阅读说明：本技术 一种抗结皮浇注料及其制备方法 (Anti-skinning castable and preparation method thereof ) 是由 朱国平 王立旺 李新明 王琪 彭晶晶 方利华 于 2021-10-12 设计创作，主要内容包括：本发明涉及耐火材料领域,尤其涉及一种抗结皮浇注料及其制备方法,所述抗结皮浇注料,按照重量份数计,包括硅砖颗粒49～64份,石英颗粒8～12份,熔融石英6～12份,硅微粉5～8份,碳黑粉8～12份,石墨粉4～8份,金属硅粉2～4份,石墨烯粉1～2份,锰矿粉0.5～1份,铁矿粉0.3～0.8份,聚丙烯纤维0.01～0.03份,硅油0.01～0.02份。本发明克服了现有技术中的耐火浇注料的抗结皮效果较差的缺陷,本发明制备的抗结皮浇注料中最终形成的是SiO-(2)—C—SiC复合体系,充分发挥了含碳材料的性能特点,形成的组份高温体积稳定性好,抗热震性和耐蚀性优异,高温强度大,线膨胀系数小,完全不与水泥生料反应,具有良好的抗结皮性。(The invention relates to the field of refractory materials, and particularly relates to an anti-skinning castable and a preparation method thereof, wherein the anti-skinning castable comprises, by weight, 49-64 parts of silica brick particles, 8-12 parts of quartz particles, 6-12 parts of fused quartz, 5-8 parts of silica micropowder, 8-12 parts of carbon black powder, 4-8 parts of graphite powder, 2-4 parts of metal silicon powder, 1-2 parts of graphene powder, 0.5-1 part of manganese mineral powder, 0.3-0.8 part of iron mineral powder, 0.01-0.03 part of polypropylene fibers and 0.01-0.02 part of silicone oil. The invention overcomes the defect of poor anti-skinning effect of the refractory castable in the prior art, and SiO is finally formed in the anti-skinning castable prepared by the invention 2 The C-SiC composite system gives full play to the performance characteristics of the carbon-containing material, and the formed components have good high-temperature volume stability, excellent thermal shock resistance and corrosion resistance, large high-temperature strength and small linear expansion coefficient, and are completely free from waterThe mud raw material reacts and has good anti-skinning property.)

1. The anti-skinning castable is characterized by comprising, by weight, 49-64 parts of silica brick particles, 8-12 parts of quartz particles, 6-12 parts of fused quartz, 5-8 parts of silica powder, 8-12 parts of carbon black powder, 4-8 parts of graphite powder, 2-4 parts of metal silicon powder, 1-2 parts of graphene powder, 0.5-1 part of manganese ore powder, 0.3-0.8 part of iron ore powder, 0.01-0.03 part of polypropylene fibers and 0.01-0.02 part of silicone oil.

2. The anti-skinning castable material according to claim 1,

the silica brick particle comprises:

22-26 parts of silica brick particles with the particle size of 10-6 mm;

12-18 parts of silica brick particles with the particle size of 6-2 mm;

15-20 parts of silica brick particles with the particle size of 2-0 mm.

3. The anti-skinning castable material according to claim 1 or 2, wherein SiO in the silica brick particles₂The mass percentage of (A) is not less than 94%.

4. The anti-skinning castable according to claim 1, wherein the particle size of the quartz particles is 2-0 mm, and the particle size of the fused quartz is not more than 320 meshes.

5. The castable material for resisting skinning according to claim 1 or 4, wherein SiO in the quartz particles and the fused quartz₂The mass percentage of (A) is not less than 99%.

6. The anti-skinning castable according to claim 1, wherein SiO in the fine silica powder₂The mass percentage of (A) is not less than 94%.

7. A preparation method of the anti-skinning castable material according to any one of claims 1 to 6, characterized by comprising the following steps:

(S.1) crushing and processing the recycled silica bricks into particles of 10-6 mm, 2-6 mm and 2-0 mm;

(S.2) weighing the raw materials according to the proportion and uniformly mixing;

and (S.3) adding silica sol into the mixture, and uniformly stirring to obtain the anti-skinning castable.

