CN118125839A - Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof - Google Patents
Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof Download PDFInfo
- Publication number
- CN118125839A CN118125839A CN202410177573.5A CN202410177573A CN118125839A CN 118125839 A CN118125839 A CN 118125839A CN 202410177573 A CN202410177573 A CN 202410177573A CN 118125839 A CN118125839 A CN 118125839A
- Authority
- CN
- China
- Prior art keywords
- periclase
- microporous
- powder
- shell structure
- aggregate
- 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.)
- Pending
Links
- 239000011258 core-shell material Substances 0.000 title claims abstract description 100
- 239000011819 refractory material Substances 0.000 title claims abstract description 93
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 90
- 238000002360 preparation method Methods 0.000 title claims abstract description 54
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims abstract description 515
- 239000000395 magnesium oxide Substances 0.000 claims abstract description 301
- 235000012245 magnesium oxide Nutrition 0.000 claims abstract description 301
- 239000000843 powder Substances 0.000 claims abstract description 86
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims abstract description 67
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 51
- 239000005011 phenolic resin Substances 0.000 claims abstract description 46
- 229920001568 phenolic resin Polymers 0.000 claims abstract description 46
- 239000007788 liquid Substances 0.000 claims abstract description 44
- 229920001187 thermosetting polymer Polymers 0.000 claims abstract description 44
- 239000011159 matrix material Substances 0.000 claims abstract description 35
- 238000002156 mixing Methods 0.000 claims abstract description 31
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000011863 silicon-based powder Substances 0.000 claims abstract description 24
- 239000000126 substance Substances 0.000 claims abstract description 24
- 238000000465 moulding Methods 0.000 claims abstract description 13
- 238000003756 stirring Methods 0.000 claims abstract description 11
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 87
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 75
- 229910052749 magnesium Inorganic materials 0.000 claims description 75
- 239000011777 magnesium Substances 0.000 claims description 75
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 claims description 62
- 239000000347 magnesium hydroxide Substances 0.000 claims description 62
- 229910001862 magnesium hydroxide Inorganic materials 0.000 claims description 62
- 239000011858 nanopowder Substances 0.000 claims description 37
- 239000002245 particle Substances 0.000 claims description 28
- 239000011859 microparticle Substances 0.000 claims description 25
- 239000000203 mixture Substances 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 20
- 239000011148 porous material Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 238000001816 cooling Methods 0.000 claims description 10
- 239000011812 mixed powder Substances 0.000 claims description 10
- 238000003825 pressing Methods 0.000 claims description 10
- 238000012216 screening Methods 0.000 claims description 10
- 230000003628 erosive effect Effects 0.000 abstract description 15
- 230000035939 shock Effects 0.000 abstract description 4
- 239000002893 slag Substances 0.000 description 16
- 239000002994 raw material Substances 0.000 description 10
- 239000000919 ceramic Substances 0.000 description 8
- 239000001095 magnesium carbonate Substances 0.000 description 8
- 235000014380 magnesium carbonate Nutrition 0.000 description 8
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 8
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 8
- 229910002804 graphite Inorganic materials 0.000 description 7
- 239000010439 graphite Substances 0.000 description 7
- 239000012071 phase Substances 0.000 description 7
- 230000003647 oxidation Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 6
- 230000035515 penetration Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 239000011449 brick Substances 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 239000012466 permeate Substances 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 229920000049 Carbon (fiber) Polymers 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 210000000988 bone and bone Anatomy 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000004917 carbon fiber Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052909 inorganic silicate Inorganic materials 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000008092 positive effect Effects 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000011799 hole material Substances 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910001404 rare earth metal oxide Inorganic materials 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000011269 tar Substances 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
The invention relates to a lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The technical proposal is as follows: 16 to 24 weight percent of microporous periclase refractory aggregate I, 22 to 32 weight percent of microporous periclase refractory aggregate II and 16 to 24 weight percent of microporous periclase refractory aggregate III are taken as total aggregates, and 24 to 38 weight percent of magnesia fine powder, 0.1 to 1.5 weight percent of simple substance silicon powder and 0.5 to 3 weight percent of crystalline flake graphite powder are taken as total matrixes. Firstly, placing the total aggregate into a stirrer, adding modified liquid thermosetting phenolic resin accounting for 2-6wt% of the sum of the total aggregate and the total matrix, and uniformly mixing; then adding the total matrix and stirring; and (3) performing mechanical press molding, and preserving heat for 12-36 h at the temperature of 200-320 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure. The product has the characteristics of multi-scale core-shell structure, low heat conductivity coefficient, high strength, good thermal shock stability and strong erosion resistance.
Description
Technical Field
The invention belongs to the technical field of periclase-carbon refractory materials. In particular to a lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof.
Background
Periclase-carbon refractory materials have excellent thermal shock resistance and high-temperature slag erosion resistance due to the inclusion of carbon components such as crystalline flake graphite and the like, and are widely used as ladle slag line bricks for steel smelting.
There are many methods for preparing periclase-carbon refractory materials at present:
For example, a magnesia-carbon refractory material is prepared by using magnesia, tar, phenolic resin, silicon carbide whisker, carbon fiber powder and nano rare earth oxide as raw materials, but adopts compact magnesia as aggregate, and has poor combination at an aggregate/matrix interface and poor strength.
In another example, the technology of the patent of magnesia-carbon brick and the preparation method thereof (CN 201611236533.5) is to prepare a periclase-carbon refractory material by taking fused magnesia particles, fused magnesia fine powder, carbon, antioxidant and silica sol as raw materials, but adopts compact fused magnesia as aggregate, so that the heat conductivity coefficient is high, and the energy waste is caused.
