CN117362012A - Alkali-resistant wear-resistant corrosion-resistant castable and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of kiln castable preparation, specifically to an alkali-resistant, wear-resistant and erosion-resistant castable and a preparation method thereof, including: 25 to 30% MgO, 65 to 75% Al ₂ O ₃ , 10 to 15 % of auxiliary materials, 5 to 15% of functional fillers, 0.1 to 1.5% of water reducing agent and the balance of main materials; the present invention adds high content of MgO and Al ₂ O ₃ to effectively resist the erosion of alkaline media , to improve alkali resistance, the present invention adds alumina, calcium carbonate, calcium peroxide and aluminum powder, as well as fibers and aggregates in functional fillers, which can improve the corrosion resistance of the material and adapt to various corrosive media and corrosion conditions. ; The component ratio of the alkali-resistant, wear-resistant and corrosion-resistant castable of the present invention can provide excellent alkali resistance, wear resistance and corrosion resistance, and at the same time has good process performance, and is suitable for applications in high alkali and wear environments. need.

Description

An alkali-resistant, wear-resistant and corrosion-resistant castable and its preparation method

Technical field

The invention relates to the technical field of kiln castable preparation, and in particular to an alkali-resistant, wear-resistant and erosion-resistant castable and a preparation method thereof.

Background technique

In recent years, the alkaline substances that cause the greatest damage to kiln linings are alkali metal sodium and potassium compounds. Alkali metal compounds can undergo a series of physical and chemical reactions during the kiln smelting process, resulting in the circulation and enrichment of alkali metal compounds, which is harmful to The kiln is adversely affected. Alkali metal compounds corrode refractory materials, causing problems such as furnace lining cracking and damage, causing industrial kiln shutdowns and environmental pollution.

When alkaline substances are burned in the kiln, the alkali metal compounds decomposed will cause high-temperature corrosion on the heating surface in the furnace. Waste from chemical, pharmaceutical, leather and other industries contains a large amount of alkali metal compounds (such as compounds containing potassium and sodium, etc.), and the refractory materials used in industrial hazardous waste incinerators are mainly chromium corundum bricks, chromium corundum castables and High aluminum castable.

The main components of these refractory materials are Al ₂ O _3. Al ₂ O ₃ is a neutral substance that can react with alkaline compounds containing K and Na to form β-A1 ₂ O _3. With a certain volume expansion, the new phase The formation leads to the destruction of the organizational structure, severe cracks, spalling and damage to the furnace lining matrix, thereby causing further corrosion of the internal materials. As a result, the service life of the refractory materials is greatly shortened, which has a serious impact on the stable operation and safe production of the incinerator.

Contents of the invention

In view of the shortcomings of the existing technology, the present invention provides an alkali-resistant, wear-resistant and corrosion-resistant castable and a preparation method thereof.

The technical solution of the present invention is: an alkali-resistant, wear-resistant and corrosion-resistant castable. In terms of weight percentage, the proportion of the corrosion-resistant castable is: 25-30% MgO, 65-75% Al ₂ O ₃ , 10 ~15% of auxiliary materials, 5-15% of functional fillers, 0.1-1.5% of water reducing agent and the balance of main materials;

The main ingredients include, in percentage by weight: 5-7% cordierite particles, 35-40% tricalcium aluminate, 20-30% dicalcium aluminate and the balance water;

The auxiliary materials include, by weight percentage: 25-30% alumina, 10-15% calcium carbonate, 7-8% calcium peroxide, 3-5% aluminum powder and the balance calcium citrate tetrahydrate;

The functional fillers include, by weight percentage: 20-30% heavy calcium hexaaluminate, 15-20% Secar71 cement, 8-10% active α-Al ₂ O ₃ powder, 1-3% fiber and the rest. amount of aggregate.

Note: The castable contains components such as MgO and Al ₂ O ₃ , which can effectively resist the erosion of alkaline media and ensure the long-term stability of the material in an alkaline environment; the main materials include cordierite particles, tricalcium aluminate and dicalcium aluminate. Calcium aluminate, etc. can provide good anti-wear properties and maintain the stability of materials in high-wear environments; ingredients such as alumina, calcium carbonate, calcium peroxide and aluminum powder in auxiliary materials, as well as heavy materials in functional fillers Calcium hexaaluminate and others have good corrosion resistance and can protect materials from damage by corrosive substances; by adding functional fillers such as Secar71 cement, active α-Al ₂ O ₃ powder and fiber, the reliability of castables can be improved. Processability, flow and crack resistance.

