CN111875398B - Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof - Google Patents
Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof Download PDFInfo
- Publication number
- CN111875398B CN111875398B CN202010809854.XA CN202010809854A CN111875398B CN 111875398 B CN111875398 B CN 111875398B CN 202010809854 A CN202010809854 A CN 202010809854A CN 111875398 B CN111875398 B CN 111875398B
- Authority
- CN
- China
- Prior art keywords
- powder
- silicon carbide
- temperature
- magnesia
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/66—Monolithic refractories or refractory mortars, including those whether or not containing clay
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/44—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 aluminates
- C04B35/443—Magnesium aluminate spinel
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
- C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
- C04B35/597—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on silicon oxynitride, e.g. SIALONS
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- 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
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
- C04B2235/9669—Resistance against chemicals, e.g. against molten glass or molten salts
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Ceramic Products (AREA)
Abstract
The invention belongs to the field of refractory materials, and mainly relates to a nitride-silicon carbide-magnesia-alumina spinel complex-phase refractory material product and a preparation method thereof. The raw materials of the related nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product comprise aggregate and matrix; the aggregate is silicon carbide particles; the matrix contains magnesia-alumina spinel fine powder, active alumina micro powder, metal Al powder and elemental Si powder, wherein the content of the magnesia-alumina spinel fine powder accounts for 30-45% of the total mass of the raw materials, the content of the active alumina micro powder accounts for 1-6% of the total mass of the raw materials, the content of the metal Al powder accounts for 1-5% of the total mass of the raw materials, and the content of the elemental Si powder accounts for 3-10% of the total mass of the raw materials; the silicon carbide particles account for 50-65% of the total mass of the raw materials. The invention has the advantages of low expansion coefficient, high chemical stability, excellent high-temperature mechanical property and good hot spot of slag erosion resistance.
Description
Technical Field
The invention belongs to the field of refractory materials, and mainly relates to a nitride-silicon carbide-magnesia-alumina spinel complex-phase refractory material product and a preparation method thereof.
Background
The core for promoting clean and efficient conversion and utilization of coal is to realize high-quality development of a coal gasification technology; based on the characteristics of energy structure (rich coal, lean oil and less gas) and the ecological concept of green and sustainable development in China, the coal gasification is promotedThe high-quality development of the technology has important significance for realizing the deep processing and the clean and high-efficiency utilization of the coal; at present, with the mature development of the coal water slurry gasification technology, the coal water slurry gasification furnace has become the mainstream equipment for coal gasification, but the coal water slurry gasification furnace has high temperature (1300-1500 ℃), high pressure (2.0-8.7 MPa) and strong reducing atmosphere (main components of CO and H)2) The working environment of the coal gasification furnace puts more rigorous requirements on the lining refractory material, the selected refractory material not only can meet the service environment of high-temperature, high-pressure and strong reducing atmosphere, but also must bear coal slag (CaO, FeO) generated in the low-rank coal gasification processx、Al2O3、MgO、TiO2、K2O、Na2O, etc.) and physical scouring of high-temperature gases such as coal-water slurry gas, etc., so that the refractory material is required to have excellent erosion resistance, high-temperature mechanical strength and stability; . The most widely used lining material in the coal water slurry gas furnace at the present stage is Cr2O3More than 75wt% Cr2O3-Al2O3-ZrO2Systematic pure oxide bricks (high chrome bricks); but the chromium resource is limited, the exploitation cost is high, the environmental pollution is large, and particularly, the chromium can react with certain substances in the coal slag to generate Cr in the service process6+Ions, which have potential environmental hazards; therefore, how to develop a novel high-temperature material to realize the chromium-free treatment of the lining material for the coal water slurry gasification furnace becomes a technical problem which must be overcome in the popularization and application of the coal water slurry gasification furnace and the matched technology thereof.
Research shows that compared with pure oxide material or pure non-oxide material, the non-oxide composite material prepared by selecting proper oxide and non-oxide has special high-temperature performance which is not possessed by the oxide and the non-oxide, and can be used as an important exploration direction for promoting the realization of the chromium-free of the refractory material for the water-coal-slurry gasification furnace. Application document CN201711187027.6 discloses a silicon carbide-magnesium aluminate spinel composite refractory material, which is prepared by mixing silicon carbide and a binder uniformly, adding magnesium aluminate spinel, and pressing and sintering, but because of the poor sintering property of silicon carbide, the silicon carbide can be sintered to a certain extent at a very high temperature above 2200 ℃, and in addition, the high melting point (2135 ℃) of magnesium aluminate spinel makes the sintering temperature of the composite material reach above 1800 ℃.
To prevent oxidation of the silicon carbide, such composites are typically sintered under a protective atmosphere. Earlier exploration finds that the silicon carbide-magnesia-alumina spinel composite material still needs higher temperature even being sintered in a reducing atmosphere, the normal-temperature bending strength of the silicon carbide-magnesia-alumina spinel composite material is less than 10 MPa when the sintering condition is 1650 ℃ carbon burying, the high-temperature bending strength is less than 5MPa, and the lower mechanical strength is extremely unfavorable for the material to resist the high-speed erosion of slag in the use process. The main reason for analyzing the low mechanical strength of the composite material is because the silicon carbide and the magnesium aluminate spinel are bonded in different ways. Silicon carbide is covalently bonded, and magnesium aluminate spinel is ionically bonded oxide, so that the silicon carbide and the magnesium aluminate spinel are not wet with each other and are difficult to form effective chemical bonding.
Mg-alpha-Sialon phase and MgAlON phase materials are applied to the field of high-technology ceramics at present, and the application research on refractory materials is relatively less, but the excellent mechanical properties, high-temperature thermal stability, and excellent slag and molten metal erosion resistance and thermal shock resistance of the materials determine that the materials can be applied to the industrial production of high-temperature materials; in the current price section, the material is prepared mainly by three one-step nitridation methods, namely carbothermal reduction nitridation, solid-phase reaction and direct nitridation, but the three preparation methods all have the defects of different degrees. When the carbothermic nitridation method is utilized, the carbon residue condition exists in a material system, and the performance of the material is influenced; when a solid phase reaction is utilized, the reaction process takes much time and the cost of raw materials such as silicon nitride, aluminum nitride and the like is high; when direct nitridation is utilized, the metal powder is difficult to be completely nitrided, the purity of the prepared material cannot be ensured, and the preparation of large-size materials is particularly unfavorable. Based on this, how to realize the nitridation process with excellent performance and lower production cost of the nitrided material still needs to be further explored.
