阅读说明：本技术 一种高温瓷及其制备方法 (High-temperature porcelain and preparation method thereof ) 是由 李�根 李尧 于 2019-11-29 设计创作，主要内容包括：本发明提供了一种高温瓷及其制备方法。本发明提供的高温瓷由包括以下质量比物料的原料的制得：钾长石20％～40％；石英10％～20％；增塑剂5％～8％；活性氧化铝4％～6％；高岭土洗泥40％～60％；白云粉0.2％～0.8％。本发明在钾长石、石英、高岭土洗泥体系中引入活性氧化铝和白云粉,并将二者以特定比例搭配,再配合增塑剂,能够促使体系在反应过程中产生更多莫来石晶体,且活性氧化铝的微晶结构在瓷胎烧结反应中起到晶须增韧作用,能够提高成瓷的热稳定性和机械强度；白云粉能够促使加快高温烧结反应的进行,生成足量的液相填充,保证足够的玻璃相产生,且不影响活性氧化铝与其它成分间的反应,在保证热稳定性和机械强度的基础上提升成瓷的透光度。(The invention provides a high-temperature porcelain and a preparation method thereof. The high-temperature porcelain provided by the invention is prepared from the following raw materials in percentage by mass: 20 to 40 percent of potassium feldspar; 10% -20% of quartz; 5% -8% of a plasticizer; 4 to 6 percent of activated alumina; 40-60% of kaolin mud washing; 0.2 to 0.8 percent of dolomitic powder. According to the invention, active alumina and dolomite powder are introduced into a potash feldspar, quartz and kaolin mud washing system, the active alumina and the dolomite powder are matched according to a specific proportion, and then a plasticizer is matched, so that the system can be promoted to generate more mullite crystals in the reaction process, and the microcrystalline structure of the active alumina plays a whisker toughening role in a porcelain body sintering reaction, so that the thermal stability and the mechanical strength of the ceramic can be improved; the dolomitic powder can accelerate the high-temperature sintering reaction, generate sufficient liquid phase filling, ensure the generation of sufficient glass phase, does not influence the reaction between the activated alumina and other components, and improves the light transmittance of the finished porcelain on the basis of ensuring the thermal stability and the mechanical strength.)

1. The high-temperature porcelain is characterized by being prepared from the following raw materials in percentage by mass:

2. the high-temperature porcelain according to claim 1, wherein the activated alumina is ultra-fine activated alumina;

the particle diameter of the superfine activated alumina is 4-6 mm, and the specific surface area is 200-260 m ²(iv)/g, the crushing strength is 50-80N/granule.

3. The high-temperature porcelain according to claim 1, wherein the plasticizer is refined pug and comprises the following chemical components in percentage by mass:

4. the high-temperature porcelain according to claim 1, wherein the kaolin mud washing has a particle diameter of 0.03-0.08 mm and a water content of less than or equal to 30%.

5. The high-temperature porcelain according to claim 1, wherein the chemical composition of the high-temperature porcelain comprises, by mass:

the balance being impurities.

6. The preparation method of the high-temperature porcelain according to any one of claims 1 to 5, characterized by comprising the following steps:

a) mixing the materials with water, and performing ball milling to obtain slurry;

the materials comprise potassium feldspar, quartz, a plasticizer, activated alumina, kaolin mud washing and dolomite powder;

b) pugging and molding the slurry to obtain a biscuit;

c) and firing the biscuit to obtain the high-temperature porcelain.

7. The preparation method of the composite material as claimed in claim 6, wherein in the step a), the mass ratio of the material to the water is 1: 0.7-0.9;

the volume of the ball stone used in the ball milling is 1/3-1/2 of the volume of the ball milling tank;

ball milling until the fineness of the slurry is as follows: the 250-mesh screen residue is 0.1-0.3%.

8. The preparation method according to claim 6, wherein in the step b), before the pugging, the method further comprises the steps of preparing the mud into a mud cake;

the pugging comprises two times of rough refining and two times of refining;

the forming is to make a wet blank by using a blank rotating machine;

drying is also included after the forming.

