CN113149668A

CN113149668A - High-strength environment-friendly refractory brick and preparation method thereof

Info

Publication number: CN113149668A
Application number: CN202110202167.6A
Authority: CN
Inventors: 戴永善
Original assignee: Xinyi Beimei High-Tech Refractory Materials Co ltd
Current assignee: Xinyi Beimei High-Tech Refractory Materials Co ltd
Priority date: 2021-02-09
Filing date: 2021-02-09
Publication date: 2021-07-23

Abstract

The high-strength environment-friendly refractory brick mainly comprises the following components in parts by weight: 20-25 parts of flint clay, 20-25 parts of alumina, 10-15 parts of andalusite, 5-10 parts of clay, 10-15 parts of silicon sulfide, 2-5 parts of simple substance silicon, 2-5 parts of active alpha-Al 2O3 micro powder, 1-3 parts of adhesive and 1-3 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solution and polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by the sol. The high-strength environment-friendly refractory brick and the preparation method thereof have the advantages that the formula is reasonable, the excellent fire resistance is realized, the alkali gas phase erosion resistance and the integral strength of the refractory brick are improved, the preparation process is simple, the large-scale production is easy, the energy is saved, the environment is protected, and the application prospect is wide.

Description

High-strength environment-friendly refractory brick and preparation method thereof

Technical Field

The invention belongs to the technical field of refractory bricks, and particularly relates to a high-strength environment-friendly refractory brick and a preparation method thereof.

Background

With the continuous expansion and development of industrial scale, the application of refractory bricks is more and more extensive and the demand is more and more great. At present, the refractory brick is widely applied to the high-temperature operation fields of cement, steel, glass and the like. With the progress and development of high-temperature industrial technology, the requirement on the quality of auxiliary refractory materials is higher and higher, and the quality and the service life of the sintered refractory bricks which are applied in large quantities are directly related to the safe production and the economic benefit in the field of high-temperature operation.

Among them, refractory bricks having high temperature resistance must be installed in the rotary cement kiln. In recent years, the cement rotary kiln is utilized to cooperatively treat urban domestic garbage, and the garbage as a substitute energy source of the cement industry becomes the development direction of the modern cement industry, and remarkable economic and social benefits are obtained. However, harmful substances such as alkaline substances, chlorides and sulfides in the alternative energy sources can form gaseous substances in the combustion process, and are continuously enriched in the rotary cement kiln as the service time of the rotary cement kiln is prolonged, so that the corrosion of the refractory bricks of the kiln lining is accelerated. Of the above-mentioned aggressive substances, the attack by alkaline vapors is the most severe, and therefore, the kiln lining refractory brick needs to be optimized for increased strength and thus increased resistance to attack by gaseous alkaline substances. Therefore, it is necessary to develop a high-strength environment-friendly refractory brick and a preparation process thereof to solve the above technical problems.

Chinese patent application No. CN201921890473.8 discloses a composite wear-resistant refractory brick, which is prepared by pressing ceramic layers on two sides of a refractory brick, wherein when the refractory brick is fired at high temperature, the ceramic layers form ceramic surfaces after receiving high temperature, and the ceramic surfaces have strong wear resistance and do not improve or enhance the formula, strength and performance of the refractory brick.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects, the invention aims to provide the high-strength environment-friendly refractory brick and the preparation method thereof, the formula is reasonably arranged, the excellent fire resistance is realized, the alkali gas phase erosion resistance and the integral strength of the refractory brick are improved, the preparation process is simple, the large-scale production is easy, the energy is saved, the environment is protected, and the application prospect is wide.

The purpose of the invention is realized by the following technical scheme:

the high-strength environment-friendly refractory brick is characterized by mainly comprising the following components in parts by weight: 20-25 parts of flint clay, 20-25 parts of alumina, 10-15 parts of andalusite, 5-10 parts of clay, 10-15 parts of silicon sulfide, 2-5 parts of simple substance silicon, 2-5 parts of active alpha-Al 2O3 micro powder, 1-3 parts of adhesive and 1-3 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solution and polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by the sol.

