CN113969069B

CN113969069B - High-temperature coating capable of catalytically decomposing dioxin

Info

Publication number: CN113969069B
Application number: CN202011142060.9A
Authority: CN
Inventors: 戴雷
Original assignee: Shenzhen Youyi Material Technology Co ltd
Current assignee: Shenzhen Youyi Material Technology Co ltd
Priority date: 2020-10-23
Filing date: 2020-10-23
Publication date: 2022-11-04
Anticipated expiration: 2040-10-23
Also published as: CN113969069A

Abstract

The invention relates to a high-temperature coating capable of catalyzing dioxin, which comprises 35-70% of ceramic aggregate, wherein the ceramic aggregate comprises 32-60% of alumina, 1-5% of zirconium silicate and 2-10% of zirconia; also comprises 0.5 to 2 percent of mica powder; 1-5% carbon nanotubes; 0.5-2% graphene; 0.1-2% yttria; 0.1-2% cerium oxide; 1-5% palladium oxide; 1-8% of ₂ O ₅ ；1‑5%TiO ₂ . The raw materials are reasonably matched, so that the paint has good compatibility, shows good strength, hardness, corrosion resistance and other properties in a high-temperature complex environment, can not fall off or crack after being used for a long time, and effectively protects a boiler or a pipeline from being corroded; the invention can achieve better effect of catalyzing and decomposing dioxin through the selection of the components. And the coating can enable heat transfer of a boiler and a pipeline to be more uniform, and the performance of the coating is improved, and simultaneously dioxin can be further catalytically degraded.

Description

High-temperature coating capable of catalytically decomposing dioxin

Technical Field

The invention belongs to the field of coatings, and particularly relates to a high-temperature coating which can resist heat and corrosion and can catalytically decompose dioxin in a high-temperature environment.

Background

Along with the development of economy in China, urban population is rapidly increased, and domestic garbage is continuously increased. Current waste disposal means include landfills and incineration. The landfill inevitably causes secondary pollution, and the garbage is treated by burning in an effective method at present. The problem of corrosion of a boiler in a high-temperature environment is inevitably faced in the waste incineration process, and meanwhile, due to the complex components of the waste, new pollutants are generated in the incineration process, and dioxin is the most concerned pollutant at present.

For the protection of pipelines, boilers and the like in high-temperature environments, a protective coating is an effective method, and if the coating has strong performances of corrosion resistance and the like at high temperature, the coating is very important for avoiding the damage of the boiler pipelines and protecting the environment.

At present, research and application coatings can have certain effects, such as certain wear resistance, high-temperature oxidation resistance and the like, but under the application scenes of similar waste incineration, power plants and the like, due to the complex diversity of application environments, the performance of the coatings is reduced under the long-time use, and the coatings fall off due to the local performance reduction, so that the safe operation of the whole equipment is influenced. Therefore, it is critical to develop a coating with durable and excellent properties in high temperature environment.

Dioxin is a typical organic pollutant, brings great threat to an ecological system and human health, is very important to control the emission of the dioxin in the face of increasing garbage treatment amount, and is more strict when the emission standard of the dioxin is more recent, so that the reduction of the emission of the dioxin is also the key point of controlling the pollutants generated by the current garbage incineration.

Disclosure of Invention

Aiming at the problems of the coating in the high-temperature environment in the prior art and the requirement of dioxin control, the invention provides the coating with good strength, hardness and cold and hot shock resistance in the high-temperature environment, and further, the coating has good effect in decomposing dioxin. The technical scheme of the invention is as follows.

A high-temperature coating capable of catalytically decomposing dioxin, the coating being formed from a coating material comprising the following components in mass percent: 35-70% of ceramic aggregate, wherein the ceramic aggregate comprises 32-60% of alumina, 1-5% of zirconium silicate and 2-10% of zirconia; also comprises 0.5 to 2 percent of mica powder; 1-5% carbon nanotubes; 0.5-2% graphene; 0.1-2% yttria; 0.1-2% cerium oxide; 1-5% palladium oxide; 1-8% of V ₂ O ₅ ；1-5%TiO ₂ . The aluminum oxide, the zirconium silicate and the zirconium oxide are used in a ratio of the aluminum oxide to the zirconium silicate in the coating.