Through the discussion above, in order to promote the chromium-free of the refractory material for the coal water slurry gasification furnace, how to improve the strength of the silicon carbide-magnesium aluminate spinel composite material and optimize the slag resistance of the composite material, and also consider the high-temperature slag corrosion resistance and the melt erosion resistance of the composite material, is a technical problem.
Disclosure of Invention
In order to solve the technical problems of low bonding strength of the silicon carbide-magnesium aluminate spinel composite material and optimization of high-temperature slag corrosion resistance and melt erosion resistance of the silicon carbide-magnesium aluminate spinel composite material, the invention provides a nitride-silicon carbide-magnesium aluminate spinel complex-phase refractory material product and a preparation method thereof.
The invention adopts the following technical scheme for achieving the purpose:
a nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product comprises raw materials of aggregate and matrix; the aggregate is silicon carbide particles; the matrix contains magnesia-alumina spinel fine powder, active alumina micro powder, metal Al powder and elemental Si powder, wherein the content of the magnesia-alumina spinel fine powder accounts for 30-45% of the total mass of the raw materials, the content of the active alumina micro powder accounts for 1-6% of the total mass of the raw materials, the content of the metal Al powder accounts for 1-5% of the total mass of the raw materials, and the content of the elemental Si powder accounts for 3-10% of the total mass of the raw materials; the silicon carbide particles account for 50% -65% of the total mass of the raw materials; the nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product is a refractory material with a certain shape after high-temperature nitridation treatment in a nitriding furnace at the temperature of 1300-1600 ℃, and has the apparent porosity of 14-19%, the normal-temperature flexural strength of 25-45 MPa and the high-temperature flexural strength of 15-35 MPa at the temperature of 1400 ℃ under a carbon-buried atmosphere; XRD analysis shows that the main mineral phases comprise silicon carbide, spinel, MgAlON and Mg-alpha Sialon.
The metal Al powder is prepared by mixing Al powder,w(Al) is more than or equal to 99 percent, and the particle size is less than or equal to 60 mu m; require thatw(Al) is more than or equal to 99 percent because a certain oxygen partial pressure is still in the nitriding furnace during nitriding sintering, and if the purity is not high, impurities are easy to react with SiO2A low-melting-point phase is generated by reaction, so that the integral slag corrosion resistance and high-temperature mechanical property of the material are influenced; the metal aluminum powder is required to have smaller granularity, so as to promote the nitriding effect and improve the conversion rate of alpha-Sialon phase and AlON phase; the reason why the metallic aluminum powder is introduced is that one of them can pass through with α -Si3N4、Al2O3The alpha-Sialon phase is formed by solid solution, and the metal aluminum powder introduced into the alpha-Sialon phase can also be introduced into the alpha-Sialon phaseThe thermit nitridation reaction and the active Al added in the raw material2O3Al solid-dissolved in powder and magnesium aluminate spinel2O3MgO is subjected to direct nitriding reaction sintering (Al)2O3 +Al+N2+ MgO → MgAlON) to form MgAlON phase; MgAlON can be regarded as MgAl2O4Solid solutions with stable AlON phases, i.e. MgAl2O4Wherein the O atom in the magnesium aluminate spinel is replaced by the N atom, when the oxygen atoms at the eight vertexes of the magnesium aluminate spinel are partially replaced by the nitrogen atoms, a low nitrogen content MgAlON phase is formed, and when the oxygen atoms at the eight vertexes of the magnesium aluminate spinel are completely replaced by the nitrogen atoms, a high nitrogen content MgAlON phase is formed. Since MgAlON crystal also has a cubic spinel structure, it also has a structure similar to MgAl2O4The magnesium aluminate spinel has similar expansion coefficient and physical properties, can obviously promote the sintering of the magnesium aluminate spinel, and is a refractory material with the characteristics of oxides and non-oxides; in addition, the MgAlON phase also has the characteristics of excellent thermal shock resistance, erosion resistance and the like, and when the MgAlON phase is used as a bonding phase, the high-temperature mechanical property and the slag erosion resistance of the composite refractory material can be obviously improved.
The simple substance Si powder is prepared by mixing the following components,w(Si) is more than or equal to 97 percent, and the particle size is less than or equal to 45 mu m; require thatw(Si) ≥ 97% because SiO is an impurity if its purity is not high2The existence of the isometric phase reacts with magnesia-alumina spinel, active alumina powder, metal aluminum powder and the like to generate low-melting-point phases such as cordierite, mullite and the like, so that the integral anti-cinder erosion performance and the high-temperature mechanical property of the material are influenced; the requirement that the particle size of the elemental silicon powder is small is because the elemental silicon powder needs to be nitrided more under the high-temperature nitriding condition to generate a nitride bonding phase, and if the particle size is too large, incomplete nitriding is caused, so that more metal silicon powder remains after firing, and the overall performance of the composite product is influenced. The reason for introducing the elemental silicon powder is that the elemental silicon powder can directly react with nitrogen to generate Si at the temperature of over 1000 DEG C3N4alpha-Si at temperatures above 1300 deg.C3N4Can be mixed with Al2O3AlN forms an alpha-Sialon phase through solid solution, so that the aluminum nitride alloy has the advantages of nitride and oxide, and has excellent high-temperature mechanical property and slag corrosion resistance. In addition Mg2+、Ca2+And the metal cations are subjected to gap filling compensation on the structure of the alpha-Sialon at a high temperature state, so that a metal-based Sialon phase such as Mg-alpha-Sialon can be formed, the content of a low-melting-point phase around the grain boundary of the composite material can be obviously reduced, and the high-temperature strength of the material is improved. In view of the above, the Sialon phase is considered to be an excellent nitride-bonded phase in high-temperature industries.