And the technology adopts fused magnesia, aluminum powder, spinel-calcium aluminate complex phase material, crystalline flake graphite, bonding agent and the like as raw materials to prepare the periclase-carbon refractory material, but the technology introduces low-melting point substances into the magnesia carbon brick, so that the erosion resistance and permeability of the material are poor.
Also, for example, a magnesia carbon brick and a preparation method thereof (CN 202010565496.2) patent technology is adopted, and the technology takes fused magnesia, carbon fiber powder, graphite, carbon black, titanium carbonitride, metal aluminum powder, glycerol, phenolic resin and the like as raw materials to prepare the periclase-carbon refractory material, but the material has high heat conductivity coefficient and larger heat loss.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and aims to provide a lightweight periclase-carbon refractory material with a multi-scale core-shell structure, which has low heat conductivity, high strength and good erosion and penetration resistance, and a preparation method thereof.
In order to achieve the above purpose, the steps of the technical scheme adopted by the invention are as follows:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, taking any one of magnesium oxide nano powder, magnesium oxide micro powder and magnesium hydroxide micro powder as a magnesium source, or taking mixed powder of any two of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source, or taking mixed powder of three of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source.
And 1.2, mixing 40-94 wt% of magnesium hydroxide fine powder and 6-60 wt% of magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture to form under the condition of 100-200 MPa, then placing the blank in a high-temperature furnace, heating to 400-500 ℃ at the speed of 1-3 ℃/min, preserving heat for 1-2 h, heating to 1600-1800 ℃ at the speed of 3-5 ℃/min, preserving heat for 3-8 h, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm. The microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are collectively called microporous periclase refractory aggregate.
The microporous periclase refractory aggregate has a micro core-shell structure which takes microporous magnesia microparticles containing nanopores as cores and compact magnesia layers as shells; the particle size of the microporous magnesium oxide microparticles is 30-50 mu m, and the thickness of the compact magnesium oxide layer is 2-5 mu m; the microporous periclase refractory aggregate comprises the following components: the apparent porosity is 22.6-40%; the volume density is 2.10-2.77g/cm 3; the average pore diameter is 500-900 nm; the compressive strength is 30-100 MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
16 To 24 weight percent of the microporous periclase refractory aggregate I, 22 to 32 weight percent of the microporous periclase refractory aggregate II and 16 to 24 weight percent of the microporous periclase refractory aggregate III are taken as total aggregates, and 24 to 38 weight percent of magnesia fine powder, 0.1 to 1.5 weight percent of simple substance silicon powder and 0.5 to 3 weight percent of flake graphite powder are taken as total matrixes.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 2-6wt% of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under the condition of 150-200 MPa, and preserving heat for 12-36 h at the temperature of 200-320 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The lightweight periclase-carbon refractory material has a multi-scale core-shell structure which takes microporous magnesia microparticles containing nanopores as a core, a compact magnesia layer as a shell, and microporous periclase refractory aggregate as a core and a continuous magnesia layer as a shell; wherein: the thickness of the continuous magnesium oxide layer is 0.1-0.3 mm.
The preparation method of the modified phenolic resin comprises the following steps: uniformly mixing the liquid thermosetting phenolic resin and the magnesium source according to the mass ratio of 100:30-150 of the liquid thermosetting phenolic resin to the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The particle size of the magnesium oxide nano powder is less than 50nm; the MgO content of the magnesium oxide nano powder is more than 99 weight percent.
The particle size of the magnesium oxide micro powder is less than 3 mu m; the MgO content of the magnesium oxide micro powder is more than 99 weight percent.
The particle size of the magnesium hydroxide micropowder is less than 5 mu m; the MgO content of the magnesium hydroxide micropowder is 66-67 wt%.
The particle size of the magnesium hydroxide fine powder is less than 100 mu m; the MgO content of the magnesium hydroxide fine powder is 66-67 wt%.
The grain diameter of the magnesite fine powder is less than 88 mu m; the MgO content of the magnesia fine powder is 95-97wt%.
The grain diameter of the simple substance silicon powder is less than 50 mu m; the Si content of the simple substance silicon powder is 98 to 99.5 weight percent.
The particle size of the flake graphite powder is less than 18 mu m; the C content of the flake graphite powder is 97-98.5 wt%.
The carbon residue rate of the liquid thermosetting phenolic resin is more than or equal to 35 percent.
By adopting the technical scheme, compared with the prior art, the invention has the following positive effects:
The invention designs the whole process from raw materials, refractory bones to refractory materials, and for aggregate, the microporous periclase refractory aggregate with a micro-core-shell structure is obtained by taking microporous magnesium oxide microparticles containing nanopores as cores and introducing magnesium oxide or magnesium hydroxide with special particle sizes to form a continuous compact magnesium oxide layer as a shell. Wherein: the particle size of the microporous magnesium oxide microparticles is 30-50 mu m, and the thickness of the continuous compact magnesium oxide layer is 2-5 mu m. Compared with the prior art, the magnesium oxide with special grain diameter promotes the grain combination and growth to form a compact magnesium oxide layer, and the prepared aggregate has high purity, stable high-temperature structure, low heat conductivity coefficient and excellent high-temperature service performance. For the refractory material, after the lightweight periclase-carbon refractory material with a multi-scale core-shell structure is prepared, the lightweight periclase-carbon refractory material is sintered under the condition of carbon burying, magnesium oxide micro-nano powder promotes grain merging and growth at high temperature, and a continuous magnesium oxide layer with the thickness of 0.1-0.3 mm is constructed on the surface of aggregate with the micro-core-shell structure, on one hand, a crystalline flake graphite-compact magnesium oxide mosaic structure is formed at a shell-matrix interface, and on the other hand, a saw tooth occlusion interface structure is formed at the shell-aggregate interface, and the lightweight periclase-carbon refractory material and the microporous periclase refractory aggregate with the micro-core-shell structure form the multi-scale core-shell structure together, so that the advantages of nano pores, magnesium oxide and crystalline flake graphite are fully exerted.
