CN113877571A - Coating slurry, preparation method of coating type denitration catalyst and denitration catalyst - Google Patents

Coating slurry, preparation method of coating type denitration catalyst and denitration catalyst Download PDF

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CN113877571A
CN113877571A CN202111022032.8A CN202111022032A CN113877571A CN 113877571 A CN113877571 A CN 113877571A CN 202111022032 A CN202111022032 A CN 202111022032A CN 113877571 A CN113877571 A CN 113877571A
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slurry
coating
hour
normal temperature
silica sol
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赵羽
沈光宇
王光应
马永承
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Anhui Yuanchen Environmental Protection Science and Technology Co Ltd
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Anhui Yuanchen Environmental Protection Science and Technology Co Ltd
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Abstract

The invention provides a coating slurry, a preparation method of a coating type denitration catalyst and the denitration catalyst, wherein the preparation method comprises the following steps: ball-milling the mixed powder of titanium dioxide, vanadium pentoxide and tungsten trioxide in a ball mill by taking a silica sol solution as a dispersing agent to obtain slurry A with the average particle size of 3 mu m; taking out the slurry A, adjusting the pH value to 1-2, and stirring at normal temperature to obtain slurry B; adding a CMC solution into the slurry B, and continuously stirring at normal temperature to obtain slurry C; and adding talcum powder or nano graphite powder into the slurry C, and continuously stirring at normal temperature to obtain slurry D. And (3) carrying out loading on the slurry D by using 50-mesh commercial cordierite honeycomb ceramic as a carrier, and drying the obtained sample in an oven to obtain the coating type denitration catalyst. The invention has the advantages that: the talcum powder or the nano graphite powder is used as the flow increasing agent, so that the fluidity of the coating slurry is effectively improved, the coating slurry can rapidly flow in a honeycomb carrier pore channel in the coating process, and the accumulation in the honeycomb carrier pore channel caused by unsmooth flow of the slurry is avoided.

Description

Coating slurry, preparation method of coating type denitration catalyst and denitration catalyst
Technical Field
The invention relates to the field of environmental protection, and particularly relates to a coating slurry and a preparation method of a coating type denitration catalyst.
Background
With the increase of human energy demand, the power generation proportion of the current Chinese coal-fired power generation reaches up to 70 percent, and the coal-fired power generation must discharge a large amount of substances which pollute the environment, such as carbon dioxide (CO)2) Sulfur dioxide (SO)2) Particulate matter and nitrogen oxides (NOx), and the like. In particular, the increase in NOx emissions, the human atmospheric environment and ecology suffer serious damages. The current environmental pollution problem is becoming more serious, and NOx emission control is a subject which is always in key attack in the environmental protection field.
At present, Selective Catalytic Reduction (SCR) and selective non-catalytic reduction (SNCR) are applied to NOx emission reduction, namely flue gas denitration, and the SCR technology is widely used at present because the removal rate of the SCR technology can reach more than 90%. SCR technology is that under the catalytic action of catalyst, reductive substances such as ammonia water and urea are used to perform oxidation-reduction reaction with NOx in flue gas to finally generate harmless N2And water.
At present, the mainstream denitration catalyst is an extrusion molded monolithic catalyst, a plate type catalyst and the like, and the main effective component is vanadium pentoxide (V)2O5) Tungsten trioxide (WO)3) And molybdenum trioxide (MoO)3) Etc., a commonly used support is titanium dioxide (TiO)2). The effective active components and the carriers are extracted from the ores, a large amount of energy is consumed, pollution is caused, a large amount of active substances and carriers are needed for integral extrusion molding or plate type catalysts, and only the catalyst of the contact part of the surface and the flue gas can play a role of catalysis, so that great substance waste is caused.
The coating type honeycomb denitration catalyst takes a honeycomb carrier as a substrate, and a coating with denitration activity is coated in a honeycomb pore channel of the substrate, so that the use amount of active substances and the carrier is reduced on the premise of not reducing the denitration activity of the catalyst. However, the reaction flue gas of the denitration catalyst contains a certain amount of dust, so that the coating layer and the carrier are required to be directly and strongly bonded, and the coating layer is ensured not to fall off in the use process, so that the service life is influenced.
