阅读说明：本技术 一种新型铝钙系低密度自流浇注料的制备方法 (Preparation method of novel aluminum-calcium low-density self-flow castable ) 是由 郭勇 陈名 李洪波 邹新国 于 2020-06-16 设计创作，主要内容包括：本发明公开了一种新型铝钙系低密度自流浇注料的制备方法,该浇注料骨料中含有预合成铝钙系耐火原料六铝酸钙、板状刚玉颗粒、氧化铝空心球,其中六铝酸钙耐火骨料占比22～31份、板状刚玉颗粒占比为10～12份、氧化铝空心球的占比为8～10份；而基质中包含有电熔白刚玉、氧化铝微粉、铝酸钙水泥、少量硅微粉和外加剂,其中电熔白刚玉细颗粒占比为25～30份、氧化铝微粉占比为7～10份、铝酸钙水泥占比为10～13份、硅微粉的占比为0.5～1份、外加剂占比为0.5～0.9份。通过以上方法配置的耐火浇注料,具有优良的施工性能、较低的体积密度、优异的高温性能以及较低的热导率,因此能够满足超高温烧嘴部位所产生的热冲击作用。(The invention discloses a preparation method of a novel aluminum-calcium low-density self-flow castable, wherein aggregate of the castable contains a pre-synthesized aluminum-calcium refractory raw material of calcium hexaluminate, plate-shaped corundum particles and alumina hollow spheres, wherein the proportion of the calcium hexaluminate refractory aggregate is 22-31 parts, the proportion of the plate-shaped corundum particles is 10-12 parts, and the proportion of the alumina hollow spheres is 8-10 parts; the matrix comprises 25-30 parts of fused white corundum fine particles, 7-10 parts of alumina micropowder, 10-13 parts of calcium aluminate cement, 0.5-1 part of silicon micropowder and 0.5-0.9 part of an additive. The refractory castable prepared by the method has excellent construction performance, lower volume density, excellent high-temperature performance and lower thermal conductivity, so that the thermal shock effect generated by the ultrahigh-temperature burner can be met.)

1. A preparation method of a novel aluminum-calcium low-density self-flow castable is characterized by comprising the following steps: the aggregate of the self-flow castable mainly comprises pre-synthesized calcium aluminum refractory raw materials of calcium hexaluminate, tabular corundum, fused white corundum and a small amount of alumina hollow spheres, wherein a matrix part comprises calcium aluminate cement, fused white corundum fine powder, alumina micro powder, a small amount of silicon micro powder and a composite additive, and the raw materials are put into a stirrer to be uniformly mixed and stirred to prepare the self-flow castable.

2. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 1, characterized in that: the aluminum-calcium refractory aggregate contained in the castable is in the current marketThe main mineral phase of the pre-synthesized calcium-aluminum series refractory raw material of a certain company on the field is calcium hexaluminate with the chemical formula of CA₆The volume density of the particles is 2.80-2.85 g/cm³Porosity of about 24.00%, Al₂O₃The content is between 90.50 and 91.00 percent, the content of CaO is between 7.40 and 8.0 percent, and the material is prepared by adopting a sintering method.

3. The preparation method of the novel low-density aluminum-calcium self-flow castable according to claim 2, characterized in that: the presynthesized calcium aluminate raw material contained in the castable is mainly introduced into the castable in an aggregate mode, the particle size distribution range is 5-1mm, and the proportion is 22-31 parts.

4. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 1, characterized in that: the castable contains a certain amount of alumina hollow spheres, the particle size distribution range of the alumina hollow spheres is 3-0.2mm, and the adding amount is 8-10 parts.

5. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 1, characterized in that: the pouring material uses pure calcium aluminate cement as a bonding agent, and Al of the cement₂O₃The content of the calcium aluminate cement is 68-70%, the content of CaO is 27-29%, the proportion is 10-13 parts, and calcium oxide and alumina in the calcium aluminate cement can further react at high temperature to generate high-temperature phase calcium hexaluminate.

6. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 5, characterized in that: the castable aggregate is added with a part of plate-shaped corundum, the added granularity range is 5-1mm, and the proportion is 10-12 parts.

7. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 6, characterized in that: the castable matrix contains part of white corundum, the white corundum is mainly added in the form of fine aggregate, the added particle size range is mainly less than or equal to 1mm, and the proportion is 25-30 parts.

8. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 7, is characterized in that: two kinds of alumina micro powder with different specifications are added into the castable, and the adding proportion of the two kinds of micro powder is 3: 2, the proportion is 7-10 parts.

9. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 8 is characterized in that: a small amount of silica powder is added into the castable, the content of the silica powder is not less than 94%, and the addition amount is 0.5-1%.

10. The preparation method of the novel aluminum-calcium low-density self-flow castable according to claim 9, characterized in that: the water reducing agent in the castable admixture is compounded by an organic water reducing agent and an inorganic water reducing agent, wherein the organic water reducing agent accounts for 0.4-0.6 part, and the inorganic water reducing agent accounts for 0.1-0.3 part, so that the castable admixture has good effects of reducing water, dispersing and eliminating castable bleeding.

Technical Field

The invention relates to a preparation method of a novel aluminum-calcium low-density self-flow castable, belonging to the field of refractory materials for high-temperature kilns.

Background

At present, the application research of the pure aluminum-calcium refractory castable is less, mainly because the free CaO is easy to generate hydration in storage, and the refractory material is pulverized. However, the melting point of pure CaO is extremely high (2572 ℃), so that the pure CaO has excellent high-temperature resistance; and the calcium oxide and the alumina can generate a very stable compound calcium hexaluminate (CA) at high temperature₆) The compound has the advantages of high melting point (1875 ℃), strong alkali-resistant material capability, low volume density, stable volume after cooling and the like, so the compound is considered to be a refractory raw material with the most potential in future application by the refractory material boundary, and can be used for a ladle wall working lining, a cement kiln wall, a lime kiln lining, an incinerator lining, a high-temperature burner part and the like in future, thereby having wide application prospect. Therefore, the invention discloses a refractory self-flowing castable material applied to a burner of a kiln, which is developed for a kiln company on the basis of pre-synthesized aluminum-calcium series refractory raw materials, and aims to resist destructive thermal shock action generated by the burner by utilizing excellent high-temperature performance of an aluminum-calcium series refractory material.

Disclosure of Invention

In order to prepare the refractory material for the burner with excellent high-temperature performance, the invention firstly uses the pre-synthesized aluminum-calcium series refractory raw material to prepare the low-density refractory castable material with excellent performance, and the composition of the castable material is explained in detail below.

The novel aluminum-calcium low-density self-flow castable is characterized in that aggregate of the novel aluminum-calcium low-density self-flow castable mainly comprises a pre-synthesized aluminum-calcium refractory raw material, plate-shaped corundum, electric-melting white corundum and a small amount of alumina hollow spheres, and a matrix part of the novel aluminum-calcium low-density self-flow castable is composed of calcium aluminate cement, electric-melting white corundum fine powder, alumina micro powder, a small amount of silicon micro powder and a composite additive.

The novel aluminum-calcium low-density self-flow castable comprises an aluminum-calcium refractory aggregate which is a pre-synthesized aluminum-calcium refractory raw material in a certain company in the market at present, a main mineral phase of the castable is calcium hexaluminate, and the volume density of particles of the castable is 2.80-2.85 g/cm³Porosity of about 24.00%, Al₂O₃The content is 9050 to 91.00 percent and CaO content of 7.40 to 8.0 percent, and is prepared by a sintering method.

The novel aluminum-calcium low-density self-flow castable mainly comprises a presynthesized calcium aluminate raw material which is introduced into the castable in an aggregate mode, wherein the particle size distribution range of the presynthesized calcium aluminate raw material is 5-1mm, and the proportion of the presynthesized calcium aluminate raw material is 22-31 parts.

The novel aluminum-calcium low-density self-flow castable comprises a certain amount of alumina hollow spheres with the particle size distribution range of 3-0.2mm and the proportion of 8-10 parts, and the alumina hollow spheres are added to further reduce the volume density of the castable.