A method for preparing alkali-resistant, wear-resistant and corrosion-resistant castables, including the following steps:

S1. Preparation of main ingredients

Mix cordierite particles, tricalcium aluminate, dicalcium aluminate and water according to the formula proportion, and stir for 0.8 to 1.5 hours to obtain the main ingredient;

S2. Preparation of auxiliary materials

Weigh alumina, calcium carbonate, calcium peroxide, aluminum powder and calcium citrate tetrahydrate according to the formula proportions, then put them into a mortar and mechanically mix for 45 to 55 minutes to obtain a mixture. Put the mixture into a crucible. Its bulk density is 1~1.2g/cm ³ , place a 0.8~1.2mm thick Ti-C sheet on the mixture as an igniter, then put the crucible into the combustion synthesis reactor, and make the W wire and Ti-C in the reactor C contacts, and the power is turned on to heat the W wire to ignite Ti-C. During the combustion synthesis process, the combustion temperature of the reaction system is measured by a W-3%Re/W-25%Re thermocouple, and the auxiliary materials are obtained after the combustion wave spreads;

S3. Preparation of functional fillers

Insulate heavy calcium hexaaluminate, Secar71 cement, active α-Al ₂ O ₃ powder, fiber and aggregate according to the formula proportion at a temperature of 1400 to 1750°C for 3 hours, stir evenly, and obtain functional filler;

S4, green body forming and drying

Pour MgO, Al ₂ O ₃ , auxiliary materials, functional fillers and main materials according to the formula proportion into a cement mortar mixer for dry mixing, then add water reducing agent and water and stir for 5 to 15 minutes, then put it into the molding test mold, add The amount of water is 20-25% of the total mass of the corrosion-resistant castable; vibrate with a cement forming vibrating table for 2-6 minutes to prepare the green body; after curing the green body in moisture for 48 hours, dry it at a temperature of 110-130°C for 24-36 hours , to obtain the dried green body;

S5, heat treatment

The dried green body is placed in a muffle furnace, heat-treated at a temperature of 1100 to 1750°C, kept for 3 to 6 hours, and then cooled to room temperature to prepare corrosion-resistant castables.

Note: Through precise proportions and appropriate process control, main materials, auxiliary materials and functional fillers with high stability can be obtained, which helps ensure that the castables can maintain stable performance during use; auxiliary materials in the preparation method Part of it is obtained by combustion synthesis, which can form materials with good corrosion resistance. This helps to improve the resistance of the castable to corrosive media; the steps in the preparation method are relatively simple. This method includes the preparation of main materials, auxiliary materials and functional fillers, as well as the steps of green body shaping and drying, making the preparation process easier to control. , the method is more practical,

Further, the MgO and Al ₂ O ₃ described in step S4 are added in the form of magnesium oxide powder with a mass percentage of 20 to 30% and the balance of magnesia-aluminum spinel mixed with various particle sizes.

Description: Magnesium oxide powder has high alkali resistance, can enhance alkali corrosion resistance, and helps improve alkali resistance; the addition of magnesia-aluminum spinel particles can increase the hardness and wear resistance of the castable, making it More wear-resistant; magnesium-aluminum spinel mixed with various particle sizes has a large specific surface area and pore structure, which can strengthen the binding force with other ingredients and improve the density and uniformity of the material; magnesium-aluminum spinel has high temperature resistance Good stability, able to maintain the structural stability of the material in high temperature environments.

Further, the particle size d50 of the magnesium oxide powder is 5 μm; the magnesium-aluminum spinel is composed of magnesium-aluminum spinel particles, fine powder and micro powder, and the mass ratio is: 6:3:2; the magnesium-aluminum spinel The particle sizes of spinel particles are: 5~3mm, 3~1mm and ≤1mm, and their mass ratio is: 2:1:1; the particle size of the magnesium-aluminum spinel fine powder is ≤0.088mm; the magnesium-aluminum spinel The particle size of stone powder is ≤0.010mm.