At present, more preparation methods of the coating type SCR denitration catalyst exist. Patent CN 111167436 a discloses a coated monolithic catalyst prepared by coating a catalyst coating layer comprising a catalytically active component, a binder, a surfactant, an additive and a modifier on a substrate having a porous structure. Patent CN 102974363A discloses SCR flue gas denitration catalyst, including carrier, catalytic activity component and cocatalyst, its characterized in that: the carrier being coated with Al2O3The membrane cordierite honeycomb ceramic has an active component of copper oxide and a promoter of one of oxides of manganese, lanthanum or cerium. The general preparation method of the coating type denitration catalyst comprises the steps of loading the coating slurry on the surface of a honeycomb carrier, and drying and roasting to obtain the product. The degree of bonding of the coating slurry to the support during the catalyst preparation determines the wash-off resistance of the coating. In addition to improving the degree of slurry-to-carrier compatibility, the method of improving this firmness is also critical for the flow of the slurry. Increasing the binder (CMC-sodium carboxymethylcellulose) ratio increases the binding force, but also causes the slurry to become viscous and reduce flowability.
Disclosure of Invention
The invention aims to provide a coating slurry and a preparation method of a coating type denitration catalyst.
The invention solves the technical problems through the following technical means: a method of preparing a coating slurry comprising the steps of:
step (1), titanium dioxide: vanadium pentoxide: tungsten trioxide (91-97): (1-3): (2-6) carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent to obtain slurry A with the average particle size of 3 microns;
taking out the slurry A, adjusting the pH to 1-2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B;
adding 1-3 wt% of CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry C;
and (4) adding talcum powder or nano graphite powder into the slurry C, controlling the mass proportion of the talcum powder or the nano graphite powder in the whole slurry to be 2-4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D.
According to the invention, the talcum powder or the nano graphite powder is used as the flow increasing agent, so that the fluidity of the coating slurry can be effectively improved, the coating slurry can rapidly flow in a honeycomb carrier pore channel in the coating process, and the accumulation in the honeycomb carrier pore channel caused by the unsmooth flow of the slurry is avoided.
As an optimized technical scheme, the solid content of the silica sol solution is 10%, the granularity of silica in the silica sol is 20-60nm, the solid content of the slurry A is controlled to be 35-60% by adjusting the adding amount of the mixed powder and the silica sol, and the solid content of the coating slurry C is controlled to be 30-40% by adjusting the adding amount of the CMC solution.
As an optimized technical scheme, the parameters of wet ball milling in the ball mill in the step (1) are as follows: the rotating speed is 400 r/min, the time is 1 hour, and the ball milling temperature is 30 ℃.
As an optimized technical scheme, the stirring speed in the step (2) is 400 revolutions per minute, the stirring speed in the step (3) is 400 revolutions per minute, and the stirring speed in the step (4) is 400 revolutions per minute.
As an optimized technical scheme, the preparation method of the coating slurry specifically comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: tungsten trioxide 97: 1: 2, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 1 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 60%;
adding 1 wt% of CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 30%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 2%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 revolutions per minute.
As an optimized technical scheme, the preparation method of the coating slurry specifically comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 94% of tungsten trioxide: 2: 4, carrying out wet ball milling on the mixed powder in a ball mill at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃ by taking a silica sol solution as a dispersing agent, wherein the solid content in the silica sol solution is 10%, and the granularity of silica in the silica sol is 60nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 70%;
adding a 2 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 35%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 3%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 r/min.
As an optimized technical scheme, the preparation method of the coating slurry specifically comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 60nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 80%;
adding a 3 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 40%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 r/min.
As an optimized technical scheme, the preparation method of the coating slurry specifically comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 50nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 80%;
adding a 3 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 40%;
and (4) adding nano graphite powder with the average particle size of 500nm into the slurry C, controlling the mass proportion of the nano graphite powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 revolutions per minute.
The invention also provides a method for preparing a coated denitration catalyst by using the coating slurry prepared by the preparation method in any one of the above schemes, which comprises the following steps:
loading the coating slurry D by using 50-mesh commercial cordierite honeycomb ceramic as a carrier through a lower feeding automatic coating machine, wherein the loading amount is 80-120 g/L;
and drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
The invention also provides a coated denitration catalyst prepared by the preparation method of the coated denitration catalyst.
The invention has the advantages that: the talcum powder or the nano graphite powder is used as the flow increasing agent, so that the fluidity of the coating slurry can be effectively improved, the coating slurry can rapidly flow in a honeycomb carrier pore channel in the coating process, and the accumulation in the honeycomb carrier pore channel caused by unsmooth flow of the slurry is avoided.