The silicon carbide particles have a particle size of more than 0.1mm and less than or equal to 5mm and a purity ofw(SiC) is more than or equal to 97 percent of electric melting raw material; the reason that the silicon carbide is selected for preparation by an electric melting method is that the silicon carbide material prepared by the method has good crystal integrity and higher density and erosion resistance; the purity is required to bew(SiC) is more than or equal to 97 percent, so as to avoid the damage of the overall performance of the material due to the generation of low-melting-point solid solution caused by the existence of impurities such as silicon dioxide and the like; the granularity of SiC particles with the same granularity of 0.1-5 mm is required to be selected to meet the requirements of forming and density and bonding performance.
The magnesia-alumina spinel fine powder is one kind of magnesia-alumina spinelw(Al2O3+ MgO) is more than or equal to 99.0 percent, the content of spinel phase is more than or equal to 95 percent by X-ray diffraction analysis, and the granularity is 10-90 mu m; the magnesium aluminate spinel is Al2O3-the most stable compound under the binary system MgO; magnesium-rich spinels and aluminum-rich spinels can be classified according to the relative content of aluminum oxide and magnesium oxide in the magnesium aluminum spinels. Based on the service environment of the composite material and the special requirements of excellent slag resistance, Al2O3The total mass fraction of + MgO must be greater than 99.0%. The spinel with the particle size range of 10-90 mu m is required to be fully mixed with metal aluminum powder and elemental silicon powder, so that the nitride bonding phase is uniformly distributed with silicon carbide aggregate, and the bonding strength and the slag resistance of the spinel are optimized. If the particle size of the magnesia-alumina spinel is unreasonable, the defects of poor sintering performance of the prepared product, low compactness of the product, reduced slag resistance and the like can be caused.
The active alumina micro powder, Al2O3The mass fraction of the particle is more than or equal to 99.0 percent, and the particle size range is D50= 0.5-2 μm; the introduction of the activated alumina micro powder can not only improve the toleranceThe fire material chemically erodes the acid slag, the normal temperature and high temperature strength of the refractory material is improved, and the active alumina micro powder can generate a series of solid solution reactions with metal aluminum powder, elemental silicon powder and magnesia alumina spinel to promote the in-situ generation of MgAlON and Mg-alpha-Sialon phases;
a preparation method of a nitride-silicon carbide-magnesia-alumina spinel complex-phase refractory material product is characterized by comprising the following steps: the sintering process in the preparation method is a two-step three-section type heat preservation sintering method, namely, after metal Al powder and simple substance Si powder are mixed, 10% of the mass of the metal Al powder and the simple substance Si powder mixed with the metal powder is weighed, and the mixed powder is subjected to first-step nitrogen sintering in a flowing nitrogen atmosphere to obtain mixed powder, wherein the nitriding temperature is 1150-1250 ℃, and the nitrogen flow is 5-10L/(h.m)3) The nitrogen partial pressure in the firing atmosphere is 0.15-0.2 MPa; ball-milling the mixed powder after the first step of pre-nitridation, uniformly mixing the mixed powder with the rest of metal Al powder, simple substance Si powder, magnesia-alumina spinel fine powder and active alumina micro powder, finally uniformly mixing the mixed powder with silicon carbide particles and magnesium aluminate sol binder, ageing the mixture, pressing the mixture into a green body with a certain size and shape, drying the green body and then carrying out the second step of air pressure sintering, wherein the nitridation temperature is 1300-1600 ℃, and the nitrogen flow is 5-10L/(h.m)3) The pressure of the nitrogen gas for sintering is 6-12 MPa; the metal aluminum powder and the elemental silicon powder form a nitride binding phase after high-temperature nitridation; Mg-alpha-Sialon and MgAlON generated after the 1300-1600 ℃ nitriding air pressure sintering are composite nitride bonding phases, have excellent high-temperature performance, and can improve the wettability of magnesium aluminate spinel silicon carbide, thereby promoting the silicon carbide composite product to form stronger bonding, and the bonding can keep excellent mechanical performance and slag resistance of the refractory material under the high-temperature condition; the preparation method comprises the following specific steps:
step 1, uniformly mixing metal Al powder and simple substance Si powder, weighing 10% of the mixed powder by mass, and filling the weighed mixed powder into a crucible, and keeping the rest for later use;
step 2, performing first-step pre-nitridation firing on the crucible filled with the mixed powder in a flowing nitrogen atmosphere, wherein a two-section heat preservation method is adopted in the firing process: respectively preserving heat at 600 ℃ and the highest nitriding temperature point for 3-6 h, wherein the nitriding temperature is 1150-1250 ℃, and the nitrogen flow is 5-10L/(h)·m3) The nitrogen partial pressure in the firing atmosphere is 0.15-0.2 MPa;
step 3, ball-milling the mixed powder nitrided in the first step, uniformly mixing the ball-milled mixed powder with the rest of metal Al powder, simple substance Si powder, magnesia-alumina spinel fine powder and active alumina micro powder to obtain a matrix, and mixing the matrix with silicon carbide particles and a magnesium aluminate sol binder to obtain a sand-like material with certain viscosity;
step 4, filling the sand-shaped material into a mold after ageing, and forming a green body with a certain size and shape;
step 5, drying the green body, naturally drying for 12-48 h, and forcibly drying at 180-200 ℃ for 12-24 h;
6, placing the dried green body in a kiln to perform second-step air pressure firing in a flowing nitrogen atmosphere, wherein a three-section heat preservation method is adopted in the firing process: respectively keeping the temperature at 600 ℃, 1200 ℃ and the highest nitriding temperature point for 3-6 h, wherein the highest nitriding temperature is set to be 1300-1600 ℃, and the nitrogen flow is 5-10L/(h.m)3) The nitrogen pressure in the firing atmosphere is 6-12 MPa; and after the firing is finished, obtaining the final nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product.