The high-strength environment-friendly refractory brick is reasonable in formula arrangement, takes flint clay, alumina, clay, silicon sulfide and simple substance silicon as aggregates, takes active alpha-Al 2O3 micro powder as an additive, increases the binding force of each component through an adhesive, and is beneficial to microporosity of the refractory brick through a pore-forming agent. Wherein, flint clay, alumina and clay are all light-weight aggregates, the volume stability and sintering performance are good, the refractoriness is high, the sintering melting temperature range is wide, the refractoriness after compounding can reach more than 1800 ℃, but the composite material has excellent heat insulation performance due to relatively more pores, but the more pores can cause the composite material to be easily permeated and eroded by aggressive gas, and the strength of the refractory brick is reduced. According to the invention, through the addition of andalusite, silicon sulfide, simple substance silicon and active alpha-Al 2O3 micro powder, the apparent porosity and average pore diameter of the refractory brick are effectively reduced, and the proportion of micropores is increased, so that the permeation of gas-phase substances into the interior of the refractory brick is effectively weakened, and the alkali gas-phase corrosion resistance and the overall strength of the refractory brick are improved.

Wherein, the andalusite can lock the corrosion products in the mullite network in the andalusite corrosion process, has excellent alkali corrosion resistance and improves the thermal shock stability and refractoriness under load. When the silicon carbide is in a region with higher oxygen partial pressure, the silicon carbide can be subjected to protective oxidation and forms a film on the surface of the silicon carbide, and the silicon carbide can be subjected to active oxidation when the oxygen partial pressure is lower than 10-15 PPtheta, and by adding simple substance silicon, the simple substance silicon is subjected to reaction with oxygen in preference to the silicon carbide in thermodynamics, so that the silicon carbide can be protected; on the other hand, the oxygen partial pressure in the material is reduced after the elemental powder is oxidized, partial air holes are blocked to inhibit the active oxidation of the silicon carbide under the low oxygen partial pressure, the combination of the silicon carbide and other components is facilitated, and the strength of the refractory brick is improved; the active alpha-Al 2O3 micropowder plays a positive role in optimizing the pore diameter in the refractory brick and the refractoriness under load.

Furthermore, the specific gravity of the binding agent of the high-strength environment-friendly refractory brick is 1.3-1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 5-8:40-45, the sol is a mixture of alumina sol and silica sol, wherein the mass ratio of the alumina sol to the silica sol is 1-2: 2-3.

The sol is a mixture of alumina sol and silica sol, can inhibit the transformation of cristobalite, increases the content of free SiO2 in the refractory brick, increases the liquid phase in the refractory brick, provides a good growth environment for the development of mullite, strengthens the biological structure of sawdust per se due to the increase of the liquid phase, ensures that the refractory brick has a proper microporous structure, does not influence the heat conductivity coefficient of the refractory brick and improves the overall strength.

Furthermore, the high-strength environment-friendly refractory brick has the advantages that the average grain diameter of the flint clay is 11-13 mu m, and the A/S of the flint clay is 0.80-0.84; the alumina is special grade alumina and has an average particle size of 25-50 μm, and the andalusite has an average particle size of 5-10 μm; the average particle size of the clay is 6-10 μm; the average particle size of the silicon sulfide is 30-40 mu m, the average particle size of the simple substance silicon is 20-30 mu m, and the average particle size of the active alpha-Al 2O3 micro powder is 1-3 mu m; the average grain diameter of the pore-forming agent is 40-50 mu m.

Furthermore, the high-strength environment-friendly refractory brick mainly comprises the following components in parts by weight: 25 parts of flint clay, 50 parts of alumina, 10 parts of andalusite, 8 parts of clay, 12 parts of silicon sulfide, 5 parts of simple substance silicon, 4 parts of active alpha-Al 2O3 micro powder, 2 parts of adhesive and 2 parts of pore-forming agent.

The invention also relates to the high-strength environment-friendly refractory brick and a preparation method thereof, and the preparation method comprises the following steps:

(1) mixing materials: preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 0.5-1h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2-3h, finally adding adhesive, and mixing for 3-5min to obtain a mixture;

(2) pressing the material into a mold: filling the mixture into a die, and forming on a hydraulic testing machine under the pressure of 600KN to obtain a blank;

(3) drying: drying the blank in an oven at the drying temperature of 100 ℃ and 110 ℃ for 20-28 h;

(4) roasting: and (4) placing the dried blank into a resistance furnace for roasting to obtain the refractory brick.

