阅读说明：本技术 气相法白炭黑脱酸系统和方法 (White carbon black deacidification system and method by gas phase method ) 是由 韩怀见 曹大志 张守宽 申志忠 于 2019-07-05 设计创作，主要内容包括：本发明提供了一种气相法白炭黑脱酸系统和方法。该系统包括第一脱酸炉、第二脱酸炉、分离器和加热器,通过加热器将蒸汽加热至250℃左右,再将加热后的蒸汽通入到两个脱酸炉中,使蒸汽与白炭黑依次在两个脱酸炉中混合进行脱酸,然后使白炭黑和热空气在分离器中进一步脱酸,最终使得白炭黑pH值稳定在4.2以上。(The invention provides a system and a method for deacidifying white carbon black by a gas phase method. The system comprises a first deacidification furnace, a second deacidification furnace, a separator and a heater, wherein steam is heated to about 250 ℃ by the heater, the heated steam is introduced into the two deacidification furnaces, the steam and the white carbon black are mixed in the two deacidification furnaces in sequence for deacidification, then the white carbon black and hot air are further deacidified in the separator, and finally the pH value of the white carbon black is stabilized to be more than 4.2.)

1. A white carbon black deacidification system adopting a gas phase method comprises a first deacidification furnace, a second deacidification furnace, a separator and a heater, wherein the first deacidification furnace and the second deacidification furnace respectively comprise a white carbon black inlet, a white carbon black outlet, a steam inlet and a tail gas outlet, the separator comprises a white carbon black inlet, a white carbon black outlet, a hot air inlet and a tail gas outlet containing HCL, and the heater comprises a steam inlet and a steam outlet; the steam inlet of first deacidification stove and the steam inlet of second deacidification stove all pass through the pipe connection with the steam outlet of heater, and the white carbon black export of first deacidification stove passes through the pipe connection with the white carbon black entry of second deacidification stove, and the white carbon black export of second deacidification stove passes through the pipe connection with the white carbon black entry of separator.

2. The fumed silica deacidification system according to claim 1, characterized in that: the separator comprises a white carbon black inlet, a white carbon black outlet, a hot air inlet, a tail gas outlet containing HCL and two flower plates, wherein a plurality of small holes are distributed in the two flower plates, the inner space of the separator is divided into three parts by the two flower plates, the white carbon black inlet and the white carbon black outlet are communicated with the part positioned between the two flower plates, and the hot air inlet and the tail gas outlet containing HCL are respectively communicated with the other two parts.

3. The fumed silica deacidification system according to claim 2, characterized in that: the two flower plates are uniformly distributed with a plurality of small holes with the diameter of 0.5 mm.

4. The fumed silica deacidification system according to claim 1, characterized in that: the heater is an electric heater.

5. A deacidification method of white carbon black by a gas phase method comprises the following steps:

(1) feeding the white carbon black into a first deacidification furnace, introducing steam with the temperature of 240-280 ℃ into the first deacidification furnace, and taking away acid substances attached to the white carbon black by using the steam;

(2) allowing the white carbon black treated in the step (1) to enter a second deacidification furnace, introducing steam with the temperature of 240-280 ℃ into the second deacidification furnace, and taking away acidic substances attached to the white carbon black by using the steam;

(3) and (3) feeding the white carbon black treated in the step (2) into a separator, introducing hot air with the temperature of 240-280 ℃ into the separator, and taking away acidic substances and moisture attached to the white carbon black by using the hot air.

6. The deacidification method of fumed silica according to claim 5, characterized in that: the steam temperature is 250 ℃, and the hot air temperature is 250 ℃.

Technical Field

The invention relates to a production technology of fumed silica, in particular to a technology for improving the pH value of fumed silica.

Background

The fumed silica is generally generated by hydrolyzing chlorosilane at high temperature in oxyhydrogen flame to generate primary silicon dioxide particles with the average particle size of 7-40 nm, aggregates are formed after high-temperature high-speed collision, and the aggregates are packaged after separation and deacidification treatment. With the development of downstream industries, the requirements for fumed silica are gradually improved. The pH value of the fumed silica is one of the important indexes, and the quality of the fumed silica is directly determined by the pH value and the stability of the fumed silica.

The prior deacidification treatment process adopts a deacidification furnace to deacidify, the temperature of the deacidification furnace is controlled to be about 500 ℃, and steam and hot air of about 150 ℃ are introduced for deacidification. However, the current domestic white carbon black has unstable pH value, most of the current domestic white carbon black has the pH value of 3.8-4.0, and even the local white carbon black has the pH value of below 3.5, so that the application of downstream industries is greatly influenced. The white carbon black with low pH value easily causes the kraft paper bag for packaging the white carbon black to be embrittled, and the phenomena of bag breaking, sizing material structuring and sizing material yellowing occur. Especially, the white carbon black product with the specific surface area of more than 200 needs to be baked before use, and the bag breaking phenomenon is more likely to occur in the baking process.

Therefore, the deacidification treatment process needs to be further optimized, and the pH value of the fumed silica is increased.

Disclosure of Invention

Aiming at the problems mentioned in the background technology, the invention provides a system and a method for deacidifying white carbon black by a gas phase method.

The invention provides a white carbon black deacidification system by a gas phase method, which comprises a first deacidification furnace, a second deacidification furnace, a separator and a heater, wherein the first deacidification furnace and the second deacidification furnace respectively comprise a white carbon black inlet, a white carbon black outlet, a steam inlet and a tail gas outlet, the separator comprises a white carbon black inlet, a white carbon black outlet, a hot air inlet and a tail gas outlet containing HCL, and the heater comprises a steam inlet and a steam outlet; the steam inlet of first deacidification stove and the steam inlet of second deacidification stove all pass through the pipe connection with the steam outlet of heater, and the white carbon black export of first deacidification stove passes through the pipe connection with the white carbon black entry of second deacidification stove, and the white carbon black export of second deacidification stove passes through the pipe connection with the white carbon black entry of separator. When the heating device is used, steam is introduced from a steam inlet of the heater, the steam is heated to 240-280 ℃ by the heater, and the heated steam enters the first deacidification furnace and the second deacidification furnace from the steam inlets of the two deacidification furnaces respectively; meanwhile, the white carbon black to be deacidified enters the first deacidifying furnace from the white carbon black inlet of the first deacidifying furnace, steam contacts with the white carbon black to be deacidified in the first deacidifying furnace, and therefore part of acidic substances (mainly HCl) attached to the white carbon black to be deacidified are taken away. And then, the white carbon black enters a second deacidification furnace and is mixed with steam again for deacidification. After the white carbon black is treated by the two deacidification furnaces, a small amount of HCl is attached to the white carbon black, so that the white carbon black enters the separator from a white carbon black inlet of the separator, and meanwhile, 240-280 ℃ hot air is introduced from a hot air inlet of the separator, so that HCl attached to the surface of the white carbon black is further removed, and the pH value of the fumed silica is stabilized between 4.2-4.6.

Preferably, the separator comprises a white carbon black inlet, a white carbon black outlet, a hot air inlet, a tail gas outlet containing HCL and two pattern plates, wherein a plurality of small holes are uniformly distributed on the two pattern plates, the two pattern plates divide the inner space of the separator into three parts, the white carbon black inlet and the white carbon black outlet are communicated with the part between the two pattern plates, and the hot air inlet and the tail gas outlet containing HCL are respectively communicated with the other two parts. The hot air can pass through the small holes on the pattern plate and uniformly contact the white carbon black of the separator.

More preferably, a plurality of small holes with the diameter of 0.5mm are distributed on the two pattern plates.

Preferably, the heater is an electric heater.

The invention provides a deacidification method of white carbon black by a gas phase method, which comprises the following steps:

(1) feeding the white carbon black into a first deacidification furnace, introducing steam with the temperature of 240-280 ℃ into the first deacidification furnace, and taking away part of acidic substances attached to the white carbon black by using the steam;

(2) allowing the white carbon black treated in the step (1) to enter a second deacidification furnace, introducing steam with the temperature of 240-280 ℃ into the second deacidification furnace, and taking away part of acidic substances attached to the white carbon black again by using the steam;

(3) and (3) feeding the white carbon black treated in the step (2) into a separator, introducing hot air with the temperature of 240-280 ℃ into the separator, and taking away part of the residual acidic substances and moisture attached to the white carbon black by using the hot air.

Preferably, the steam temperature is 250 ℃ and the hot air temperature is 250 ℃.

The invention has the beneficial effects that: firstly, removing most HCl through two deacidification furnaces, and further deacidifying by utilizing hot air through a separator to stabilize the pH value of the white carbon black to be more than 4.2; the temperature of steam heated by the heater can reach about 250 ℃, HCl on the surface of the white carbon black is easier to desorb at the temperature, and the pH value of the product is greatly improved.

Drawings

FIG. 1 is a schematic diagram of a fumed silica deacidification system according to the present invention.

Fig. 2 is a schematic view of the deacidification furnace of the present invention.

Fig. 3 is a schematic view of a separator of the present invention.

The reference signs explain: 100. a first deacidification furnace, 200, a second deacidification furnace, 300, a separator, 400, a heater; 201. a slag discharge port, 202, a steam inlet, 203, a spare port, 204, a white carbon black inlet, 205, a white carbon black outlet, 206, a viewing port, 207, a tail gas outlet, 208 and a pore plate; 301. white carbon black inlet 302, white carbon black outlet 303, tail gas outlet containing HCL 304, slag discharge port 305, slag discharge port 306, hot air inlet 307, pattern plate 308 and partition plate.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.

As shown in fig. 1 to 3, the fumed silica deacidification system provided by the present invention includes a first deacidification furnace 100, a second deacidification furnace 200, a separator 300, and a heater 400.

First deacidifying stove 100 and second deacidifying stove 200 can be the same in structure, specifically, the deacidifying stove include white carbon black entry 204, white carbon black export 205, steam inlet 202, tail gas export 207 and two orifice plates 208, evenly distribute a plurality of diameter 0.8 mm's hole on two orifice plates 208 about, white carbon black entry 204 and white carbon black export 205 are located between two orifice plates 208, steam inlet 202 is located the bottom of deacidifying stove, tail gas export 207 is located the top of deacidifying stove. The deacidification furnace can further comprise a slag discharge port 201 for discharging impurities, a standby port 203 for replacing a white carbon black inlet 204 and a viewing port 206 for checking the internal condition of the deacidification furnace, wherein the slag discharge port 201, the standby port 203 and the viewing port 206 are closed during deacidification and are started when needed. The first deacidification furnace 100 and the second deacidification furnace 200 may be fluidized beds.

The separator 300 comprises a white carbon black inlet 301, a white carbon black outlet 302, a hot air inlet 306, a tail gas outlet 303 containing HCL and two flower plates 307, wherein a plurality of small holes with the diameter of 0.5mm are uniformly distributed on the two flower plates 307, and the inner space of the separator 300 is divided into an upper part, a middle part and a lower part by the two flower plates 307. The white carbon black inlet 301 and the white carbon black outlet 302 are positioned between the two flower plates 307 and are communicated with the middle part of the separator 300; a hot air inlet 306 is located at the bottom of the separator, communicating with the lower space of the separator 300; an HCL-containing tail gas outlet 303 is located at the top of the separator and communicates with the headspace of separator 300. The separator 300 may further include two partitions 308 for increasing the complexity of the white carbon passage, a slag discharge port 304 for discharging impurities, and a slag discharge port 305 for discharging impurities.

The heater 400 is used to heat steam and includes a steam inlet and a steam outlet. The heater 400 may be an electric heater or a heat exchanger heated by other media.

The white carbon black outlet of the first deacidification furnace 100 is connected with the white carbon black inlet of the second deacidification furnace through a pipeline, and the white carbon black outlet of the second deacidification furnace 200 is connected with the white carbon black inlet of the separator 300 through a pipeline. A steam outlet of the heater 400 is connected to a steam inlet of the first deacidification furnace 100 and a steam inlet of the second deacidification furnace 200, respectively, through pipes. The steam outlet of the first deacidification furnace 100, the steam outlet of the second deacidification furnace 200 and the hot air outlet of the separator 300 can be connected with a tail gas absorption system of the white carbon black production line through pipelines. The tail gas absorption system of the white carbon black production line can treat the gas containing acidic substances, so that the gas is discharged after reaching the standard.

When the device is used, firstly, white carbon black enters the first deacidifying furnace 100 from a white carbon black inlet of the first deacidifying furnace 100, steam is heated to 240-280 ℃ by the heater 400 and then enters the first deacidifying furnace 100 from a steam inlet of the first deacidifying furnace 100, and the white carbon black and the steam pass through the first deacidifying furnace 100 in a fluidized state, so that the white carbon black and the steam are well mixed and contacted, and HCl on the surface of the white carbon black is removed; white carbon black flows out from a white carbon black outlet of the first deacidification furnace 100, and HCl carried by steam and removed enters the tail gas absorption system from a tail gas outlet at the top of the first deacidification furnace 100. Then, the white carbon black enters the second deacidifying furnace 200 from the white carbon black inlet of the second deacidifying furnace 200, and steam at 240-280 ℃ enters the second deacidifying furnace 200 from the steam inlet of the second deacidifying furnace 200 to be deacidified again. The white carbon black is deacidified twice, most of acidic substances are removed, and a hot air separator 300 is additionally arranged at the rear side of the deacidification furnace for further removing the residual acidic substances. White carbon black flowing out of a white carbon black outlet of the second deacidification furnace 200 enters the separator 300 from a white carbon black inlet of the separator 300, hot air at 240-280 ℃ enters the separator 300 through a hot air inlet of the separator 300, the white carbon black and the hot air are well mixed and contacted in the process, HCl is further removed, the processed white carbon black is sent to a storage bin from the white carbon black outlet of the separator, and the hot air carries the removed HCl to enter a tail gas absorption system.

The gas phase method white carbon black deacidification system is used for deacidifying white carbon black needing deacidification, and comprises the following steps:

(1) the white carbon black needing deacidification enters a first deacidification furnace 100, steam with the temperature of 250 ℃ is introduced, and acidic substances attached to the white carbon black are taken away by the steam;

(2) the white carbon black treated in the step (1) enters a second deacidification furnace 200, steam with the temperature of 250 ℃ is introduced, and acidic substances attached to the white carbon black are taken away by the steam;

(3) and (3) feeding the white carbon black treated in the step (2) into a separator 300, introducing hot air with the temperature of 250 ℃, and taking away acidic substances and moisture attached to the white carbon black by using the hot air.

The pH of the white carbon black during and after deacidification was measured, ten central control data and ten finished product data (the central control data and the finished product data of the present invention) were continuously extracted, and the results are shown in table 1. Wherein, the central control data refers to the analysis data of small samples taken every two hours in the production process; the product data refers to analytical data of daily produced product samples.

Table 1 also lists the pH control data and finished product data (original control data and original finished product data) of the white carbon black subjected to deacidification treatment in the prior art, and the deacidification treatment in the prior art is only deacidified by two deacidification furnaces, the steam temperature for deacidification is 150 ℃, and the white carbon black is not subjected to treatment by the separator 300.

TABLE 1 comparison of pH values of deacidified white carbon black of the prior art and deacidified white carbon black of the present invention

As can be seen from the above table, the pH value of the deacidified white carbon black is stable and is between 4.15 and 4.41. The pH value of the deacidified white carbon black in the prior art is 3.56-4.10, and the fluctuation is large. In general, the pH value of the deacidified white carbon black of the present invention is significantly higher than the pH value of the deacidified white carbon black of the prior art.

In conclusion, the invention adopts the thermodynamic principle that the activity of molecules is increased at high temperature, HCl adsorbed on the surface of the white carbon black is desorbed through the violent movement of the molecules, and a separator is added to prolong the HCl desorption time, so that the pH value of the fumed white carbon black is obviously improved and is more uniform and stable.