8. The preparation method of the anti-skinning castable according to claim 7, wherein the silica sol is added in an amount of 5 to 8 parts by weight.

9. The preparation method of the anti-skinning castable according to claim 7 or 8, wherein SiO in the silica sol₂Is not less than 28 percent.

Technical Field

The invention relates to the field of refractory materials, in particular to an anti-skinning castable and a preparation method thereof.

Background

The hot air flow in the decomposition system of the novel dry production line carries a large amount of material dust and alkali steam such as alkali, sulfur, chlorine and the like volatilized by fuel, so that the corrosion to refractory materials is serious, and powdery materials are adhered along with the cyclic enrichment of the alkali, sulfur, chlorine and other volatile substances and the melting of the wall of the pre-decomposition system, so that the skinning blockage is generated, and the materials cannot pass through. The cement kiln short-flow presintering technology can raise the temperature of raw materials entering the kiln to 900-1200 ℃, and 80-90% of fuel is added into the presintering kiln, thereby causing the change of volatilization characteristics of alkali, chlorine and sulfur. Although the sulfur-alkali ratio and the chlor-alkali ratio can be controlled to improve the scaling blockage situation, the sulfur-alkali ratio and the chlor-alkali ratio cannot be controlled within a reasonable range in some regions due to the limitation of raw materials and fuels, and the scaling blockage is one of the problems to be solved in the refractory material for the pre-sintering kiln. Therefore, the research on the refractory castable material with excellent alkali resistance, wear resistance, no skinning and no blocking performance has important significance for meeting the use requirements of a decomposition system.

In order to improve the anti-skinning effect of the castable, the problem is mainly solved from the aspect of the material of the lining refractory material, so that the bonding degree of the adhesion layer and the refractory material is reduced. Some technologies enable high-silicon low-aluminum components in the castable to react with alkaline gas to generate high-viscosity liquid phase of anorthite and potassium feldspar by adjusting the raw material composition of the refractory castable, and the high-viscosity liquid phase is attached to the surface of the castable to form a glaze-shaped protective layer, so that the corrosion of alkali can be prevented to a certain extent, and the anti-skinning performance is enhanced. However, the generation of anorthite and potassium feldspar can generate a large volume expansion effect, so that pitted surfaces and spalling of the material surface are generated, and eutectic mixtures are generated, so that the use effect is seriously influenced. Most of the technologies adopt silicon carbide as a main raw material of the anti-skinning castable, and the silicon carbide has the advantages of high Mohs hardness, capability of resisting scouring and abrasion of raw materials, poor adhesion and wettability of the silicon carbide and other materials and difficulty in forming skinning.

However, although silicon carbide is easily oxidized at high temperature and a surface oxide layer formed at an initial stage can protect the body material from the corrosion of alkali vapor, silicon carbide is completely oxidized with the progress of reaction time in the use environment of the cement kiln, and further, the anti-skinning effect is lost, and it is difficult to obtain a good use effect for a long time.

Chinese patent with application number CN201110321097.2 discloses a silicon carbide anti-skinning anti-blocking castable and a preparation method thereof, and is characterized in that the castable is prepared by mixing the following substances in parts by mass: 25-35 parts of 10-3mm high-silicon porcelain insulator particles, 35-50 parts of silicon carbide particles, 10-15 parts of 320-mesh silicon carbide fine powder, 3-6 parts of silicon carbide differential powder and 5-8 parts of cement, and then adding a proper amount of antioxidant, water reducer and water; the raw materials are uniformly mixed and then added into a die cavity to be vibrated and compacted, and a product is obtained after baking and maintenance. The material is easy to construct, high in strength, wear-resistant and anti-skinning, is applied to the cone part of a predecomposition furnace, a smoke chamber, a kiln tail slope and other parts of a large and medium-sized cement rotary kiln, has the characteristics of long service life and anti-blocking and anti-skinning, but has an anti-skinning effect only at the initial stage, and silicon carbide is completely oxidized along with the use of a castable so as to lose the anti-skinning effect.

Disclosure of Invention

The invention provides an anti-skinning castable and a preparation method thereof, aiming at overcoming the defect of poor anti-skinning effect of the refractory castable in the prior art.

