CN114195535A - Preparation method for producing refined mullite corundum high-temperature material at low carbon - Google Patents
Preparation method for producing refined mullite corundum high-temperature material at low carbon Download PDFInfo
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- CN114195535A CN114195535A CN202111652960.2A CN202111652960A CN114195535A CN 114195535 A CN114195535 A CN 114195535A CN 202111652960 A CN202111652960 A CN 202111652960A CN 114195535 A CN114195535 A CN 114195535A
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- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
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- C—CHEMISTRY; METALLURGY
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- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/16—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay
- C04B35/18—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay rich in aluminium oxide
- C04B35/185—Mullite 3Al2O3-2SiO2
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
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- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/6261—Milling
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
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- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/54—Particle size related information
- C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
- C04B2235/5436—Particle size related information expressed by the size of the particles or aggregates thereof micrometer sized, i.e. from 1 to 100 micron
Abstract
The invention relates to a preparation method for producing a refined mullite corundum high-temperature material with low carbon in the field of high-temperature refractory materials, which comprises the following steps: step 1: grading the bauxite raw material; step 2: preparing materials; and step 3: fine grinding by a dry method; and 4, step 4: fine grinding by a partial wet method; and 5: mixing and blending according to a proportion; step 6: performing machine pressing; and 7: firing to obtain a finished product; the process is characterized in that dry fine grinding is taken as a main process, so that a large amount of moisture is avoided, the production cost of the process is ensured to be low, wet fine grinding slurry is taken as an auxiliary process, the slurry is taken as a binding agent, at the same time, less than 6% of moisture is brought into the slurry to wet dry materials, the forming performance is ensured, meanwhile, the wet fine grinding components are more uniform and are added as a substrate of a product, the component uniformity of a finished product can be ensured, in addition, the uniformity requirements of products with different purposes are different, and the wet and dry materials can be directly adjusted according to different proportions in the process of mixing the wet and dry materials; the adjustment of the process is more flexible.
Description
Technical Field
The invention relates to the field of high-temperature refractory materials, in particular to a preparation method for producing a refined mullite corundum high-temperature material at low carbon.
Background
The mullite corundum material is an inorganic non-metallic material with high thermal shock resistance, low creep and excellent high-temperature performance, wherein the content of alumina is 45-75%, and a mullite phase is taken as a main crystal phase and a corundum phase is taken as a secondary crystal phase.
At present, in the aspect of high-temperature refractory materials, natural bauxite accumulates a large amount of broken ores and low-grade ores through years of mining application, so that the resource utilization rate is not high, and a large amount of land resources are occupied.
At present, in the aspect of utilizing low-grade ores and crushed ores, two methods are mainly used, namely a dry process and a wet process, wherein the dry process is relatively low in drying cost, but poor in material uniformity and uneven in microstructure, so that the product quality is influenced; although the wet process has good material uniformity, the dehydration process and the drying process are complicated, and the energy consumption and the cost are high.
The two processes are difficult to consider in terms of product quality and cost, and particularly have increasingly strict energy consumption under the current mainstream 'double carbon' background, so that the two processes are difficult to widely popularize in market application.
Disclosure of Invention
The invention aims to solve the defects and provides a preparation method for producing a refined mullite corundum high-temperature material at low carbon.
The purpose of the invention is realized by the following modes:
a preparation method for producing a refined mullite corundum high-temperature material with low carbon comprises the following steps:
step 1: bauxite raw material is classified according to the relative content of chemical formed in the ore.
Step 2: proportioning, namely preparing bauxite of different grades according to the proportion to meet the aluminum content requirement of a target product;
and step 3: dry fine grinding, namely performing dry fine grinding on the bauxite raw material with the mixed components, wherein D50 is controlled to be 4-10 mu m;
and 4, step 4: performing partial wet fine grinding, and performing wet fine grinding on partial raw materials of the same batch to obtain fine grinding slurry, wherein D50 is controlled to be 0-4 mu m;
and 5: mixing and blending according to a proportion, fully stirring the dry-method fine grinding materials and the wet-method fine grinding materials according to a proportion, and fully wetting and bonding the mixed materials by using the fine grinding slurry as a bonding agent to obtain a mixed material;
step 6: performing mechanical pressing molding, namely performing mechanical pressing molding on the mixture to obtain a semi-finished product;
and 7: and firing the semi-finished product in a high-temperature kiln at 1300-1800 ℃ to obtain the refined mullite corundum high-temperature material.
Furthermore, part of the raw materials of the same batch are subjected to dry fine grinding, and D50 is controlled to be between 4 and 10 mu m.
Further, in the step 4, the D50 of the fine grinding slurry is controlled to be between 0 and 4 μm.
Further, in the step 5, the raw materials finely ground by the dry method and the wet method are mixed in proportion, the moisture of the mixed material is controlled by proportional mixing, the moisture of the mixed material is below 6%, the mixed material is wetted by the finely ground slurry, and the forming performance is ensured.