According to the preparation method of the nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product, the non-oxide silicon carbide bonded by covalent bonds has excellent slag erosion resistance and thermal shock resistance, but has lower compatibility with the magnesia-alumina spinel bonded by ionic bonds, and is difficult to form effective chemical bonding, so that the bonding strength of the non-oxide silicon carbide and the magnesia-alumina spinel bonded by ionic bonds is enhanced by introducing nitrides, but the nitriding process is more complex and is controlled by a plurality of factors such as nitrogen partial pressure, nitrogen flow and the like, and if elemental metal powder is adopted to be directly nitrided to generate a nitride bonding phase, the nitride bonding phase is influenced by a metal melting point and a nitriding reaction rate in the sintering process. Because the metal elemental powder has a nitriding reaction with nitrogen and a sintering process also exists among fine powder of the metal elemental powder, particularly when the temperature is close to the melting point (660 ℃ of metal Al powder and 1410 ℃ of elemental silicon powder), the self-sintering phenomenon of the elemental metal powder becomes more obvious, which causes the residual problem of the elemental metal powder and influences the overall performance of the material. In addition, the nitriding reaction of elemental metal powders is an exothermic reactionAccordingly, in the nitridation process, if the elemental metal powder is mixed with N2If the reaction is too violent, the composite material may be locally overheated and the metal liquid phase may overflow, so as to block and seal the sample pores, which may also hinder the proceeding degree of nitridation, resulting in the problem of residual metal simple substance. Therefore, in order to improve the generation rate of alpha-Sialon phase and AlON phase and reduce the content of residual elemental metal powder, a two-step three-section type nitriding firing system is adopted, and the nitriding rate can be obviously improved and the seepage of a metal liquid phase can be slowed down by adjusting the nitriding partial pressure, the nitrogen flow and the temperature around the metal melting point during the first step of nitriding firing so as to prepare the Si with higher activity3N4Mixing with AlN powder, and ball milling to obtain Si powder3N4The AlN mixed powder, other components in the matrix, silicon carbide and magnesium aluminate sol binder are subjected to secondary mixing, pressing and drying, and then secondary nitridation firing is carried out, the control of nitridation reaction rate and degree can be realized and the decomposition of alpha-Sialon phase and MgAlON phase can be inhibited by utilizing the combined influence of a three-section heat preservation system of gas phase pressurization and the dilution effect of the pre-nitrided powder, so that the generation rate of the alpha-Sialon phase and the MgAlON phase can be obviously improved, and the amount of residual elemental metal powder can be reduced. When a two-step three-section type nitriding firing system is adopted, the mass fraction of N in the nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product can be obviously improved compared with the one-step direct firing system, which shows that Si generated in the first step of nitriding firing3N4The AlN mixed powder can play a role of crystal nucleus in the second step of nitriding firing, can obviously improve the nitriding rate of the nitride-combined silicon carbide-magnesium aluminate spinel complex phase refractory material product, and simultaneously can inhibit the decomposition of the nitride by adopting the air pressure sintering in the second step, improve the compactness of the composite material and reduce the nitriding temperature of the material.
Mg-alpha-Sialon is Mg2+Filling alpha-Si formed by alpha-Sialon structure gap3N4The molecular formula of the solid solution is MgxSi12-(m+n)Alm+nOnN16-n(x is less than or equal to 2, m is the amount of Al-N substituted Si-N, and N is the amount of Al-O substituted Si-N). Because the aggregate silicon carbide surface is depositedIn the presence of SiO2And the generated Mg-alpha-Sialon is mainly attached to the surface of the spinel substrate, so that the silicon carbide and the magnesium aluminate spinel are combined tightly, the sintering degree of the magnesium aluminate spinel is improved, and the generated Mg-alpha-Sialon has higher nitrogen content, so that the liquid phase viscosity at high temperature is high, and the slag corrosion resistance of the magnesium aluminate spinel is improved. In particular it has a structure of3N4Due to the similar crystal lattices, the Mg-alpha-Sialon has not only excellent physical properties such as mechanical strength and hardness, but also excellent high-temperature mechanical property, thermal property and chemical stability.
MgAlON can be considered as a substitution of MgAl by N atom2O4A bonding phase with a stable crystal structure formed after the O atom in the (B) group, and the molecular general formula of the bonding phase is Mg（8-x）/3Al(64+x)O32-xNx(x is the amount of N substituted for O). By substitution of MgAl by N atoms2O4The atomic weight of O in the alloy can be divided into MgAlON phase with low nitrogen content and MgAlON phase with high nitrogen content. Al dissolved in magnesium aluminate spinel by using thermite reaction through introduced metal aluminum powder2O3MgO direct nitriding sintering (Al)2O3+Al+N2+ MgO → MgAlON) to form a MgAlON phase. Research shows that the composite material has excellent mechanical performance and oxidation resistance at normal temperature, can well maintain the advantages at high temperature, and has the advantages of low expansion coefficient, high chemical stability, excellent high-temperature mechanical performance, good slag corrosion resistance and the like.
The nitride-silicon carbide-magnesia-alumina spinel complex-phase refractory product is mainly applied to a coal gasification high-temperature service environment with a reducing atmosphere at 1300-1500 ℃, under the condition, coal slag seriously erodes the refractory material and seriously physically erodes the refractory material at high temperature, and in order to meet the requirements of excellent high-temperature mechanical strength and slag resistance of the refractory product, raw materials of the product have high chemical purity and high phase content; the nitride-silicon carbide-magnesia alumina spinel complex-phase refractory material product which is formed by nitriding the introduced metal aluminum powder and the elemental silicon powder at high temperature and takes Mg-alpha-Sialon and MgAlON as composite nitride phases has the characteristics of high chemical purity, low glass phase content, excellent mechanical strength, high-temperature slag corrosion resistance, high-temperature wear resistance and the like, and can obviously improve the performance of the composite refractory product.
Detailed Description
The invention is illustrated by the examples given, but is not to be construed as being in any way limited thereto.