Description: Smaller particle size helps to improve the density and uniformity of the material, thereby enhancing its alkali resistance and wear resistance. Mixing magnesium aluminum spinel particles, fine powder and micro powder in a certain proportion can effectively adjust the material The structure and characteristics of the material can improve its overall performance. The mixed use of magnesium-aluminum spinel particles with multiple particle size levels can increase the pore structure and surface area of the material, improve its corrosion resistance and wear resistance, and the small size of fine powder and micro-powder The particle size helps to enhance the density and cohesion of the material and improve the corrosion resistance of the castable.

Further, the method for measuring the combustion temperature of the reaction system by the thermocouple described in step S2 is: uniaxially and bidirectionally press the mixture into a cylindrical sample with a relative density of 60 to 80% in a steel mold; Drill a small hole and insert one end of the W-3%Re/W-25%Re thermocouple into the two holes. The other end of the thermocouple is connected to the X-Y paperless recorder. Ignite the sample in the reaction chamber and use the X-Y paperless recorder. The recorder measures and records the combustion wave propagation process.

Note: Use the X-Y paperless recorder to record and draw the time-temperature curve. The maximum temperature value in the time-temperature curve is the combustion temperature. The time difference between the two curves when the combustion temperature appears is △t, and the combustion wave rate is 20mm/△ t.

Further, the diameter of the small holes on both sides of the cylindrical sample is 2~5mm, the depth is 7~9mm, and the distance between the two holes is 20~30mm; the wire diameter of the W-3%Re/W-25%Re thermocouple It is 0.08~0.12mm.

Description: By inserting a thermocouple to measure the combustion process of the sample, and using a paperless recorder to draw a time-temperature curve, the maximum value of the combustion temperature can be accurately measured. By adjusting the size of the holes on both sides of the cylindrical sample and the parameters of the thermocouple, It can adapt to different experimental requirements and can be repeated, making the measurement results more reliable.

Further, the aggregate in the functional filler is sintered or fused synthetic spinel, sintered or fused magnesite, SiC, quartz, chromite, AZS, Silons, calcium aluminate, vermiculite , foamed aluminum, perlite, calcium aluminate porous polymeric materials, one or more combinations thereof.

Description: Synthetic spinel, SiC, and quartz can significantly improve the wear resistance and extend the service life of the material; cordierite, AZS, and calcium aluminate can improve the corrosion resistance of the material and adapt to corrosive environments such as acid and alkali media; choose Porous polymer materials, aluminum foam, and perlite can adjust the pore structure of the material and increase the lightweight performance of the material, thereby improving the thermal insulation performance of the material and reducing the weight load.

Further, in terms of mass percentage, the fibers in the functional filler include: 4% to 6% organic fibers and the balance steel fibers; the organic fibers are polypropylene fibers.

Note: Adding polypropylene fiber can accelerate the drying process, minimize heat stress damage, and shorten drying and firing time; adding steel fiber can increase the tension, compression and bending strength of the castable, enhance resistance to crack growth and Resistance to peeling.

Further, the functional filler in step S3 also includes refractory auxiliary materials. The preparation method of the refractory auxiliary materials is: in terms of mass percentage, 5 to 9% flake graphite, 3 to 5% phenolic resin, 1 to 2% Si powder, 1 to 2% Al powder, 0 to 8% calcium hexaaluminate fine powder and the remaining fused magnesia fine powder are premixed in a polyurethane barrel for 2 to 4 hours to obtain refractory raw materials. After mixing and grinding, refractory auxiliary materials are obtained.

Description: Flake graphite has good high temperature resistance, can remain stable in high temperature environments, and enhances the heat resistance of refractory materials; flake graphite and phenolic resin can provide certain antioxidant properties, effectively preventing oxidation reactions from damaging materials; add Si powder and Al powder can provide active metal elements, promote reactions, and increase the stability and service life of the material; calcium hexaaluminate fine powder and fused magnesia fine powder can improve the structure of the material, increase porosity and density, Improve the mechanical strength and pressure resistance of refractory auxiliary materials.