In order to achieve the purpose, the invention is realized by the following technical scheme:

the anti-skinning castable comprises, by weight, 49-64 parts of silica brick particles, 8-12 parts of quartz particles, 6-12 parts of fused silica, 5-8 parts of silica micropowder, 8-12 parts of carbon black powder, 4-8 parts of graphite powder, 2-4 parts of metal silicon powder, 1-2 parts of graphene powder, 0.5-1 part of manganese ore powder, 0.3-0.8 part of iron ore powder, 0.01-0.03 part of polypropylene fibers and 0.01-0.02 part of silicone oil.

The anti-skinning castable disclosed by the invention adopts the recycled silica bricks as the main raw material of the anti-skinning castable, the recycled silica bricks are an acidic refractory material mainly composed of tridymite, cristobalite, a small amount of residual quartz and a glass phase, the silica content of the silica bricks is more than 94%, and the true density of the silica bricks is 2.35g/cm³Has acid resistanceSlag corrosion performance, high-temperature strength and refractoriness under load of 1620-1670 ℃, so that the material is not deformed after being used for a long time at high temperature. The invention adopts the recycled silica bricks as main raw materials, not only reduces the cost of the raw materials, but also realizes the recycling of solid wastes.

SiO in silica brick under conventional conditions₂The crystal form of (A) is changed at high temperature, so that the volume of silica brick particles is expanded, and the defect of low stability is caused. However, in the invention, a certain amount of iron ore powder is added into the castable to be used as a mineralization stabilizer, which can be used for treating SiO in the silica brick₂The crystal form plays a stabilizing role, and volume expansion caused by the change of the crystal form is avoided. In addition, due to SiO in the fused silica₂The crystal form does not change along with the temperature, and the volume expansion effect is not generated, so the volume stability of the casting material can be improved.

The silicon micropowder plays a role in dispersing in the anti-skinning castable, can improve the fluidity of the castable, and can lubricate the castable due to the addition of the graphite powder in the flowing process, thereby reducing the frictional resistance among component particles in the castable and improving the fluidity of the castable. Meanwhile, the characteristic that the carbonaceous material is difficult to infiltrate is utilized to improve the wetting angle of the adhering melt and the castable in the kiln, and the adhesive force between the adhering substance and the castable is reduced, so that the anti-skinning effect of the refractory castable is greatly improved.

According to the invention, a certain amount of carbon black powder is added into the castable, which can form a reducing atmosphere in the castable, so that conditions are created for the reaction of the metal silicon powder and the graphene powder, and the manganese ore powder as a catalyst for the reaction can reduce the activation energy of the reaction and promote the in-situ reaction to generate silicon carbide, so that the anti-skinning effect of the castable is improved.

Therefore, SiO is finally formed in the anti-skinning castable prepared by the invention₂The C-SiC composite system gives full play to the performance characteristics of the carbon-containing material, and the formed components have good high-temperature volume stability, excellent thermal shock resistance and corrosion resistance, large high-temperature strength and small linear expansion coefficient, do not react with cement raw materials at all, and have good performanceThe anti-skinning property of (1). And the silicone oil is used as an organic liquid additive, so that the dust generated in the production process of the anti-skinning castable can be reduced, the dispersibility of the carbon-containing material is improved, and the associativity of quartz and carbon is improved.

In addition, the polypropylene fiber can form air holes in the anti-skinning casting material, which is beneficial to discharging water vapor in the temperature rising process.

Preferably, the silica brick particles comprise:

22-26 parts of silica brick particles with the particle size of 10-6 mm;

12-18 parts of silica brick particles with the particle size of 6-2 mm;

15-20 parts of silica brick particles with the particle size of 2-0 mm.

The silica brick particles in the invention are particle compositions with different particle sizes, wherein the number of the silica brick particles with the particle sizes of 10-6 mm is the largest, the silica brick particles with the particle sizes of 6-2 mm are the smallest, the silica brick particles can be filled in the aggregates with the particle sizes of 10-6 mm, and the content of the silica brick particles with the smallest particle sizes is between the aggregates with the particle sizes of 10-6 mm and 10-6 mm, so that the castable can be most tightly stacked.