Furthermore, the particle size of the zirconium silicate is 30-80nm, and the particle size of the zirconium oxide is 10-30 μm. Preferably, the particle size of zirconium silicate may be 40 to 60nm, the particle size of zirconium oxide may be 15 to 20 μm, and the like.

In a waste incineration boiler or a pipeline, due to the instability of heat in a high-temperature environment and the complexity of components during incineration, a coating is easy to fall off and crack, and researches find that the selection of zirconium silicate and zirconium oxide with the particle size range in ceramic aggregate is very critical for enhancing the crack resistance and the strength. The zirconium silicate and zirconium oxide in the particle size range and other components such as mica powder and the like obviously influence the performance of the coating, and the dosage of the materials is important.

Furthermore, the dosage of the TiO2 is 1-3%.

For dioxin removal, the current modes comprise catalytic degradation, adsorption and the like, and if the coating can have the effect of degrading dioxin, the coating has a very good promotion effect on strictly reaching emission standards. Therefore, in the invention, V2O5, tiO2, carbon nanotubes and graphene are selected from the coating raw materials, and the components are added into the coating raw materials, so that the effect of catalyzing and degrading dioxin is remarkable besides the performances such as strength, hardness and the like required by the coating material. In the prior art, tiO2 is generally used in a larger amount and is compatible with V2O5 to realize a certain effect, but in the invention, researches find that after the components are added into a coating, the amount of TiO2 is far less than that in the prior art, and a better catalytic degradation effect can still be achieved.

Further, the coating also comprises 15-35% of a binder and the balance of water.

For the above-mentioned amounts of the components, further, in order to achieve a better effect, said components are further 40-60% of alumina, 1-4% of zirconium silicate, 2-8% of zirconia; 0.5-1.5% of mica powder; 1-4% carbon nanotubes; 0.5-1% graphene; 0.1-1% yttria; 0.2-1% cerium oxide; 1-4% palladium oxide; 1-6% V2O5;1-3% tio2, 20-30% binder; the balance being water.

Further, the binder is one or more of aluminum dihydrogen phosphate, aluminum phosphate or silica sol.

The invention also comprises a preparation method of the coating, which comprises the following steps:

(1) Mixing and stirring the nano zirconium silicate and the micron zirconium oxide with the binder and part of water uniformly; the water is used in an amount capable of being uniformly mixed; (2) Adding alumina and mica powder, and stirring at 200-600 r/min; (3) Adding the rest of the other materials, and uniformly mixing to obtain the coating; the surface of the target part is treated by the coating in a spraying mode, and the coating is the coating.

The beneficial effects of the invention include: the coating has good compatibility through reasonable matching of raw materials, shows good strength, hardness, corrosion resistance and other properties under a high-temperature complex environment, can not fall off or crack after being used for a long time, and effectively protects a boiler or a pipeline from being corroded; the invention can achieve better effect of catalyzing and decomposing dioxin through the selection of the components. And the coating can enable heat transfer of a boiler and a pipeline to be more uniform, and the performance of the coating is improved, and simultaneously dioxin can be further catalytically degraded.

Detailed Description

The coating according to the invention is further illustrated by the following embodiments. Particularly, the coating is suitable for high-temperature and complex environments such as power plants, waste incineration plants and the like.

Example 1

The high-temperature coating for catalyzing the decomposition of the dioxin is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 1% of mica powder; 2% carbon nanotubes; 0.8% graphene; 0.3% yttria; 0.4% cerium oxide; 2% palladium oxide; 2% V2O5;1% tio2, 25% binder; the balance of water, wherein the particle size of the zirconium silicate is 45nm, and the particle size of the zirconium oxide is 20 microns.