Drawings
FIG. 1 is a schematic illustration of the effect of modifying a flow enhancer on the denitration stability of a catalyst.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
the embodiment provides a preparation method of coating slurry and a coating type denitration catalyst, which comprises the following specific steps:
mixing titanium dioxide: vanadium pentoxide: tungsten trioxide 97: 1: 2, carrying out wet ball milling (the rotating speed is 400 r/min, the time is 1 hour, the ball milling temperature is 30 ℃) in a ball mill by taking a silica sol solution (the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20-60nm) as a dispersing agent to obtain slurry A with the average granularity of 3 mu m.
And taking the slurry A out, adjusting the pH value to 1 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 rpm, the solid content of the slurry A is controlled to be 60 percent by adjusting the adding amount of the aluminum sol.)
To the slurry B, a CMC solution (1 wt%) was added, and stirring was continued at normal temperature for 0.5 hour to obtain a coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 30% by adjusting the adding amount of the CMC solution.)
And adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 2%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D. (stirring speed 400 rpm.)
The above-mentioned coating slurry D was loaded at a load of 80g/L by a lower feed automatic coater using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Example 2:
mixing titanium dioxide: vanadium pentoxide: 94% of tungsten trioxide: 2: and 4, carrying out wet ball milling (the rotating speed is 400 r/min, the time is 1 hour, the ball milling temperature is 30 ℃) in a ball mill by taking a silica sol solution (the solid content in the silica sol solution is 10%, and the granularity of silica in the silica sol is 20-60nm) as a dispersing agent to obtain the slurry A with the average granularity of 3 mu m.
And taking the slurry A out, adjusting the pH to 2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 rpm, the solid content of the slurry A is controlled to be 70 percent by adjusting the adding amount of the aluminum sol.)
To the slurry B, a CMC solution (2 wt%) was added, and stirring was continued at normal temperature for 0.5 hour to obtain a coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 35% by adjusting the adding amount of the CMC solution.)
And adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 3%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D. (stirring speed 400 rpm.)
The above-mentioned coating slurry D was loaded by a down-feed automatic coating machine with a load of 100g/L using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Example 3:
mixing titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: and 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution (the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20-60nm) as a dispersing agent in the ball mill (the rotating speed is 400 r/min, the time is 1 hour, and the ball milling temperature is 30 ℃) to obtain slurry A with the average granularity of 3 mu m.
And taking the slurry A out, adjusting the pH value to 1-2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 rpm, the solid content of the slurry A is controlled to be 80 percent by adjusting the adding amount of the aluminum sol.)
To the slurry B, a CMC solution (3 wt%) was added, and stirring was continued at normal temperature for 0.5 hour to obtain a coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 40% by adjusting the adding amount of the CMC solution.)
And adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D. (stirring speed 400 rpm.)
The above-mentioned loading of the coating slurry D was carried out by a lower feed automatic coater using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier, at a loading of 120 g/L. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Example 4:
mixing titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: and 6, carrying out wet ball milling on the mixed powder in a ball mill (the rotating speed is 400 r/min, the time is 1 hour, the ball milling temperature is 30 ℃) by taking a silica sol solution (the solid content in the silica sol solution is 10%, and the granularity of silica in the silica sol is 50nm) as a dispersing agent to obtain the slurry A with the average granularity of 3 microns.
And taking the slurry A out, adjusting the pH to 2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 rpm, the solid content of the slurry A is controlled to be 80 percent by adjusting the adding amount of the aluminum sol.)
To the slurry B, a CMC solution (3 wt%) was added, and stirring was continued at normal temperature for 0.5 hour to obtain a coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 40% by adjusting the adding amount of the CMC solution.)
Adding nano graphite powder (with average particle size of 500nm) into the slurry C, controlling the mass proportion of the nano graphite powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D. (stirring speed 400 rpm.)
The above-mentioned loading of the coating slurry D was carried out by a lower feed automatic coater using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier, at a loading of 120 g/L. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Comparative example 1:
mixing titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: and 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution (the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20-60nm) as a dispersing agent in the ball mill (the rotating speed is 400 r/min, the time is 1 hour, and the ball milling temperature is 30 ℃) to obtain slurry A with the average granularity of 3 mu m.
And taking the slurry A out, adjusting the pH value to 1-2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 r/min, the solid content of the slurry is controlled to be 80% by adjusting the adding amount of the aluminum sol.)