In addition, the particle size of the existing castable generally shows the distribution of less two ends and more middle parts, but the invention improves the fluidity of the castable by the characteristic of more two ends and less middle parts, so that the pumping performance of the castable is more excellent.

Preferably, SiO is contained in silica brick particles₂The mass percentage of (A) is not less than 94%.

Preferably, the granularity of the quartz particles is 2-0 mm, and the granularity of the fused quartz is less than or equal to 320 meshes.

Preferably, the SiO in the quartz particles and fused silica₂The mass percentage of (A) is not less than 99%.

Preferably, SiO is contained in the fine silica powder₂The mass percentage of (A) is not less than 94%.

The preparation method of the anti-skinning castable comprises the following steps:

(S.1) crushing and processing the recycled silica bricks into particles of 10-6 mm, 2-6 mm and 2-0 mm;

(S.2) weighing the raw materials according to the proportion and uniformly mixing;

and (S.3) adding silica sol into the mixture, and uniformly stirring to obtain the anti-skinning castable.

The invention adds the silica sol into the mixture after weighing each raw material, because the solid component in the silica gel is SiO₂Mainly used as a bonding agent of the anti-skinning castable of the system, has excellent anti-explosion performance and can meet the baking requirement of rapid temperature rise.

Preferably, the silica sol is added in an amount of 5 to 8 parts by weight.

Preferably, SiO in the silica sol₂Is not less than 28 percent.

Therefore, the invention has the following beneficial effects:

(1) the recycled silica bricks are used as the main raw materials of the anti-skinning castable, so that the raw material cost is reduced, and the recycling of solid wastes is realized;

(2) SiO finally formed in the anti-skinning castable prepared by the invention is₂The C-SiC composite system gives full play to the performance characteristics of the carbon-containing material, and the formed components have good high-temperature volume stability, excellent thermal shock resistance and corrosion resistance, high-temperature strength and small linear expansion coefficient, are completely not reacted with cement raw materials, and have good anti-skinning property;

(3) it is especially suitable for the four-stage and five-stage cylinders of preheater, decomposing furnace, tail smoke chamber, ascending flue and discharging pipe of cement dry kiln.

Detailed Description

The invention is further described with reference to specific examples. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Example 1

The anti-skinning castable in the embodiment is characterized in that recycled silica bricks are crushed and processed into particles of 10-6 mm, 2-6 mm and 2-0 mm, and the raw materials and the parts by mass of the anti-skinning castable comprise 26 parts of silica brick particles with the particle size of 10-6 mm, 12 parts of silica brick particles with the particle size of 6-2 mm, 20 parts of silica brick particles with the particle size of 2-0 mm, 8 parts of quartz particles with the particle size of 2-0 mm, 12 parts of fused quartz with the particle size not larger than 320 meshes, 8 parts of silicon micropowder, 12 parts of carbon black powder, 4 parts of graphite powder, 4 parts of metal silicon powder, 1 part of graphene powder, 0.5 part of manganese ore powder, 0.3 part of iron ore powder, 0.03 part of polypropylene fiber and 0.02 part of silicone oil. The anti-skinning castable is prepared by weighing the raw materials in proportion, uniformly mixing, adding 5 parts of silica sol and uniformly stirring.

The performance of the anti-skinning castable prepared in this example is shown in table 1 below.

Table 1 anti-skinning castable prepared in example 1 performance table

Example 2

The anti-skinning castable is characterized by firstly crushing and processing recycled silica bricks into particles of 10-6 mm, 2-6 mm and 2-0 mm, and then adopting raw materials of 22 parts of silica brick particles with the particle size of 10-6 mm, 18 parts of silica brick particles with the particle size of 6-2 mm, 15 parts of silica brick particles with the particle size of 2-0 mm, 12 parts of quartz particles with the particle size of 2-0 mm, 6 parts of fused quartz with the particle size not larger than 320 meshes, 5 parts of silicon micropowder, 8 parts of carbon black powder, 8 parts of graphite powder, 2 parts of metal silicon powder, 2 parts of graphene powder, 1 part of manganese ore powder, 0.8 part of iron ore powder, 0.01 part of polypropylene fiber and 0.01 part of silicone oil. The anti-skinning castable is prepared by weighing the raw materials in proportion, uniformly mixing, adding 8 parts of silica sol and uniformly stirring.