Example 1:
respectively weighingw(Al) is more than or equal to 99 percent, and the granularity of the metal aluminum powder is less than or equal to 60 mu m by 1 kg,w3 Kg of (Si) metal silicon powder with the particle size of more than or equal to 99 percent and the particle size of less than or equal to 45 mu m are uniformly mixed, 0.4Kg of the mixture is taken and put into a crucible, the crucible is put into a flowing nitrogen atmosphere with the pressure of 0.15MPa and the volume of 10L/h, the temperature is respectively kept at 600 ℃ and 1250 ℃ for 3h for the first-step pre-nitridation sintering, the mixed powder is subjected to ball milling after natural cooling, and then the mixed powder is weighedw(Al2O3) ≥99%、D501 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O345kg of magnesium aluminate spinel fine powder with 99.0 percent of MgO) =99.0 percent, the granularity is less than or equal to 0.1mm and the magnesium aluminate spinel phase is 95 percent, the mixed powder after the pre-nitriding ball milling is uniformly mixed with the rest metal Al powder, the simple substance Si powder, the magnesium aluminate spinel fine powder and the active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 50kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln to be sintered at the pressure of 1300 ℃ under the flowing nitrogen atmosphere of 6Mpa and 10L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1300 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 19 percent, the normal temperature rupture strength of 25MPa and the high temperature rupture strengthThe temperature (1400 ℃ for 30min, carbon burying) is 15 MPa.
Example 2:
respectively weighingw(Al) is more than or equal to 99 percent, and the granularity of the metal aluminum powder is less than or equal to 60 mu m by 1 kg,w3 Kg of (Si) metal silicon powder with the particle size of more than or equal to 99 percent and the particle size of less than or equal to 45 mu m are uniformly mixed, 0.4Kg of the mixture is taken and put into a crucible to be subjected to first-step pre-nitridation sintering under the flowing nitrogen atmosphere of 0.2MPa and 5L/h at the temperature of 600 ℃ for 3h and at the temperature of 1150 ℃ for 6h, the mixed powder is subjected to ball milling after natural cooling, and then the mixed powder is weighedw(Al2O3) ≥99%、D501 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O345kg of magnesium aluminate spinel fine powder with 99.0 percent of MgO) =99.0 percent, the granularity is less than or equal to 0.1mm and the magnesium aluminate spinel phase is 95 percent, the mixed powder after the pre-nitriding ball milling is uniformly mixed with the rest metal Al powder, the simple substance Si powder, the magnesium aluminate spinel fine powder and the active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 50kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln to be sintered at the pressure of 1300 ℃ under the flowing nitrogen atmosphere of 6Mpa and 10L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1300 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 19 percent, the normal-temperature flexural strength of 27MPa and the high-temperature flexural strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 16 MPa.
Example 3:
respectively weighingw(Al) is more than or equal to 99 percent, and the granularity of the metal aluminum powder is less than or equal to 60 mu m by 1 kg,w3 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, uniformly mixing, taking 0.4Kg of the mixture, putting the mixture into a crucible, preserving heat for 3h at 600 ℃ and 6h at 1250 ℃ under the flowing nitrogen atmosphere with the pressure of 0.15MPa and the volume of 10L/h, performing the first-step pre-nitridation sintering, and naturally coolingBall milling the mixed powder after cooling, and weighingw(Al2O3) ≥99%、D501 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 65kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln to be sintered under the flowing nitrogen atmosphere of 6Mpa and 10L/h at the temperature of 1400 ℃ for 3h at the temperature of 600 ℃ and 1200 ℃ and the temperature of 1400 ℃ is kept for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 18 percent, the normal temperature flexural strength of 29MPa and the high temperature flexural strength (the temperature of 1400 ℃ is kept for 30min, and the carbon is buried) of 18 MPa.
Example 4:
respectively weighingw(Al) is more than or equal to 99 percent, and the granularity of the metal aluminum powder is less than or equal to 60 mu m by 1 kg,w3 Kg of (Si) metal silicon powder with the particle size of more than or equal to 99 percent and the particle size of less than or equal to 45 mu m are uniformly mixed, 0.4Kg of the mixture is taken and put into a crucible to be subjected to first-step pre-nitridation sintering under the flowing nitrogen atmosphere of 0.15MPa and 10L/h at the temperature of 600 ℃ for 3h and at the temperature of 1250 ℃ for 6h, the mixed powder is subjected to ball milling after natural cooling, and then the mixed powder is weighedw(Al2O3) ≥99%、D501 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 65kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln to be sintered at the pressure of 1400 ℃ under the flowing nitrogen atmosphere of 12Mpa and 5L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1400 ℃ for 3 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 17 percent, the normal-temperature rupture strength of 32MPa and the high-temperature rupture strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 20 MPa.
Example 5:
respectively weighingw(Al) is more than or equal to 99 percent, the granularity of the metal aluminum powder is less than or equal to 60 mu m, 2 kg of the metal aluminum powder,wuniformly mixing 6 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, taking 0.8Kg of the mixture, putting the mixture into a crucible, preserving heat for 3h at 600 ℃ and 6h at 1250 ℃ under the flowing nitrogen atmosphere with the pressure of 0.15MPa and the pressure of 10L/h, performing the first-step pre-nitridation sintering, naturally cooling, ball-milling the mixed powder, weighing the mixed powder, andw(Al2O3) ≥99%、D502 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 35kg of magnesia alumina spinel fine powder with 95%, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 55kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then placing the dried green body inThe furnace is sintered at the pressure of 1500 ℃ under the flowing nitrogen atmosphere of 6Mpa and 10L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1500 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 16 percent, the normal temperature rupture strength of 33MPa and the high temperature rupture strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 21 MPa.
Example 6:
respectively weighingw(Al) is more than or equal to 99 percent, the granularity of the metal aluminum powder is less than or equal to 60 mu m, 2 kg of the metal aluminum powder,wuniformly mixing 6 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, taking 0.8Kg of the mixture, putting the mixture into a crucible, keeping the temperature of the crucible under the flowing nitrogen atmosphere of 0.2MPa and 5L/h for 3h at 600 ℃ and 6h at 1150 ℃, performing the first-step pre-nitridation sintering, naturally cooling, ball-milling the mixed powder, weighing the mixed powder, andw(Al2O3) ≥99%、D502 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 35kg of magnesia alumina spinel fine powder with 95%, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 55kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln and sintered at the pressure of 1500 ℃ under the flowing nitrogen atmosphere of 6Mpa and 10L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1500 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 16 percent, the normal temperature flexural strength of 35MPa and the high temperature flexural strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 23 MPa.
