阅读说明：本技术 一种碳素焙烧炉用特种粘土砖及其制备方法 (Special clay brick for carbon roasting furnace and preparation method thereof ) 是由 武本有 郝良军 韩八斤 秦迎军 于 2020-05-19 设计创作，主要内容包括：本发明涉及耐火材料技术领域,更具体而言,涉及一种碳素焙烧炉用特种粘土砖,该粘土砖由三级铝矾土熟料、红柱石、粘土制得,本发明另一方面提供了一种碳素焙烧炉用特种粘土砖的制备方法,制备过程中将纸浆液过筛,低于22目加水稀释与粉料混合,避免形成泥团,造成烧成后砖坯产生溶洞,高于22目浆料细化后用于经一次烘焙后坯制品的浸渍,细化后形成不团聚的小分子,浆料中细小纤维高温焙烧下在坯制品孔隙结构中重新分布,提高坯制品体积密度,使其内部结构进一步密制化,坯料在浆料中多次焙烧、干燥,保证良好接枝,构成纤维补强,避免在收缩时产生裂纹；通过最终烧结,降低Fe<Sub>2</Sub>O<Sub>3</Sub>含量,体积收缩,粘土出现玻璃液态相,塞满未熔颗粒空隙。(The invention relates to the technical field of refractory materials, in particular to a special clay brick for a carbon roasting furnace, which is prepared from three-level bauxite chamotte, andalusite and clay, and the invention also provides a preparation method of the special clay brick for the carbon roasting furnaceImpregnating the baked blank product, thinning the impregnated blank product to form non-agglomerated small molecules, re-distributing the fine fibers in the slurry in the pore structure of the blank product under high-temperature baking, improving the volume density of the blank product, further compacting the internal structure of the blank product, and repeatedly baking and drying the blank in the slurry to ensure good grafting, form fiber reinforcement and avoid generating cracks during shrinkage; reduction of Fe by final sintering 2 O 3 Content, volume shrinkage, clay appearance of glass liquid phase, plugging up unmelted particle voids.)

1. A special clay brick for a carbon roasting furnace is characterized in that: the feed comprises the following raw materials in parts by weight: 25-35 parts of coarse powder of the tertiary bauxite clinker, 10-25 parts of medium powder of the tertiary bauxite clinker, 10 parts of medium powder of andalusite, 20 parts of fine clay powder and 23 parts of fine powder of the secondary bauxite clinker.

2. The special clay brick for the carbon roasting furnace as claimed in claim 1, wherein: al in the three-stage bauxite clinker₂O₃≥55%，Fe₂O₃Less than or equal to 1.4 percent; powdered Al in andalusite₂O₃≥55%，Fe₂O₃Less than or equal to 1.2 percent; clay fine powder Al₂O₃≥25%，Fe₂O₃Less than or equal to 1.0 percent; fine powder Al of secondary alumina clinker₂O₃≥75% ，Fe₂O₃≤1.2%。

3. The special clay brick for the carbon roasting furnace as claimed in claim 1, wherein: in the three-stage bauxite clinker coarse powder, the grain size of the three-stage bauxite clinker is 64-74% within the range of 3-1mm, the grain size of the three-stage bauxite clinker is 24-34% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the grain size of the third-level bauxite clinker in the third-level bauxite clinker medium powder is 1-2% within the range of 3-1mm, 64-74% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the andalusite medium powder has a particle size range of 3-1mm accounting for 1-2%, a particle size range of 1-0.088mm accounting for 64-74%, and a particle size range of the rest particles less than 0.088 mm; the clay fine powder accounts for 5-15% of the clay fine powder with the particle size range of 1-0.088mm, and the rest clay fine powder has the particle size range of less than 0.088 mm; the secondary bauxite clinker fine powder accounts for 5-15% of the clinker fine powder with the grain size range of 1-0.088mm, and the grain size range of the rest grains is less than 0.088 mm.