The invention adopts the microporous periclase refractory aggregate with higher purity and nano-scale air holes and micro-core-shell structure, and the compact magnesia shell layer bridging microporous magnesia microparticles with cross-network structure in the aggregate, thereby improving the strength of the aggregate. And the aggregate has high purity, less impurity content, less liquid phase quantity at high temperature, stable structure at high temperature and excellent high-temperature service performance. In the aspect of refractory materials, the invention prepares a core-shell structure of the continuous compact magnesia shell-coated microporous periclase refractory aggregate, a saw tooth occlusion interface structure is formed at the interface of the shell and the aggregate, so that the interface of the shell and the aggregate is tightly combined, and a crystalline flake graphite-compact magnesia mosaic structure is formed at the interface of the shell and the matrix, so that the combination of the shell and the matrix is tight, and the strength of the product is improved. Overcomes the problems of weak bonding and poor strength of the existing dense magnesia carbon refractory aggregate/matrix interface.
The microporous periclase refractory aggregate with the nano-scale air holes is adopted, slag and gas phase are not easy to permeate, meanwhile, the purity of the aggregate is high, the liquid phase in the aggregate is less at high temperature, the dissolution into the slag is less, and the erosion resistance and the oxidation resistance of the refractory material are improved. For the aspect of refractory materials, the saw tooth meshed interface structure formed at the shell-aggregate interface enables interface combination to be more compact, prevents slag and gas phase from penetrating along the shell-aggregate interface, and effectively improves oxidation resistance and erosion resistance of the refractory materials; the wettability of the crystalline flake graphite in the crystalline flake graphite-compact magnesia mosaic structure formed at the shell-matrix to slag is poor, and the compact magnesia in the mosaic structure can prevent oxygen from oxidizing carbon at the interface, so that the erosion resistance and oxidation resistance of the product are effectively improved. The problems that the existing compact magnesia refractory material has more microcracks between aggregates/matrixes, slag and oxygen are easy to permeate along the microcracks, and the problems that the compact aggregate grain boundary has more low melting phase and Ca 2SiO4, the dissolution speed in the slag is high, and the slag is easy to peel and damage are solved.
According to the invention, through designing the raw material proportion, the raw material granularity and the forming pressure, a structure is prepared that magnesium hydroxide microparticles are taken as a framework, magnesium sources with larger particle size difference are filled among the magnesium hydroxide microparticles, and the pore size inside microporous magnesium oxide microparticles and the particle size of the microparticles formed after magnesium hydroxide is decomposed are controlled by adjusting a firing system. And meanwhile, the magnesium oxide micro-nano powder promotes the crystal grains to merge and grow up to form a continuous compact magnesium oxide shell at high temperature, the thickness of the continuous compact magnesium oxide shell is controlled by adjusting the proportion of the micro-nano powder, so that the formed cross network structure bridges microporous magnesium oxide microparticles together through neck connection, and the microporous periclase refractory aggregate with the structure that the continuous compact magnesium oxide shell tightly wraps a microporous magnesium oxide core-micro core-shell structure is prepared. And then the proportion of the micro-nano powder and the liquid thermosetting phenolic resin is designed, and the micro-nano powder is uniformly dispersed in the liquid thermosetting phenolic resin, so that the micro-nano powder is uniformly coated on the surface of the microporous periclase refractory aggregate. In the reaction sintering process, the sintering driving force is increased, so that the grains of the micro-nano powder are combined and grown to form a compact magnesia shell, a tight combination interface of aggregate-shell and shell-matrix is formed, a multi-scale core-shell structure is formed together with a core-shell structure in the aggregate, and the strength and erosion penetration resistance of the lightweight periclase-carbon refractory material with the multi-scale core-shell structure are improved.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 22-30%; the volume density is 2.31-2.57 g/cm 3; the compressive strength is 70-150 MPa.
Therefore, the lightweight periclase-carbon refractory material with the multi-scale core-shell structure has the characteristics of low heat conductivity coefficient, high strength, good thermal shock stability and strong erosion and penetration resistance.
Detailed Description
The invention is further described in connection with the following detailed description, which is not intended to limit the scope of the invention.
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
step 1.1, taking any one of magnesium oxide nano powder, magnesium oxide micro powder and magnesium hydroxide micro powder as a magnesium source, or taking mixed powder of any two of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source, or taking mixed powder of three of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source.
And 1.2, mixing 40-94 wt% of magnesium hydroxide fine powder and 6-60 wt% of magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture to form under the condition of 100-200 MPa, then placing the blank in a high-temperature furnace, heating to 400-500 ℃ at the speed of 1-3 ℃/min, preserving heat for 1-2 h, heating to 1600-1800 ℃ at the speed of 3-5 ℃/min, preserving heat for 3-8 h, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 22.6-40%; the volume density is 2.10-2.77g/cm 3; the average pore diameter is 500-900 nm; the compressive strength is 30-100 MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
16 To 24 weight percent of the microporous periclase refractory aggregate I, 22 to 32 weight percent of the microporous periclase refractory aggregate II and 16 to 24 weight percent of the microporous periclase refractory aggregate III are taken as total aggregates, and 24 to 38 weight percent of magnesia fine powder, 0.1 to 1.5 weight percent of simple substance silicon powder and 0.5 to 3 weight percent of flake graphite powder are taken as total matrixes.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 2-6wt% of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under the condition of 150-200 MPa, and preserving heat for 12-36 h at the temperature of 200-320 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: uniformly mixing the liquid thermosetting phenolic resin and the magnesium source according to the mass ratio of 100:30-150 of the liquid thermosetting phenolic resin to the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide nano powder is more than 99 weight percent.
