CN111004029B

CN111004029B - Far infrared energy-saving radiation coating for high-temperature furnace

Info

Publication number: CN111004029B
Application number: CN201911299731.XA
Authority: CN
Inventors: 于文齐; 平玉峰; 张峰
Original assignee: Hebei Honghua Energy Saving Technology Co ltd
Current assignee: Hebei Honghua Energy Saving Technology Co ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2021-04-13
Anticipated expiration: 2039-12-17
Also published as: JP7112639B2; JP2021095326A; CN111004029A

Abstract

The invention provides a far infrared energy-saving radiation coating for a high-temperature furnace, which belongs to the technical field of energy-saving coatings and comprises LaAl_1‑xRu_xO₃The preparation method of the far infrared radiation base material comprises the following steps: preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into aqueous solution, and mixing to prepare solution A; dissolving amino acid and organic acid in water, adding a catalyst, and preparing a solution B; stirring and mixing the solution A and the solution B, then performing microwave radiation, drying and grinding to obtain a precursor; and roasting the precursor, cooling and grinding to obtain the nano particles. The far infrared radiation base material has better far infrared radiation performance, the coating containing the far infrared radiation base material has higher emissivity and lower heat conductivity coefficient, and the coating sprayed by the coating has good far infrared radiation performance and heat insulation performance, excellent bonding strength and thermal shock resistance and energy-saving effect.

Description

Far infrared energy-saving radiation coating for high-temperature furnace

Technical Field

The invention belongs to the technical field of energy-saving coatings, and particularly relates to a far infrared energy-saving radiation coating for a high-temperature furnace.

Background

With the rapid development of the world economy, the consumption of energy is increasing day by day, however, the energy on the earth is limited, especially the non-renewable energySuch as coal mine, oil, natural gas, etc. On one hand, the consumption of energy sources brings environmental pollution; on the other hand, the exhaustion of energy severely restricts the development of global economy. China is a world with large energy consumption, the energy utilization rate of China is different from that of developed countries in the world, the environmental pollution of China is serious, the energy consumption of industrial furnaces accounts for 25-40% of the total energy, and the thermal efficiency of the furnaces is only about 30%. In order to effectively improve the thermal efficiency of kilns, infrared radiation paints, which are a new material utilizing the molecular and atomic properties of substances, have been introduced. The infrared radiation heating device can be designed and manufactured by matching the infrared radiation coating with the heating element. The infrared radiation coating is coated on refractory materials on the inner wall of various heating devices, so that the heating device with the infrared radiation characteristic is formed. The infrared radiation heating device and the infrared radiation heating equipment are proved by production practice to have obvious energy-saving effect. Therefore, the infrared radiation coating has a very good energy-saving effect on the industrial furnace, and meanwhile, the infrared radiation coating isolates the direct contact between the furnace wall and the flue gas, so that the corrosion of the flue gas to the furnace wall is reduced, the furnace wall is well protected, the service life of the furnace is prolonged, and the maintenance cost of the furnace is reduced. In addition, the infrared radiation coating makes the heat-conducting wall thicker in heat conduction, and the heat conductivity coefficient of the coating is about 1/10 of the refractory brick, so that the thermal resistance is increased, the heat conduction quantity to the outside of the kiln is reduced, and the heat efficiency is improved; from the perspective of radiation heat transfer, because the surface emissivity of the infrared coating is high, the infrared coating radiates most of absorbed heat to a heated object in the form of infrared rays, and the heat efficiency is greatly improved; the infrared coating also changes the thermal energy spectrum. Combustion products H of a typical kiln₂O、CO₂、CO、NO₂The spectrum of the smoke such as NO is discontinuous (and the infrared absorption spectrum of the heated blank is continuous), if the heat energy generated by the combustion of the fuel is reflected back from the furnace wall, the spectrum is discontinuous, is not easy to be absorbed by the workpiece and is easy to be absorbed by the smoke and discharged out of a chimney, and the high-emissivity infrared coating can change the radiation spectrum by absorbing the heat energy generated by the combustion of the fuelThe infrared rays with own special infrared ray form (the spectrum is continuous) are radiated to the green body, so that the heat taken away by the smoke is reduced, and the energy is well utilized. Therefore, the infrared coating has great application prospect as a novel energy-saving material on an industrial furnace.

Disclosure of Invention

The invention aims to provide a far infrared radiation base material which has the emissivity of more than or equal to 0.960 at the wavelength band of 8-14 mu m at the temperature of 1000 ℃ and has better far infrared radiation performance.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a far infrared radiation base material containing LaAl_1-xRu_xO₃Nanoparticles, wherein the value of X is 0 to 0.95. LaAl_1- _xRu_xO₃Ru ions in the nano particles enter LaAlO₃After the crystal lattice, Ru is introduced⁴⁺And Ru³⁺Impurity level, forming Ru with lower transition activation energy⁴⁺↔Ru³⁺The polaron absorption band is small, and the free carrier concentration is increased, so that the impurity level absorption and the free carrier absorption are enhanced; the presence of Ru ions also causes the cell structure to be distorted, thereby widening and strengthening the absorption region corresponding to lattice vibration. Therefore, LaAl_1-xRu_xO₃The doping of Ru in the nano particles can obviously improve LaAlO₃The far infrared emissivity of the base ceramic material is more than or equal to 0.960 at 1000 ℃ in a wave band of 8-14 mu m, namely the far infrared radiation base material has better far infrared radiation performance. In addition, under the condition that other raw materials for the coating are the same, the coating obtained by the far infrared radiation base material coating has higher bonding strength and better thermal shock resistance.

According to one embodiment of the invention, the emissivity of the far infrared radiation base material at 1000 ℃ in the wave band of 8-14 μm is more than or equal to 0.960.

It is another object of the present invention to provide a method for producing LaAl which has high yield, high porosity, uniform pore size distribution, and easy grinding_1-xRu_xO₃Has loose and porous structure, and is easier to obtainTo LaAl_1-xRu_xO₃The preparation method of the infrared radiation base material with nano particles and high yield adopts a sol-gel method, and comprises the following steps:

preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into aqueous solution, and mixing to prepare solution A;

dissolving amino acid and organic acid in water, adding a catalyst, and preparing a solution B;

stirring and mixing the solution A and the solution B, then performing microwave radiation, drying and grinding to obtain a precursor;

roasting the precursor, cooling and grinding to obtain LaAl_1-xRu_xO₃Nanoparticles.