Further, the mixing method is: first add the fused magnesia fine powder into the mixer and dry mix for 4 to 10 minutes, then pour in phenolic resin accounting for 60 to 70% of the total phenolic resin mass ratio and mix for 4 to 10 minutes, and mix the refractory The raw materials are divided into four parts with equal mass ratio, and poured into the mixer in batches. Each time a part is added, mix for 4 to 10 minutes. Finally, add the remaining phenolic resin binder, mix for 3 to 4 hours, and mold at 200 to 240°C. The refractory auxiliary material was obtained by curing for 24 hours.

Note: Adding refractory raw materials in batches according to equal mass ratio and mixing will help control the reaction process, promote the reaction and combination between the components, and ensure the complete reaction and thermal curing of the material; after molding, the refractory auxiliary materials will be at a lower temperature Long-term curing at high temperatures helps to improve the curing effect and the structural stability of the material; through the above mixing methods and curing conditions, the integrity and uniformity of the molding and curing of the refractory auxiliary materials can be ensured, with good strength and Fire resistance.

Compared with the prior art, the beneficial effects of the present invention are:

The invention adds high contents of MgO and Al ₂ O ₃ , which can effectively resist the erosion of alkaline media and improve alkali resistance; the combination of cordierite particles and aluminate in the main material, and the heavy weight in the functional filler The addition of calcium hexaaluminate and Secar71 cement can significantly improve the wear resistance of the material and extend its service life; alumina, calcium carbonate, calcium peroxide and aluminum powder, as well as fibers and aggregates in functional fillers, can improve the material's wear resistance. Excellent corrosion resistance, adaptable to various corrosive media and corrosion conditions; the composition ratio of the alkali-resistant, wear-resistant and corrosion-resistant castable of the present invention can provide excellent alkali resistance, wear resistance and corrosion resistance, and at the same time have good Process performance, suitable for application requirements in high alkali and abrasive environments.

Detailed ways

The present invention will be described in further detail below in conjunction with specific embodiments to better reflect the advantages of the present invention.

Example 1

Example 1 is used to illustrate the component ratio of an alkali-resistant, wear-resistant and corrosion-resistant castable designed by the present invention. The content is as follows:

An alkali-resistant, wear-resistant and corrosion-resistant castable. In terms of weight percentage, the proportion of the corrosion-resistant castable is: 27.5% MgO, 60% Al ₂ O ₃ , 12.5% auxiliary materials, 10% functional filler, 0.125% water reducing agent and the remainder of the main ingredient;

The main ingredients include, by weight percentage: 6% cordierite particles, 37.5% tricalcium aluminate, 25% dicalcium aluminate and the balance water;

The auxiliary materials include, by weight percentage: 27.5% alumina, 12.5% calcium carbonate, 7.5% calcium peroxide, 4% aluminum powder and the balance calcium citrate tetrahydrate;

The functional filler includes, by weight percentage: 25% heavy calcium hexaaluminate, 17.5% Secar71 cement, 9% active α-Al ₂ O ₃ powder, 2% fiber and the remainder of aggregate; the bone The material is electro-fused synthetic spinel.

Example 2

Example 2 is designed based on the solution in Example 1, mainly to illustrate another alkali-resistant, wear-resistant and corrosion-resistant castable with different component ratios, including: 25% MgO, 65% Al ₂ O ₃ , 10% auxiliary materials, 5% functional fillers, 0.1% water reducing agent and the remainder main materials;

The main ingredients include, by weight percentage: 5% cordierite particles, 35% tricalcium aluminate, 20% dicalcium aluminate and the balance water;

The auxiliary materials include, by weight percentage: 25% alumina, 10% calcium carbonate, 7% calcium peroxide, 3% aluminum powder and the balance calcium citrate tetrahydrate;

The functional filler includes, by weight percentage: 20% heavy calcium hexaaluminate, 15% Secar71 cement, 8% active α-Al ₂ O ₃ powder, 1% fiber and the balance aggregate.

Example 3

Example 3 is designed based on the solution in Example 1, mainly to illustrate another alkali-resistant, wear-resistant and corrosion-resistant castable with different component ratios, including: 30% MgO, 75% Al ₂ O ₃ , 15% auxiliary materials, 15% functional fillers, 1.5% water reducing agent and the remaining main materials;

The main ingredients include, by weight percentage: 7% cordierite particles, 40% tricalcium aluminate, 30% dicalcium aluminate and the balance water;

The auxiliary materials include, by weight percentage: 30% alumina, 15% calcium carbonate, 8% calcium peroxide, 5% aluminum powder and the balance calcium citrate tetrahydrate;

The functional filler includes, by weight percentage: 30% heavy calcium hexaaluminate, 20% Secar71 cement, 10% active α-Al ₂ O ₃ powder, 3% fiber and the balance aggregate.