The novel aluminum-calcium low-density self-flow castable takes pure calcium aluminate cement as a bonding agent, the proportion of the pure calcium aluminate cement is 10-13 parts, and Al is₂O₃The content of the calcium oxide and the content of the CaO are 68-70% and 27-29%, the calcium oxide and the alumina in the calcium aluminate cement can further react at high temperature to generate high-temperature phase calcium hexaluminate, and the high-temperature phase paths are embedded between a matrix and particles in a flaky manner, so that the purpose of enhancing the high-temperature strength is achieved.

The novel aluminum-calcium low-density self-flow castable is characterized in that a part of plate-shaped corundum is added into a castable aggregate, the added granularity range is 5-1mm, and the proportion is 10-12 parts.

The novel aluminum-calcium low-density self-flow castable is characterized in that a part of white corundum is added into a castable substrate, the white corundum is mainly added in the form of fine aggregate, the added particle size range is mainly particles with the particle size of less than or equal to 1mm, and the proportion is 25-30 parts.

The novel aluminum-calcium low-density self-flow castable is characterized in that two kinds of alumina micro powder with different specifications are added into the castable, and the adding proportion of the two kinds of micro powder is 3: 2, the proportion is 7-10 parts, and the addition of the alumina is used for further improving the construction performance of the castable.

The novel aluminum-calcium low-density self-flow castable is characterized in that a small amount of silica powder is added into the castable, the content of the silica powder is not less than 94%, and the silica powder accounts for 0.5-1 part. The purpose of adding the silica powder is to generate a proper amount of liquid phase at high temperature for relieving excessive thermal expansion after high-temperature firing.

The novel aluminum-calcium low-density self-flow castable is prepared by compounding an organic water reducing agent and an inorganic water reducing agent, wherein the organic water reducing agent accounts for 0.4-0.6 part, and the inorganic water reducing agent accounts for 0.1-0.3 part, and has good effects of reducing water, dispersing and preventing the castable from bleeding.

The aluminum-calcium self-flow castable prepared by the method has the following characteristics: firstly, the pre-synthesized calcium aluminum series refractory aggregate (calcium hexaluminate CA) is adopted₆) And the in-situ generated aluminum-calcium refractory material, so the aluminum-calcium refractory material has good hydration resistance; secondly, the construction performance is excellent, and the harsh pouring operation requirements can be met; thirdly, the volume density is lower, compared with the common corundum castable, the volume density at normal temperature is reduced by about 15 percent, and the use weight of the refractory material is greatly reduced; and finally, as the aggregate and the matrix are made of stable refractory raw materials with excellent high-temperature resistance, the aggregate and the matrix have excellent high-temperature performance and can meet the strong thermal shock effect generated when the burner nozzle part is in service.

Detailed Description

The invention is further described with reference to the following examples.

In order to avoid repetition between the examples, it is preferable to unify the raw material indexes used in this patent.

Al of the pre-synthesized calcium-aluminum series refractory raw material₂O₃The content is more than or equal to 90 percent, the content of CaO is more than or equal to 7 percent, the size range of the particles is 5-1mm, and the volume density is more than or equal to 2.80g/cm³The apparent porosity is less than or equal to 25.00 percent, and the water absorption is less than or equal to 9.00 percent;

the plate-shaped corundum aggregate Al₂O₃The content is more than or equal to 99.3 percent, R₂O content is less than or equal to 0.4 percent, the size range of the particles is 5-1mm, and the volume density is more than or equal to 3.50g/cm³The apparent porosity is less than or equal to 4.5 percent, the water absorption is less than or equal to 1.3 percent, and the material is prepared by a sintering method;

the alumina hollow sphere aggregate Al₂O₃Content is not less than 99%, R₂O content is less than or equal to 0.2 percent, and the granulesThe size range of the granules is 3-0.2mm, and the volume density is more than or equal to 3.10g/cm³；

Al of the electric melting white corundum fine powder₂O₃The content is more than or equal to 99.3 percent, the particle size range is 1-0mm and less than or equal to 75 mu m;

the silicon micropowder SiO₂The content is more than or equal to 94 percent, and the grain diameter is less than or equal to 3 mu m.

The specification of the alumina micro powder is less than or equal to 5 mu m, Al₂O₃The content is more than or equal to 99.2 percent.

The specification of the calcium aluminate cement is less than or equal to 5 mu m, Al₂O₃The content is more than or equal to 68 percent, and the content of CaO is more than or equal to 27 percent.