9. The method according to claim 6, wherein the firing temperature in step c) is 1360 to 1380 ℃ for 6 to 8 hours.

10. The method of claim 6, further comprising glazing the greenbody prior to firing the greenbody.

Technical Field

The invention relates to the technical field of ceramic materials, in particular to a high-temperature ceramic and a preparation method thereof.

Background

The high-temperature ceramic is one of special ceramics, and refers to a ceramic material with the melting temperature above a silicon oxide melting point (1728 ℃) and the firing temperature above 1200 ℃. Compared with low-temperature porcelain, the high-temperature porcelain is fired at high temperature, has large crystallization density, high porcelain surface strength and fine and white porcelain quality, and can be fired and processed at high temperature again; the high-temperature-resistant high-hardness high-temperature-resistant high-hardness high-performance electrical property material can be used as a high-temperature structural material and is used in the fields of aerospace, machinery, chemical engineering, metallurgy and the like.

However, compared with low-temperature porcelain, the formula design of high-temperature porcelain is more difficult, the high-temperature porcelain needs to be fired under high-temperature conditions, and the grain boundary, microstructure and the like can generate changes which are difficult to control, so that the material performance is influenced; however, the correlation between the property change caused by the microstructure change and the effect of the chemical components of the ceramic does not have a mature mechanism, and the property of the ceramic does not correspond to the material or the additive in a one-to-one simple manner, for example, the thermal stability of the material and the apparent transmittance of the material are often influenced when the reinforcing agent is added to improve the strength, the mechanical property of the material is easily influenced when the additive is introduced to improve the transmittance, the interaction among the components does not have a mature rule, and the different properties are difficult to balance and harmonize, so that the improvement and the design of the formula are very difficult. At present, the high-temperature porcelain on the market generally has the defects of poor high-temperature deformation resistance, poor mechanical strength, poor apparent quality and the like, and the application of the high-temperature porcelain is influenced.

Disclosure of Invention

In view of the above, the present invention aims to provide a high temperature porcelain and a preparation method thereof. The high-temperature porcelain provided by the invention has high thermal stability, mechanical strength and transmittance.

The invention provides a high-temperature porcelain which is prepared from the following raw materials in percentage by mass:

preferably, the activated alumina is ultrafine activated alumina;

the particle diameter of the superfine activated alumina is 4-6 mm, and the specific surface area is 200-260 m ²(iv)/g, the crushing strength is 50-80N/granule.

Preferably, the plasticizer is refined pug and comprises the following chemical components in percentage by mass:

preferably, the particle diameter of the kaolin mud washing is 0.03-0.08 mm, and the water content is less than or equal to 30%.

Preferably, the chemical composition of the high-temperature ceramic comprises, by mass:

the invention also provides a preparation method of the high-temperature porcelain in the technical scheme, which comprises the following steps:

a) mixing the materials with water, and performing ball milling to obtain slurry;

the materials comprise potassium feldspar, quartz, a plasticizer, activated alumina, kaolin mud washing and dolomite powder;

b) pugging and molding the slurry to obtain a biscuit;

c) and firing the biscuit to obtain the high-temperature porcelain.

Preferably, in the step a), the mass ratio of the material to the water is 1: 0.7-0.9;

the volume of the ball stone used in the ball milling is 1/3-1/2 of the volume of the ball milling tank;

ball milling until the fineness of the slurry is as follows: the 250-mesh screen residue is 0.1-0.3%.

Preferably, in the step b), before the pugging, the mud is made into mud cakes;

the pugging comprises two times of rough refining and two times of refining;

the forming is to make a wet blank by using a blank rotating machine;

drying is also included after the forming.

Preferably, in the step c), the sintering temperature is 1360-1380 ℃ and the time is 6-8 h.

Preferably, before firing the biscuit, glazing the biscuit is also included.