Example 4

Example 4 is used to illustrate the preparation method of an alkali-resistant, wear-resistant and corrosion-resistant castable designed in Example 1 of the present invention. The content is as follows:

S1. Preparation of main ingredients

Mix cordierite particles, tricalcium aluminate, dicalcium aluminate and water according to the formula proportion, and stir for 1.15h to obtain the main ingredient;

S2. Preparation of auxiliary materials

Weigh alumina, calcium carbonate, calcium peroxide, aluminum powder and calcium citrate tetrahydrate according to the formula proportion, put them into a mortar and mechanically mix for 50 minutes to obtain a mixture, and put the mixture into a crucible with a bulk density of 1.1 g/cm ³ , place a 1mm thick Ti-C sheet on the mixture as an igniter, then put the crucible into the combustion synthesis reactor, make the W wire in the reactor contact with Ti-C, and turn on the power. W wire generates heat to ignite Ti-C. During the combustion synthesis process, the combustion temperature of the reaction system is measured by a W-3%Re/W-25%Re thermocouple. After the combustion wave spreads, the auxiliary materials are obtained; the thermocouple measures the temperature of the reaction system. The combustion temperature method is as follows: press the mixture uniaxially and bidirectionally in a steel mold into a cylindrical sample with a relative density of 70%; drill a small hole on both sides of the cylindrical sample and use W-3%Re/W-25 One end of the %Re thermocouple is inserted into the two holes, and the other end of the thermocouple is connected to the XY paperless recorder. The sample is ignited in the reaction chamber, and the XY paperless recorder is used to measure and record the combustion wave spread process; the cylindrical sample The diameter of the small holes on both sides is 3.5mm, the depth is 8mm, and the distance between the two holes is 25mm; the wire diameter of the W-3%Re/W-25%Re thermocouple is 0.1mm;

S3. Preparation of functional fillers

According to the formula proportion, heavy calcium hexaaluminate, Secar71 cement, active α-Al ₂ O ₃ powder, fiber and aggregate are kept at a temperature of 1575°C for 3 hours, and stirred evenly to obtain functional filler; the aggregate is Equivalent mass proportions of fused synthetic spinel, fused magnesite, cordierite, SiC, quartz, and chromite; the fibers in the functional filler include: 5% organic fibers and the balance steel fibers; The above-mentioned organic fiber adopts polypropylene fiber;

S4, green body forming and drying

Pour MgO, Al ₂ O ₃ , auxiliary materials, functional fillers and main materials into a cement mortar mixer according to the formula proportion for dry mixing, then add water reducing agent and water and stir for 10 minutes before placing it into the molding test mold. The amount of water added is 22.5% of the total mass of the corrosion-resistant castable; use a cement forming vibrating table to vibrate for 4 minutes to obtain a green body; after curing the green body in moisture for 48 hours, dry it at a temperature of 120°C for 30 hours to obtain a dried green body; as described MgO and Al ₂ O ₃ are added in the form of magnesium oxide micropowder with a mass percentage of 25% and the balance magnesia-aluminum spinel mixed with various particle sizes; the particle size d50 of the magnesium oxide micropowder is 5 μm; the magnesium-aluminum tip The crystal is composed of magnesia-aluminum spinel particles, fine powder and micro-powder, and its mass ratio is: 6:3:2; the magnesia-aluminum spinel particle size is: 4.1~4mm, 1.1~1mm and 1mm, and its mass The ratio is: 2:1:1;

The particle size of the magnesium-aluminum spinel fine powder is 0.088mm; the particle size of the magnesia-aluminum spinel powder is 0.01mm;

S5, heat treatment

The dried green body is placed in a muffle furnace, heat-treated at a temperature of 1400°C, kept at the temperature for 4.5 hours, and then cooled to room temperature to prepare an anti-corrosion castable.