The properties of the anti-skinning castable prepared in this example are shown in table 2 below.

TABLE 2 anti-skinning castable prepared in example 2 Performance Table

Example 3

The anti-skinning castable is characterized by firstly crushing and processing recycled silica bricks into particles of 10-6 mm, 2-6 mm and 2-0 mm, and then adopting raw materials of 25 parts of silica brick particles with the particle size of 10-6 mm, 15 parts of silica brick particles with the particle size of 6-2 mm, 18 parts of silica brick particles with the particle size of 2-0 mm, 10 parts of quartz particles with the particle size of 2-0 mm, 9 parts of fused quartz with the particle size not larger than 320 meshes, 5-8 parts of silicon micropowder, 11 parts of carbon black powder, 6 parts of graphite powder, 3 parts of metal silicon powder, 1.5 parts of graphene powder, 0.8 part of manganese mineral powder, 0.5 part of iron mineral powder, 0.02 part of polypropylene fiber and 0.015 part of silicone oil. The anti-skinning castable is prepared by weighing the raw materials in proportion, uniformly mixing, adding 6 parts of silica sol and uniformly stirring.

The properties of the anti-skinning castable prepared in this example are shown in table 3 below.

Table 3 anti-skinning castable prepared in example 3 performance table

Example 4

The anti-skinning castable is characterized by firstly crushing and processing recycled silica bricks into particles of 10-6 mm, 2-6 mm and 2-0 mm, and then adopting 24 parts of silica brick particles of 10-6 mm, 17 parts of silica brick particles of 6-2 mm, 16 parts of silica brick particles of 2-0 mm, 11 parts of quartz particles of 2-0 mm, 10 parts of fused quartz of not more than 320 meshes, 7 parts of silicon micropowder, 10 parts of carbon black powder, 7 parts of graphite powder, 3 parts of metal silicon powder, 1.8 parts of graphene powder, 0.7 part of manganese ore powder, 0.6 part of iron ore powder, 0.015 part of polypropylene fiber and 0.02 part of silicone oil as raw materials in parts by mass. The anti-skinning castable is prepared by weighing the raw materials in proportion, uniformly mixing, adding 7 parts of silica sol and uniformly stirring.

The properties of the anti-skinning castable prepared in this example are shown in table 4 below.

Table 4 anti-skinning castable prepared in example 4 performance table

Comparative example 1

Comparative example 1 was configured with the components of example 2 having an authorization publication number CN 102503458B:

the method comprises the following specific steps: 35 parts of 10-3mm high-silicon porcelain bottle particles, 15 parts of 3-1mm silicon carbide particles, 25 parts of 1-0mm silicon carbide particles, 10 parts of 320-mesh silicon carbide fine powder, 6 parts of 2-10 mu m silicon carbide micro powder, 8 parts of high-alumina cement, 6.5 parts of water, 6 parts of micro silicon powder and 0.2 part of concrete water reducing agent.

Adding 6.5 parts of water in a using site, uniformly mixing, adding into a die cavity, vibrating and compacting, and baking and curing conventionally to obtain the product.

The properties of the anti-skinning castable prepared in comparative example 1 are shown in table 5 below.

TABLE 5 Performance Table of anti-skinning castable prepared in comparative example 1

Comparing the data in examples 1-4 with comparative example 1, we find that the castable in the technical scheme of the invention has the characteristics of good mechanical property, high-temperature volume stability and excellent thermal shock resistance. Meanwhile, the cement raw material does not react at all, and the cement raw material has good anti-skinning property.

In addition, in order to compare the change of the anti-skinning performance after a certain period of use, particularly the anti-skinning performance after the conventional half year of use, we found that the anti-skinning castable in the examples 1-4 still keeps the anti-skinning grade at the first grade after the conventional half year of use, while the castable in the comparative example 1 is reduced from the initial first grade to the second grade,the silicon carbide in the comparative example 1 is easy to generate oxidation reaction at high temperature, so that the anti-skinning effect of the integral castable is reduced. Further shows the SiO finally formed in the technical scheme of the invention₂The C-SiC composite system has more excellent anti-skinning effect than the SiC system alone in comparative example 1.