Example 2

A coating has good performance in applications such as power plants and waste incineration, has the effect of catalyzing and degrading dioxin, and is prepared by processing the following raw materials: 56% of alumina, 2.2% of zirconium silicate and 4% of zirconium oxide; 1.1% mica powder; 3% carbon nanotubes; 1% graphene; 0.5% yttria; 0.4% cerium oxide; 1% palladium oxide; 1.5% V2O5;2% tio2, 22% binder; the balance of water, wherein the particle size of zirconium silicate is 40nm, and the particle size of zirconium oxide is 22 microns.

Example 3

A method of preparing a coating comprising: (1) Mixing nano zirconium silicate and micron zirconium oxide with a binder and half of water, and stirring for 3-5min at 200-300 r/min; (2) Adding alumina and mica powder, and stirring at 200-600 rpm for 5-8min; (3) Adding the rest of the materials, and stirring and mixing uniformly to obtain the coating; the surface of the target part is treated by the coating in a spraying mode, and the coating is the coating.

To verify the good results of the coatings of the present invention, a verification is made by the following comparative examples.

Comparative example 1

A coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 0.8% graphene; 0.3% yttrium oxide; 0.4% cerium oxide; 2% palladium oxide; 2% V2O5;1% tio2, 25% binder; the balance of water, wherein the zirconium silicate has a particle size of 40 microns and the zirconium oxide has a particle size of 100 microns.

Comparative example 2

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 2% carbon nanotubes; 0.3% yttria; 0.4% cerium oxide; 2% palladium oxide; 2% V2O5;1% tio2, 25% binder; the balance of water, wherein the particle size of the zirconium silicate is 40 microns and the particle size of the zirconium oxide is 80 microns.

The heat alternation resistance is determined according to GB4653-84 paint determination test, the experimental condition is that a sample is put into a heating furnace, treated at 650 ℃ for 30min, then taken out and forced air-cooled to room temperature, and the sample is circularly treated until the phenomena of peeling, cracking and the like occur. The hot crossover resistance was measured in example 1 and comparative example 1, and the test results were as follows: in example 1, the peeling and cracking phenomenon occurred in 52 cycles, while in comparative example 1, the peeling and cracking phenomenon occurred in 37 cycles, and in comparative example 2, the peeling and cracking phenomenon occurred in 34 cycles. Test results show that the coating has good heat alternation resistance.

Comparative example 3

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 1% of mica powder; 2.8% carbon nanotubes; (ii) a 0.7% cerium oxide; 2% palladium oxide; 2% V2O5;1% tio2, 25% binder; the balance of water, wherein the particle size of the zirconium silicate is 45nm, and the particle size of the zirconium oxide is 20 microns.

Comparative example 4

The coating is prepared by processing the following raw materials: 55% of alumina, 5% of zirconia; (ii) a 3.8% carbon nanotubes; 0.3% yttrium oxide; 0.4% cerium oxide; 2% palladium oxide; 2% V2O5;1% tio2, 25% binder; the balance being water, wherein the zirconia has a particle size of 20 microns.

Comparative example 5

The coating is prepared by processing the following raw materials: 40% of alumina, 1% of zirconium silicate and 1% of zirconia; 1% of mica powder; 0.1% carbon nanotubes; 0.1% graphene; 0.1% yttrium oxide; 0.5% palladium oxide; 0.5% V2O5;1% tio2, 25% binder; the balance of water, wherein the particle size of the zirconium silicate is 45nm, and the particle size of the zirconium oxide is 20 microns.

Abrasion resistance and water resistance are important performance indexes of the coating, and the case of comparing abrasion resistance and water resistance was measured in example 2 and comparative examples 3 to 5, and the results are as follows:

the wear resistance of the embodiment 1 reaches 9.4L/mum, and the water resistance reaches 780h; the wear resistance of comparative example 3 was 5.6L/μm, and the water resistance reached 368h; the abrasion resistance of comparative example 4 was 6.1L/μm, and the water resistance reached 380 hours; the abrasion resistance of comparative example 5 was 4.2L/. Mu.m, and the water resistance reached 298h. It can be seen that, in the case of the change of the coating raw material composition, the influence on the wear resistance and water resistance of the coating is large, and the invention has outstanding performance in terms of wear resistance and water resistance.