The invention provides a high-temperature porcelain which is prepared from the following raw materials in percentage by mass: 20 to 40 percent of potassium feldspar; 10% -20% of quartz; 5% -8% of a plasticizer; 4 to 6 percent of activated alumina; 40-60% of kaolin mud washing; 0.2 to 0.8 percent of dolomitic powder. According to the invention, active alumina and dolomite powder are introduced into a potash feldspar, quartz and kaolin mud washing system, the active alumina and the dolomite powder are matched according to a specific proportion, and then a plasticizer is matched, so that the system can be promoted to generate more mullite crystals in the reaction process, and the microcrystalline structure of the active alumina plays a whisker toughening role in a porcelain body sintering reaction, so that the thermal stability and the mechanical strength of the ceramic can be improved; the dolomitic powder can accelerate the high-temperature sintering reaction, generate sufficient liquid phase filling, ensure the generation of sufficient glass phase, does not influence the reaction between the activated alumina and other components, and improves the light transmittance of the finished porcelain on the basis of ensuring the thermal stability and the mechanical strength.

The test result shows that the high-temperature porcelain provided by the invention has the advantages that the heat stability can reach 180-20 ℃, the porcelain is not cracked after heat exchange once, the strength reaches more than 170N/mm, and the light transmittance is more than 75%.

Detailed Description

The invention provides a high-temperature porcelain which is prepared from the following raw materials in percentage by mass:

according to the invention, active alumina and dolomite powder are introduced into a potash feldspar, quartz and kaolin mud washing system, the active alumina and the dolomite powder are matched according to a specific proportion, and then a plasticizer is matched, so that the system can be promoted to generate more mullite crystals in the reaction process, and the microcrystalline structure of the active alumina plays a whisker toughening role in a porcelain body sintering reaction, so that the thermal stability and the mechanical strength of the ceramic can be improved; the dolomitic powder can accelerate the high-temperature sintering reaction, generate sufficient liquid phase filling, ensure the generation of sufficient glass phase, does not influence the reaction between the activated alumina and other components, and improves the light transmittance of the finished porcelain on the basis of ensuring the thermal stability and the mechanical strength.

In the present invention, the chemical composition of potassium feldspar is K ₂O·Al ₂O ₃·6SiO ₂Belongs to the monoclinic system. In the invention, the potash feldspar can play a role in cooling, provide a liquid phase and ensure that the firing temperature of the formula pug reaches the normal firing temperature. In the invention, the using amount of the potassium feldspar is 20-40%, and preferably 20-22%; in some embodiments of the invention, potassium feldspar is used in an amount of 20%, 21%, 22%, 30% or 40%.

In the present invention, the quartz is a mineral composed of silica, which reacts with alumina to produce a mullite crystalline phase. In the invention, the quartz is used in an amount of 10-20%, preferably 18-20%; in some embodiments of the invention, quartz is used in an amount of 10%, 15%, 18%, or 20%.

In the invention, the plasticizer is refined pug and comprises the following chemical compositions in percentage by mass:

in the invention, the plasticizer is formed by refining pug, and specifically comprises the following raw materials in percentage by mass:

in the invention, the black mud refers to remains of animals and plants, algae, waterweeds, crustaceans and the like, silts for many years under the condition of oxygen deficiency, and is formed by mixing colloidal substances, organic substances and other substances generated by decomposition due to complicated physical and chemical changes of activities of various microorganisms. The source of the black mud is not particularly limited, and the black mud can be a general commercial product. In the invention, the white mud is a non-metal mineral product, is clay and claystone which mainly comprise kaolinite clay minerals, and is also called white and fine cloud soil. The source of the white mud is not particularly limited, and the white mud can be a general commercial product.

The plasticizer is prepared by the following steps: the plasticizer is obtained by ball milling, sieving, iron removing and drying the firewood saving porcelain clay, Guizhou kaolin, Datong coal gangue, bentonite, black mud and white mud. Wherein the rotation speed of the ball milling is 20-21 r/min, and the ball milling time is 20-22 hours. Wherein, the sieving is preferably carried out by a 325-mesh sieve, and the residue on the sieve is 0.3 to 0.5 percent. Wherein the iron removal is preferably high gradient iron removal and can be carried out by means of a high gradient iron removal machine. After the iron removal, the method preferably further comprises: and pressing the slurry into a mud cake. Then drying is carried out; the drying mode is not particularly limited, and the drying can be carried out by drying in the sun. In the present invention, the drying is preferably performed until the water content of the mud cake is 15% to 20%. In the present invention, after the drying, it is preferable to perform an extrusion process, and in some embodiments, a cylindrical clay section with a diameter of 0.3mm and a length of 50mm can be extruded through a press, that is, a clay material containing the above chemical composition is formed as a plasticizer. In the invention, the water content of the plasticizer is 15-20%, and the dry breaking strength is more than 7N/mm ²。

