Description
Name of the invention: monolithic refractories
Technology areas
[0001] 　The present invention relates to the monolithic refractories used steel processing equipment mainly.
His innovations.
[0002] 　As shown in non-patent literature 1 and 2 as a contact with molten steel and slag in steelmaking process equipment, refractory, alumina - spinel bricks, magnesia - alumina and alumina - spinel - magnesia monolithic refractories are used. The herein, spinel and MgO-Al2O3 series of compounds, chemical stoichiometry of MgO and Al2O3 and MgO or Al2O3 overly solid "means non-stoichiometric composition doped compound.
[0003] 　Monolithic refractory on alumina - spinel, spinel FeO, solid strength, hot, in solution with high corrosion resistance to oxygen cleaning and steelmaking slag and slag corrosion resistance of features heavily, after sustained heat remaining expansion shrinkage is reduced, high volume stability.
[0004] 　Monolithic refractory on alumina - magnesia during 1100-indicates infiltration of slag corrosion resistance and corrosion in alumina and magnesia react when heated to 1,200 ° C or higher, this fine-fine spinels are formed. Higher corrosion resistance and slag corrosion resistance of spinel fine so monolithic refractory on alumina - magnesia than the monolithic refractory on alumina - spinel invasive slag corrosion resistance and corrosion resistance good in General. However, flawed big Peel and crack because the production side of spinel formation may occur alone working on volume expansion with a heated reaction to form spinel fine, monolithic refractory on alumina - magnesia in General thermal spalling resistance inferior to the monolithic refractories on alumina - spinel.
[0005] 　Monolithic refractory on alumina - spinel - magnesia has the characteristics of both the monolithic refractories on alumina - spinel and magnesia - alumina and volume stability, corrosion resistance, resistance slug invasion shows characteristics of both 不定形 between.
[0006] 　Patent literature 1 shows the monolithic refractories using fine-5 μm particle size alumina - spinel and to improve from the first minute formed during use in the monolithic refractories on alumina - magnesia spinel, raises corrosion resistance of alumina - spinel monolithic refractories and slag corrosion resistance of.
[0007] 　In addition, non-patent literature 1 and 2 and the patent literature 2 is doped spinel-High alumina cement (spinel-containing high alumina cement and rather herein. ) Has shown indefinite shape refractory alumina - spinel - magnesia and alumina - spinel bricks were used.
[0008] 　And containing 12-7 Al2O3 and Al2O3 and even some alumina cement, alumina cement in General and the main ingredient, 2 Al2O3 and CaO CaO-Al2O3and CaO-Al2O3-2 Al2 Indicates the hydraulic O3 and 12-7 Al2O3 , so being used as monolithic refractory binder.
[0009] 　Also the monolithic refractory alumina - spinel - magnesia and alumina - spinel using alumina cement in General, part which is also called the matrix, except for aggregate Al2O3 and Al2O3, spinel and 6 Al2O3 and CaO phase near the running surface being used is primarily a-main and 6 Al-2 Formed from O3 and finely and evenly distributed two phase indicates infiltration of slag corrosion resistance and high corrosion resistance.
[0010] 　Spinel-containing high alumina cement has been shown in non-patent literature 1 and 2 which are evenly dispersed fine spinels and CaO-Al2O3 and CaO-2 Al2O3 , monolithic Refractories in alumina - spinel using this spinel-containing alumina cement and alumina - spinel - magnesia spinel fine and evenly distributed in the matrix of CaO and 6 Al2o Since the formation of 3 indicates infiltration of slag corrosion resistance and high corrosion resistance.