4. A preparation method of a special clay brick for a carbon roasting furnace is characterized by comprising the following steps:

s1, taking paper pulp, sieving the paper pulp, wherein pulp of minus 22 meshes is pulp A, and pulp of plus 22 meshes is pulp B;

s2, kneading 25-35 parts by weight of coarse powder of the tertiary bauxite clinker, 10-25 parts by weight of medium powder of the tertiary bauxite clinker, 10 parts by weight of medium powder of andalusite, 20 parts by weight of fine powder of clay and 23 parts by weight of fine powder of the secondary bauxite clinker to obtain primary powder;

s3, weighing 2-3 parts by weight of slurry A, adding water into the slurry A to dilute the slurry A until the concentration of paper pulp is 1.18-1.25g/cm to prepare a diluent, adding the diluent into the primary powder in S2, and kneading to prepare a pug;

s4, pressing and molding the pug in the S3 by a press with the weight of more than 400t to obtain a blank product;

s5, placing the blank product in the S4 in a roasting furnace for roasting at the temperature of 700-800 ℃;

s6, thinning the slurry B to 150-200 meshes, and adding water for dispersion;

s7, soaking the blank product subjected to primary roasting in S5 in the dispersed slurry B in S6;

s8, drying the blank product at 70-100 ℃ until the residual moisture is not more than 0.8%;

s9, repeating the operations S8-S9 for 3-5 times;

s10, placing the blank product into a kiln, sintering the blank product into a finished product at the temperature of 1320-1380 ℃ for 8-12 hours, and cooling to normal temperature to obtain the clay brick.

5. The method for preparing the special clay brick for the carbon roasting furnace according to claim 4, which is characterized by comprising the following steps: the specific gravity of the pulp slurry is 1.18-1.25g/cm³The pH value is 4-5.

6. The method for preparing the special clay brick for the carbon roasting furnace according to claim 4, which is characterized by comprising the following steps: and in the S2, the kneading temperature is 150-250 ℃, the kneading time is 0.5-1h, and the mixture is naturally cooled to the normal temperature after being kneaded.

7. The method for preparing the special clay brick for the carbon roasting furnace according to claim 4, which is characterized by comprising the following steps: and in the S3, the kneading temperature is 160-220 ℃, the kneading time is 1.5-3h, and the mixture is naturally cooled to the normal temperature after being kneaded.

8. The method for preparing the special clay brick for the carbon roasting furnace according to claim 4, which is characterized by comprising the following steps: and maintaining the pressure for 10-20min after forming in S4.

Technical Field

The invention relates to the technical field of refractory materials, in particular to a special clay brick for a carbon roasting furnace and a preparation method thereof.

Background

In the industrial field, the application of carbon products is wider and wider, and the carbon products play a significant role in the field of national defense science and technology. The selection of the carbon furnace refractory is critical. A great deal of research and study on refractory materials used in carbon calciners, calciners and graphitizing furnaces at home and abroad have been carried out for many years, and the types of the furnaces commonly used for the raw material calciners are tank furnaces and rotary kilns. The outer sides of the working layers of the tank body and the flame path of the tank furnace and the working layers of the flame path brickwork, the regenerative chamber, the flue and the like are built by adopting clay bricks, the outer side of the working layer of the flame path mainly adopts special clay bricks for the flame path, and in order to adapt to the large scale of the carbon furnace and prolong the service life, higher requirements are provided for the quality of refractory materials for the carbon furnace, the design, the complexity and the overall dimension of brick shapes far exceed the traditional design, and the requirements for physical and chemical indexes of the brick shapes also exceed the relevant industrial standards and national standards. At present, due to the defects of difference in quality and selection of refractory raw materials, overproof iron content, poor thermal shock stability and the like at home and abroad, the physical and chemical indexes of the material often cannot reach the expected value of people.

Disclosure of Invention

The invention provides a special clay brick for a carbon roasting furnace and a preparation method thereof, aiming at solving the problem that the existing special clay brick for the carbon roasting furnace often cannot reach the expected value of people due to the defects of different refractory raw material quality, selection, overproof iron content, poor thermal shock stability and the like.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a special clay brick for a carbon roasting furnace comprises the following raw materials in parts by weight: 25-35 parts of coarse powder of the tertiary bauxite clinker, 10-25 parts of medium powder of the tertiary bauxite clinker, 10 parts of medium powder of andalusite, 20 parts of fine clay powder and 23 parts of fine powder of the secondary bauxite clinker.