The MgO content of the magnesium oxide micro powder is more than 99 weight percent.
The MgO content of the magnesium hydroxide micropowder is 66-67 wt%.
The MgO content of the magnesium hydroxide fine powder is 66-67 wt%.
The MgO content of the magnesia fine powder is 95-97wt%.
The Si content of the simple substance silicon powder is 98-99.5 wt%.
The C content of the flake graphite powder is 97-98.5 wt%.
The carbon residue rate of the liquid thermosetting phenolic resin is more than or equal to 35 percent.
In this embodiment:
The particle size of the magnesium oxide nano powder is less than 50nm;
the particle size of the magnesium oxide micro powder is less than 3 mu m;
the particle size of the magnesium hydroxide micropowder is less than 5 mu m;
the particle size of the magnesium hydroxide fine powder is less than 100 mu m;
the grain diameter of the magnesite fine powder is less than 88 mu m;
The grain diameter of the simple substance silicon powder is less than 50 mu m;
the particle size of the flake graphite powder is less than 18 mu m;
the microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are collectively called microporous periclase refractory aggregate;
The microporous periclase refractory aggregate of the specific embodiment has a micro-core-shell structure which takes microporous magnesia microparticles containing nanopores as cores and compact magnesia layers as shells;
The lightweight periclase-carbon refractory material with the multi-scale core-shell structure is of a multi-scale core-shell structure which takes microporous magnesia microparticles containing nanopores as cores, a microporous periclase refractory aggregate with a compact magnesia layer as a shell as cores and a continuous magnesia layer as a shell.
The embodiments are not described in detail.
The light periclase-carbon refractory material with the multi-scale core-shell structure is detected by the following steps: the thickness of the continuous magnesium oxide layer is 0.1-0.3 mm; the microporous periclase refractory aggregate and the lightweight periclase-carbon refractory material with the multi-scale core-shell structure are detected: the particle size of the microporous magnesium oxide microparticles is 30-50 mu m, and the thickness of the compact magnesium oxide layer is 2-5 mu m.
Example 1
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
And 1.1, taking the magnesium oxide nano powder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to 94 weight percent of the magnesium hydroxide fine powder and 6 weight percent of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture to form under the condition of 100MPa, then placing the blank in a high-temperature furnace, heating to 400 ℃ at the speed of 1 ℃/min, preserving heat for 2.2h, heating to 1600 ℃ at the speed of 3 ℃/min, preserving heat for 6h, cooling with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 40%; the bulk density is 2.10g/cm 3; the average pore diameter is 900nm; the compressive strength was 30MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
16Wt% of the microporous periclase refractory aggregate I, 22wt% of the microporous periclase refractory aggregate II and 24wt% of the microporous periclase refractory aggregate III are taken as total aggregates, and 37wt% of magnesia fine powder, 0.1wt% of simple substance silicon powder and 0.9wt% of crystalline flake graphite powder are taken as total matrixes.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 6wt% of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 150MPa, and preserving heat for 12 hours at 200 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:150, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide nano powder is 99.9wt%.
The MgO content of the magnesium hydroxide fine powder was 66.2wt%.
The MgO content of the magnesite fine powder is 95.8wt%.
The Si content of the simple substance silicon powder is 98wt%.
The C content of the flake graphite powder is 97.7wt%.
The carbon residue ratio of the liquid thermosetting phenolic resin is 35.5.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 28.0%; the bulk density is 2.38g/cm 3; the compressive strength was 109MPa.
Example 2
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, using magnesium oxide micropowder as magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to the proportion of 91wt% of the magnesium hydroxide fine powder and 9wt% of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture under the condition of 120MPa to form, then placing the blank in a high-temperature furnace, heating to 380 ℃ at the speed of 1.5 ℃/min, preserving heat for 4 hours, heating to 1650 ℃ at the speed of 3.5 ℃/min, preserving heat for 8 hours, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 33.2%; the bulk density is 2.37g/cm 3; the average pore diameter is 832nm; the compressive strength was 65MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
The microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are taken as total aggregates in an amount of 18 weight percent, and the magnesia fine powder, the simple substance silicon powder and the crystalline flake graphite powder are taken as total matrixes in an amount of 28 weight percent, 1 weight percent and 3 weight percent.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 4.2 weight percent of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 170MPa, and preserving heat for 22 hours at 320 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:30, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide micropowder is 99.8wt%.
The MgO content of the magnesium hydroxide fine powder was 67% by weight.
The MgO content of the magnesia fine powder is 95 weight percent.
The Si content of the simple substance silicon powder is 98.2wt%.
The C content of the crystalline flake graphite powder is 97.9wt%.
The liquid thermosetting phenolic resin has a carbon residue ratio of 35.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 23.0%; the bulk density is 2.54g/cm 3; the compressive strength was 135MPa.