The introduction of the plasticizer can improve the process operability of the pug, so that the performance of the porcelain can be fully exerted. In the invention, the dosage of the plasticizer is 5-8%; in some embodiments of the invention, the plasticizer is present in an amount of 5%, 6%, or 7%.

In the present invention, the activated alumina is also called activated alumina, which is a porous and highly dispersed solid material, and is usually used as a drying agent, an adsorbent or a catalyst. The invention introduces a proper amount of active alumina to promote the reaction to generate more mullite crystal phases, improve the ceramic forming strength and reduce the high-temperature deformation of the porcelain, and the microcrystal structure of the active alumina plays a whisker toughening role in the sintering reaction of the porcelain body, thereby further helping to improve the porcelain forming stability and the mechanical strength and leading the whole porcelain to have high stability. In the invention, the activated alumina is preferably superfine activated alumina;more preferably, the particle diameter of the superfine activated alumina is 4-6 mm, and the specific surface area is 200-260 m ²(iv)/g, the crushing strength is 50-80N/granule; the physical property of the whole porcelain body is greatly improved by introducing a proper amount of superfine activated alumina. The source of the ultrafine activated alumina is not particularly limited, and the ultrafine activated alumina is a general commercial product.

In the invention, the use level of the activated alumina is 4-6%, the property of the porcelain body can be improved only in the use level range, and the physical and mechanical properties can be adversely affected by too low or too high use level. In some embodiments of the invention, the amount of activated alumina is 4%, 5%, or 6%.

In the invention, the kaolin mud washing is refined mud obtained by washing and filter-pressing kaolin crude ore. The kaolin mud washing is introduced into the material system, and the kaolin mud washing and the plasticizer have synergistic effect, so that the process operability of the mud is improved, and the performance of the ceramic is fully exerted. In the invention, the kaolin mud washing is preferably as follows: the particle diameter is 0.03-0.08 mm, and the water content is less than or equal to 30%.

In the invention, the dosage of the kaolin mud washing is 40-60%, preferably 46-52%; in some embodiments of the invention, the kaolin mud wash is used in an amount of 40.4%, 42.4%, 46.5%, 48.5%, or 50.8%.

In the invention, the dolomite powder is obtained by crushing and crushing dolomite. The proper amount of the dolomite powder is introduced into the material system, so that the high-temperature sintering reaction is more complete, the generation of sufficient stripping phase is ensured, the transmittance of the ceramic is improved, the reaction and the action between the activated alumina and other components are not influenced, and the high thermal stability and the mechanical strength are ensured; meanwhile, the dolomite powder contains magnesium element, so that the porcelain has greenish-blue tone in the sintering reaction of the material system, and the whole porcelain is relatively mellow and transparent.

In the invention, the dosage of the dolomite powder is 0.2 to 0.8 percent; in some embodiments of the invention, it is used in an amount of 0.2%, 0.3%, 0.5%, 0.7%, or 0.8%.

In the invention, the preferable mixture ratio of the materials is as follows:

in the invention, the optimal mixture ratio of the materials is as follows, and the ceramic has the best performance in the following mixture ratio:

in the invention, the materials are used as raw materials, and the chemical composition of the formed high-temperature porcelain comprises the following components in percentage by weight through mixing and sintering reaction:

the aluminum content of the traditional high-temperature high-aluminum porcelain is generally 21-23%, and the raw material formula of the high-temperature high-aluminum porcelain can enable the aluminum content of the porcelain to reach 26-28%.

The invention also provides a preparation method of the high-temperature porcelain in the technical scheme, which comprises the following steps:

a) mixing the materials with water, and performing ball milling to obtain slurry;

the materials comprise potassium feldspar, quartz, a plasticizer, activated alumina, kaolin mud washing and dolomite powder;

b) pugging and molding the slurry to obtain a biscuit;

c) and firing the biscuit to obtain the high-temperature porcelain.

According to the invention, the materials are mixed with water and ball-milled to obtain slurry.

Wherein the materials comprise potassium feldspar, quartz, a plasticizer, activated alumina, kaolin mud washing and dolomite powder; the types, the use amounts and the like of the materials are consistent with those in the technical scheme, and are not described in detail herein.

In the invention, the mass ratio of the material to the water is preferably 1 to (0.7-0.9). In the invention, the ball milling medium adopted by the ball milling is preferably high alumina ball stone. The volume ratio of the ball stones to the volume of the ball milling tank is preferably 1/3-1/2.

In the invention, the ball milling speed, the ball milling time and the loading capacity are strictly controlled in the ball milling process, so that the slurry with certain fineness is obtained. In the invention, the rotation speed of a 10Kg ball milling tank is preferably 60-62 r/min, the ball milling time is 16-18 h, and the ball milling load is 6Kg raw material; the rotation speed of a 500Kg ball milling tank is preferably 21r/min, the ball milling time is 16-18 h, and the ball milling load is 300Kg raw material.

After ball milling, the slurry was discharged and the slurry fineness was determined. In the invention, the ball milling is preferably carried out until the fineness of the slurry is: the 250-mesh screen residue is 0.1-0.3%. Specifically, after ball milling, the discharged slurry is sieved (220-mesh national standard steel sieve) to remove iron for later use.

According to the invention, after the slurry is obtained, the slurry is pugged and formed to obtain a biscuit.

In the invention, before the pugging, the mud is preferably made into mud cakes. Specifically, the mud can be pressed into mud cakes by a mud press, and then the mud cakes are refined into mud strips by a mud connecting machine. In the invention, the pugging comprises two times of rough refining and two times of refining. And obtaining the mud strips after pugging.

In the invention, the mud strip is molded. The forming method is not particularly limited, and may be performed according to a ceramic forming method known to those skilled in the art, such as wet forming the clay strips by using a rotary forming machine. In the present invention, after forming to obtain a wet green, drying is preferably further included. The drying temperature is preferably 60-90 ℃, and the drying time is preferably 6-8 h. After drying, post-treatment such as rinsing may be performed. And (4) obtaining a biscuit after the molding.

In the present invention, after obtaining a green body, it is preferable to further perform glazing. The glazing mode is not particularly limited by the invention, and the glazing mode is performed according to the glazing mode known to the skilled person, and the glazing mode is performed by adopting a manual glazing mode. The glaze adopted in the glazing process is not particularly limited, and the glaze is a conventional glaze adopted for glazing porcelain in the field.

According to the invention, the blank is obtained and then sintered to obtain the high-temperature porcelain.

In the invention, the sintering temperature is 1360-1380 ℃ and the time is 6-8 h. By the material formula and the combination of the firing conditions, the aluminum content in the porcelain is improved to 26-28%, and the high transmittance is obtained while the high-temperature deformation resistance and the porcelain forming strength of the whole porcelain are improved through the synergistic effect of the additive.

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In the following examples, the technical specifications of the activated alumina used are as follows: the particle diameter is 4-6 mm, and the specific surface area is 200-260 m ²(iv)/g, the crushing strength is 50 to 80N/pellet, and is provided by Zhongai Shandong Co., Ltd. The particle diameter of the kaolin mud washing is 0.03-0.08 mm, and the water content is less than or equal to 30%. The glaze used in the glazing procedure was high temperature white glaze, provided by carinlong letter transfer inorganic materials ltd. The plasticizer is refined pug and comprises the following chemical compositions: 47% of silicon dioxide, 35% of aluminum oxide, 0.2% of ferric oxide, 0.2% of titanium oxide, 1% of calcium oxide, 1% of magnesium oxide, 0.5% of potassium oxide, 0.5% of sodium oxide and 15% of ignition loss; the plasticizer is prepared according to the raw material mud formula and the preparation method.