And adding deionized water into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 40% by adjusting the adding amount of deionized water.)
Adding nano graphite powder (with average particle size of 500nm) into the slurry C, controlling the mass proportion of the nano graphite powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D. (stirring speed 400 rpm.)
The above-mentioned loading of the coating slurry D was carried out by a lower feed automatic coater using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier, at a loading of 120 g/L. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Comparative example 2:
mixing titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: and 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution (the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20-60nm) as a dispersing agent in the ball mill (the rotating speed is 400 r/min, the time is 1 hour, and the ball milling temperature is 30 ℃) to obtain slurry A with the average granularity of 3 mu m.
And taking the slurry A out, adjusting the pH value to 1-2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B. (the stirring speed is 400 r/min, the solid content of the slurry is controlled to be 80% by adjusting the adding amount of the aluminum sol.)
To the slurry B, a CMC solution (3 wt%) was added, and stirring was continued at normal temperature for 0.5 hour to obtain a coating slurry C. (stirring speed is 400 rpm, and the solid content of the slurry is controlled to be 30% by adjusting the adding amount of the CMC solution.)
The above-mentioned loading of the coating slurry C was carried out by a lower feed automatic coater using a commercial cordierite honeycomb ceramic (50 mesh) as a carrier, at a loading of 120 g/L. And drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
Testing the denitration performance of the catalyst: the denitration performance test is carried out in a fixed bed, the catalyst is cut into samples with the size of 20mm multiplied by 30mm along the pore channel direction, and the samples are placed into a bed layer along the axis of a reactor. The components of the flue gas are NO (1000ppm) and NH3(1000ppm)、O2(6vol.％)、N2As carrier gas, the airspeed of the mixed gas is 6000h-1(ii) a The reaction temperature was 150 ℃. Before introducing the reaction gas, introducing air into the fixed bed reactor, raising the temperature to 400 ℃, keeping the temperature for 4 hours, reducing the temperature to 150 ℃, and then introducing the reaction gas for carrying out a denitration performance test.
Testing the scouring resistance of the catalyst: cutting the catalyst into samples with the sizes of 20mm multiplied by 30mm along the pore channel direction, blowing for 10min along the pore channel direction of the samples by using compressed air with the pressure of 0.8MPa, and judging the scouring resistance of the catalyst according to the mass loss.
In the above examples, the amounts and types of CMC binder and flow enhancer were examined, and the active material content and the monolith coating material in the catalyst were examined.
As shown in fig. 1, the SCR denitration catalytic reaction stability of the coated catalyst sample added with CMC and talc powder or nano graphite powder is good, while the sample added with only CMC or only nano graphite powder is quickly deactivated, and the sample added with only nano graphite powder is more quickly deactivated.
TABLE 1
Example 1 Example 2 Example 3 Example 4 Comparative example 1 Comparative example 2
Percent exfoliation (%) 0 0 0 0 2.1％ 0.8％
As can be seen from the shedding table in table 1 above, the shedding rate of the coated catalyst sample added with CMC and talc powder or nano graphite powder is 0, the shedding rate of the sample added with only nano graphite powder is 2.1%, and the shedding rate of the sample added with only CMC is 0.8%. The flow increasing agent such as talcum powder or nano graphite powder can effectively improve the fluidity of the slurry on the premise of not influencing the viscosity of the slurry, so that the coating slurry can be better contacted with a carrier, and the scouring resistance of the coating type denitration catalyst is improved.
While the present invention provides a novel concept and method, and many ways of implementing the same, it will be apparent to those skilled in the art that various modifications can be made to the embodiments and the generic principles defined herein may be applied to other embodiments without undue inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims (10)

1. A preparation method of coating slurry is characterized by comprising the following steps: the method comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: tungsten trioxide (91-97): (1-3): (2-6) carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent to obtain slurry A with the average particle size of 3 microns;
taking out the slurry A, adjusting the pH to 1-2 by adding nitric acid, and continuously stirring for 1 hour at normal temperature to obtain coating slurry B;
adding 1-3 wt% of CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry C;
and (4) adding talcum powder or nano graphite powder into the slurry C, controlling the mass proportion of the talcum powder or the nano graphite powder in the whole slurry to be 2-4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D.