Example 3
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, taking magnesium hydroxide micropowder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with a magnesium source according to 88 weight percent of the magnesium hydroxide fine powder and 12 weight percent of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture to form under 150MPa, then placing the blank in a high-temperature furnace, heating to 350 ℃ at the speed of 2.5 ℃/min, preserving heat for 3.5h, heating to 1600 ℃ at the speed of 4.5 ℃/min, preserving heat for 3h, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 36%; the bulk density is 2.29g/cm 3; average pore diameter is 859nm; the compressive strength was 45MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
The microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are taken as total aggregates in an amount of 20 weight percent, and the magnesia fine powder, the simple substance silicon powder and the crystalline flake graphite powder are taken as total matrixes in an amount of 35 weight percent, 0.7 weight percent and 1.3 weight percent.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 5.3 weight percent of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 160MPa, and preserving heat for 18 hours at 220 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:60, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium hydroxide micropowder is 66 weight percent.
The MgO content of the magnesium hydroxide fine powder was 66wt%.
The MgO content of the magnesite fine powder was 97wt%.
The Si content of the simple substance silicon powder is 98.6wt%.
The C content of the flake graphite powder is 97.2wt%.
The carbon residue ratio of the liquid thermosetting phenolic resin is 35.2.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 27.0%; the bulk density is 2.41g/cm 3; the compressive strength was 88MPa.
Example 4
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, taking mixed powder of magnesium oxide nano powder and magnesium oxide micro powder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to the proportion of 40wt% of the magnesium hydroxide fine powder and 60wt% of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture under the condition of 200MPa to form, then placing the blank in a high-temperature furnace, heating to 360 ℃ at the speed of 3 ℃/min, preserving heat for 1.5h, heating to 1750 ℃ at the speed of 4.8 ℃/min, preserving heat for 4h, cooling with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 22.6%; the bulk density is 2.77g/cm 3; the average pore diameter is 500nm; the compressive strength was 100MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
Taking 24 weight percent of the microporous periclase refractory aggregate I, 30 weight percent of the microporous periclase refractory aggregate II and 18 weight percent of the microporous periclase refractory aggregate III as total aggregates, and taking 24 weight percent of magnesia fine powder, 1.5 weight percent of simple substance silicon powder and 2.5 weight percent of crystalline flake graphite powder as total matrixes.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 2.8 weight percent of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 180MPa, and preserving heat for 36h at 260 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:80, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide nano powder is 99.6wt%.
The MgO content of the magnesium oxide micropowder is 99.6wt%.
The MgO content of the magnesium hydroxide fine powder was 66.5wt%.
The MgO content of the magnesite fine powder is 96.2wt%.
The Si content of the simple substance silicon powder is 99.1wt%.
The C content of the flake graphite powder is 97wt%.
The carbon residue ratio of the liquid thermosetting phenolic resin is 36.2.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 22.0%; the bulk density is 2.57g/cm 3; the compressive strength was 150MPa.
Example 5
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, taking mixed powder of magnesium oxide nano powder and magnesium hydroxide micro powder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to the mixture of 60 weight percent of the magnesium hydroxide fine powder and 40 weight percent of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture under 180MPa for molding, then placing the blank in a high-temperature furnace, heating to 300 ℃ at the speed of 1.8 ℃/min, preserving heat for 3.8h, heating to 1720 ℃ at the speed of 5 ℃/min, preserving heat for 6h, cooling with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 25.1%; the bulk density is 2.68g/cm 3; the average pore diameter is 586nm; the compressive strength was 91MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
The microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are taken as total aggregates in an amount of 22wt%, and the magnesia fine powder, the simple substance silicon powder and the crystalline flake graphite powder are taken as total matrixes in an amount of 25wt%, 0.9wt% and 2.1 wt%.
Firstly, placing the total aggregate into a stirrer, adding 3.4wt% of the modified liquid thermosetting phenolic resin to the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 200MPa, and preserving heat for 29 hours at 280 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:130, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide nano powder is 99.5wt%.
The MgO content of the magnesium hydroxide micropowder is 67wt%.
The MgO content of the magnesium hydroxide fine powder was 67% by weight.
The MgO content of the magnesite fine powder is 96.8wt%.
The Si content of the simple substance silicon powder is 99.5wt%.
The C content of the flake graphite powder is 98.2wt%.
The carbon residue ratio of the liquid thermosetting phenolic resin is 35.8.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 24.0%; the bulk density is 2.51g/cm 3; the compressive strength was 141MPa.
Example 6
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
Step 1.1, using mixed powder of magnesium oxide micropowder and magnesium hydroxide micropowder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to the proportion of 50wt% of the magnesium hydroxide fine powder and 50wt% of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture to form under 140MPa, then placing the blank in a high-temperature furnace, heating to 330 ℃ at the speed of 2.8 ℃/min, preserving heat for 1.8h, heating to 1700 ℃ at the speed of 4.2 ℃/min, preserving heat for 5h, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 27.8%; the bulk density is 2.58g/cm 3; the average pore diameter is 685nm; the compressive strength was 81MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
The microporous periclase refractory aggregate I, the microporous periclase refractory aggregate II and the microporous periclase refractory aggregate III are taken as total aggregates in an amount of 17wt%, 32wt% and 16wt%, and the magnesia fine powder, the simple substance silicon powder and the crystalline flake graphite powder are taken as total matrixes in an amount of 32 wt%.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 4.6 weight percent of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 190MPa, and preserving heat for 25 hours at 300 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:90, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide micropowder is 99.3wt%.
The MgO content of the magnesium hydroxide micropowder is 66.4wt%
The MgO content of the magnesium hydroxide fine powder was 66.4wt%.
The MgO content of the magnesite fine powder is 95.2wt%.
The Si content of the simple substance silicon powder is 98.8wt%.
The C content of the crystalline flake graphite powder is 97.3wt%.
The liquid thermosetting phenolic resin had a carbon residue ratio of 36.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 26.0%; the bulk density is 2.44g/cm 3; the compressive strength was 126MPa.