Experimental example

In this experimental example, the preparation method in the above-mentioned Example 4 is used as the control group. Different experimental groups are designed by changing different process parameters in the preparation method to verify the performance of the anti-sedimentation foaming and discharging agent. The design plan is as follows:

Control group: adopt the preparation method and process parameters in Example 4;

Experimental group 1: Except for the following, other parameters are the same as the control group: in terms of weight percentage, the proportion of corrosion-resistant castables is: 25% MgO, 65% Al ₂ O ₃ , 10% auxiliary materials, 5% Functional filler, 0.1% water reducing agent and the balance of main ingredients;

Experimental Group 2: Other parameters are the same as the control group except for the following: In terms of weight percentage, the proportion of corrosion-resistant castables is: 30% MgO, 75% Al ₂ O ₃ , 15% auxiliary materials, 15% Functional filler, 1.5% water reducing agent and the remainder of the main ingredient;

Experimental group 3: Other parameters are the same as the control group except for the following: the main ingredients include: 5% cordierite particles, 35% tricalcium aluminate, 20% dicalcium aluminate and the rest by weight. amount of water;

Experimental Group 4: Other parameters are the same as Experimental Group 4 except for the following: the main ingredients include: 7% cordierite particles, 40% tricalcium aluminate, 30% dicalcium aluminate and remaining water;

Experimental group 5: Other parameters are the same as the control group except for the following: the auxiliary materials include: 25% alumina, 10% calcium carbonate, 7% calcium peroxide, 3% aluminum powder and the rest by weight. amount of calcium citrate tetrahydrate;

Experimental Group 6: Other parameters are the same as Experimental Group 5 except for the following: the auxiliary materials include by weight: 30% alumina, 15% calcium carbonate, 8% calcium peroxide, 5% aluminum powder and the balance calcium citrate tetrahydrate;

Experimental Group 7: Other parameters are the same as the control group except for the following: the functional filler also includes refractory auxiliary materials. The preparation method of the refractory auxiliary materials is: in terms of mass percentage, 5% flake graphite, 3% Phenolic resin, 1% Si powder, 1% Al powder and the remaining fused magnesia fine powder are premixed in a polyurethane barrel for 2 hours to obtain refractory raw materials. The refractory raw materials are mixed and milled to obtain refractory auxiliary materials; the mixing is The method is: first add the fused magnesia fine powder into the mixer and dry mix for 4 minutes, then pour in the phenolic resin accounting for 60% of the total phenolic resin mass ratio and mix for 4 minutes. Divide the refractory raw materials into four parts with equal mass ratio, and divide them into batches. Pour it into a mixer and mix for 4 minutes each time. Finally, add the remaining phenolic resin binder and mix for 3 hours. After molding, cure at 200°C for 24 hours to obtain refractory auxiliary materials.

Experimental group 8: Other parameters are the same as experimental group 7 except for the following: the functional filler also includes refractory auxiliary materials. The preparation method of the refractory auxiliary materials is: in terms of mass percentage, 9% flake graphite, 5% Phenolic resin, 2% Si powder, 2% Al powder, 8% calcium hexaaluminate fine powder and the remaining fused magnesia fine powder were premixed in a polyurethane barrel for 4 hours to obtain refractory raw materials. After mixing, the refractory auxiliary materials are obtained; the mixing method is: first add the fused magnesia fine powder into the mixer and dry mix for 10 minutes, then pour in the phenolic resin accounting for 70% of the total phenolic resin mass ratio and mix for 10 minutes, and divide the refractory raw materials into Four parts with equal mass ratio were poured into the mixer in batches. Each time a part was added, the mixture was mixed for 10 minutes. Finally, the remaining phenolic resin binder was added, mixed for 4 hours, and cured at 240°C for 24 hours after molding to obtain refractory auxiliary materials.

Anti-erosion castable performance testing

Nine different corrosion-resistant castables were prepared using the methods of the control group and experimental group 1 to 8, and the performance of the prepared corrosion-resistant castables was tested. The corrosion tests were conducted at 800°C, 1000°C, and 1200°C for 30 hours. , the specific test results are shown in Table 1;

Table 1: Performance test table of 9 different corrosion-resistant castables

The following conclusions can be drawn from the data in Table 1:

1. Explore the effects of different parameters of the corrosion-resistant castable ratio on the performance of the prepared corrosion-resistant castables.