2. The method for preparing a coating slurry according to claim 1, wherein: the solid content of the silica sol solution is 10%, the granularity of silica in the silica sol is 20-60nm, the solid content of the coating slurry A is controlled to be 35-60% by adjusting the adding amount of the mixed powder and the silica sol, and the solid content of the coating slurry C is controlled to be 30-40% by adjusting the adding amount of the CMC solution.
3. The method for preparing a coating slurry according to claim 1, wherein: the parameters of wet ball milling in the ball mill in the step (1) are as follows: the rotating speed is 400 r/min, the time is 1 hour, and the ball milling temperature is 30 ℃.
4. The method for preparing a coating slurry according to claim 1, wherein: the stirring speed in the step (2) is 400 rpm, the stirring speed in the step (3) is 400 rpm, and the stirring speed in the step (4) is 400 rpm.
5. The method for preparing a coating slurry according to claim 1, wherein: the method comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: tungsten trioxide 97: 1: 2, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 20nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 1 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 60%;
adding 1 wt% of CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 30%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 2%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 revolutions per minute.
6. The method for preparing a coating slurry according to claim 1, wherein: the method comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 94% of tungsten trioxide: 2: 4, carrying out wet ball milling on the mixed powder in a ball mill at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃ by taking a silica sol solution as a dispersing agent, wherein the solid content in the silica sol solution is 10%, and the granularity of silica in the silica sol is 60nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 70%;
adding a 2 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 35%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 3%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 r/min.
7. The method for preparing a coating slurry according to claim 1, wherein: the method comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 60nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 80%;
adding a 3 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 40%;
and (4) adding talcum powder into the slurry C, controlling the mass proportion of the talcum powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 r/min.
8. The method for preparing a coating slurry according to claim 1, wherein: the method comprises the following steps:
step (1), titanium dioxide: vanadium pentoxide: 91 parts of tungsten trioxide: 3: 6, carrying out wet ball milling on the mixed powder in a ball mill by taking a silica sol solution as a dispersing agent at the rotation speed of 400 r/min for 1 hour at the ball milling temperature of 30 ℃, wherein the solid content in the silica sol solution is 10 percent, and the granularity of silica in the silica sol is 50nm to obtain slurry A with the average granularity of 3 mu m;
step (2), taking out the slurry A, adjusting the pH value to 2 by adding nitric acid, continuously stirring for 1 hour at normal temperature to obtain coating slurry B, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 80%;
adding a 3 wt% CMC solution into the slurry B, and continuously stirring for 0.5 hour at normal temperature to obtain a coating slurry C, wherein the stirring speed is 400 r/min, and the solid content of the slurry is controlled to be 40%;
and (4) adding nano graphite powder with the average particle size of 500nm into the slurry C, controlling the mass proportion of the nano graphite powder in the whole slurry to be 4%, and continuously stirring for 0.5 hour at normal temperature to obtain coating slurry D, wherein the stirring speed is 400 revolutions per minute.
9. A method for preparing a coated denitration catalyst using the coating slurry prepared by the preparation method of any one of claims 1 to 8, characterized in that: the method comprises the following steps:
loading the coating slurry D by using 50-mesh commercial cordierite honeycomb ceramic as a carrier through a lower feeding automatic coating machine, wherein the loading amount is 80-120 g/L;
and drying the obtained sample in a 100 ℃ oven to constant weight, heating to 300 ℃ and preserving heat for 3 hours to obtain the coating type denitration catalyst.
10. A coated denitration catalyst prepared by the method for preparing a coated denitration catalyst according to claim 9.
CN202111022032.8A 2021-09-01 2021-09-01 Coating slurry, preparation method of coating type denitration catalyst and denitration catalyst Withdrawn CN113877571A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114308069A (en) * 2022-01-07 2022-04-12 安徽元琛环保科技股份有限公司 Preparation method of denitration catalyst with ammonia decomposition function
CN115487802A (en) * 2022-09-29 2022-12-20 浙江德创环保科技股份有限公司 Preparation method of coating type denitration catalyst

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114308069A (en) * 2022-01-07 2022-04-12 安徽元琛环保科技股份有限公司 Preparation method of denitration catalyst with ammonia decomposition function
CN114308069B (en) * 2022-01-07 2023-11-03 安徽元琛环保科技股份有限公司 Preparation method of denitration catalyst with ammonia decomposition function
CN115487802A (en) * 2022-09-29 2022-12-20 浙江德创环保科技股份有限公司 Preparation method of coating type denitration catalyst

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