Example 7:
respectively weighingwMore than or equal to 99 percent of (Al) and 5kg of metal aluminum powder with the granularity of less than or equal to 60 mu m,wuniformly mixing 9 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, taking 1.4Kg of the mixture, filling the mixture into a sagger, preserving heat for 3h at 600 ℃ and preserving heat for 6h at 1250 ℃ under the flowing nitrogen atmosphere with the pressure of 0.15MPa and 10L/h for the first-step pre-nitridation sintering, naturally cooling, ball-milling the mixed powder, weighing the mixed powder, andw(Al2O3) ≥99%、D506 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 50kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln and sintered in a flowing nitrogen atmosphere of 6Mpa and 10L/h at 1600 ℃ of air pressure, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1600 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 16%, the normal temperature flexural strength of 38MPa and the high temperature flexural strength (the temperature of 1400 ℃ is kept for 30min, and the carbon is buried) of 25 MPa.
Example 8:
respectively weighingwMore than or equal to 99 percent of (Al) and 5kg of metal aluminum powder with the granularity of less than or equal to 60 mu m,wuniformly mixing 9 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, taking 1.4Kg of the mixture, filling the mixture into a sagger, preserving heat for 3h at 600 ℃ and preserving heat for 6h at 1250 ℃ under the flowing nitrogen atmosphere with the pressure of 0.15MPa and 10L/h for the first-step pre-nitridation sintering, naturally cooling, ball-milling the mixed powder, weighing the mixed powder, andw(Al2O3) ≥99%、D506 kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 50kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln and sintered by the pressure of 1600 ℃ under the flowing nitrogen atmosphere of 12Mpa and 5L/h, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1600 ℃ for 3 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 15 percent, the normal temperature flexural strength of 40MPa and the high temperature flexural strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 27 MPa.
Example 9:
respectively weighingwMore than or equal to 99 percent of (Al) and 5kg of metal aluminum powder with the granularity of less than or equal to 60 mu m,wuniformly mixing 10 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and the grain size of less than or equal to 45 mu m, taking 1.4Kg of the mixture, filling the mixture into a sagger, preserving heat for 3h at 600 ℃ and preserving heat for 6h at 1250 ℃ under the flowing nitrogen atmosphere with the pressure of 0.15MPa and the volume of 10L/h for the first-step pre-nitridation sintering, naturally cooling, ball-milling the mixed powder, weighing the mixed powder, andw(Al2O3) ≥99%、D505kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0% and carbonization with particle size of more than 0.1mm and less than or equal to 5mm50kg of silicon particles and 4kg of magnesium aluminate sol binder are uniformly mixed in a roller mill, the early mixed fine powder is added and stirred and uniformly mixed to form viscous sand-shaped material, and the material is ageing for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln and sintered in a flowing nitrogen atmosphere of 6Mpa and 10L/h at 1600 ℃ of air pressure, and the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1600 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 15 percent, the normal temperature rupture strength of 42MPa and the high temperature rupture strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 28 MPa.
Example 10:
respectively weighingwMore than or equal to 99 percent of (Al) and 5kg of metal aluminum powder with the granularity of less than or equal to 60 mu m,w10 Kg of metal silicon powder with the grain size of more than or equal to 99 percent (Si) and less than or equal to 45 mu m are uniformly mixed, 1.4Kg of the mixture is taken and put into a sagger to be subjected to first-step pre-nitridation sintering under the flowing nitrogen atmosphere of 0.2MPa and 5L/h at the temperature of 600 ℃ for 3h and 1250 ℃ for 6h, the mixed powder is subjected to ball milling after natural cooling, and then the weighed mixed powder is weighedw(Al2O3) ≥99%、D505kg of active alumina powder with the thickness of 0.5-2 μm,w(Al2O3+ MgO) =99.0%, particle size is less than or equal to 0.1mm, and magnesia alumina spinel phase is 95% of 30kg of magnesia alumina spinel fine powder, the mixed powder after pre-nitriding ball milling is uniformly mixed with the rest of metal Al powder, simple substance Si powder, magnesia alumina spinel fine powder and active alumina micro powder to be used as a substrate, and then the substrate is weighed w(SiC) =97.0%, 50kg of silicon carbide particles with the particle size of more than 0.1mm and less than or equal to 5mm are uniformly mixed with 4kg of magnesium aluminate sol binder in a grinding wheel type sand mixer, the early-mixed fine powder is added, the mixture is stirred and uniformly mixed, a viscous sand-shaped material is formed, and the ageing process is carried out for 24 hours; molding a blank body on a 630T friction brick press in a steel mould after the sand-shaped material is subjected to ageing treatment; drying naturally for 12-48 h through two-step drying, and forcibly drying for 12-24 h at 180-200 ℃; then the dried green body is placed in a kiln and sintered at the pressure of 1600 ℃ under the flowing nitrogen atmosphere of 12Mpa and 5L/hWherein the temperature is respectively kept at 600 ℃ and 1200 ℃ for 3h and 1600 ℃ for 6 h. The detection shows that the nitride-silicon carbide-magnesia alumina spinel complex phase refractory material product with silicon carbide and magnesia alumina spinel as main crystal phases and Mg-alpha-Sialon and MgAlON as composite nitride phases has the apparent porosity of 14 percent, the normal temperature flexural strength of 45MPa and the high temperature flexural strength (the temperature is 1400 ℃ and the time is 30min, the carbon is buried) of 30 MPa.