Comparative example 6

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 1% of mica powder; 0.3% yttria; 0.4% cerium oxide; 2% palladium oxide; 30% of a binder; the balance of water, wherein the particle size of the zirconium silicate is 45nm, and the particle size of the zirconium oxide is 20 microns.

Comparative example 7

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 1% of mica powder; 2% carbon nanotubes; 2.8% graphene; 2% V2O5;25% of a binder; the balance of water, wherein the particle size of the zirconium silicate is 45nm, and the particle size of the zirconium oxide is 20 microns.

Comparative example 8

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 1% of mica powder; 2.8% carbon nanotubes; 0.4% cerium oxide; 1% tio2, 25% binder; the balance of water, wherein the particle size of zirconium silicate is 45nm, and the particle size of zirconium oxide is 20 microns.

Comparative example 9

The coating is prepared by processing the following raw materials: 55% of alumina, 2% of zirconium silicate and 3% of zirconia; 3.8% of mica powder; (ii) a 2.7% palladium oxide; 0.5% V2O5;4% tio2, 25% binder; the balance of water, wherein the particle size of zirconium silicate is 45nm, and the particle size of zirconium oxide is 20 microns.

The effect on the catalytic degradation of dioxins was determined in example 2 and comparative examples 6 to 9, the test method being carried out in accordance with the general methods of the prior art. A flue gas bypass pilot plant is established in a waste incineration power plant, the flow rate of flue gas is 5000Nm & lt 3 & gt/h, the temperature of the flue gas is 180 ℃, inlet and outlet gas samples are collected for analysis after stable operation is carried out for 48 hours, and experimental results are as follows.

	Concentration of dioxins in inlet (ng/m 3)	Outlet dioxin concentration (ng/m 3)	Conversion rate
				Example 2	7.5	0.035	99.53%
Comparative example 6	7.9	0.24	96.92%
				Comparative example 7	7.2	0.34	95.28%
Comparative example 8	8.1	0.28	96.54%
				Comparative example 9	7.7	0.36	95.33%

According to example 2 and the comparative example, it can be seen that the present invention has a good effect of catalytically degrading dioxin.

The above examples are merely illustrative for clearly illustrating the present invention and are not intended to limit the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any obvious variations or modifications which come within the spirit and scope of the invention are desired to be protected by the following claims.

Claims

1. A high-temperature coating capable of catalytically decomposing dioxin, characterized in that a coating forming the coating comprises the following components in mass%: 35-70% of ceramic aggregate, 15-35% of binder and the balance of water; the ceramic aggregate comprises 32-60% of alumina, 1-5% of zirconium silicate and 2-10% of zirconia; also comprises 0.5 to 2 percent of mica powder; 1-5% carbon nanotubes; 0.5-2% graphene; 0.1-2% yttria; 0.1-2% cerium oxide; 1-5% palladium oxide; 1-8% V ₂ O ₅ ；1-5%TiO ₂ ；

The particle size of the zirconium silicate is 30-80nm, and the particle size of the zirconium oxide is 10-30 mu m;

the binder is one or more of aluminum dihydrogen phosphate, aluminum phosphate or silica sol.

2. The high temperature coating capable of catalytically decomposing dioxin according to claim 1, characterized in that the TiO ₂ The amount is further 1-3%.

3. The high temperature coating capable of catalytically decomposing dioxin according to claim 2, characterized in that the components are further 40 to 60% of alumina, 1 to 4% of zirconium silicate, 2 to 8% of zirconia; 0.5-1.5% of mica powder; 1-4% carbon nanotubes; 0.5-1% graphene; 0.1-1% yttria; 0.2-1% cerium oxide; 1-4% palladium oxide; 1-6% V ₂ O ₅ ；1-3%TiO ₂ 20-30% of a binder; the balance of water.