Comparing the control group with experimental group 1 and experimental group 2, it can be seen that in the two sets of experiments, the performance of experimental group 2 is significantly better than that of the control example. Overall, the apparent porosity of experimental group 1 has the highest change at different temperatures. , it can be seen that increasing the proportioning parameters can enhance the comprehensive performance of the composite material, and the corrosion resistance is significantly improved.

2. Explore the influence of different parameter ratios of the main raw materials on the performance of the prepared corrosion-resistant castables.

When comparing the control group with experimental group 3 and experimental group 4, it can be seen that among the three groups of experiments, the control example has the best performance and the best parameter ratio. Experimental group 3 is better than experimental group 4.

3. Explore the influence of different parameter ratios of preparation auxiliary materials on the performance of the prepared corrosion-resistant castables.

When comparing the control group with experimental group 5 and experimental group 6, it can be seen that among the three groups of experiments, the apparent porosity and density of experimental group 5 changed the smallest, and the control group was better than experimental group 6. When preparing anti-erosion castables , the parameter ratio of excipients in Experimental Group 5 can be used with priority.

4. Explore the impact of different process parameters for preparing refractory auxiliary materials on the performance of the prepared corrosion-resistant castables.

When comparing the control group with experimental group 7 and experimental group 8, the difference is not obvious. The anti-erosion castable has the best corrosion resistance under the parameter ratio of experimental group 7. Compared with the control group and experimental group 8, experimental group 8 The corrosion resistance is better.

Claims (10)

1. The alkali-resistant wear-resistant corrosion-resistant castable is characterized by comprising the following components in percentage by weight: 25 to 30 percent of MgO and 65 to 75 percent of Al ₂ O ₃ 10-15% of auxiliary materials, 5-15% of functional filler, 0.1-1.5% of water reducer and the balance of main materials;

the main materials comprise the following components in percentage by weight: 5-7% of cordierite particles, 35-40% of tricalcium aluminate, 20-30% of dicalcium aluminate and the balance of water;

the auxiliary materials comprise the following components in percentage by weight: 25-30% of aluminum oxide, 10-15% of calcium carbonate, 7-8% of calcium peroxide, 3-5% of aluminum powder and the balance of calcium citrate tetrahydrate;

the functional filler comprises the following components in percentage by weight: 20-30% of calcium hexaaluminate, 15-20% of Secar71 cement and 8-10% of active alpha-Al ₂ O ₃ Micro powder, 1-3% of fiber and the balance of aggregate.

2. The method for preparing the alkali-resistant wear-resistant corrosion-resistant castable, as set forth in claim 1, comprising the steps of:

s1, preparing a main material

Mixing cordierite particles, tricalcium aluminate, dicalcium aluminate and water according to a formula ratio, and stirring for 0.8-1.5 h to obtain a main material;

s2, preparing auxiliary materials

Weighing aluminum oxide, calcium carbonate, calcium peroxide, aluminum powder and calcium citrate tetrahydrate according to the formula proportion, mechanically mixing in a mortar for 45-55 min to obtain a mixture, and filling the mixture into a crucible with the bulk density of 1-1.2 g/cm ³ Placing a Ti-C sheet with the thickness of 0.8-1.2 mm on the mixture as an ignition agent, then placing a crucible into a combustion synthesis reactor, enabling a W wire in the reactor to be in contact with Ti-C, switching on a power supply to enable the W wire to heat and ignite the Ti-C, measuring the combustion temperature of a reaction system through a W-3%Re/W-25%Re thermocouple in the combustion synthesis process, and obtaining auxiliary materials after combustion waves spread;

s3, preparing functional filler

Mixing heavy calcium hexaaluminate, secar71 cement and active alpha-Al according to the formula proportion ₂ O ₃ The micro powder, the fiber and the aggregate are kept at the temperature of 1400-1750 ℃ for 3 hours and are stirred uniformly to obtain the functional filler;

s4, forming and drying the blank

MgO and Al are mixed according to the formula proportion ₂ O ₃ Pouring the auxiliary materials, the functional filler and the main materials into a cement mortar stirrer for dry mixing, adding a water reducing agent and water for stirring for 5-15 min, and then placing into a molding test mold, wherein the water addition amount is 20-25% of the total mass of the erosion resistant castable; vibrating for 2-6 min by using a cement molding vibrating table to prepare a blank; after the green body is subjected to wet curing for 48 hours, drying for 24-36 hours at the temperature of 110-130 ℃ to obtain a dried green body;

s5, heat treatment

And (3) placing the dried blank in a muffle furnace, performing heat treatment at the temperature of 1100-1750 ℃, preserving heat for 3-6 h, and cooling to room temperature to obtain the anti-erosion castable.

