阅读说明：本技术 一种耐火材料砖及其制备方法 (Refractory brick and preparation method thereof ) 是由 贺延奎 于 2020-07-20 设计创作，主要内容包括：本发明公开了一种耐火材料砖,由以下重量份的原料制成：大颗粒红柱石、小颗粒红柱石、大颗粒熔融石英、中颗粒熔融石英、小颗粒熔融石英、石墨烯片改性纳米氧化铝、C@SiC晶须粉末、纳米氧化铝、纳米氧化钛、纳米氧化钒、结合剂。本发明通过分级混料,使得物料颗粒充分活化,同时采用分层铺料,使物料层之间形成了有序的功能结构,使得耐火材料砖具有良好的抗腐蚀性能、抗渣性能和抗水化性能,由外层向内层颗粒粒度逐层增大,经压制及烧结后形成抗裂纹能力逐步增强的骨架结构,使得耐火材料砖具有高的耐压强度和韧性。(The invention discloses a refractory brick which is prepared from the following raw materials in parts by weight: large-particle andalusite, small-particle andalusite, large-particle fused quartz, medium-particle fused quartz, small-particle fused quartz, graphene sheet modified nano alumina, C @ SiC whisker powder, nano alumina, nano titanium oxide, nano vanadium oxide and a bonding agent. According to the invention, material particles are fully activated by grading and mixing, and meanwhile, an ordered functional structure is formed between material layers by adopting layering and paving, so that the refractory brick has good corrosion resistance, slag resistance and hydration resistance, the particle size of the particles from the outer layer to the inner layer is increased layer by layer, and a skeleton structure with gradually enhanced crack resistance is formed after pressing and sintering, so that the refractory brick has high compressive strength and toughness.)

1. The refractory brick is characterized by being prepared from the following raw materials in parts by weight: 6-12 parts of large-particle andalusite, 9-18 parts of small-particle andalusite, 15-30 parts of large-particle fused quartz, 5-10 parts of medium-particle fused quartz, 10-20 parts of small-particle fused quartz, 5-9 parts of graphene sheet modified nano alumina, 7-12 parts of C @ SiC whisker powder, 8-16 parts of nano alumina, 3-5 parts of nano titanium oxide, 2-3 parts of nano vanadium oxide and 4-8 parts of a binding agent.

2. The refractory brick according to claim 1, wherein the large granular andalusite has a grain size of 1 to 3mm, and the small granular andalusite has a grain size of 0.1 to 1 mm; the particle size of the large-particle fused quartz is 1-3 mm, the particle size of the medium-particle fused quartz is 0.1-1 mm, and the particle size of the small-particle fused quartz is 400 meshes; the particle sizes of the nano aluminum oxide, the nano titanium oxide and the nano vanadium oxide are all 200-500 nm.

3. The refractory brick according to claim 1, wherein the graphene sheet modified nano alumina is prepared by the following steps: adding 0.25-3.0 wt% of graphene sheets into the nano alumina powder, putting the nano alumina powder into a high-frequency induction heating machine, and carrying out heat treatment for 1-2 h at 1500 ℃.

4. The refractory brick according to claim 1, wherein the C @ SiC whisker powder is prepared by a method comprising: s1, baking the SiC whisker powder in an air atmosphere, and soaking the SiC whisker powder in an HF solution; s2, using NiCl₂▪6H₂Preparing NiCl by O particles and deionized water₂A solution; s3, configuring NiCl to the step two₂Adding the SiC crystal whiskers treated in the step one into the solution, stirring in water bath, drying, and uniformly grinding to obtain NiCl₂Coating SiC whisker powder; and S4, performing high-temperature treatment under the protection of inert gas, removing impurities, drying and grinding to obtain C @ SiC whisker powder.

5. The refractory brick of claim 1 wherein the bonding agent comprises bonding agent a and bonding agent B; the binding agent A is one or more of polyaluminium chloride, dextrin and polyethylene glycol; the binder B is alkaline nano silica sol.