Further, the high-strength environment-friendly refractory brick and the preparation method thereof are characterized in that after the blank material obtained by roasting and drying in the step (4) is placed into a resistance furnace, the temperature of the resistance furnace is firstly increased to 550-600 ℃ at a rate of 3-5 ℃/min, the temperature is kept at 550-600 ℃ for 1-1.5 h, then increased to 1150-1300 ℃ at a rate of 5-7 ℃/min, the temperature is kept at 0.2-0.5 h, the temperature is increased to 1400-1500 ℃ at a rate of 3-5 ℃/min, and the temperature is kept at 2.5-3.0 h.

Further, the preparation of the pore-forming agent comprises the following steps:

(1) mixing the sol and the sawdust in a mixing barrel for 0.5-1h, standing for 2-5min in a vacuum drying oven under the pressure of-0.1-0.2 MPa, taking out and stirring, repeating the steps for 5 times, and drying at the temperature of 100 ℃ and 120 ℃;

(2) crushing for 1min by a high-speed crusher at the rotating speed of 38000-40000r/min to obtain the pore-forming agent with the average particle size of 40-50 μm.

Compared with the prior art, the invention has the following beneficial effects:

(1) the high-strength environment-friendly refractory brick disclosed by the invention is reasonable in formula arrangement, takes flint clay, alumina, clay, silicon sulfide and simple substance silicon as aggregates, takes active alpha-Al 2O3 micro powder as an additive, increases the binding force of each component through an adhesive, and promotes the microporosity of the refractory brick through a pore-forming agent;

(2) the high-strength environment-friendly refractory brick disclosed by the invention has good sintering performance and excellent refractoriness by compounding flint clay, alumina and clay; through the addition of andalusite, silicon sulfide, simple substance silicon and active alpha-Al 2O3 micro powder, the apparent porosity and the average pore diameter of the refractory brick are effectively reduced, and the proportion of micropores is improved, so that the permeation of gas-phase substances into the interior of the refractory brick is effectively weakened, and the alkali gas phase corrosion resistance and the overall strength of the refractory brick are improved; the sol is a mixture of alumina sol and silica sol, can inhibit the transformation of cristobalite, increases the content of free SiO2 in the refractory brick, increases the liquid phase in the refractory brick, provides a good growth environment for the development of mullite, strengthens the biological structure of sawdust per se due to the increase of the liquid phase, ensures that the refractory brick has a proper microporous structure, does not influence the heat conductivity coefficient of the refractory brick and improves the overall strength.

(3) The high-strength environment-friendly refractory brick and the preparation method thereof provided by the invention have the advantages of simple preparation method, high flexibility, energy conservation, environmental friendliness and better economy, and can be used for large-scale production.

Detailed Description

In the following, the technical solutions in the embodiments of the present invention are clearly and completely described in the embodiments with reference to specific experimental data, and it is obvious that the described embodiments are only a part of the 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.

The following embodiment provides a high-strength environment-friendly refractory brick and a preparation method thereof, wherein the refractory brick mainly comprises the following components in parts by weight: 20-25 parts of flint clay, 20-25 parts of alumina, 10-15 parts of andalusite, 5-10 parts of clay, 10-15 parts of silicon sulfide, 2-5 parts of simple substance silicon, 2-5 parts of active alpha-Al 2O3 micro powder, 1-3 parts of adhesive and 1-3 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solution and polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by the sol.

Further, the average grain diameter of the flint clay is 11-13 μm, and the A/S of the flint clay is 0.80-0.84; the alumina is special grade alumina and has an average particle size of 25-50 μm, and the andalusite has an average particle size of 5-10 μm; the average particle size of the clay is 6-10 μm; the average particle size of the silicon sulfide is 30-40 mu m, the average particle size of the simple substance silicon is 20-30 mu m, and the average particle size of the active alpha-Al 2O3 micro powder is 1-3 mu m; the average grain diameter of the pore-forming agent is 40-50 mu m.

Example 1

(1) Mixing materials: the refractory brick mainly comprises the following components in parts by weight: 22 parts of flint clay, 20-parts of alumina, 10 parts of andalusite, 7 parts of clay, 12 parts of silicon sulfide, 4 parts of simple substance silicon, 5 parts of active alpha-Al 2O3 micro powder, 2 parts of adhesive and 1 part of pore-forming agent; the adhesive is aluminum dihydrogen phosphate solution, and the pore-forming agent is saw dust impregnated by the sol; the specific gravity of the adhesive is 1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 7:440, the sol is a mixture of alumina sol and silica sol, and the mass ratio of the alumina sol to the silica sol is 1: 2; preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 0.8h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2.0h, finally adding adhesive, and mixing for 5min to obtain a mixture;

(3) drying: drying the blank in an oven at the drying temperature of 110 ℃ for 24 h;

(4) roasting: and (3) after the dried blank is placed into a resistance furnace, the resistance furnace is heated to 600 ℃ at a speed of 5 ℃/min, the temperature is kept constant for 1.0h at 600 ℃, then is heated to 1300 ℃ at a speed of 7 ℃/min, the temperature is kept constant for 0.3h, is heated to 1400 ℃ at a speed of 3 ℃/min, and the temperature is kept constant for 2.5h, so that the refractory brick is obtained.