Preferably, the calcination temperature is 1000-. The preparation method of the invention prepares LaAl by using a sol-gel method_1-xRu_xO₃The nano particles are polymerized with amino acid and organic acid in a microwave heating mode, the amino acid and the malic acid are polar molecules, the nano particles have strong absorption effect on microwaves, can be directly polymerized under microwave radiation, the time required by sol-gel is short, the prepared gel has high porosity, uniform pore size distribution and higher yield and complexing ability, and further the precursor has high yield, high porosity, uniform pore size distribution and easy grinding, and the subsequently generated LaAl is obtained_1-xRu_xO₃Has a loose and porous structure, and is easier to obtain LaAl_1-xRu_xO₃The nano particles have high yield and reduce energy consumption.

Still another object of the present invention is to provide a far infrared energy-saving type radiation coating for high temperature furnaces with high emissivity and low thermal conductivity, which comprises: the infrared radiation base material, the regulator and the binder. The far infrared energy-saving radiation coating has high emissivity and low heat conductivity coefficient, and the prepared coating has good far infrared radiation performance, heat insulation performance, excellent bonding strength and thermal shock resistance.

According to one embodiment of the invention, the conditioning agent is a fine silica powder. This is because the fine silica powder has an extremely small thermal expansion coefficient (0).5×10^-6and/K) and has better infrared radiance, effectively avoids the reduction of the infrared radiance of the coating caused by using mullite or cordierite and the like as expansion coefficient regulators, and in addition, when the coating is dried, the silicon dioxide can quickly form a network structure, thereby improving the construction performance of the coating.

According to one embodiment of the present invention, the binder is silica sol and GeO₂Fine powder and/or In₂O₃And (4) mixing the micro powder. The adhesive has the advantages of strong adhesive force, high surface drying speed, high temperature resistance, difficult introduction of volatile impurities and no pollution to products in a kiln. Especially GeO₂Fine powder and/or In₂O₃The existence of the micro powder can also gain LaAl_1-xRu_xO₃The nano particles have far infrared radiation performance, and do not have adverse effects on the heat insulation performance, bonding strength and thermal shock resistance of a coating made of the coating.

According to one embodiment of the invention, the thermal conductivity of the coating is < 0.13W/(m.K). Therefore, the coating can play a role in heat insulation and preservation, reduce heat loss and play a role in energy conservation.

The invention also aims to provide a high-temperature furnace far infrared energy-saving radiation coating with good far infrared radiation performance and heat insulation performance, excellent bonding strength and thermal shock resistance and energy-saving effect, which is formed by spraying the coating on the surface of the inner furnace wall of a furnace by a thermal spraying method. After the coating is sprayed on the surface of the furnace wall in the furnace kiln, a black ceramic coating with the thickness of 0.3-0.5mm is formed after sintering, the coefficient of thermal conductivity of the porcelainized layer is lower, the furnace wall and the furnace top have the functions of heat insulation and heat preservation, the temperature of the outer wall of the furnace can be reduced, the heat dissipation loss is reduced, and the fuel heat is effectively utilized, so that the heat efficiency of the heating furnace is improved, and the aim of saving energy is fulfilled; in addition, the blackness of the surface of the furnace wall in the furnace kiln is improved by 20-30%, the heat radiation rate of the inner wall of the heating furnace is improved to more than 0.9 from 0.7-0.8, the temperature rising and reducing speed and the temperature of the heating section are greatly improved, the production efficiency of the furnace kiln can be improved, and the energy is saved.

According to one embodiment of the invention, the bond strength of the coating is > 31.8 MPa.

According to one embodiment of the invention, the coating can withstand at least 56 times 1100 ℃ air-cooled thermal shock.

Compared with the prior art, the invention has the beneficial effects that: the far infrared radiation base material has better far infrared radiation performance, and the preparation method thereof ensures that the precursor has high yield, high porosity, uniform pore size distribution and easy grinding, and ensures that subsequently generated LaAl is_1-xRu_xO₃Has a loose and porous structure, and is easier to obtain LaAl_1-xRu_xO₃The nano particles have high yield; the paint containing the far infrared radiation base material has higher emissivity and lower heat conductivity coefficient, and the used binder can gain LaAl_1-xRu_xO₃The nano particles have far infrared radiation performance, and do not have adverse effects on the heat insulation performance, bonding strength and thermal shock resistance of a coating made of the coating; the coating obtained by spraying the coating disclosed by the invention has good far infrared radiation performance and heat insulation performance, excellent bonding strength and thermal shock resistance and an energy-saving effect.

The invention adopts the technical scheme to provide the far infrared energy-saving radiation coating for the high-temperature furnace, overcomes the defects of the prior art, and has reasonable design and convenient operation.

Drawings

FIG. 1 is a schematic diagram showing the internal configuration of a precursor in test example 1 of the present invention;

FIG. 2 is a graph showing the pore size distribution of the precursor in Experimental example 1 of the present invention;

FIG. 3 shows the yield of the precursor in Experimental example 1 of the present invention;

FIG. 4 is an XRD pattern of far infrared radiation base material in experimental example 2 of the present invention;

FIG. 5 is a particle size distribution of far infrared radiation base material in test example 2 of the present invention;

FIG. 6 is an XPS spectrum of a far infrared radiation base material in test example 2 of the present invention;

FIG. 7 is an emissivity of a far infrared radiation base material in test example 2 of the present invention;

FIG. 8 is an emissivity of a far infrared energy saving type radiation coating in a test example 3 of the present invention;

FIG. 9 is a graph showing the thermal conductivity of the far infrared energy saving type radiation coating in test example 3 of the present invention;

FIG. 10 is a graph showing the results of a thermal shock test of the coating layer of example 1 in test example 3 of the present invention.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It is not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

These examples are provided only for more specifically illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited to these examples according to the gist of the present invention.

One embodiment of the present invention provides a far infrared radiation base material containing LaAl_1-xRu_xO₃Nanoparticles wherein X has a value of 0-0.95, such as 0.05, 0.1, 0.23, 0.3, 0.4, 0.46, 0.5, 0.53, 0.61, 0.67, 0.72, 0.76, 0.8, 0.88, 0.9, 0.93, and the like. LaAl_1-xRu_xO₃Ru ions in the nano particles enter LaAlO₃After the crystal lattice, Ru is introduced⁴⁺And Ru³⁺Impurity level, forming Ru with lower transition activation energy⁴⁺↔Ru³⁺The polaron absorption band is small, and the free carrier concentration is increased, so that the impurity level absorption and the free carrier absorption are enhanced; the presence of Ru ions also causes the cell structure to be distorted, thereby widening and strengthening the absorption region corresponding to lattice vibration. Therefore, LaAl_1-xRu_xO₃The doping of Ru in the nano particles can obviously improve LaAlO₃The far infrared emissivity of the base ceramic material has better far infrared radiation performance. In addition, under the condition that other raw materials for the coating are the same, the coating obtained by the far infrared radiation base material coating has higher bonding strength and better thermal shock resistance.

In one embodiment of the invention, the emissivity of the far infrared radiation base material at 1000 ℃ in the wave band of 8-14 μm is more than or equal to 0.960.

The invention also provides a preparation method of the infrared radiation base material, which adopts a sol-gel method and comprises the following steps:

In one embodiment of the present invention, the baking temperature is 1000-1200 deg.C, such as 1050 deg.C, 1085 deg.C, 1100 deg.C, 1110 deg.C, 1125 deg.C, 1140 deg.C, 1150 deg.C, 1160 deg.C, 1175 deg.C, 1180 deg.C, 1190 deg.C, etc. The preparation method of the invention prepares LaAl by using a sol-gel method_1-xRu_xO₃The nano particles are polymerized with amino acid and organic acid in a microwave heating mode, the amino acid and the malic acid are polar molecules, the nano particles have strong absorption effect on microwaves, can be directly polymerized under microwave radiation, the time required by sol-gel is short, the prepared gel has high porosity, uniform pore size distribution and higher yield and complexing ability, and further the precursor has high yield, high porosity, uniform pore size distribution and easy grinding, and the subsequently generated LaAl is obtained_1-xRu_xO₃Has a loose and porous structure, and is easier to obtain LaAl_1-xRu_xO₃The nano particles have high yield and reduce energy consumption.

In one embodiment of the present invention, the amino acid is selected from glycine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, serine, threonine, cysteine, histidine or arginine. More preferably, the amino acid is selected from glutamic acid or aspartic acid. Glutamic acid or aspartic acid can obtain stable colloid without adjusting the pH of the reaction system.

In one embodiment of the present invention, the organic acid is selected from maleic acidCitric acid, ascorbic acid, salicylic acid, malic acid or tartaric acid. More preferably, the organic acid is selected from citric acid, malic acid or tartaric acid. In order to further improve the porosity and the pore size distribution uniformity of the precursor, simultaneously provide more binding sites for metal ions and improve LaAl_1-xRu_xO₃The yield of the nano particles is that the organic acid is citric acid phosphate (formula I) or malic acid phosphate (formula II),

(formula I);

(formula II).

In one embodiment of the present invention, the catalyst is one or more selected from potassium dihydrogen phosphate, dipotassium hydrogen phosphate, phosphoric acid, and potassium sulfate. More preferably, the catalyst is dipotassium hydrogen phosphate. In chemical reactions, the role of the catalyst is to reduce the activation energy required for the reaction to occur, increasing the yield and the amount of complexing. More preferably, the molar ratio of the amino acid, organic acid starting material to the catalyst is from 1:0.05 to 0.1.

In one embodiment of the present invention, a method for preparing an infrared radiation base comprises the steps of:

preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.15-0.25mol/L aqueous solution, and mixing to prepare solution A;

dissolving amino acid and organic acid in water according to the molar ratio of 1:0.8-1.2, and adding a catalyst to prepare solution B;

stirring and mixing the solution A and the solution B according to the mass ratio of 1-1.5:1 for 1-2h, then performing microwave radiation for 3-5min under the microwave power of 800-;

roasting the precursor in air atmosphere of 1000-1200 ℃ for 3-4h, naturally cooling in a furnace, cooling and grinding to obtain LaAl_1-xRu_xO₃Nanoparticles.

The invention also provides an infrared radiationThe base material is LaAl_1-xRu_xO₃Tourmaline nano-particles. LaAl in the far infrared radiation base material_1-xRu_xO₃The nano particles can promote Fe in tourmaline²⁺To make more BO₃The charge distribution symmetry is reduced, the electric dipole moment is increased, and the infrared emissivity of the tourmaline in a far infrared band is further enhanced; and can play a gain role with tourmaline, so that LaAl can be obtained_1-xRu_xO₃The tourmaline nano composite material has higher far infrared emissivity.

The above LaAl_1-xRu_xO₃The preparation method of the tourmaline nano particles comprises the following steps:

mixing tourmaline powder and deionized water in a mass ratio of 1:8-15 for 1-2h to prepare solution C;

stirring and mixing the solution A, the solution B and the solution C for 1-2h according to the mass ratio of 1-1.5:1:1, then performing microwave radiation for 3-5min under the microwave power of 800-;

roasting the precursor in air atmosphere of 1000-1200 ℃ for 3-4h, naturally cooling in a furnace, cooling and grinding to obtain LaAl_1-xRu_xO₃Tourmaline nano-particles.

The embodiment of the invention also provides a far infrared energy-saving radiation coating for a high-temperature furnace, which comprises the following components: the infrared radiation base material, the regulator and the binder. The far infrared energy-saving radiation coating has high emissivity and low heat conductivity coefficient, and the prepared coating has good far infrared radiation performance, heat insulation performance, excellent bonding strength and thermal shock resistance.

In one embodiment of the present invention, the coating comprises the following components in parts by weight: 5-28 parts of infrared radiation base material, 8-20 parts of regulator and 20-60 parts of binder.

In one embodiment of the present invention, the conditioning agent is a fine silica powder. This is because the fine silica powder has an extremely small thermal expansion coefficient (0.5X 10)^-6and/K) and has better infrared radiance, effectively avoids the reduction of the infrared radiance of the coating caused by using mullite or cordierite and the like as expansion coefficient regulators, and in addition, when the coating is dried, the silicon dioxide can quickly form a network structure, thereby improving the construction performance of the coating.

In one embodiment of the present invention, the binder is silica sol and GeO₂Fine powder and/or In₂O₃And (4) mixing the micro powder. The adhesive has the advantages of strong adhesive force, high surface drying speed, high temperature resistance, difficult introduction of volatile impurities and no pollution to products in a kiln. Especially GeO₂Fine powder and/or In₂O₃The existence of the micro powder can also gain LaAl_1-xRu_xO₃The nano particles have far infrared radiation performance, and do not have adverse effects on the heat insulation performance, bonding strength and thermal shock resistance of a coating made of the coating. Preferably, the weight ratio of the silica sol to the micro powder in the binder is 1: 0.7-1.5.

In one embodiment of the present invention, the thermal conductivity of the coating is < 0.13W/(mK). Therefore, the coating can play a role in heat insulation and preservation, reduce heat loss and play a role in energy conservation.

The preparation method of the far infrared energy-saving radiation coating for the high-temperature furnace comprises the following steps: the infrared radiation base material, the high-temperature thermal expansion coefficient regulator and the binder are uniformly mixed and are placed in a ball mill for ball milling at the rotating speed of 300-400r/min for 5-10h, and then the coating is obtained.

The invention also provides a far infrared energy-saving radiation coating for the high-temperature furnace, which is formed by spraying the coating on the surface of the inner furnace wall of the furnace by a thermal spraying method. The surface of the wall in the kiln is coated with high-temperature far infrared insulating energy-saving paint, and a black ceramic coating with the thickness of 0.3-0.5mm is formed after sintering, the coefficient of thermal conductivity of the ceramic coating is lower, the ceramic coating plays a role in heat insulation and heat preservation on the top of the kiln wall, the temperature of the outer wall of the kiln can be reduced, the temperature of the outer surface of the whole heating furnace is averagely reduced by more than 20 ℃, the heat dissipation loss is reduced, the fuel heat is effectively utilized, and therefore the heat efficiency of the heating furnace is improved; in addition, the thermal radiance of the furnace wall in the furnace kiln is improved to more than 0.9 from 0.7-0.8, the temperature rising and reducing speed and the temperature of the heating section are greatly improved, the maximum temperature rising speed and the maximum temperature reducing speed before spraying are about 3 ℃/min, the maximum temperature rising speed and the maximum temperature reducing speed after spraying are more than or equal to 7 ℃/min, meanwhile, the temperature of the heating section is improved by at least 85 ℃, the production efficiency of the furnace kiln can be improved, and the energy is saved.

In one embodiment of the invention, the bond strength of the coating is > 31.8 MPa.

In one embodiment of the invention, the coating can withstand at least 56 times 1100 ℃ air-cooled thermal shock. Preferably, the coating can bear 56-72 times of 1100 ℃ air cooling thermal shock, and does not have the stripping failure phenomenon, and has good thermal shock resistance.

The invention is further illustrated by the following examples. It is to be understood that the examples are for illustrative purposes only and are not intended to limit the scope and spirit of the present invention.

Example 1:

the preparation method of the infrared radiation base material comprises the following steps:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.6:0.4 to prepare solution A;

2) dissolving glutamic acid and citric acid in water according to a molar ratio of 1:1, adding a catalyst, and preparing a solution B;

3) stirring and mixing the solution A and the solution B according to the mass ratio of 1.25:1 for 1.5h, then performing microwave radiation for 4min under the microwave power of 1000W, then drying for 15h at 100 ℃, and grinding to obtain a precursor;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.6Ru_0.4O₃Nanoparticles, i.e. infrared radiation binders.

A far infrared energy-saving radiation coating for a high-temperature furnace comprises: 14 parts by weight of the IR-base of this example, 16 parts by weight of microsilicaPowder and 30 parts by weight of binder, wherein the binder is silica sol and GeO₂Fine powder, In₂O₃Mixing the micro powder, wherein the weight ratio of the silica sol to the micro powder is 1:1.2, and GeO₂Fine powder and In₂O₃The weight ratio of the micro powder is 1: 0.8.

A far infrared energy-saving radiation coating for a high-temperature furnace is prepared by spraying the coating on the surface of the inner wall of the furnace by a thermal spraying method, raising the temperature to 50 ℃ at a heating rate of 10 ℃/min for 2h, raising the temperature to 100 ℃ at a heating rate of 5 ℃/min for 2h, maintaining the temperature at 300 ℃ at a heating rate of 3 ℃/min for 1h, and forming a far infrared energy-saving radiation coating with the thickness of 0.3-0.5 mm.

Example 2:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.5:0.5 to prepare solution A;

2) dissolving glutamic acid and malic acid in water according to a molar ratio of 1:1, and adding a catalyst to prepare a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.5Ru_0.5O₃Nanoparticles, i.e. infrared radiation binders.

A far infrared energy-saving radiation coating for a high-temperature furnace comprises: 14 parts by weight of the infrared radiation base material of the embodiment, 16 parts by weight of fine silica powder, and 30 parts by weight of a binder, wherein the binder is silica sol and In₂O₃The weight ratio of the micro powder to the silica sol is 1: 1.2.

Example 3:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.4:0.6 to prepare solution A;

2) dissolving glutamic acid and tartaric acid in water according to a molar ratio of 1:1, adding a catalyst, and preparing a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.4Ru_0.6O₃Nanoparticles, i.e. infrared radiation binders.

A far infrared energy-saving radiation coating for a high-temperature furnace comprises: 14 parts by weight of the infrared radiation base material, 16 parts by weight of silicon dioxide micropowder and 30 parts by weight of binder, wherein the binder is silica sol and GeO₂Mixing the micro powder, wherein the weight ratio of the silica sol to the micro powder is 1: 1.2.

Example 4:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.3:0.7 to prepare solution A;

2) dissolving aspartic acid and citric acid in water according to the molar ratio of 1:1, adding a catalyst, and preparing a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.3Ru_0.7O₃Nanoparticles, i.e. infrared radiation binders.

A far infrared energy-saving radiation coating for a high-temperature furnace comprises: 14 parts by weight of the infrared radiation base material, 16 parts by weight of silicon dioxide micropowder and 30 parts by weight of binder, wherein the binder is silica sol and GeO₂Fine powder, In₂O₃Mixing the micro powder, wherein the weight ratio of the silica sol to the micro powder is 1:1.2, and GeO₂Fine powder and In₂O₃The weight ratio of the micro powder is 1: 0.8.

Example 5:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.2:0.8 to prepare solution A;

2) dissolving aspartic acid and malic acid in water according to the molar ratio of 1:1, and adding a catalyst to prepare a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.2Ru_0.8O₃Nanoparticles, i.e. infrared radiation binders.

Example 6:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.1:0.9 to prepare solution A;

2) dissolving aspartic acid and tartaric acid in water according to the molar ratio of 1:1, adding a catalyst, and preparing a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.1Ru_0.9O₃Nanoparticles, i.e. infrared radiation binders.

A far infrared energy-saving radiation coating for a high-temperature furnace comprises: 14 parts by weight of BenshiExample infrared radiation base material, 16 weight portions of silicon dioxide micro powder and 30 weight portions of adhesive, wherein the adhesive is silica sol and GeO₂Fine powder, In₂O₃Mixing the micro powder, wherein the weight ratio of the silica sol to the micro powder is 1:1.2, and GeO₂Fine powder and In₂O₃The weight ratio of the micro powder is 1: 0.8.

Example 7:

2) dissolving glutamic acid and citric acid phosphate (formula I) in water according to a molar ratio of 1:1, and adding a catalyst to prepare a solution B;

Example 8:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.7:0.3 to prepare solution A;

2) dissolving glutamic acid and malic acid phosphate (formula II) in water according to a molar ratio of 1:1, and adding a catalyst to prepare a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.7Ru_0.3O₃Nanoparticles, i.e. infrared radiation binders.

Example 9:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.8:0.2 to prepare solution A;

2) dissolving aspartic acid and citric acid phosphate (formula I) in water according to the molar ratio of 1:1, adding a catalyst, and preparing a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.8Ru_0.2O₃Nanoparticles, i.e. infrared radiation binders.

Example 10:

1) preparing lanthanum nitrate, aluminum nitrate and ruthenium nitrate into 0.2mol/L aqueous solution, and then mixing according to the molar ratio of La to Al to Ru of 1:0.9:0.1 to prepare solution A;

2) dissolving aspartic acid and malic acid phosphate (formula II) in water according to a molar ratio of 1:1, adding a catalyst, and preparing a solution B;

4) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.9Ru_0.1O₃Nanoparticles, i.e. infrared radiation binders.

Example 11:

3) mixing tourmaline powder and deionized water at a mass ratio of 1:10, stirring for 1h to obtain solution C;

4) stirring and mixing the solution A, the solution B and the solution C according to the mass ratio of 1.25:1:1 for 1.5h, then performing microwave radiation for 4min under the microwave power of 1000W, then drying for 15h at 100 ℃, and grinding to obtain a precursor;

5) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.6Ru_0.4O₃Nanoparticles, i.e. infrared radiation binders.

Example 12:

5) the precursor is put in an air atmosphere at 1100 DEG CRoasting for 3.5h, naturally cooling in a furnace, cooling and grinding to obtain LaAl_0.7Ru_0.3O₃Nanoparticles, i.e. infrared radiation binders.

Example 13:

Be used for high temperature kiln farAn infrared energy-saving radiant coating comprising: 14 parts by weight of the infrared radiation base material, 16 parts by weight of silicon dioxide micropowder and 30 parts by weight of binder, wherein the binder is silica sol and GeO₂Fine powder, In₂O₃Mixing the micro powder, wherein the weight ratio of the silica sol to the micro powder is 1:1.2, and GeO₂Fine powder and In₂O₃The weight ratio of the micro powder is 1: 0.8.

Example 14:

5) roasting the precursor in air atmosphere at 1100 deg.C for 3.5h, naturally cooling in furnace, cooling, and grinding to obtain LaAl_0.8Ru_0.2O₃Nanoparticles, i.e. infrared radiation binders.

Comparative example 1:

the difference from example 1 is that: glutamic acid was changed to ethylene glycol.

Comparative example 2:

the difference from example 1 is that: ruthenium nitrate was replaced by nickel nitrate.

Comparative example 3:

the difference from example 11 is that: the infrared radiation base is only an electronized stone.

Comparative example 4:

the difference from example 1 is that: the binder for the far infrared energy-saving radiation coating is silica sol.

Test example 1:

1. morphological structure of precursor

And spraying gold on the section of the dried precursor, observing the internal network structure of the precursor by using a scanning electron microscope, and analyzing the porosity, the average pore size and the pore size distribution of the precursor by using a mercury intrusion instrument.

The internal form structure diagram of the precursor is shown in figure 1, the pore diameter of the precursor obtained in the examples 1 and 7 is smaller, and the pore diameter distribution is more uniform, while the pore diameter of the precursor obtained in the comparative examples 1 and 2 is larger, and the pore diameter distribution is not uniform; meanwhile, compared with the embodiment 1, the aperture distribution of the precursor obtained in the embodiment 7 is more uniform, which shows that the aperture of the precursor prepared by the preparation method is smaller and the aperture distribution is uniform, and the aperture distribution uniformity of the precursor can be further improved by utilizing a citric acid phosphate preparation formula.

Table 1 shows the porosity and average pore diameter of the precursor measured by mercury porosimeter, and it can be seen that the porosities of the precursors obtained in examples 1 and 7 are larger than those of comparative examples 1 and 2, and the average pore diameters are smaller than those of comparative examples 1 and 2 (the results are consistent with those of fig. 1), which shows that the precursor prepared by the preparation method of the present invention has high porosity and smaller pore diameter; compared with the embodiment 1, the porosity of the precursor obtained in the embodiment 7 is higher, and the average pore diameter is smaller, which shows that the porosity of the precursor can be further improved and the average pore diameter can be reduced by using citric acid phosphate in the preparation process.

FIG. 2 is a graph of pore size distribution of a precursor measured by a mercury porosimeter, and it can be seen that the precursor obtained in example 1 has an obvious distribution peak at about 15 μm and the distribution peak has the strongest intensity, which indicates that many mesopores with a pore size of 15 μm exist in the precursor obtained in example 1; the precursor obtained in example 7 has an obvious distribution peak with the strongest intensity around 8 μm, which indicates that many mesopores with the pore diameter of 8 μm exist in the precursor obtained in example 1; and example 1 and example 7 gave better pore size concentration of the precursor than comparative example 1 and comparative example 2, while example 7 gave better pore size concentration of the precursor than example 1. Therefore, the preparation method can improve the aperture distribution uniformity of the precursor, and the citric acid phosphate can further improve the aperture distribution uniformity of the precursor.

TABLE 1 pore size and pore size distribution of the precursors

Group of	Porosity (%)	Average pore diameter (μm)
			Examples1	91.03	13.26
Example 7	94.74	9.87
			Comparative example 1	81.25	16.23
Comparative example 2	78.69	15.88

2. Yield of precursor

As can be seen from FIG. 3, the yields of the precursors obtained in examples 1 to 10 were higher than those obtained in comparative example 1, and the yields of the precursors obtained in comparative examples 2 and examples 7 to 10 were slightly higher than those obtained in examples 1 to 6, so that it could be confirmed that: the preparation method can improve the yield of the precursor, and the use of the citric acid phosphate or the malic acid phosphate can also improve the yield of the precursor.

3. Complexing power of the gel

In the process of preparing the precursor, the solution A and the solution C are not added, the prepared precursor is xerogel, and the xerogel is placed into 20mL of solution A (prepared by preparing 0.2mol/L aqueous solution from lanthanum nitrate, aluminum nitrate and ruthenium nitrate and then mixing according to the molar ratio of La to Al to Ru of 1:0.6:0.4 to prepare solution A) for soaking for 12 hours at 25 ℃. Taking out the hydrogel after adsorption, measuring the mass of the hydrogel, measuring the concentration of metal ions in the solution by using inductively coupled plasma mass spectrometry, and calculating the equilibrium adsorption capacity of the gel according to the following formulaq _e(mg/g)：

In the formula (I), wherein,

m-xerogel mass, g;

V-volume of solution, ml;

c ₀the concentration of metal ions in the initial solution is mg/L;

c _ethe concentration of metal ions in the solution at equilibrium, mg/L.

By calculation, the adsorption amount of the xerogel prepared in example 1 is 832.38mg/g, the adsorption amount of the xerogel prepared in example 7 is 891.15mg/g, and the adsorption amount of the xerogel prepared in comparative example 1 is 357.21mg/g, so that the preparation method of the invention enables the gel to have higher yield and complexing ability, and further enables the precursor to have high yield, which is consistent with the above results; the invention utilizes phosphoric acid citrate to prepare LaAl_1-xRu_xO₃The nano particles can provide more binding sites for metal ions, thereby improving LaAl_1-xRu_xO₃The yield of nanoparticles, which is consistent with the above results.

Test example 2:

1. XRD analysis of far infrared radiation base material

The phase composition of the far infrared radiation base material sample is analyzed by an X-ray powder diffractometer. By using Cu K_αThe radiation source has a scanning speed of 6(°)/min, a step length of 0.02 degrees and a scanning angle of 10-90 degrees. The XRD patterns of the far infrared radiation base materials obtained in examples 1, 7, 1 and 2 are shown in fig. 4. as can be seen from fig. 4, the preparation method of comparative example 2 resulted in a pure phase of lanthanum aluminate containing nickel ions, whereas the preparation methods of examples 1, 7 and 1 all resulted in a peak position shift in the high angle direction, resulting in a pure phase of lanthanum aluminate containing ruthenium ions, with the peak value of comparative example 2 being lower, followed by example 1 and the peak value of example 7 being highest.

2. Particle size testing of far infrared radiation base material

The particle size distribution of the far infrared radiation base material was analyzed by a laser particle size tester, and the results are shown in FIG. 5. The particle size distribution of the far infrared radiation base materials obtained in example 1, example 7 and comparative example 2 is concentrated, wherein the particle size of the far infrared radiation base material obtained in example 1 is mainly distributed between 50nm and 230nm, and the particle size with the highest occurrence frequency is 173 nm; the particle size of the far infrared radiation base material obtained in example 7 is mainly distributed between 76nm and 183nm, and the particle size with the highest occurrence frequency is 100 nm; the particle size of the far infrared radiation base material obtained in the comparative example 2 is mainly distributed between 87nm and 451nm, and the particle size with the highest occurrence frequency is 235 nm; comparing example 1 with example 7, it can be seen that the far infrared radiation base material obtained in example 7 has a finer size and a more uniform particle size distribution. The particle size distribution range of the far infrared radiation base material obtained in the comparative example 1 is wide, the far infrared radiation base material is mainly distributed between 73nm and 1752nm, and the particle size with the highest occurrence frequency is 1055 nm; the particle size analysis result shows that the far infrared radiation base material prepared by the invention has fine particle size and uniform particle size distribution.

3. XPS analysis of base materials for far infrared radiation

In order to deeply research LaAl in far infrared radiation base material_1-xRu_xO₃The influence on the infrared radiation performance of the tourmaline is tested on the valence states and the contents of elements such as iron, cerium and the like in the tourmaline, and the test equipment is an X-ray photoelectron energy spectrum analyzer. Firstly, the far infrared radiation base material samples of the example 11 and the comparative example 3 are respectively subjected to etching test to detect Fe in the deep layer of the tourmaline²⁺The variation of (2). FIG. 6 shows XPS spectra of far infrared radiation base samples of example 11 and comparative example 3 after argon ion etching for 10min, with a XPS probe depth of about 10 nm. As can be seen from FIG. 6, comparative example 3 far-infrared radiation base material sample is Fe at this detection depth²⁺The peak shape is obvious, and example 11 Fe in the far infrared radiation base material sample²⁺The peak is obviously reduced, corresponding to Fe³⁺The peak is obviously enhanced, which indicates that Fe in tourmaline²⁺Can be coated with LaAl_1-xRu_xO₃And is oxidized, thereby further enhancing the infrared emissivity of the tourmaline in the far infrared band.

4. Analysis of infrared radiation Properties of far Infrared radiation base Material

For evaluating materialsAnd (3) infrared emission performance, testing the infrared emission rate of the material, and measuring the emission rate of the powder by adopting an IR-dual-waveband emission rate measuring instrument. The instrument mainly adopts a standard black body transmitter and a gray body receiver. And comparing the received radiation energy with a standard black body to obtain the emissivity of the tested material, wherein the far infrared test wave band is 8-14 mu m. FIG. 7 is a diagram showing the normal emissivity of a sample in the far infrared band of 8 to 14 μm at 1000 deg.C, and it can be seen that the emissivity in the far infrared band of 8 to 14 μm at 1000 deg.C of the base material obtained in examples 1 to 14 of the present invention is greater than 0.960, because the base material obtained in examples 1 to 14 has a complex crystal structure and element valence, the transition between the vibrational energy level and rotational energy level of the lattice is more likely to occur, and the energy required for the transition between the energy levels matches the energy in the short infrared band range, so that the emissivity in the far infrared band of the infrared radiation paint is greatly improved; the emissivity of the far infrared radiation base material obtained in the embodiments 1-6 of the invention at 1000 ℃ in the wave band of 8-14 μm is larger than that of the comparative example 1 and the comparative example 2, which shows that the far infrared radiation base material of the invention has better far infrared radiation performance; the emissivity of the far infrared radiation base materials obtained in examples 11 to 14 at 1000 ℃ in the 8 to 14 μm band is superior to that of examples 1 to 10 and comparative example 3, which shows that LaAl in the far infrared radiation base materials_1-xRu_xO₃The nano particle energy and the tourmaline can play a gain role, so that LaAl can play a role_1-xRu_xO₃The tourmaline nano composite material has higher far infrared emissivity.

Test example 3:

1. infrared radiation performance of far infrared energy-saving radiation coating

In order to evaluate the infrared radiation performance of the far infrared energy-saving radiation coating at 1000 ℃ in the wave band of 8-14 μm, the emissivity test is carried out on the far infrared energy-saving radiation coating, the result is shown in fig. 8, and it can be seen from the table that the infrared radiation performance of the coatings of examples 1-14 is better, the emissivity is not less than 0.970, and the infrared radiation performance of the coatings of comparative examples 1-3 is poorer. Comparative example 1 and comparative examples 1 to 2, which show that the far infrared energy-saving type radiation coating of the present invention has a better far infrared radiation performance; comparative example 11 and comparative example 3, it is explained that the far infrared energy saving type radiation paint of the present invention hasBetter far infrared radiation performance; comparing example 1 and comparative example 4 coatings, it can be seen that GeO is present in the binder₂Fine powder and In₂O₃LaAl gain by existence of micro powder_1-xRu_xO₃Far infrared radiation performance of the nano particles.

2. Heat-insulating property of far infrared energy-saving radiation coating

2.1 Heat conductivity coefficient of far-infrared energy-saving radiation coating

The heat conductivity coefficient is the most important index of the heat insulation performance of the reaction coating, and the heat absorbed by the water flow flowing through the central calorimeter after the heat flow longitudinally flows from the hot surface to the cold surface of the sample in a unit time one-dimensional temperature field in a steady state is measured according to the basic principle of stable heat conduction of a Fourier one-dimensional flat plate. The heat is in direct proportion to the heat conductivity coefficient of the sample, the temperature difference of the cold and hot surfaces and the area of the absorption surface of the central calorimeter, and in inverse proportion to the thickness of the sample. The test example adopts a thermal conductivity meter to measure the thermal conductivity of the far infrared energy-saving radiation coating, the result is shown in figure 9, the thermal conductivity of the far infrared energy-saving radiation coatings of examples 1-14 is less than 0.13W/(m.K), the far infrared energy-saving radiation coatings have good heat insulation effect, and GeO in the binder₂Fine powder and/or In₂O₃The micro powder has no adverse effect on the heat-insulating property of the coating made of the coating.

2.2 Heat-insulating Properties of far-Infrared energy-saving radiation coating

And testing the heat insulation performance of the thermal barrier coating by adopting a high-temperature gas thermal shock simulator. During testing, a sample is fixed on a clamp, so that the surface of a coating is opposite to a gun mouth of a spray gun, propane is used as fuel, mixed oxygen is used for heating the surface of the sample, the surface of the coating and the back of a matrix of the sample are measured, the change curve of the temperature along with time is recorded, the surface of the coating adopts an infrared temperature measurement mode, and the back of the matrix adopts a thermocouple for measuring the temperature. The power of the spray gun is automatically controlled by a program, the fixed power is kept to ensure that the surface temperature of the coating is raised to 1000 ℃, the power of the spray gun is adjusted to keep the temperature for 2min, then the spray gun is turned off, and the sample is cooled to the room temperature by compressed air. The thermal shock test results of the coating of example 1 are shown in fig. 10, which shows that the thermal insulation performance of the coating can be quantified by taking the infrared temperature measurement starting point of 750 ℃ as the starting pointPoint, the time t for the coating surface to reach the highest temperature is selected_topAnd the temperature T of the substrate back at that time_topAnd the maximum temperature T of the substrate back surface when the temperature distribution in the coating reaches quasi-steady state_max. The lower the surface temperature of the substrate is, the higher the thermal insulation capacity of the coating is, the larger the temperature gradient in the coating is, and the higher the thermal insulation capacity is. As can be seen from the coating surface temperature curve in fig. 10, after the set 1000 ℃ is reached, the oxygen-propane spray gun is in a pulse operating state, which results in the fluctuation of the coating surface temperature around 1000 ℃, the fluctuation range is about 25 ℃, but the substrate back surface temperature is basically kept unchanged, and the fluctuation of the temperature is only 2-3 ℃ after the substrate temperature reaches the maximum point within the holding time. That is, the temperature distribution in the coating reaches a substantially dynamic equilibrium state, and the measured data may reflect the thermal insulation capability of the coating. It can be seen from the figure that the time taken for the surface temperature of the coating of example 1 to reach the maximum value of 1085 ℃ is 34s, the temperature of the substrate is 744 ℃, and the maximum temperature of the substrate is 771 ℃ when the temperature of the coating is substantially stabilized at about 1000 ℃. In addition, the results of the thermal insulation performance test of each of the coatings of examples and comparative examples are shown in Table 2, and the maximum temperature T of the back surface of the substrate of the far infrared energy saving type radiation coatings of examples 1 to 14_maxLow content of GeO in binder, good heat-insulating ability₂Fine powder and/or In₂O₃The micro powder has no adverse effect on the heat-insulating property of the coating made of the coating.

TABLE 2 Heat insulation Performance test results for far infrared energy-saving radiation coatings

3. Bonding strength of far infrared energy-saving radiation coating

The bonding of the coating is strongThe degree is a key index for reflecting the properties of the coating. The size of the particles is related to the size of the mechanical embedding force between the coating and the substrate, the binding force between the particles, and the pores and stress release conditions inside the coating. In this test example, the bonding strength of the coating was measured by a hydraulic universal testing machine, and the bonding strength of the coating was shown in table 3. It can be seen that the bonding strength of the far infrared energy-saving radiation coatings of examples 1-14 is more than 31.8Mpa, the coatings have certain bonding strength and can meet the use requirements of the coatings, and GeO in the binder₂Fine powder and/or In₂O₃The micro powder has no adverse effect on the bonding strength of a coating made of the coating.

4. Determination of thermal shock resistance of far infrared energy-saving radiation coating

The method for measuring the thermal shock resistance comprises the following steps: and (3) putting the sprayed sample into a muffle furnace, heating to 1100 ℃, preserving heat for 30min, taking out, immersing in cold water for 10min, taking out the substrate coated with the high-emissivity coating from the water, repeating the process after the coating is wiped dry until the repeated experiment times are recorded when the coating is peeled or cracked, and representing the quality of the thermal shock resistance of the infrared radiation coating according to the size of the repeated experiment times. The more the number of cold and hot cycles, the better the thermal shock resistance of the coating. Table 3 shows the thermal shock resistance of the far infrared energy-saving type radiation coatings of the examples and the comparative examples, and it can be seen that the far infrared energy-saving type radiation coatings of the examples 1 to 14 have better thermal shock resistance, can bear at least 56 times of 1100 ℃ air cooling thermal shock, and GeO in the binder₂Fine powder and/or In₂O₃The micro powder has no adverse effect on the thermal shock resistance of the coating made of the coating.

5. Roughness test of far infrared energy-saving radiation coating

The roughness of the coating can directly affect the ir-radiating properties of the coating, since the greater the roughness of the coating surface, the greater its specific surface area and, relatively speaking, the greater the ir-radiating area of the coating, while ensuring its normal structure. The roughness of the coatings was measured using a portable roughness meter and averaged over a number of measurements on a test platform, and the results of the measurements for the arithmetic mean deviation Ra of the profiles for the coatings of examples 1-14 are shown in table 3, and Ra =9.534-9.887 for the coatings of examples 1-14, which indicates that the coatings have a roughness such that the roughened surface is favorable for the ir properties of the coatings.

TABLE 3 thermal shock resistance of far infrared energy-saving radiation coating

Test example 4:

application effect analysis of far infrared energy-saving radiation coating

The fuel consumption of the heat-treated workpiece is the most important index for evaluating whether the heat treatment furnace is energy-saving or not, the gas consumption in the two heat treatment processes before and after the heat treatment of the workpiece is completely the same as the material and the heat treatment process curve before and after the far infrared energy-saving radiation coating sprayed on the high-temperature furnace kiln in the embodiment 1 is tested and compared, and the specific test data is shown in table 4, it can be seen that the gas consumption per hour of each ton of the workpiece is 14.0 Nm after the high-temperature far infrared radiation coating is sprayed³And has better energy-saving effect.

TABLE 4 analysis result of application effect of far infrared energy-saving radiation coating

Conventional techniques in the above embodiments are known to those skilled in the art, and therefore, will not be described in detail herein.

The above embodiments are merely illustrative, and not restrictive, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions also belong to the scope of the present invention, and the protection scope of the present invention should be defined by the claims.

Claims

1. A far infrared energy-saving radiation coating for a high-temperature furnace comprises the following components in parts by weight: 5-28 parts of infrared radiation base material, 8-20 parts of regulator and 20-60 parts of binder;

the infrared radiation base material is prepared by adopting a sol-gel method, and comprises the following steps:

dissolving amino acid and citric acid phosphate (formula I) in water, adding a catalyst to prepare a solution B; or dissolving amino acid and malic acid phosphate (formula II) in water, adding catalyst, and making into solution B;

(formula I);

(formula II);

-roasting, cooling and grinding the precursor to obtain LaAl_1-xRu_xO₃The roasting temperature is 1000-;

the regulator is silicon dioxide micropowder;

the binder is a mixture of silica sol and micro powder, and the micro powder is GeO₂Fine powder and/or In₂O₃And the weight ratio of the silica sol to the micro powder in the adhesive is 1: 0.7-1.5.

2. The far infrared energy-saving radiation coating for the high-temperature kiln as claimed in claim 1, characterized in that: the amino acid is selected from glycine, aspartic acid, asparagine, glutamic acid, lysine, glutamine, serine, threonine, cysteine, histidine or arginine.

3. The far infrared energy-saving radiation coating for the high-temperature kiln as claimed in claim 1, characterized in that: the catalyst is one or a mixture of potassium dihydrogen phosphate, dipotassium hydrogen phosphate, phosphoric acid and potassium sulfate.

4. The far infrared energy-saving radiation coating for the high-temperature kiln as claimed in claim 1, characterized in that: the thermal conductivity coefficient of the coating is less than 0.13W/(m.K).

5. The far infrared energy-saving radiation coating for the high-temperature furnace is characterized in that: spraying the coating of any one of claims 1 to 4 onto the surface of the inner wall of the kiln by a thermal spraying method to form a far infrared energy-saving radiation coating.

6. The far infrared energy-saving type radiation coating of the high temperature furnace according to claim 5, characterized in that: the bonding strength of the coating is more than 31.8 MPa.

7. The far infrared energy-saving type radiation coating of the high temperature furnace according to claim 5, characterized in that: the coating can bear at least 56 times of 1100 ℃ air cooling thermal shock.