6. A method for producing the refractory brick according to any one of claims 1 to 5, comprising the steps of:

(1) preparing materials: uniformly mixing large-particle andalusite and large-particle fused quartz, grinding by adopting a shock ball mill, drying, adding a bonding agent A into the dried material, and stirring to wet the surface of the material to obtain a material 1;

uniformly mixing small-particle andalusite and medium-particle fused quartz, grinding by using a shock ball mill, and drying to obtain a material 2;

uniformly mixing small-particle fused quartz, graphene sheet modified nano alumina and C @ SiC whisker powder, grinding by using a shock type ball mill, and drying to obtain a material 3;

uniformly mixing nano aluminum oxide, nano titanium oxide and nano vanadium oxide, grinding by using a nano grinder, drying, adding a bonding agent B into the dried material, and stirring to wet the surface of the material to obtain a material 4;

(2) spreading materials: laying a layer of material 4 at the bottom of the mold, then laying a layer of material 3, then laying a layer of material 2, finally laying a layer of material 1, then laying a layer of material 2, then laying a layer of material 3, and laying a layer of material 4 on the uppermost layer;

(3) blank preparation: pressing and forming to obtain a refractory brick blank;

(4) and (3) sintering: baking the refractory brick blank at 110-130 ℃ for 4-12 h, then sintering at 1200-1500 ℃ for 3-5 h in a high-temperature furnace, and naturally cooling and cutting after sintering to obtain the refractory brick.

7. The preparation method of the refractory brick according to claim 6, wherein the concrete operation of grinding by using a jar ball mill in the step (1) is as follows: adding a grinding aid which is 2 times of the weight of the material, grinding balls which are half of the weight of the material, grinding by using a shock type ball mill, and drying the ground material at 60-80 ℃.

8. The preparation method of the refractory brick according to claim 6, wherein a grinding aid used for grinding by using a shock type ball mill in the step (1) is absolute ethyl alcohol, and the grinding time is 0.5-2 h; grinding aid used for grinding by adopting a nano grinder is an oleic acid solution with the mass fraction of 40-60%, and the grinding time is 2-4 h.

9. The method for producing the refractory brick according to claim 6, wherein the strength of the pressing in the step (3) is 60 to 130 MPa.

Technical Field

The invention relates to the technical field of refractory materials, in particular to a refractory material brick and a preparation method thereof.

Background

The refractory material is inorganic non-metal material or product with refractoriness not lower than 1580 deg.c, and is used mainly in blast furnace, converter and coke oven in iron making industry, converter, secondary refining furnace, continuous casting, etc. in steel making industry, cement kiln, glass and non-ferrous metal kiln, etc.

With the continuous innovation of the industry technology, the comprehensive performance requirements of various industries on the used refractory materials are also improved. The apparent porosity can be reduced by selecting the materials with medium and small particle sizes, the corrosion resistance and the water resistance of the refractory material are improved, but the compressive strength and the toughness are obviously reduced due to the weak blocking capability of the medium and small particles to cracks, so that the service life of the refractory material is shortened. Therefore, the research and development of the refractory material product which has low apparent porosity, good toughness, hydration resistance and corrosion resistance and long service cycle is of great significance.

Disclosure of Invention

Aiming at the defects of the existing refractory material, the invention provides the refractory material brick with good toughness, strong corrosion resistance and long service cycle. The invention also provides a preparation method of the refractory brick.

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

a refractory brick is prepared from the following raw materials in parts by weight: 6-12 parts of large-particle andalusite, 9-18 parts of small-particle andalusite, 15-30 parts of large-particle fused quartz, 5-10 parts of medium-particle fused quartz, 10-20 parts of small-particle fused quartz, 5-9 parts of graphene sheet modified nano alumina, 7-12 parts of C @ SiC whisker powder, 8-16 parts of nano alumina, 3-5 parts of nano titanium oxide, 2-3 parts of nano vanadium oxide and 4-8 parts of a binding agent.

Further, the particle size of the large-particle andalusite is 1-3 mm, and the particle size of the small-particle andalusite is 0.1-1 mm.

Furthermore, the particle size of the large-particle fused quartz is 1-3 mm, the particle size of the medium-particle fused quartz is 0.1-1 mm, and the particle size of the small-particle fused quartz is 400 meshes.

Further, the preparation method of the graphene sheet modified nano aluminum oxide comprises the following steps: adding 0.25-3.0 wt% of graphene sheets into the nano alumina powder, putting the nano alumina powder into a high-frequency induction heating machine, and carrying out heat treatment for 1-2 h at 1500 ℃.

Further, the preparation method of the C @ SiC whisker powder comprises the following steps: s1, baking the SiC whisker powder in an air atmosphere, and soaking the SiC whisker powder in an HF solution; s2, using NiCl₂·6H₂Preparing NiCl by O particles and deionized water₂A solution; s3, configuring NiCl to the step two₂Adding the SiC crystal whiskers treated in the step one into the solution, stirring in water bath, drying, and uniformly grinding to obtain NiCl₂Coating SiC whisker powder; and S4, performing high-temperature treatment under the protection of inert gas, removing impurities, drying and grinding to obtain C @ SiC whisker powder.