The preparation method of the pore-forming agent comprises the following steps:

(1) mixing the sol and sawdust in a mixing barrel for 0.5h, standing in a vacuum drying oven under-0.1 MPa for 5min, taking out, stirring, repeating the above steps for 5 times, and oven drying at 120 deg.C;

(2) crushing for 1min by a high-speed crusher at the rotation speed of 40000r/min to obtain the pore-forming agent with the average particle size of 40-50 μm.

Example 2

(1) Mixing materials: the refractory brick mainly comprises the following components in parts by weight: 25 parts of flint clay, 22 parts of alumina, 10 parts of andalusite, 6 parts of clay, 11 parts of silicon sulfide, 5 parts of simple substance silicon, 4 parts of active alpha-Al 2O3 micro powder, 3 parts of adhesive and 2 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solutions, and the pore-forming agent is saw dust impregnated by the sol; the specific gravity of the adhesive is 1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 8:40, the sol is a mixture of alumina sol and silica sol, and the mass ratio of the alumina sol to the silica sol is 1: 3; preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 0.6h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2.4h, finally adding adhesive, and mixing for 4min to obtain a mixture;

(3) drying: drying the blank in an oven at 105 ℃ for 25 h;

(4) roasting: and (3) after the dried blank is placed into a resistance furnace, the resistance furnace is heated to 600 ℃ at a speed of 5 ℃/min, the temperature is kept constant at 600 ℃ for 1-1.5 h, then heated to 1250 ℃ at a speed of 6 ℃/min, the temperature is kept constant for 0.4h, heated to 1450 ℃ at a speed of 5 ℃/min, and the temperature is kept constant for 2.5h, so that the refractory brick is obtained.

The preparation method of the pore-forming agent comprises the following steps:

(1) mixing the sol and sawdust in a mixing barrel for 0.6h, standing in a vacuum drying oven under-0.2 MPa for 3min, taking out, stirring, repeating the above steps for 5 times, and oven drying at 120 deg.C;

(2) crushing for 1min by a high-speed crusher at a rotating speed of 38000r/min to obtain a pore-forming agent with an average particle size of 40-50 μm.

Example 3

(1) Mixing materials: the refractory brick mainly comprises the following components in parts by weight: 20 parts of flint clay, 22 parts of alumina, 15 parts of andalusite, 5 parts of clay, 12 parts of silicon sulfide, 4 parts of simple substance silicon, 5 parts of active alpha-Al 2O3 micro powder, 1 part of adhesive and 2 parts of pore-forming agent; the adhesive is one of polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by sol; the specific gravity of the adhesive is 1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 7:42, the sol is a mixture of alumina sol and silica sol, and the mass ratio of the alumina sol to the silica sol is 2: 3; preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 0.7h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2.2h, finally adding adhesive, and mixing for 4min to obtain a mixture;

(3) drying: drying the blank in an oven at 100 ℃ for 26 h;

(4) roasting: and (3) after the dried blank is placed into a resistance furnace, the resistance furnace is heated to 580 ℃ at the speed of 5 ℃/min, the temperature is kept for 1.5h at the temperature of 580 ℃, then is heated to 1300 ℃ at the speed of 7 ℃/min, is kept for 0.5h, is heated to 1500 ℃ at the speed of 3 ℃/min, and is kept for 2.5h, so that the refractory brick is obtained.