Example 7
A lightweight periclase-carbon refractory material with a multi-scale core-shell structure and a preparation method thereof. The preparation method of the specific embodiment comprises the following steps:
Step1, preparation of microporous periclase ceramic with micro core-shell structure
And 1.1, taking mixed powder of three of magnesium oxide nano powder, magnesium oxide micro powder and magnesium hydroxide micro powder as a magnesium source.
And 1.2, mixing the magnesium hydroxide fine powder with the magnesium source according to the mixture of 70 weight percent of the magnesium hydroxide fine powder and 30 weight percent of the magnesium source to obtain a mixture.
Step 1.3, mechanically pressing the mixture under 160MPa for molding, then placing the blank in a high-temperature furnace, heating to 380 ℃ at the speed of 2 ℃/min, preserving heat for 2.8h, heating to 1800 ℃ at the speed of 3.8 ℃/min, preserving heat for 7h, cooling with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm.
The microporous periclase refractory aggregate comprises the following components: the apparent porosity is 26%; the bulk density is 2.64g/cm 3; average pore diameter is 645nm; the compressive strength was 86MPa.
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
Taking 19wt% of the microporous periclase refractory aggregate I, 25wt% of the microporous periclase refractory aggregate II and 17wt% of the microporous periclase refractory aggregate III as total aggregates, and taking 38wt% of magnesia fine powder, 0.5wt% of simple substance silicon powder and 0.5wt% of crystalline flake graphite powder as total matrixes.
Firstly, placing the total aggregate into a stirrer, adding the modified liquid thermosetting phenolic resin accounting for 2wt% of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; and (3) performing mechanical press molding under 150MPa, and preserving heat for 31h at 240 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure.
The preparation method of the modified phenolic resin comprises the following steps: according to liquid thermosetting phenolic resin: the mass ratio of the magnesium source is 100:110, uniformly mixing the liquid thermosetting phenolic resin and the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
The MgO content of the magnesium oxide nano powder is 99.5wt%.
The MgO content of the magnesium oxide micropowder is 99.5wt%.
The MgO content of the magnesium hydroxide micropowder is 66.8wt%.
The MgO content of the magnesium hydroxide fine powder was 66.8wt%.
The MgO content of the magnesite fine powder is 96.4wt%.
The Si content of the simple substance silicon powder is 99.2wt%.
The C content of the flake graphite powder is 98.5wt%.
The carbon residue ratio of the liquid thermosetting phenolic resin is 35.6.
The light-weight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the invention is detected: the apparent porosity is 30.0%; the bulk density is 2.31g/cm 3; the compressive strength was 70MPa.
Therefore, the lightweight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the specific embodiment has the characteristics of nanoscale air holes, multi-scale core-shell structure, low heat conductivity coefficient, high strength and strong erosion and penetration resistance.
Compared with the prior art, the specific embodiment has the following positive effects:
The design of the whole flow process is carried out from raw materials, refractory bones to refractory materials, and in the aspect of aggregate, microporous magnesia microparticles containing nanopores are formed by in-situ decomposition of magnesium hydroxide and serve as cores, and a continuous compact magnesia layer is formed by introducing magnesia with special particle size or magnesium hydroxide and serves as a shell, so that the microporous periclase refractory aggregate with a micro-core-shell structure is obtained, wherein: the particle size of the microporous magnesium oxide microparticles is 30-50 mu m, and the thickness of the continuous compact magnesium oxide layer is 2-5 mu m. Compared with the prior art, the magnesium oxide with special grain diameter promotes the grain combination and growth to form a compact magnesium oxide layer, and the prepared aggregate has high purity, stable high-temperature structure, low heat conductivity coefficient and excellent high-temperature service performance. In the aspect of refractory materials, after the lightweight periclase-carbon refractory materials with the multi-scale core-shell structure are prepared, the lightweight periclase-carbon refractory materials are sintered under the condition of carbon burying, magnesium oxide micro-nano powder promotes the grain combination growth and is large at high temperature, a continuous magnesium oxide layer with the thickness of 0.1-0.3 mm is constructed on the surface of aggregate with the micro-core-shell structure, on one hand, a crystalline flake graphite-compact magnesium oxide mosaic structure is formed at a shell-matrix interface, on the other hand, a sawtooth occlusion-shaped interface structure is formed at the shell-aggregate interface, and the lightweight periclase-carbon refractory materials and the microporous periclase refractory aggregate with the micro-core-shell structure form the multi-scale core-shell structure together, so that the advantages of nano pores, magnesium oxide and crystalline flake graphite are fully exerted.
The specific embodiment adopts the microporous periclase refractory aggregate with higher purity and a nano-scale air hole and micro-core-shell structure, and the dense magnesia shell layer bridging microporous magnesia microparticles with a cross-network structure in the aggregate improve the strength of the aggregate. And the aggregate has high purity, less impurity content, less liquid phase quantity at high temperature, stable structure at high temperature and excellent high-temperature service performance. For the aspect of refractory materials, the embodiment prepares a core-shell structure of continuous and compact magnesia shell-wrapped microporous periclase refractory aggregate, a sawtooth occlusion-shaped interface structure is formed at the interface of the shell and the aggregate, so that the interface of the shell and the aggregate is tightly combined, and a crystalline flake graphite-compact magnesia mosaic structure is formed at the interface of the shell and the matrix, so that the combination of the shell and the matrix is tight, and the strength of the product is improved. Overcomes the problems of weak bonding and poor strength of the existing dense magnesia carbon refractory aggregate/matrix interface.