Furthermore, the particle sizes of the nano aluminum oxide, the nano titanium oxide and the nano vanadium oxide are all 200-500 nm.

Further, the binding agent comprises binding agent a and binding agent B; the binding agent A is one or more of polyaluminium chloride, dextrin and polyethylene glycol; the binder B is alkaline nano silica sol.

A preparation method of a refractory brick comprises the following steps:

(1) preparing materials: uniformly mixing large-particle andalusite and large-particle fused quartz, grinding by using a shock type ball mill, drying, adding 3-5 parts of a bonding agent A into the dried material, and stirring to wet the surface of the material to obtain a material 1;

uniformly mixing small-particle andalusite and medium-particle fused quartz, grinding by using a shock ball mill, and drying to obtain a material 2;

uniformly mixing small-particle fused quartz, graphene sheet modified nano alumina and C @ SiC whisker powder, grinding by using a shock type ball mill, and drying to obtain a material 3;

uniformly mixing nano aluminum oxide, nano titanium oxide and nano vanadium oxide, grinding by using a nano grinder, drying, adding 1-3 parts of a binding agent B into the dried material, and stirring to wet the surface of the material to obtain a material 4;

(2) spreading materials: laying a layer of material 4 at the bottom of the mold, then laying a layer of material 3, then laying a layer of material 2, finally laying a layer of material 1, then laying a layer of material 2, then laying a layer of material 3, and laying a layer of material 4 on the uppermost layer;

(3) blank preparation: pressing and forming to obtain a refractory brick blank;

(4) and (3) sintering: baking the refractory brick blank at 110-130 ℃ for 4-12 h, then sintering at 1200-1500 ℃ for 3-5 h in a high-temperature furnace, and naturally cooling and cutting after sintering to obtain the refractory brick.

Further, the concrete operation of grinding by adopting the jar ball mill in the step (1) is as follows: adding a grinding aid which is 2 times of the weight of the material, grinding balls which are half of the weight of the material, grinding by using a shock type ball mill, and drying the ground material at 60-80 ℃.

Further, a grinding aid used for grinding by using the shock type ball mill in the step (1) is absolute ethyl alcohol, and the grinding time is 0.5-2 hours.

Further, in the step (1), grinding aid used for grinding by using a nano grinder is an oleic acid solution with the mass fraction of 40% -60%, and the grinding time is 2-4 h.

Further, the drying temperature of the ground material in the step (1) is 60-80 ℃.

Further, the pressing strength in the step (3) is 60-130 MPa.

The method adopts the method of graded mixing and grinding, the components with approximate grain sizes are uniformly mixed and ground, the material particles can fully contact with the grinding ball, the phenomena of bottom sinking and agglomeration can not occur, along with the increase of grinding time, the surface of the material particles can have some abrasion wound surfaces with mechanical damage, so that new activation points are generated, and simultaneously, defects and cracks are generated in the particles, thus being beneficial to the crystal lattice activation in the sintering process and forming mullite.

The invention adopts a layered paving method, breaks through the conventional grinding and mixing method to ensure that the particle size and the distribution of each material are as uniform as possible, because the materials are paved from bottom to top in the sequence of a nano particle layer, a small particle layer, a middle particle layer, a large particle layer, a middle particle layer and a material 1, the large particle layer of which the surface is soaked with a binding agent, and the middle particle layer of which the material 2 are positioned in the middle of a refractory brick, the middle particles are combined with the large particles into a whole through the action of the binding agent and are used as a framework of the refractory material to ensure the mechanical strength of the refractory brick, the small particle layer of the material 3 contains graphene sheet modified nano alumina and C @ SiC whisker powder, the large particle layer and the middle particle layer can be combined together in the calcining process, and the nano particle layer of the material 4 can improve the hydration resistance of the refractory material through the toughening effect of the, meanwhile, the nano particle layer wetted by the silica sol has a compact structure after being pressed and sintered, and can reduce the introduction of impurities, so that the refractory material brick has good hydration resistance and corrosion resistance.

Andalusite used in the invention can undergo irreversible crystal transformation in the sintering process of a refractory brick blank so as to form mullite with a mullite network, a large granular layer and a middle granular layer in the layering and paving process respectively contain large andalusite particles with the grain size of 1-3 mm and small andalusite particles with the grain size of 0.1-1 mm, and the mullite network transformed from the andalusite in the sintering process penetrates through the large granular layer and the middle granular layers on two sides to form an integral body, so that the prepared refractory brick has the refractory performance of over 1800 ℃, and has the advantages of large mechanical strength, strong thermal impact resistance and slag resistance, shock and shock resistance, high load conversion point, excellent chemical stability and chemical corrosion resistance.