3. The method for preparing alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 2, wherein the MgO and Al in step S4 are as follows ₂ O ₃ The magnesium aluminate powder is added in the form of 20-30% of magnesium oxide micro powder by mass percent and the balance of magnesium aluminate spinel mixed by various granularities.

4. The method for preparing alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 3, wherein the particle size d50 of the magnesium oxide micro powder is 5 μm; the magnesia-alumina spinel consists of magnesia-alumina spinel particles, fine powder and micro powder, and the mass ratio of the magnesia-alumina spinel particles to the micro powder is as follows: 6:3:2; the particle size of the magnesia alumina spinel is as follows: 5-3 mm, 3-1 mm and less than or equal to 1mm, and the mass ratio is as follows: 2:1:1, a step of; the granularity of the magnesia-alumina spinel fine powder is less than or equal to 0.088mm; the granularity of the magnesia-alumina spinel micropowder is less than or equal to 0.010mm.

5. The method for preparing the alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 2, wherein the method for measuring the combustion temperature of the reaction system by the thermocouple in the step S2 is as follows: uniaxially and bidirectionally pressing the mixture into a cylindrical sample with the relative density of 60-80% in a steel die; and drilling a small hole on two sides of the cylindrical sample, inserting one end of a W-3%Re/W-25%Re thermocouple into the two holes, connecting the other end of the thermocouple with an X-Y paperless recorder, igniting the sample in a reaction chamber, and measuring and recording the combustion wave spreading process by using the X-Y paperless recorder.

6. The method for preparing the alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 5, wherein the diameter of the small holes on the two sides of the cylindrical sample is 2-5 mm, and the distance between the two holes with the depth of 7-9 mm is 20-30 mm; the wire diameter of the W-3%Re/W-25%Re thermocouple is 0.08-0.12 mm.

7. The method for preparing the alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 1, wherein the aggregate in the functional filler is one or more of sintered or fused synthetic spinel, sintered or fused magnesia, siC, quartz, chromite, AZS, silons, calcium aluminate, vermiculite, foamed aluminum, perlite and calcium aluminate porous polymeric materials.

8. The method for preparing the alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 1, wherein the fibers in the functional filler comprise, in mass percent: 4-6% of organic fiber and the balance of steel fiber; the organic fiber adopts polypropylene fiber.

9. The method for preparing the alkali-resistant, wear-resistant and corrosion-resistant castable according to claim 1, wherein the functional filler in the step S3 further comprises a refractory auxiliary material, and the method for preparing the refractory auxiliary material comprises the following steps: according to the mass percentage, 5 to 9 percent of crystalline flake graphite, 3 to 5 percent of phenolic resin, 1 to 2 percent of Si powder, 1 to 2 percent of Al powder, 0 to 8 percent of calcium hexaluminate fine powder and the balance of fused magnesia fine powder are premixed in a polyurethane barrel for 2 to 4 hours to obtain a refractory raw material, and the refractory raw material is mixed and ground to obtain a refractory auxiliary material.

10. The method for preparing the alkali-resistant wear-resistant corrosion-resistant castable according to claim 9, wherein the mixing and grinding method is as follows: firstly adding fused magnesia fine powder into a stirrer to dry mix for 4-10 min, then pouring phenolic resin accounting for 60-70% of the total phenolic resin mass ratio to mix for 4-10 min, dividing the fireproof raw material into four parts with equal mass ratio, pouring the four parts into the stirrer in batches, mixing for 4-10 min each time when adding one part, finally adding the residual phenolic resin binder, mixing for 3-4 h, and solidifying for 24h at 200-240 ℃ after molding to obtain the fireproof auxiliary material.