Claims (6)
1. A preparation method of a nitride-silicon carbide-magnesia-alumina spinel complex-phase refractory material product is characterized by comprising the following steps: the raw materials of the nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product comprise aggregate and matrix; the aggregate is silicon carbide particles; the matrix contains magnesia-alumina spinel fine powder, active alumina micro powder, metal Al powder and elemental Si powder, wherein the content of the magnesia-alumina spinel fine powder accounts for 30-45% of the total mass of the raw materials, the content of the active alumina micro powder accounts for 1-6% of the total mass of the raw materials, the content of the metal Al powder accounts for 1-5% of the total mass of the raw materials, and the content of the elemental Si powder accounts for 3-10% of the total mass of the raw materials; the silicon carbide particles account for 50% -65% of the total mass of the raw materials; the sintering process in the preparation method is a two-step three-section type heat preservation sintering method, namely, after metal Al powder and simple substance Si powder are mixed, 10% of the mass of the metal Al powder and the simple substance Si powder mixed with the metal powder is weighed, and the mixed powder is subjected to first-step nitrogen sintering in a flowing nitrogen atmosphere to obtain mixed powder, wherein the nitrogen temperature is 1150-1250 ℃, and the nitrogen flow is 5-10L/(h.m)3) The nitrogen partial pressure in the firing atmosphere is 0.15-0.2 MPa; ball-milling the mixed powder after the first step of pre-nitridation, uniformly mixing the mixed powder with the rest of metal Al powder, simple substance Si powder, magnesia-alumina spinel fine powder and active alumina micro powder, finally uniformly mixing the mixed powder with silicon carbide particles and magnesium aluminate sol binder, ageing the mixture, pressing the mixture into a green body with a certain size and shape, drying the green body and then carrying out the second step of air pressure sintering, wherein the nitridation temperature is 1300-1600 ℃, and the nitrogen flow is 5-10L/(h.m)3) The pressure of the nitrogen gas for sintering is 6-12 MPa; the metal aluminum powder and the elemental silicon powder form a nitride binding phase after high-temperature nitridation; the Mg-alpha-Sialon and MgAlON generated after the 1300-1600 ℃ nitriding air pressure sintering are composite nitride bonding phases with excellent high performanceThe temperature performance can be improved, and the wettability of magnesium aluminate spinel silicon carbide can be improved, so that a silicon carbide composite product is promoted to form stronger combination, and the combination can keep excellent mechanical performance and slag resistance of the refractory material under the high-temperature condition; the preparation method comprises the following specific steps:
step 1, uniformly mixing metal Al powder and simple substance Si powder, weighing 10% of the mixed powder by mass, and filling the weighed mixed powder into a crucible, and keeping the rest for later use;
step 2, performing first-step pre-nitridation firing on the crucible filled with the mixed powder in a flowing nitrogen atmosphere, wherein a two-section heat preservation method is adopted in the firing process: respectively preserving heat at 600 ℃ and the highest nitriding temperature point for 3-6 h, wherein the nitriding temperature is 1150-1250 ℃, and the nitrogen flow is 5-10L/(h.m)3) The nitrogen partial pressure in the firing atmosphere is 0.15-0.2 MPa;
step 3, ball-milling the mixed powder nitrided in the first step, uniformly mixing the ball-milled mixed powder with the rest of metal Al powder, simple substance Si powder, magnesia-alumina spinel fine powder and active alumina micro powder to obtain a matrix, and mixing the matrix with silicon carbide particles and a magnesium aluminate sol binder to obtain a sand-like material with certain viscosity;
step 4, filling the sand-shaped material into a mold after ageing, and forming a green body with a certain size and shape;
step 5, drying the green body, naturally drying for 12-48 h, and forcibly drying at 180-200 ℃ for 12-24 h;
6, placing the dried green body in a kiln to perform second-step air pressure firing in a flowing nitrogen atmosphere, wherein a three-section heat preservation method is adopted in the firing process: respectively keeping the temperature at 600 ℃, 1200 ℃ and the highest nitriding temperature point for 3-6 h, wherein the highest nitriding temperature is set to be 1300-1600 ℃, and the nitrogen flow is 5-10L/(h.m)3) The nitrogen pressure in the firing atmosphere is 6-12 MPa; after the firing is finished, the final nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product is obtained; the nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product is a refractory material with a certain shape after high-temperature nitridation treatment in a nitriding furnace at the temperature of 1300-1600 ℃, and has the apparent porosity of 14-19%, the normal-temperature flexural strength of 25-45 MPa and the high-temperature flexural strength of 15-35 MPa at the temperature of 1400 ℃ under a carbon-buried atmosphere.
2. The method of claim 1, wherein the preparation method comprises the following steps: the mass fraction of the Al powder is more than or equal to 99.0%, and the particle size range is 0-60 mu m.
3. The method of claim 1, wherein the preparation method comprises the following steps: the mass fraction of the simple substance Si powder is more than or equal to 97.0%, and the particle size range is 0-45 mu m.
4. The method of claim 1, wherein the preparation method comprises the following steps: the silicon carbide particles are an electric melting raw material, the mass fraction of SiC is more than or equal to 98.0%, and the particle size range is 0.1-5 mm.
5. The method of claim 1, wherein the preparation method comprises the following steps: the magnesia-alumina spinel is an electric melting raw material or a sintering raw material, and Al2O3The total mass fraction of the + MgO is more than or equal to 99.0 percent, wherein Al2O3The mass fraction of the composite is 65-90%, and the particle size range is 10-90 μm.