The fused quartz used in the invention is divided into three stages according to the particle size, and the large-particle fused quartz and the large-particle andalusite are mixed and ground and then wetted by a bonding agent to be used as a material 1, so that the thermal expansion rate and the chemical stability of a refractory brick framework can be greatly reduced, and the comprehensive performance of the refractory brick is improved; the viscosity of the liquid phase of the fused quartz at high temperature is very high, so the erosion and scouring resistance at high temperature is very good, the medium-particle fused quartz and the small-particle fused quartz are distributed in a layered manner, and the small-particle fused quartz is distributed near the outer side, so that the corrosion resistance and the high-temperature erosion resistance of the refractory brick can be greatly improved after being sintered with the nano particle layer.

According to the graphene sheet modified nano-alumina, the reinforcing and toughening modes of the graphene are mainly particle pinning, graphene pulling-out and crack bridging through observation of a high-power transmission electron microscope, and the introduction of the graphene can inhibit the growth of nano-alumina grains. The C @ SiC whisker powder is used as a material of a small particle layer and is tightly combined with a surface layer, the C @ SiC whisker powder is of a core-shell structure with graphite wrapping silicon carbide, the silicon carbide can still keep high bonding strength at high temperature, the hardness is high, the elastic film amount is large, a refractory material can be prevented from being eroded by an acid-base solution, the graphite layer can prevent the silicon carbide from being oxidized at high temperature, so that the situation that the structure is loose due to a thick oxidation layer generated inside the material is avoided, the toughening effect of the C @ SiC whisker powder can be kept for a long time, and the service life of a refractory brick is prolonged.

The bonding mechanism of the silica sol is SiO in the sol₂The particles are subjected to dehydration condensation reaction through polar siloxy (-Si-O-) on the surface to form SiO in the silica sol₂The particles are linked together to form a stable three-dimensional network structure, which in turn bonds the small particle layer and the nanoparticle layer together to provide early strength to the refractory brick. The alkaline nano silica sol as a binding agent can overcome the defect that other binding agents are too sensitive to temperature, and improve the medium-temperature strength of the material; in addition, the alkaline nano silica sol is used as a bonding agent, so that the introduction of impurities can be reduced, and the high-temperature performance and the corrosion resistance of the material can be improved.

Vanadium oxide (V)₂O₅) The growth of mullite whiskers is promoted, and the method is mainly embodied in two aspects: firstly, vanadium oxide volatilizes at high temperature to promote a mullite gas-solid growth mechanism; and vanadium oxide has an activating effect, can increase the lattice defect of alumina, activate the lattice and promote the formation of mullite. Research shows that the addition of a proper amount of vanadium oxide is beneficial to the formation of mullite, and excessive addition of vanadium oxide promotes the increase of the scaly (blocky) mullite content, so that the strength of the material is reduced.

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

(1) according to the preparation method of the refractory brick, the material particles are fully activated through grading and mixing, meanwhile, the material layers form an ordered functional structure by adopting layering and paving, and the large particles and the medium particle layer are used as frameworks of the refractory brick, so that the mechanical strength of the refractory brick is ensured; the small granular layer contains toughening material graphene sheet modified nano alumina to improve the toughness of the refractory brick, the C @ SiC whisker powder improves the oxidation resistance and corrosion resistance of the material, and in addition, the C @ SiC whisker powder has good wave absorption performance and can also greatly improve the heat insulation performance of the material; the nano granular layer material has small grain diameter, is modified by oleic acid, has compact structure and stable property after being pressed and sintered, and has good slag resistance, corrosion resistance and water resistance.

(2) The refractory brick provided by the invention has the advantages that due to the special layered paving process, fused quartz is coated on the surfaces of mullite particles generated by crystallization of andalusite during high-temperature sintering, internal crystal grains are well developed under a high-temperature condition, a large number of closed pores exist, the volume density of the refractory material is reduced, the prepared refractory brick is light in weight, good in heat preservation and heat insulation performance, and a surface nano particle layer is compact, and a compact ceramic structure is formed in the pressing and sintering processes under the action of alkaline nano silica sol, so that the refractory brick has good corrosion resistance, slag resistance and hydration resistance, the particle size of the particles from the outer layer to the inner layer is gradually increased layer by layer, and a skeleton structure with gradually enhanced crack resistance is formed after pressing and sintering, so that the refractory brick has high compressive strength and toughness.

Drawings

FIG. 1 is a schematic view of the layered paving of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention, the following detailed description is given with reference to the accompanying drawings and specific embodiments.