The preparation method for producing the refined mullite corundum high-temperature material with low carbon has the following beneficial effects:
1. the process is characterized in that the dry fine grinding is mainly used, so that a large amount of moisture is prevented from being brought in, and the production cost in the process is ensured to be low; the wet fine grinding slurry is used as an auxiliary material and is used as a binding agent, and meanwhile, a proper amount of moisture (less than 6%) is brought into the slurry to wet the dry materials, so that the forming performance is ensured, and meanwhile, the wet fine grinding components are more uniform and are added into micron-sized materials as a substrate of a product, so that the component uniformity of the finished product can be ensured. In addition, for products with different purposes, the uniformity requirements are different, and the product can be directly adjusted according to different proportions in the process of mixing dry and wet materials; the process is more flexible to adjust;
2. the process has the most important characteristics that the process is a combination of a dry method and a wet method, the moisture brought in is less, the energy consumption link of drying is not needed, the process can save 10-50 parts of natural gas, the product quality is ensured, the process is more energy-saving, and the process is an environment-friendly and resource-saving product under the background of 'double carbon'.
Drawings
FIG. 1 is a flow diagram of a preparation method for producing a refined mullite corundum high-temperature material with low carbon.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
A preparation method for producing a refined mullite corundum high-temperature material with low carbon comprises the following steps:
step 1: grading the bauxite raw material, and carrying out grading treatment according to the relative content of chemical forming in the bauxite;
step 2: proportioning, proportionally preparing the aluminum content requirement of the target product by the alumina at different grades;
and step 3: dry fine grinding, namely performing dry fine grinding on the bauxite raw material with the mixed components, performing dry fine grinding on part of the raw material in the same batch, and performing dry fine grinding on the bauxite raw material with the mixed components, wherein D50 is 5.6 mu m;
and 4, step 4: performing partial wet fine grinding, and performing wet fine grinding on partial raw materials of the same batch to obtain fine grinding slurry, wherein D50 of the fine grinding slurry is controlled to be 1.8 mu m;
and 5: mixing and blending according to a proportion, fully stirring the dry-method fine grinding materials and the wet-method fine grinding materials according to a proportion, fully wetting and bonding the mixed materials by using fine grinding slurry as a binding agent to obtain a mixed material, mixing the raw materials of the dry-method fine grinding materials and the raw materials of the wet-method fine grinding materials according to a proportion, and controlling the water content of the mixed materials by mixing the raw materials according to a proportion, wherein the water content of the mixed materials is 5.2%, and the mixed materials are wetted by the fine grinding slurry to ensure the forming performance;
step 6: performing machine pressing molding, namely performing machine pressing molding on the mixed material under a 2100-ton press to obtain a semi-finished product, and obtaining the semi-finished product;
and 7: and firing the finished product, namely sintering the semi-finished product in a high-temperature kiln, placing the semi-finished product in the kiln, and firing at 1650 ℃ to obtain the refined mullite corundum high-temperature material.
The process is a preparation method for producing fine mullite corundum with low carbon, and any mullite corundum production method which combines a dry method and a wet method and has the alumina content of a finished product within 45-75 percent is within the process range regardless of the addition form of waste materials after use or the addition form of natural materials.
The key point of the process is that a dry-wet method is combined, the advantages of the traditional dry method and the traditional wet method are kept, the intermediate drying link is omitted, and the energy consumption equivalent to 10-50 square of natural gas can be saved in the comprehensive process.
The above detailed description of the method for preparing a low-carbon refined mullite corundum high-temperature material provided by the present invention is provided, and the principle and implementation method of the present invention are explained in this text by using specific embodiments, and the description of the above embodiments is only used to help understanding the method and the core idea of the present invention, and also to enable any person skilled in the art to practice the present invention, it should be noted that, for a person skilled in the art, the present invention may be subjected to several improvements and modifications without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims (4)
1. A preparation method for producing a refined mullite corundum high-temperature material with low carbon is characterized by comprising the following steps:
step 1: grading the bauxite raw material, namely grading the bauxite raw material according to the relative content of chemical molding in the ore;
step 2: proportioning, proportionally preparing the aluminum content requirement of the target product by the alumina at different grades;
and step 3: dry fine grinding, namely performing dry fine grinding on the bauxite raw material with the mixed components, wherein D50 is controlled to be 4-10 mu m;
and 4, step 4: performing partial wet fine grinding, and performing wet fine grinding on partial raw materials of the same batch to obtain fine grinding slurry, wherein D50 is controlled to be 0-4 mu m;
and 5: mixing and blending according to a proportion, fully stirring the dry-method fine grinding materials and the wet-method fine grinding materials according to a proportion, and fully wetting and bonding the mixed materials by using the fine grinding slurry as a bonding agent to obtain a mixed material;
step 6: performing mechanical pressing molding, namely performing mechanical pressing molding on the mixture to obtain a semi-finished product;
and 7: and firing the semi-finished product in a high-temperature kiln at 1300-1800 ℃ to obtain the refined mullite corundum high-temperature material.
2. The preparation method of the refined mullite corundum high-temperature material with low carbon production according to claim 1, is characterized in that: in the step 3, part of the raw materials in the same batch are subjected to dry fine grinding.