Further, Al in the three-stage bauxite chamotte₂O₃≥55%，Fe₂O₃Less than or equal to 1.4 percent; powdered Al in andalusite₂O₃≥55%，Fe₂O₃Less than or equal to 1.2 percent; clay fine powder Al₂O₃≥25%，Fe₂O₃Less than or equal to 1.0 percent; fine powder Al of secondary alumina clinker₂O₃≥75% ，Fe₂O₃≤1.2%。

Further, the grain size of the third-stage bauxite clinker in the third-stage bauxite clinker coarse powder is 64-74% within the range of 3-1mm, 24-34% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the grain size of the third-level bauxite clinker in the third-level bauxite clinker medium powder is 1-2% within the range of 3-1mm, 64-74% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the andalusite medium powder has a particle size range of 3-1mm accounting for 1-2%, a particle size range of 1-0.088mm accounting for 64-74%, and a particle size range of the rest particles less than 0.088 mm; the clay fine powder accounts for 5-15% of the clay fine powder with the particle size range of 1-0.088mm, and the rest clay fine powder has the particle size range of less than 0.088 mm; the secondary bauxite clinker fine powder accounts for 5-15% of the clinker fine powder with the grain size range of 1-0.088mm, and the grain size range of the rest grains is less than 0.088 mm.

A preparation method of a special clay brick for a carbon roasting furnace comprises the following steps:

s1, taking paper pulp, sieving the paper pulp, wherein pulp of minus 22 meshes is pulp A, and pulp of plus 22 meshes is pulp B;

s2, kneading 25-35 parts by weight of coarse powder of the tertiary bauxite clinker, 10-25 parts by weight of medium powder of the tertiary bauxite clinker, 10 parts by weight of medium powder of andalusite, 20 parts by weight of fine powder of clay and 23 parts by weight of fine powder of the secondary bauxite clinker to obtain primary powder;

s3, weighing 2-3 parts by weight of slurry A, adding water into the slurry A to dilute the slurry A until the concentration of paper pulp is 1.18-1.25g/cm to prepare a diluent, adding the diluent into the primary powder in S2, and kneading to prepare a pug;

s4, pressing and molding the pug in the S3 by a press with the weight of more than 400t to obtain a blank product;

s5, placing the blank product in the S4 in a roasting furnace for roasting at the temperature of 700-800 ℃;

s6, thinning the slurry B to 150-200 meshes, and adding water for dispersion;

s7, soaking the blank product subjected to primary roasting in S5 in the dispersed slurry B in S6;

s8, drying the blank product at 70-100 ℃ until the residual moisture is not more than 0.8%;

s9, repeating the operations S8-S9 for 3-5 times;

s10, placing the blank product into a kiln, sintering the blank product into a finished product at the temperature of 1320-1380 ℃ for 8-12 hours, and cooling to normal temperature to obtain the clay brick.

Further, the specific gravity of the pulp slurry is 1.18-1.25g/cm³The pH value is 4-5. The paper pulp is purchased from a Jincheng paper mill in Linhai city of Liaoning, and can enhance the plasticity and mechanical strength of the brick body.

Further, the kneading temperature in the S2 is 150-250 ℃, the kneading time is 0.5-1h, and the mixture is naturally cooled to the normal temperature after being kneaded.

Further, the kneading temperature in the S3 is 160-220 ℃, the kneading time is 1.5-3h, and the mixture is naturally cooled to the normal temperature after being kneaded.

Further, the pressure is maintained for 10-20min after the forming in S4.

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

the invention provides a special clay brick for a carbon roasting furnace, which is prepared from three-level bauxite chamotte, andalusite and clay₂O₃The content is obviously lower, and the thermal shock resistance is better; the prepared clay brick has the advantages of high mechanical strength, high refractoriness under load and high thermal stability. The invention also provides a preparation method of the special clay brick for the carbon roasting furnace, wherein the preparation process comprises the steps of sieving the pulp liquid, adding water below 22 meshes for dilution, mixing with the powder, and avoiding the formationThe brick is agglomerated to cause the green brick after being fired to generate a karst cave, thereby enhancing the plasticity of the brick body; the slurry with the particle size of more than 22 meshes is refined and then is used for impregnating a blank product after primary baking, non-agglomerated small molecules are formed after the refinement, fine fibers in the slurry are redistributed in the pore structure of the blank product under the high-temperature baking, the volume density of the blank product is improved, the internal structure of the blank product is further densified, the integral heat transfer capacity is improved, the blank is baked and dried in the slurry for multiple times, good grafting is ensured, fiber reinforcement is formed, and cracks are prevented from being generated during shrinkage; reduction of Fe by final sintering₂O₃The content and the volume are shrunk, the clay is in a glass liquid phase and fills up the gaps of the unmelted particles; the special clay brick prepared by the preparation method provided by the invention completely meets the requirements of the design, complexity and overall dimension of the furnace, has strong corrosion resistance and stable dimension, and meets the requirements of large-scale production of carbon furnaces.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A special clay brick for a carbon roasting furnace comprises the following raw materials in parts by weight: 25-35 parts of coarse powder of the tertiary bauxite clinker, 10-25 parts of medium powder of the tertiary bauxite clinker, 10 parts of medium powder of andalusite, 20 parts of fine clay powder and 23 parts of fine powder of the secondary bauxite clinker.

Further, Al in the three-stage bauxite chamotte₂O₃≥55%，Fe₂O₃Less than or equal to 1.4 percent; powdered Al in andalusite₂O₃≥55%，Fe₂O₃Less than or equal to 1.2 percent; clay fine powder Al₂O₃≥25%，Fe₂O₃Less than or equal to 1.0 percent; fine powder Al of secondary alumina clinker₂O₃≥75% ，Fe₂O₃≤1.2%。

Further, the grain size of the third-stage bauxite clinker in the third-stage bauxite clinker coarse powder is 64-74% within the range of 3-1mm, 24-34% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the grain size of the third-level bauxite clinker in the third-level bauxite clinker medium powder is 1-2% within the range of 3-1mm, 64-74% within the range of 1-0.088mm, and the grain size of the rest grains is less than 0.088 mm; the andalusite medium powder has a particle size range of 3-1mm accounting for 1-2%, a particle size range of 1-0.088mm accounting for 64-74%, and a particle size range of the rest particles less than 0.088 mm; the clay fine powder accounts for 5-15% of the clay fine powder with the particle size range of 1-0.088mm, and the rest clay fine powder has the particle size range of less than 0.088 mm; the secondary bauxite clinker fine powder accounts for 5-15% of the clinker fine powder with the grain size range of 1-0.088mm, and the grain size range of the rest grains is less than 0.088 mm.

In this embodiment, the fineness refers to the particle size of the refractory raw material, the particle size distribution refers to the weight percentage of particles in each fineness class in the range of continuous and different fineness classes, and the particle size distribution of the refractory raw material has a great influence on the volume density, porosity, mechanical strength, plasticity, firing performance and stability performance indexes of the refractory brick

A preparation method of a special clay brick for a carbon roasting furnace comprises the following steps:

s1, taking paper pulp, sieving the paper pulp, wherein pulp of minus 22 meshes is pulp A, and pulp of plus 22 meshes is pulp B;

s2, kneading 25-35 parts by weight of coarse powder of the tertiary bauxite clinker, 10-25 parts by weight of medium powder of the tertiary bauxite clinker, 10 parts by weight of medium powder of andalusite, 20 parts by weight of fine powder of clay and 23 parts by weight of fine powder of the secondary bauxite clinker to obtain primary powder; kneading at 150-250 deg.c for 0.5-1 hr, and cooling naturally to normal temperature;

s3, weighing 2-3 parts by weight of slurry A, adding water into the slurry A to dilute the slurry A until the concentration of paper pulp is 1.18-1.25g/cm to prepare a diluent, adding the diluent into the primary powder in S2, and kneading to prepare a pug; kneading at 160-220 deg.c for 1.5-3 hr, and cooling naturally to normal temperature;

s4, pressing and molding the pug in the S3 by a press of more than 400t to obtain a blank product, and maintaining the pressure for 10-20min after molding;

s5, placing the blank product in the S4 in a roasting furnace for roasting at the temperature of 700-800 ℃;

s6, thinning the slurry B to 150-200 meshes, and adding water for dispersion;

s7, soaking the blank product subjected to primary roasting in S5 in the dispersed slurry B in S6;

s8, drying the blank product at 70-100 ℃ until the residual moisture is not more than 0.8%;

s9, repeating the operations S8-S9 for 3-5 times;

s10, placing the blank product into a kiln, sintering the blank product into a finished product at the temperature of 1320-1380 ℃ for 8-12 hours, and cooling to normal temperature to obtain the clay brick.

In the embodiment, the specific gravity of the pulp slurry is 1.18-1.25g/cm³The pH value is 4-5. The paper pulp is purchased from a Jincheng paper mill in Linhai city of Liaoning, and can enhance the plasticity and mechanical strength of the brick body.

Although only the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art, and all changes are encompassed in the scope of the present invention.