The specific embodiment adopts the microporous periclase refractory aggregate with the nanoscale air holes, slag and gas phase are not easy to permeate, meanwhile, the purity of the aggregate is high, the liquid phase in the aggregate is less at high temperature, the dissolution into the slag is less, and the erosion resistance and the oxidation resistance of the refractory material are improved. For the aspect of refractory materials, the saw tooth meshed interface structure formed at the shell-aggregate interface enables interface combination to be more compact, prevents slag and gas phase from penetrating along the shell-aggregate interface, and effectively improves oxidation resistance and erosion resistance of the refractory materials; the wettability of the crystalline flake graphite in the crystalline flake graphite-compact magnesia mosaic structure formed at the shell-matrix to slag is poor, and the compact magnesia in the mosaic structure can prevent oxygen from oxidizing carbon at the interface, so that the erosion resistance and oxidation resistance of the product are effectively improved. The problems that the existing compact magnesia refractory material has more microcracks between aggregates/matrixes, slag and oxygen are easy to permeate along the microcracks, and the problems that the compact aggregate grain boundary has more low melting phase and Ca 2SiO4, the dissolution speed in the slag is high, and the slag is easy to peel and damage are solved.
According to the specific embodiment, the structure that magnesium hydroxide microparticles are taken as a framework and magnesium sources with larger particle size difference are filled among the magnesium hydroxide microparticles is prepared by designing the raw material proportion, the raw material granularity and the forming pressure, and the pore size inside microporous magnesium oxide microparticles and the particle size of the microparticles formed after magnesium hydroxide is decomposed are controlled by adjusting a sintering system. And meanwhile, the magnesium oxide micro-nano powder promotes the crystal grains to merge and grow up to form a continuous compact magnesium oxide shell at high temperature, the thickness of the continuous compact magnesium oxide shell is controlled by adjusting the proportion of the micro-nano powder, so that the formed cross network structure bridges microporous magnesium oxide microparticles together through neck connection, and the microporous periclase refractory aggregate with the structure that the continuous compact magnesium oxide shell tightly wraps a microporous magnesium oxide core-micro core-shell structure is prepared. And then the proportion of the micro-nano powder and the liquid thermosetting phenolic resin is designed, and the micro-nano powder is uniformly dispersed in the liquid thermosetting phenolic resin, so that the micro-nano powder is uniformly coated on the surface of the microporous periclase refractory aggregate. In the reaction sintering process, the sintering driving force is increased, so that the grains of the micro-nano powder are combined and grown to form a compact magnesia shell, a tight combination interface of aggregate-shell and shell-matrix is formed, a multi-scale core-shell structure is formed together with a core-shell structure in the aggregate, and the strength and erosion penetration resistance of the lightweight periclase-carbon refractory material with the multi-scale core-shell structure are improved.
The lightweight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the specific embodiment is detected: the apparent porosity is 22-30%; the volume density is 2.31-2.57 g/cm 3; the compressive strength is 70-150 MPa.
Therefore, the lightweight periclase-carbon refractory material with the multi-scale core-shell structure prepared by the specific embodiment has the characteristics of low heat conductivity coefficient, high strength, good thermal shock stability and strong erosion and penetration resistance.
Claims (10)
1. The preparation method of the lightweight periclase-carbon refractory material with the multi-scale core-shell structure is characterized by comprising the following steps of:
Step 1, preparation of microporous periclase refractory aggregate
Step 1.1, taking any one of magnesium oxide nano powder, magnesium oxide micro powder and magnesium hydroxide micro powder as a magnesium source, or taking mixed powder of any two of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source, or taking mixed powder of three of the magnesium oxide nano powder, the magnesium oxide micro powder and the magnesium hydroxide micro powder as the magnesium source;
step 1.2, mixing 40-94 wt% of magnesium hydroxide fine powder and 6-60 wt% of magnesium source uniformly to obtain a mixture;
Step 1.3, mechanically pressing the mixture to form under the condition of 100-200 MPa, then placing the formed blank in a high-temperature furnace, heating to 300-400 ℃ at the speed of 1-3 ℃/min, preserving heat for 1-4 h, heating to 1600-1800 ℃ at the speed of 3-5 ℃/min, preserving heat for 3-8 h, cooling along with the furnace, crushing and screening; respectively obtaining microporous periclase refractory aggregate I with the grain diameter of less than 5mm and more than or equal to 3mm, microporous periclase refractory aggregate II with the grain diameter of less than 3mm and more than or equal to 1mm and microporous periclase refractory aggregate III with the grain diameter of less than 1mm and more than or equal to 0.1 mm;
The microporous periclase refractory aggregate has a micro core-shell structure which takes microporous magnesia microparticles containing nanopores as cores and compact magnesia layers as shells; the particle size of the microporous magnesium oxide microparticles is 30-50 mu m, and the thickness of the compact magnesium oxide layer is 2-5 mu m; the microporous periclase refractory aggregate comprises the following components: the apparent porosity is 22.6-40%, the volume density is 2.10-2.77g/cm 3, the average pore diameter is 500-900 nm, and the compressive strength is 30-100 MPa;
Step 2, preparation of lightweight periclase-carbon refractory material with multi-scale core-shell structure
Taking 16-24 wt% of the microporous periclase refractory aggregate I, 22-32 wt% of the microporous periclase refractory aggregate II and 16-24 wt% of the microporous periclase refractory aggregate III as total aggregates, and taking 24-38 wt% of magnesia fine powder, 0.1-1.5 wt% of simple substance silicon powder and 0.5-3 wt% of flake graphite powder as total matrixes;
Firstly, placing the total aggregate into a stirrer, adding modified phenolic resin accounting for 2-6wt% of the sum of the total aggregate and the total matrix, and mixing; then adding the total matrix and stirring uniformly; performing mechanical press molding under 150-200 MPa, and preserving heat for 12-36 h at 200-320 ℃ to obtain the lightweight periclase-carbon refractory material with the multi-scale core-shell structure;
The preparation method of the modified phenolic resin comprises the following steps: uniformly mixing the liquid thermosetting phenolic resin and the magnesium source according to the mass ratio of 100:30-150 of the liquid thermosetting phenolic resin to the magnesium source to obtain modified phenolic resin;
the magnesium source in step2 is the same as the magnesium source in step 1.
2. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the magnesia nano-powder is less than 50nm; the MgO content of the magnesium oxide nano powder is more than 99 weight percent.
3. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the magnesium oxide micro powder is less than 3 μm; the MgO content of the magnesium oxide micro powder is more than 99 weight percent.
4. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the magnesium hydroxide micro powder is less than 5 μm; the MgO content of the magnesium hydroxide micropowder is 66-67 wt%.
5. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the magnesium hydroxide fine powder is less than 100 μm; the MgO content of the magnesium hydroxide fine powder is 66-67 wt%.
6. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the grain size of the fine magnesia powder is less than 88 μm; the MgO content of the magnesia fine powder is 95-97wt%.
7. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the elemental silicon powder is less than 50 μm; the Si content of the simple substance silicon powder is 98-99.5 wt%.
8. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the particle size of the crystalline flake graphite powder is less than 18 μm; the C content of the flake graphite powder is 97-98.5 wt%.
9. The method for preparing a lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to claim 1, wherein the carbon residue ratio of the liquid thermosetting phenolic resin is more than or equal to 35%.
10. A lightweight periclase-carbon refractory material with a multi-scale core-shell structure, characterized in that the lightweight periclase-carbon refractory material with a multi-scale core-shell structure is a lightweight periclase-carbon refractory material with a multi-scale core-shell structure prepared by the preparation method of the lightweight periclase-carbon refractory material with a multi-scale core-shell structure according to any one of claims 1 to 9;
The lightweight periclase-carbon refractory material has a multi-scale core-shell structure which takes microporous magnesia microparticles containing nanopores as a core, a compact magnesia layer as a shell and a microporous periclase refractory aggregate as a core and a continuous magnesia layer as a shell; wherein: the thickness of the continuous magnesium oxide layer is 0.1-0.3 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410177573.5A CN118125839A (en) | 2024-02-08 | 2024-02-08 | Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410177573.5A CN118125839A (en) | 2024-02-08 | 2024-02-08 | Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118125839A true CN118125839A (en) | 2024-06-04 |
Family
ID=91232814
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410177573.5A Pending CN118125839A (en) | 2024-02-08 | 2024-02-08 | Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118125839A (en) |
-
2024
- 2024-02-08 CN CN202410177573.5A patent/CN118125839A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109987941B (en) | High-entropy ceramic composite material with oxidation resistance and preparation method and application thereof | |
| CN113072364A (en) | Lightweight refractory castable for blast furnace swinging chute and preparation method thereof | |
| CN115466123B (en) | Preparation method of silicon carbide ceramic wafer boat | |
| CN108546093B (en) | Alumina short fiber reinforced magnesium oxide base crucible and preparation method thereof | |
| CN111423233A (en) | Silicon carbide reinforced boron carbide-based ceramic material and preparation method thereof | |
| CN109665848B (en) | Ultrahigh-temperature SiC-HfB2Composite ceramic and preparation method and application thereof | |
| CN107417260A (en) | The hot pressing method for preparing of magnesia ceramics | |
| CN110218080A (en) | Nitridation in situ generates silicon nitride magnesium combination magnesia-carbon refractory material and preparation method thereof | |
| CN111995413A (en) | Silicon carbide whisker toughened aluminum oxide composite ceramic material for bulletproof armor and preparation method thereof | |
| CN113248270A (en) | Carbon fiber composite ZrO2-C material and preparation method thereof | |
| CN118125839A (en) | Lightweight periclase-carbon refractory material with multi-scale core-shell structure and preparation method thereof | |
| CN117164348A (en) | Aluminum carbide whisker reinforced alumina-silicon carbide-carbon baking-free refractory material and preparation method and application thereof | |
| CN116730732A (en) | Low-pollution long nozzle body material | |
| CN108503342B (en) | Carbon-free refractory material and preparation method and application thereof | |
| CN112645731B (en) | Lightweight spinel-corundum-carbon refractory material and preparation method thereof | |
| CN114736007A (en) | Low-heat-conductivity high-performance aluminum-magnesia-carbon molten pool brick and preparation method thereof | |
| CN112811917B (en) | Whisker reinforced lightweight aluminum-carbon refractory material and preparation method thereof | |
| CN112745138B (en) | Whisker-reinforced lightweight aluminum-zirconium-carbon refractory material and preparation method thereof | |
| CN113307625A (en) | ZrO (ZrO)2-C fiber composite material and preparation method thereof | |
| CN108439959B (en) | Zirconium dioxide short fiber and magnesium oxysulfate whisker composite reinforced magnesium oxide-based crucible and preparation method thereof | |
| CN116410008B (en) | Long-service-life low-carbon magnesia carbon brick and preparation method thereof | |
| CN112811928B (en) | Lightweight periclase-silicon carbide-carbon refractory material and preparation method thereof | |
| CN115093238B (en) | Refractory castable for tapping channel of submerged arc furnace and preparation method thereof | |
| CN114685173B (en) | Thermal shock resistant corundum-mullite crucible for metal precision casting and preparation method thereof | |
| CN112794730B (en) | Composite reinforced porous spinel-corundum-carbon ceramic filter and preparation method 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 |