6. The method of claim 1, wherein the preparation method comprises the following steps: the active alumina micro powder is an electric melting raw material or a sintering raw material, and Al2O3The mass fraction of the particle is more than or equal to 99.0 percent, and the particle size range is D50=0.5～2 μm。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010809854.XA CN111875398B (en) | 2020-08-13 | 2020-08-13 | Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010809854.XA CN111875398B (en) | 2020-08-13 | 2020-08-13 | Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111875398A CN111875398A (en) | 2020-11-03 |
| CN111875398B true CN111875398B (en) | 2022-02-15 |
Family
ID=73202438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010809854.XA Active CN111875398B (en) | 2020-08-13 | 2020-08-13 | Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111875398B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115073181B (en) * | 2022-06-09 | 2023-03-17 | 大连海事大学 | High-sintering-activity pure-phase MgAlON fine powder and preparation method and application thereof |
| CN115073193A (en) * | 2022-07-28 | 2022-09-20 | 中钢集团洛阳耐火材料研究院有限公司 | SiC-MgAl 2 O 4 -(Al 2 OC)x(AlN) 1-x Preparation method of complex phase refractory material |
| CN116143528A (en) * | 2023-04-20 | 2023-05-23 | 淄博雷法耐火材料有限公司 | Refractory material binding agent and application method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07187826A (en) * | 1993-12-27 | 1995-07-25 | Kurosaki Refract Co Ltd | Nonoxide thermal spraying material and thermally spraying method therefor |
| CN101456740A (en) * | 2009-01-04 | 2009-06-17 | 北京科技大学 | MgAlON/beta-sialon composite ceramic material in situ synthesized by reduction and nitridation process |
| CN102050625A (en) * | 2010-10-28 | 2011-05-11 | 中钢集团洛阳耐火材料研究院有限公司 | Sialon-graphite composite silicon carbide material and preparation method thereof |
| CN102695689A (en) * | 2009-12-24 | 2012-09-26 | 法商圣高拜欧洲实验及研究中心 | Powder comprising ceramic granules |
| CN102838360A (en) * | 2012-09-12 | 2012-12-26 | 首钢总公司 | Composite fireproof material and preparation method thereof |
| CN104496504A (en) * | 2015-01-06 | 2015-04-08 | 北京科技大学 | Sialon-bonded magnesium aluminate spinel refractory material for rotary cement kiln and preparation method |
| CN104909764A (en) * | 2015-05-18 | 2015-09-16 | 上海海大技术转移有限公司 | Modified heterogeneous Sialon (Si-Al-O-N) ceramic and preparation method and use thereof |
| CN107879753A (en) * | 2017-11-24 | 2018-04-06 | 中钢集团洛阳耐火材料研究院有限公司 | A kind of carborundum magnesia-aluminum spinel composite fire-resistant material |
-
2020
- 2020-08-13 CN CN202010809854.XA patent/CN111875398B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07187826A (en) * | 1993-12-27 | 1995-07-25 | Kurosaki Refract Co Ltd | Nonoxide thermal spraying material and thermally spraying method therefor |
| CN101456740A (en) * | 2009-01-04 | 2009-06-17 | 北京科技大学 | MgAlON/beta-sialon composite ceramic material in situ synthesized by reduction and nitridation process |
| CN102695689A (en) * | 2009-12-24 | 2012-09-26 | 法商圣高拜欧洲实验及研究中心 | Powder comprising ceramic granules |
| CN102050625A (en) * | 2010-10-28 | 2011-05-11 | 中钢集团洛阳耐火材料研究院有限公司 | Sialon-graphite composite silicon carbide material and preparation method thereof |
| CN102838360A (en) * | 2012-09-12 | 2012-12-26 | 首钢总公司 | Composite fireproof material and preparation method thereof |
| CN104496504A (en) * | 2015-01-06 | 2015-04-08 | 北京科技大学 | Sialon-bonded magnesium aluminate spinel refractory material for rotary cement kiln and preparation method |
| CN104909764A (en) * | 2015-05-18 | 2015-09-16 | 上海海大技术转移有限公司 | Modified heterogeneous Sialon (Si-Al-O-N) ceramic and preparation method and use thereof |
| CN107879753A (en) * | 2017-11-24 | 2018-04-06 | 中钢集团洛阳耐火材料研究院有限公司 | A kind of carborundum magnesia-aluminum spinel composite fire-resistant material |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111875398A (en) | 2020-11-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111875398B (en) | Nitride-silicon carbide-magnesia-alumina spinel complex phase refractory material product and preparation method thereof | |
| CN107879753B (en) | Silicon carbide-magnesium aluminate spinel composite refractory material | |
| CN101747068B (en) | Self-bonding SiC product with content of SiC more than 92 percent and preparation method thereof | |
| CN107892575B (en) | Silicon carbide-calcium hexaluminate composite refractory material | |
| CN110818437B (en) | Preparation method of silicon carbide-oxide composite refractory product | |
| US20080280152A1 (en) | Fireproof Molded Articles or Materials and Method for the Production Thereof | |
| CN111620709B (en) | Silicon carbide composite refractory product containing rare earth oxide | |
| US5925585A (en) | Materials formed by refractory grains bound in a matrix of aluminum nitride or sialon containing titanium nitride | |
| JPH0665624B2 (en) | Novel refractory having high alumina content and method for producing the same | |
| CN114988879B (en) | Large-scale complex-phase reaction sintered silicon carbide product and preparation method thereof | |
| CN101798232B (en) | Preparation method of Sialon-carbofrax-corundum composite refractory material | |
| CN112876265A (en) | Titanium-silicon-carbon metal composite converter slag-stopping sliding plate brick and preparation method thereof | |
| CN101798222A (en) | Al2O3-Ni-C-B4C composite ceramic and preparation method thereof | |
| CN111056833B (en) | Nitride-bonded spinel sliding plate and preparation process thereof | |
| CN111892411B (en) | Nitride-silicon carbide-calcium hexaluminate composite refractory product and preparation method thereof | |
| CN113979761B (en) | Ternary composite self-repairing baking-free sliding plate brick and preparation method thereof | |
| CN115259839B (en) | Integral refractory castable for preheating section side wall of belt type roasting machine and preparation method thereof | |
| CN1108212C (en) | Slide sprue brick containg sialon | |
| CN114349520A (en) | Al for blast furnace body4SiC4-SiC composite refractory material and preparation method thereof | |
| CN114853489A (en) | beta-SiC combined SiC refractory material with low binding phase content and preparation method and product thereof | |
| DePoorter et al. | Structural ceramics | |
| CN1298676C (en) | Method for preparing beta-'Sailong' ceramic powder | |
| CN116655356B (en) | Low-carbon magnesia-zirconia-carbon converter sliding brick and preparation method thereof | |
| KR100308922B1 (en) | Method of Manufacturing Silicon Nitride Bonded Silicon Carbide Composites by Silicon Nitriding Reaction | |
| CN115028455B (en) | Baking-free silicon carbide-magnesia alumina spinel refractory material, preparation method and product thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |