producing the ammonium fluoride solution and co-producing the white carbon black, the first ammoniation reaction and the second ammoniation reaction are carried out in the tubular reactor in a material flowing state, so that continuous production can be realized, the process flow is reduced, the automation degree is improved, the reaction efficiency is accelerated, stable and continuous production is realized, and the control accuracy degree and the production efficiency are improved.

And 2) adding ammonia water into the mixed solution with the pH of 6-7 for carrying out a second ammoniation reaction, wherein the mixed solution with the pH of 6-7 is also in a flowing state in the tubular reactor.

The tubular reactor is a continuous production reactor in the form of a tube. Further, the tubular reactor is a plug flow reactor. Ideally, the flow of material in the plug flow reactor has the following characteristics: firstly, no flow velocity distribution exists on a section vertical to the flow direction; and no back mixing phenomenon exists in the material flowing direction. According to the invention, the material is controlled by the plug flow reactor to firstly reach the reaction end point of pH 6-7 in the flow direction, seed crystals are generated at each reaction infinitesimal of pH 6-7, then ammonia water is added into the mixed liquid of pH 6-7 for continuous reaction to enable each reaction infinitesimal to reach the reaction end point of pH 8-9 to generate the white carbon black, the reaction time is shortened by reducing back mixing of the material in the process, the seed crystals in each reaction infinitesimal of pH 6-7 are kept at a higher concentration, and the particle size of the white carbon black generated by crystallization is reduced.

Preferably, the tubular reactor is provided with a first ammonia water feeding port and a second ammonia water feeding port; the first ammonia water adding port is used for adding ammonia water into the mixed solution to carry out a first ammoniation reaction; and the first ammonia water adding port is used for adding ammonia water into the mixed liquid with the pH value of 6-7 to perform a second ammoniation reaction. Ammonia water required by the first ammoniation reaction is added through a first ammonia water adding port; the ammonia water required by the second ammoniation reaction is added through a second ammonia water adding port. The number of the first aqueous ammonia addition port is one or more. The number of the second ammonia water adding ports is one or more.

Preferably, in the step 1), the method for obtaining the mixed solution with the pH of 1-2 comprises the following steps: mixing ammonia water and fluorosilicic acid solution, introducing the mixture into a tubular reactor, and reacting in a flowing state until the end point pH is 1-2 to obtain the fluorine-containing silicon dioxide-fluorine composite material; or introducing the fluorosilicic acid solution into a tubular reactor, and adding ammonia water to react under a flowing state until the end point pH is 1-2 to obtain the fluorosilicic acid. Preferably, in the step 1), the reaction temperature of the mixed solution with the pH of 1-2 is controlled to be less than or equal to 50 ℃ in the obtaining process. When the ammonium hydroxide is mixed with a fluosilicic acid solution to prepare a mixed solution with the pH value of 1-2, the concentration of the adopted ammonia water is preferably 9-10 mol/L.

When high-concentration fluosilicic acid is adopted to react with ammonia water, the obtained white carbon black has poor quality and particularly has the problem of low specific surface. In order to increase the specific surface area of the obtained white carbon black while improving the production efficiency, it is preferable that the concentration of the fluorosilicic acid solution is 15 to 22%.

In order to improve the purity of the obtained white carbon black, preferably, the method for producing ammonium fluoride solution and co-producing white carbon black further comprises the following steps: washing the obtained white carbon black; the number of washing treatments is at least one. Further, the method for producing the ammonium fluoride solution and the white carbon black simultaneously comprises the step of drying the washed white carbon black. The drying treatment is preferably spray drying.

Because the adopted tubular reactor is a continuous reactor, the prepared white carbon black can be washed in batches when the white carbon black obtained by solid-liquid separation is washed. If each batch of white carbon black paste is washed for m times; except for the m times of washing treatment of the first batch of white carbon black ointment and the m times of washing treatment of the rest batches of white carbon black ointment, the n times of washing treatment of each batch of white carbon black ointment is washed by adopting the washing water generated by the n +1 times of washing treatment of the previous batch of white carbon black ointment; wherein m is more than or equal to 2, n is more than or equal to 1 and less than or equal to m-1, and m and n are natural numbers. For example, m may be a natural number such as 2, 3, 4 or 5.

Preferably, the fluorosilicic acid solution is obtained by diluting a high-concentration fluorosilicic acid solution with a diluent. The diluent is primary washing water generated by carrying out primary washing treatment on the white carbon black. The concentration of the high-concentration fluorosilicic acid solution is 35-45%. The concentration fluosilicic acid is diluted by the washing water generated by washing the white carbon black, the discharge amount of waste water in the production process is reduced, the concentration of fluorine in the fluosilicic acid solution is improved, the concentration of the obtained ammonium fluoride solution is further improved, the high-concentration fluosilicic acid can be directly utilized, the production efficiency is further improved, and the production cost is reduced.

The concentration of the aqueous ammonia used in the first and second ammonification reactions is not particularly limited, and in order to obtain a high-concentration ammonium fluoride solution, a high-concentration aqueous ammonia is preferably used. Preferably, the concentration of ammonia water adopted in the first ammoniation reaction and the second ammoniation reaction is independently selected to be 9-10 mol/L. Further, the ammonia water adopted in each step of the method for producing ammonium fluoride solution and co-producing white carbon black has the same concentration.

Preferably, the solid-liquid separation is filtration, and the aperture of a filtering material used for the filtration is 30-50 μm. The filtering material with the aperture of 30-50 mu m is adopted for filtering, so that the rapid filtering can be realized, and the leakage filtering can be prevented.

The reaction temperature of the first amination in step 1) influences the crystal growth rate and the crystal grain size during the production process. In order to obtain the white carbon black with larger specific surface area, preferably, in the step 1), the temperature is controlled to be less than or equal to 50 ℃ in the first ammoniation reaction process.

In order to make the reaction more complete, it is preferable that the temperature in the second ammonification reaction in the step 2) is controlled to be less than or equal to 45 ℃. And in the step 3), a filter press which can be used for carrying out solid-liquid separation on the mixed liquid with the pH of 8-9 is adopted.

Drawings

Fig. 1 is a process flow chart of a method for producing ammonium fluoride solution and co-producing white carbon black in example 1.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Example 1

The method for producing ammonium fluoride solution and co-producing white carbon black of the embodiment is shown in fig. 1, and comprises the following steps:

1) diluting the high-concentration fluorosilicic acid solution with the mass concentration of 42.19% by using a diluent to obtain a low-concentration fluorosilicic acid solution with the mass concentration of 20.63%;

2) introducing a low-concentration fluorosilicic acid solution and ammonia water into a plug flow reactor, controlling the introduction amount of the low-concentration fluorosilicic acid solution to be 0.4kg/min and the introduction amount of the ammonia water to be 0.1L/min, reacting while the materials flow in the plug flow reactor, controlling the reaction temperature to be 45 ℃, controlling the materials to flow to a certain position A of the plug flow reactor to react to reach an end point, wherein the materials are clear and transparent, the pH value is 2, introducing the ammonia water from the position A in an amount of 0.1L/min to continue reacting in the plug flow reactor, controlling the reaction temperature to be 48 ℃, controlling the materials to flow to a certain position B of the plug flow reactor to react to reach the end point, wherein the materials are in a jelly shape, the pH value is 6, introducing the ammonia water from the position B in an amount of 0.3L/min to continue reacting in the plug flow reactor, controlling the reaction temperature to be 47 ℃, and controlling the materials to flow to a certain position C of the, a slurry with a pH of 9.0 is obtained;

3) sending the obtained slurry to a filter press for filtering to respectively obtain an ammonium fluoride solution and a white carbon black ointment, washing the white carbon black ointment in batches, and drying to obtain white carbon black powder; the aperture of the filter cloth in the filter press is 38 mu m;

washing each batch of white carbon black ointment for three times; except for the three washing treatments of the first batch of white carbon black ointment and the third washing treatments of the rest batches of white carbon black ointment, the first washing treatment of each batch of white carbon black ointment adopts the washing water generated by the second washing treatment of the previous batch of white carbon black ointment, the second washing treatment adopts the washing water generated by the third washing treatment of the previous batch of white carbon black ointment, and the washing water generated by the first washing treatment of each batch of white carbon black ointment is collected and reused as the diluent in the step 1).

When washing water for washing the white carbon black paste for the first time is not generated in the initial production, clear water is used as a diluent in the step 1).

The concentration of the ammonia water used in this example is 9.37mol/L, and the volume of the ammonia water introduced when the low-concentration fluorosilicic acid solution is introduced, the volume of the ammonia water introduced at the position a, and the volume of the ammonia water introduced at the position B are 9.8L, 8.5L, and 29.3L, respectively, for each treatment of 40kg of the low-concentration fluorosilicic acid solution obtained in step 1).

The concentration of ammonium fluoride in the ammonium fluoride solution obtained in the embodiment reaches 20.5%; the obtained white carbon black powder has the white carbon black main content of 94 percent and the specific surface area of 237m²G, oil absorption value 2.86cm³The concentration/g meets the requirements of HG/T3061-2009.

In another embodiment of the present invention, the aqueous ammonia added from point A in example 1 is added from a point A downstream of point A₁Point-of-addition, the aqueous ammonia added from point B in example 1 is added from some point B downstream of point B₁The point addition, which is not described, is completely the same as in example 1, and the concentration of the obtained ammonium fluoride solution, the purity of the white carbon black powder, the specific surface area and the oil absorption value are basically the same as those in example 1.

In another embodiment of the present invention, when the white carbon black paste is washed in step 3) of example 1 in batches, each batch is washed three times, and each washing is performed with clean water.

Example 2

The method for producing ammonium fluoride solution and co-producing white carbon black of the embodiment comprises the following steps:

1) diluting the high-concentration fluorosilicic acid solution with the mass concentration of 44.25% by using a diluent to obtain a low-concentration fluorosilicic acid solution with the mass concentration of 17.47%;

2) introducing a low-concentration fluorosilicic acid solution and ammonia water into a plug flow reactor, controlling the introduction amount of the low-concentration fluorosilicic acid solution to be 0.6kg/min and the introduction amount of the ammonia water to be 0.1L/min, reacting while the materials flow in the plug flow reactor, controlling the reaction temperature to be 46 ℃, controlling the materials to flow to a certain position A of the plug flow reactor to react to reach an end point, wherein the materials are clear and transparent, the pH value is 2, introducing the ammonia water from the position A in an amount of 0.1L/min to continue reacting in the plug flow reactor, controlling the reaction temperature to be 47 ℃, controlling the materials to flow to a certain position B of the plug flow reactor to react to reach the end point, wherein the materials are in a jelly shape, the pH value is 6, introducing the ammonia water from the position B in an amount of 0.3L/min to continue reacting in the plug flow reactor, controlling the reaction temperature to be 44 ℃, and controlling the materials to flow to a certain position C of the, a slurry with a pH of 8.5 is obtained;

3) sending the obtained slurry to a filter press for filtering to respectively obtain an ammonium fluoride solution and a white carbon black ointment, washing the white carbon black ointment in batches, and drying to obtain white carbon black powder; the aperture of the filter cloth in the filter press is 48 mu m;

washing each batch of white carbon black ointment for three times; except for the three washing treatments of the first batch of white carbon black ointment and the third washing treatments of the rest batches of white carbon black ointment, the first washing treatment of each batch of white carbon black ointment adopts the washing water generated by the second washing treatment of the previous batch of white carbon black ointment, the second washing treatment adopts the washing water generated by the third washing treatment of the previous batch of white carbon black ointment, and the washing water generated by the first washing treatment of each batch of white carbon black ointment is collected and reused as the diluent in the step 1).

When washing water for washing the white carbon black paste for the first time is not generated in the initial production, clear water is used as a diluent in the step 1).

The concentration of the ammonia water adopted in the embodiment is 9.82mol/L, and when 30kg of the low-concentration fluorosilicic acid solution obtained in the step 1) is treated, the volume of the ammonia water introduced when the low-concentration fluorosilicic acid solution is introduced, the volume of the ammonia water introduced at the position A, and the volume of the ammonia water introduced at the position B are 5.9L, 5.2L, and 15.6L, respectively.

The concentration of ammonium fluoride in the ammonium fluoride solution obtained in the embodiment reaches 18.5%; the obtained white carbon black powder has the white carbon black content of 93 percent and the specific surface area of 284m²G, oil absorption value 3.05cm³The concentration/g meets the requirements of HG/T3061-2009.

In other embodiments of the present invention, a certain amount of ammonia water with a concentration of 9.82mol/L may also be added to the fluorosilicic acid solution obtained in step 1) of example 2, so that the pH of the system is 2 after the reaction end point is reached, then the system with a pH of 2 is introduced into the plug flow reactor, then ammonia water with a concentration of 9.82mol/L is introduced from a certain position a of the plug flow reactor in an amount of 0.1L/min to react in the plug flow reactor, the reaction temperature is controlled to 47 ℃, the material flows to a certain position B of the plug flow reactor, the reaction reaches the end point, the material is in a jelly shape at the time, the pH value is 6, ammonia water with a concentration of 9.82mol/L is introduced from the position B to continue the reaction in the plug flow reactor in an amount of 0.3L/min, the reaction temperature is controlled to 44 ℃, the material flows to a certain position C of the plug flow reactor, the reaction reaches the, a slurry with a pH of 8.5 was obtained. The slurry obtained is then further processed according to step 3) of example 2, finally obtaining ammonium fluoride solution and white carbon black powder. The concentration of the ammonium fluoride solution, the purity of the white carbon black powder, the specific surface area and the oil absorption value are basically the same as those of the ammonium fluoride solution in the example 2.