Prior art documents
Patent documents
[0011] Patent literature 1: special square no. 5-238838 bulletin
Patent literature 2: special square no. 8-198649 bulletin

Non-patent literature
[0012] Non-patent literature 1: Christoph Wohrmeyer et al.: New Spinel Containing Calcium AluminateCement for Corrosion Resistant Castable, Unitecr2011
Non-patent literature 2: Chris Parr et al.: Castables with Improved Corrosion Resistance forSteel-making Applications, Unitecr2011

Summary of the invention
Inventors are trying to solve a problem
[0013] 　Although enhanced corrosion resistance and slag corrosion resistance of alumina - spinel using monolithic refractories on alumina - spinel using ultrafine spinel, such as shown in the patent literature 1, non-patent literature 1, as shown in 2-containing high alumina cement and alumina - spinel - magnesia monolithic refractories, steelmaking process is severe and also reduce costs for further durability improvements are sought.
[0014] 　In addition, to get the desired characteristics of alumina - spinel using ultrafine spinel monolithic refractories rely ultrafine spinel and alumina cement evenly mixed to balance the strong mixing equipment and mixers.
[0015] 　In order to balance the fine, uniform, monolithic refractory on alumina - spinel, on the other hand, using spinel-containing high alumina cement and alumina - spinel - magnesia to form spinel fine and evenly distributed in the matrix of CaO and 6 Al2O3 easily should be sintered and prone crack detachment due to thermal spalling. Also, having increased infiltration of slag corrosion resistance and corrosion resistance and dense refractory materials in General, but increases the separation of thermal spalling cracks fault.
[0016] 　Reduces the occurrence of crack detachment, as well as to enhance the corrosion resistance of monolithic refractories using spinel-containing high alumina cement and slag corrosion resistance of a challenge trying to solve the present invention, there is. In addition to suppress crack detachment due to dense, monolithic refractory thermal spalling, to reduce crack detachment in the terms of use for demanding heating and cooling;
Means for resolving problems
[0017] 　To solve such problems, and the gist of the invention to
(1) the alumina cement include at least a spinel-containing high alumina cement particle size less than 8 mm fire stuff 100 WT % in total, contained in alumina cement CaO content is 0. 5-2. Amount of spinel-containing high alumina cement, 5 mass % 3... 5-10. 5 mass % in monolithic refractories,
(2)-wherein refractory raw materials 100 mass percent total, included in spinel-containing high alumina cement and grain size 0. less than 1 mm spinel raw material and the total amount is 5. 5-22 WT % in (1) to the monolithic Refractories in the
(3) percentage above refractory raw materials 100 mass percent with particle diameter 0. content of magnesia raw materials less than 1 mm 2-9 WT % in (1) to the monolithic Refractories in the
(4) percentage above refractory raw materials 100 mass percent, grain size should 10% less than 3 μm or less formal fired alumina content (1) and (3) either in amorphous refractory materials,
(5) percentage above refractory raw materials 100 mass percent, grain size should 4 mass less than 3 μm or less formal fired alumina content (1) and (3) either in amorphous refractory materials,
(6) wherein refractory raw material particle size is 0. 1 mm 8 mm or less alumina spinel raw material of at least one 50 in total-75 mass % content that (1)-(5) either in amorphous refractory materials,
In there.
Advantageous effects of invention
[0018] 　You can increase corrosion resistance of monolithic refractories and slag corrosion resistance of CaO amount and-according to the present invention, spinel-containing high alumina cement from the monolithic refractories that are formulated to optimize and further reduce the delamination crack due to thermal spalling occurs.
For carrying out the invention
[0019] 　This invention can mainly apply to alumina - spinel monolithic refractories and alumina - spinel - magnesia monolithic refractories.
[0020] 　According to the present invention alumina - spinel monolithic refractories are, composed by spinel-containing high alumina cement, alumina raw material, spinel raw material, and usually monolithic refractories used the admixture and admixture. In addition, according to the present invention alumina - spinel - magnesia monolithic refractories is the composed by spinel-containing high alumina cement, alumina raw material, spinel raw material, magnesia raw materials, keiwa, and usually monolithic refractories used the admixture and admixture. However, if the digestion of dry magnesia hot strength may not use keiwa etc if that is important.