The preparation method of the pore-forming agent comprises the following steps:

(1) mixing the sol and sawdust in a mixing barrel for 1h, standing in a vacuum drying oven under-0.1 MPa for 2min, taking out, stirring, repeating the above steps for 5 times, and drying at 120 deg.C;

Example 4

(1) Mixing materials: the refractory brick mainly comprises the following components in parts by weight: 22 parts of flint clay, 20 parts of alumina, 15 parts of andalusite, 7 parts of clay, 10 parts of silicon sulfide, 2 parts of simple substance silicon, 2 parts of active alpha-Al 2O3 micro powder, 1 part of adhesive and 1 part of pore-forming agent; the adhesive is one of polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by sol; the specific gravity of the adhesive is 1.3; the mass ratio of the sol to the sawdust in the pore-forming agent is 8:45, the sol is a mixture of alumina sol and silica sol, and the mass ratio of the alumina sol to the silica sol is 1: 2.5; preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 0.8h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2.5h, finally adding adhesive, and mixing for 3min to obtain a mixture;

(3) drying: drying the blank in an oven at the drying temperature of 110 ℃ for 22 h;

(4) roasting: and (3) after the dried blank is placed into a resistance furnace, heating the resistance furnace to 590 ℃ at a speed of 3 ℃/min, keeping the temperature at 590 ℃ for 1.5h, heating to 1300 ℃ at a speed of 6 ℃/min, keeping the temperature for 0.4h, heating to 1400 ℃ at a speed of 5 ℃/min, and keeping the temperature for 3.0h to obtain the refractory brick.

The preparation method of the pore-forming agent comprises the following steps:

(1) mixing the sol and sawdust in a mixing barrel for 1h, standing in a vacuum drying oven under-0.2 MPa for 3min, taking out, stirring, repeating the above steps for 5 times, and oven drying at 110 deg.C;

(2) crushing for 1min by a high-speed crusher at the rotating speed of 39000r/min to obtain the pore-forming agent with the average particle size of 40-50 mu m.

Example 5

(1) Mixing materials: the refractory brick mainly comprises the following components in parts by weight: 25 parts of flint clay, 50 parts of alumina, 10 parts of andalusite, 8 parts of clay, 12 parts of silicon sulfide, 5 parts of simple substance silicon, 4 parts of active alpha-Al 2O3 micro powder, 2 parts of adhesive and 2 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solution and polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by the sol; the specific gravity of the adhesive is 1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 7:40, the sol is a mixture of alumina sol and silica sol, and the mass ratio of the alumina sol to the silica sol is 1: 1.5; preparing materials according to the formula; dry-mixing flint clay, alumina, andalusite, clay, silicon sulfide, elemental silicon and active alpha-Al 2O3 micro powder in a mixing barrel for 1h, adding saw powder of which pore-forming agent is impregnated by sol, continuously dry-mixing in the mixing barrel for 2.5h, finally adding adhesive, and mixing for 3.5min to obtain a mixture;

(4) roasting: and (3) after the dried blank is placed into a resistance furnace, heating the resistance furnace to-600 ℃ at a speed of 5 ℃/min, keeping the temperature at 600 ℃ for 1-1.5 h, heating to 1300 ℃ at a speed of 7 ℃/min, keeping the temperature for 0.4h, heating to 1450 ℃ at a speed of 3 ℃/min, and keeping the temperature for 2.5h to obtain the refractory brick.

The preparation method of the pore-forming agent comprises the following steps:

Effect verification:

the high-strength eco-friendly firebricks obtained in examples 1, 2, 3, 4 and 5 were tested for their performance according to the following criteria, and the test results are shown in tables 1 and 2.

(1) The apparent porosity and the bulk density of the high-strength environmentally friendly firebrick samples obtained in examples 1, 2, 3, 4 and 5 were measured by the archimedes principle;

(2) the high-strength eco-friendly firebrick specimens obtained in examples 1, 2, 3, 4 and 5 were tested for their compressive strength in accordance with GB/T5072.2.2004 NIJ;

(3) recording the pre-firing mass and the post-firing mass of the high-strength environment-friendly refractory brick samples obtained in the above examples 1, 2, 3, 4 and 5, and calculating the mass change rate after heat treatment according to the formula;

(4) the pre-firing diameter and the post-firing diameter of the high-strength eco-friendly refractory brick samples obtained in examples 1, 2, 3, 4 and 5 were recorded, and the linear change rate after the heat treatment was calculated from the formula.

(5) The thermal conductivity of the high-strength environmentally friendly firebrick specimens obtained in examples 1, 2, 3, 4 and 5 was measured at 300 ℃, 500 ℃, 800 ℃ and 1000 ℃ according to YB/T4130.2005.

TABLE 1 sample Performance test results

TABLE 2 sample thermal conductivity Performance test results

Further, the alkali gas resistance test was performed on the high-strength eco-friendly firebricks obtained in examples 1, 2, 3, 4 and 5, and the test procedure was as follows: (1) mixing potassium carbonate powder and charcoal powder in a ratio of 1: 1 mass percent premixing; (2) the high-strength environment-friendly refractory brick samples obtained in the above examples 1, 2, 3, 4 and 5 were placed in a graphite crucible filled with a mixture of potassium carbonate powder and charcoal powder; (3) after the graphite crucible is placed into an alumina sagger with coke fully spread at the bottom, the graphite crucible is buried by the coke, and alumina micro powder is spread on the upper layer of the coke; (4) the alumina sagger was put into a high temperature furnace, and the furnace was cooled after the furnace was kept at 1000 ℃ for 10 hours, and the high-strength environment-friendly firebrick samples obtained in examples 1, 2, 3, 4 and 5 after the erosion were tested for compressive strength, mass change rate and linear change rate.

The test results are shown in tables 3 and 4

TABLE 3 sample Performance test results after alkaline gas resistance test

TABLE 4 sample thermal conductivity coefficient Performance test results after alkaline gas resistance experiment

The invention has many applications, and the above description is only a preferred embodiment of the invention. It should be noted that the above examples are only for illustrating the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications can be made without departing from the principles of the invention and these modifications are to be considered within the scope of the invention.

Claims

1. The high-strength environment-friendly refractory brick is characterized by mainly comprising the following components in parts by weight: 20-25 parts of flint clay, 20-25 parts of alumina, 10-15 parts of andalusite, 5-10 parts of clay, 10-15 parts of silicon sulfide, 2-5 parts of simple substance silicon, 2-5 parts of active alpha-Al 2O3 micro powder, 1-3 parts of adhesive and 1-3 parts of pore-forming agent; the adhesive is one of aluminum dihydrogen phosphate solution and polyvinyl alcohol, and the pore-forming agent is saw dust impregnated by the sol.

2. The high-strength environmentally friendly refractory brick as claimed in claim 1, wherein the binder has a specific gravity of 1.3 to 1.4; the mass ratio of the sol to the sawdust in the pore-forming agent is 5-8:40-45, the sol is a mixture of alumina sol and silica sol, wherein the mass ratio of the alumina sol to the silica sol is 1-2: 2-3.

3. The environment-friendly, high-strength refractory brick as claimed in claim 1, wherein the flint clay has an average particle size of 11 to 13 μm, and an A/S of 0.80 to 0.84; the alumina is special grade alumina and has an average particle size of 25-50 μm, and the andalusite has an average particle size of 5-10 μm; the average particle size of the clay is 6-10 μm; the average particle size of the silicon sulfide is 30-40 mu m, the average particle size of the simple substance silicon is 20-30 mu m, and the average particle size of the active alpha-Al 2O3 micro powder is 1-3 mu m; the average grain diameter of the pore-forming agent is 40-50 mu m.

4. The high-strength environment-friendly refractory brick as claimed in claim 1, which is mainly composed of the following components in parts by weight: 25 parts of flint clay, 50 parts of alumina, 10 parts of andalusite, 8 parts of clay, 12 parts of silicon sulfide, 5 parts of simple substance silicon, 4 parts of active alpha-Al 2O3 micro powder, 2 parts of adhesive and 2 parts of pore-forming agent.

5. The method for manufacturing the high-strength environmentally friendly refractory brick according to any one of claims 1 to 4, comprising the steps of:

6. The preparation method of the high-strength environment-friendly refractory brick as claimed in claim 5, wherein after the blank obtained by roasting and drying in the step (4) is placed in a resistance furnace, the temperature of the resistance furnace is raised to 550-600 ℃ at 3-5 ℃/min, the temperature is kept constant at 550-600 ℃ for 1-1.5 h, then raised to 1150-1300 ℃ at 5-7 ℃/min, the temperature is kept constant for 0.2-0.5 h, raised to 1400-1500 ℃ at 3-5 ℃/min, and the temperature is kept constant for 2.5-3.0 h.

7. The method for preparing the high-strength environment-friendly refractory brick as claimed in claim 6, wherein the preparation of the pore-forming agent comprises the following steps:

(1) mixing the sol and the sawdust in a mixing barrel for 0.5-1h, standing for 2-5min in a vacuum drying box under the pressure of-0.1 to-0.2 MPa, taking out, stirring, repeating the steps for 5 times, and drying at the temperature of 100 ℃ and 120 ℃;