3. The preparation method of the refined mullite corundum high-temperature material with low carbon production according to claim 1, is characterized in that: in step 4, the D50 of the fine grinding slurry is controlled to be between 0 and 4 mu m.
4. The preparation method of the refined mullite corundum high-temperature material with low carbon production according to claim 1, is characterized in that: in the step 5, the raw materials finely ground by the dry method and the wet method are mixed in proportion, the moisture of the mixed material is controlled by mixing in proportion, the moisture of the mixed material is below 6%, and the mixed material is wetted by the finely ground slurry, so that the forming performance is ensured.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116835969A (en) * | 2023-09-01 | 2023-10-03 | 北京利尔高温材料股份有限公司 | Corundum mullite and preparation method thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1341609A (en) * | 1970-05-20 | 1973-12-25 | Tatabanyai Szenbanyak | Process for the treatment of alumina-containing ores |
| CN1047847A (en) * | 1990-06-15 | 1990-12-19 | 中国建材工业协会新型干法水泥生产技术研究会 | Do the new energy-saving and production-increase process of the legal transformation wet-process cement of wet mixing kiln |
| CN102351522A (en) * | 2011-07-15 | 2012-02-15 | 郑州大学 | Method for preparing homogeneous mullite material from kyanite |
| CN102910923A (en) * | 2012-11-15 | 2013-02-06 | 北京科技大学 | Method for synthesizing corundum-mullite composite phase material by using bauxite tailings |
| CN103056959A (en) * | 2011-10-21 | 2013-04-24 | 咸阳陶瓷研究设计院 | Ceramics raw material preparation dry method and short process craft |
| CN105503219A (en) * | 2015-12-29 | 2016-04-20 | 通达耐火技术股份有限公司 | Alumina-base sintered corundum mullite and preparation method thereof |
| CN105750060A (en) * | 2014-12-16 | 2016-07-13 | 沈阳铝镁设计研究院有限公司 | New dry-wet mixed grinding technology of bauxite |
| US20170073275A1 (en) * | 2014-10-23 | 2017-03-16 | Ashapura Minechem Ltd. | Composites of sintered Mullite reinforced corundum granules and method for its preparation |
| CN106747497A (en) * | 2016-11-29 | 2017-05-31 | 江苏省冶金设计院有限公司 | The method for preparing corundum-mullite composite diphase material |
-
2021
- 2021-12-30 CN CN202111652960.2A patent/CN114195535A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1341609A (en) * | 1970-05-20 | 1973-12-25 | Tatabanyai Szenbanyak | Process for the treatment of alumina-containing ores |
| CN1047847A (en) * | 1990-06-15 | 1990-12-19 | 中国建材工业协会新型干法水泥生产技术研究会 | Do the new energy-saving and production-increase process of the legal transformation wet-process cement of wet mixing kiln |
| CN102351522A (en) * | 2011-07-15 | 2012-02-15 | 郑州大学 | Method for preparing homogeneous mullite material from kyanite |
| CN103056959A (en) * | 2011-10-21 | 2013-04-24 | 咸阳陶瓷研究设计院 | Ceramics raw material preparation dry method and short process craft |
| CN102910923A (en) * | 2012-11-15 | 2013-02-06 | 北京科技大学 | Method for synthesizing corundum-mullite composite phase material by using bauxite tailings |
| US20170073275A1 (en) * | 2014-10-23 | 2017-03-16 | Ashapura Minechem Ltd. | Composites of sintered Mullite reinforced corundum granules and method for its preparation |
| CN105750060A (en) * | 2014-12-16 | 2016-07-13 | 沈阳铝镁设计研究院有限公司 | New dry-wet mixed grinding technology of bauxite |
| CN105503219A (en) * | 2015-12-29 | 2016-04-20 | 通达耐火技术股份有限公司 | Alumina-base sintered corundum mullite and preparation method thereof |
| CN106747497A (en) * | 2016-11-29 | 2017-05-31 | 江苏省冶金设计院有限公司 | The method for preparing corundum-mullite composite diphase material |
Non-Patent Citations (6)
| Title |
|---|
| 杨中正等: "刚玉-莫来石复合材料的制备研究", 《中国陶瓷》 * |
| 沈阳等: "烧结温度对莫来石刚玉复相材料微观结构的影响", 《稀有金属材料与工程》 * |
| 申献江等: "铝土矿尾矿除杂及合成刚玉-莫来石研究", 《耐火材料》 * |
| 罗民华: "《陶瓷工业节能减排技术丛书 陶瓷工业节能减排与污染综合治理》", 30 September 2017, 中国建材工业出版社 * |
| 西北建筑设计院编译: "《国外烧结建筑制品进展 第3辑》", 30 September 1981, 中国建筑工业出版社 * |
| 高振昕: "铝土矿的烧结与均化烧结", 《耐火材料》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116835969A (en) * | 2023-09-01 | 2023-10-03 | 北京利尔高温材料股份有限公司 | Corundum mullite and preparation method thereof |
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Application publication date: 20220318 |