[0021] 　All refractory materials except the above admixture in the present invention, called refractory materials. That separation is difficult after the refractory raw materials include the admixture in the invention, but this is as monolithic refractory mixed all ingredients.
[0022] 　Admixture is superplasticizers are used in monolithic refractories for normal AE water reducing agent, anti-foaming agents, hardeners adjustment, liquidity regulator, gastrointestinal agents of magnesia, spalling prevention of organic fibers are used in monolithic refractories for normal, Al powders, metal fiber, additives are.
[0023] 　Consisting of a mixture of, as CMA72 has been launched by Kerneos spinel-containing high alumina cement and indicating spinel fine and hydraulic the Lord CaO-Al2O3and CaO-2 Al2O3 cement in the calcium aluminate and other, 12-7 Al2O3 andAl 2O 3 May contain. You may also contain ingredients derived from impurities such as SiO2 , Fe2O3 , amorphous phase, admixture, admixture for setting adjustment.
[0024] 　Also, CaO of monolithic Refractories in the invention needed to use alumina cement in addition to spinel-containing high alumina cement and alumina cement in the present invention, include at least spinel-containing high alumina cement particle size less than 8 mm fire stuff 100 mass percent in total, contained high alumina cement (total of spinel-containing high alumina cement and alumina cement otherwise) is 0. 5-2. Should be 5 mass %. These spinel-containing high alumina cement and alumina cement otherwise the grain size 0 is the most... 1 mm or less, and make up the matrix of monolithic refractories.
[0025] 　In this invention, diameter 8 mm or less refractory raw materials 100 WT % in percentage of the stipulated amount of CaO or later-but this monolithic refractories corrosion and infiltration of slag corrosion resistance and strength, but particle size alumina cement content and chemical composition of refractory materials of less than 8 mm greatly affected.
[0026] 　Monolithic refractories on alumina - spinel or alumina - spinel - magnesia chemical composition, except for impurities and Al2O3-MgO-CaO systems or Al2O3-MgO-Cao-IO2 , and low CaO content for steel slag melting against the amount less corrosion resistance high. In addition, CaO in slag slag reacts with the monolithic Refractories in Al2O3 -6 Al2O3 as captured and infiltrating slowly CaO/SiO2 smaller fast increase of viscosity due to decrease in infiltration and increases viscosity, so CaO content of monolithic Refractories in less slag tips CaO/SiO2 , As a result less infiltration of slag.
[0027] 　Was flawed and thus reduce the amount of CaO, namely alumina cement consumption to reduce higher corrosion resistance and slag corrosion resistance of traditional monolithic refractories or similar is far less to alumina cement strength decreases more than necessary. For monolithic refractory invention derived from spinel-containing high alumina cement to the matrix of the spinel, CaO-Al2O3and CaO-2 Al2O3 distributed finely and evenly for sintering, and less loss of strength with less use of CaO-content namely aluminous cement.
[0028] 　CaO of up 0. 5-2. 5 mass % of CaO-content is 0. In 5 mass % less cement strength reduces too much, CaO volume 2. By not getting improved corrosion resistance of slag corrosion resistance of 5 mass % more. Less strength of invention indefinite shape refractory as stated above usage of CaO-content namely aluminous cement with fewer, but CaO-content is 0. 5 mass percent less strength is lower too.
[0029] 　Invention monolithic Refractories in particle size less than 8 mm fire stuff 100 WT % in percentage the amount of spinel to spinel-containing high alumina cement contained 3. 5-10. 5 mass % is in. Spinel included in spinel-containing high alumina cement, particle size is 0. is less than 1 mm fine-2 Al2O3 and CaO CaO-Al2O3and evenly distributed, but is this-3... Obtained will greatly improve the infiltration of slag corrosion resistance and corrosion resistance 5 mass % less, and that the purpose of the present invention. Also, the amount of spinel to spinel-containing high alumina cement contained 10... 5 mass % more and used in sintering production side go crack detachment increases.
[0030] 　Invention indefinite shape refractory percentage diameter 8 mm or less refractory raw materials 100 WT % to the amount of CaO on high alumina cement 0. 5-2. Amount of spinel-containing high alumina cement, 5 mass % 3... 5-10. 5 mass percent, included in spinel-containing high alumina cement, spinel and particle diameter 0. less than 1 mm spinel raw material and the total amount is 5. 5-preferred by 22%. You can get to adjust to this and high corrosion resistance and infiltration of slag corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractories. In addition to 0. among users that use a combination of diameter greater than 1 mm spinel raw material can increase the infiltration of slag corrosion resistance and corrosion resistance.
[0031] 　Also the invention monolithic Refractories in particle size less than 8 mm fire stuff 100 WT % in percentage, 0 is the amount of CaO on high alumina cement. 5-2. Amount of spinel-containing high alumina cement, 5 mass % 3... 5-10. 5 mass % which, in addition to grain size 0. content of magnesia raw materials less than 1 mm 2-preferred by 9%. You can get to adjust to this and high corrosion resistance and infiltration of slag corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractories.
[0032] 　In addition to invention indefinite shape refractory percentage of less than 8 mm fire stuff 100 mass percent of grain and that diameter of 3 μm or less formal fired alumina content 10% less than preferred. You can get to adjust to this and high corrosion resistance and infiltration of slag corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractories. Percentage of less than 8 mm fire stuff 100 mass percent of grain, especially to improve the thermal spalling resistance of the particle size is preferred 4 mass percent less than 3 μm or less formal fired alumina content. Advances on the other hand increases the corrosion resistance and slag corrosion resistance of monolithic refractory obtained from strong vibration and high-range water-reducing agent used in the mixing of low moisture become dense sintering tend prone crack detachment due to thermal spalling. In this case, you can cause sintering and grain size to 4 mass less than 3 μm or less formal fired alumina content and also dense monolithic refractory suppress crack detachment. Also dense monolithic Refractories in able to reduce crack detachment in the heating and cooling in very harsh terms, even. Rather than increase the mixing mixing water may have lower liquidity of well-kneaded water and grain size to 4 mass less than 3 μm or less formal fired alumina content, strong vibration and the filling is preferable.
[0033] 　Particle size as a percentage of less than 8 mm fire stuff 100 mass percent in grain size, where the content of 3 μm or less formal fired alumina has shown, ask. That is, particle size as a percentage of less than 8 mm fireproof material 100 mass percent in grain size and temporarily fired alumina grain size was temporarily fired alumina particle size distributions measured by laser diffraction scattering particle size distribution Analyzer and A mass % and percentage of 3 μm or less, grain size of 8 mm or less refractory raw materials 100 WT % in proportion to mass % B, 3 μm or less formal fired alumina content A x B/100 mass %. Contained in refractory materials to use, containing provisional fired alumina refractory raw materials grain size to total amount of 3 μm or less formal fired alumina.
[0034] 　Invention monolithic Refractories in the aggregate particle size is 0. 1 mm 8 mm or less fire-resistant materials, alumina spinel raw material of at least class 1 with key can be configured. Typically, particle size less than 8 mm fire stuff 100 WT % in percentage with 0. less than 1 mm 8 mm alumina spinel raw material of at least one species is 50-75 mass %.
[0035] 　To demonstrate to monolithic refractories or invention can be used suitable for refractory materials and described below.
[0036] 　Use as alumina raw material manufactured by electric fusion or sintering and grain-controlled raw materials and raw materials manufactured by the Bayer process known as temporarily fired alumina. 99% or more of alumina raw material manufactured by electric fusion or sintering and grain-controlled Al2O3 content is 90% or more, preferably using. Temporarily fired alumina is called reactive alumina or calcined alumina and raw materials.
[0037] 　MgO-Al2O3 series of compounds as spinel raw material and chemical composition to excess stoichiometric MgO and Al2O3 and MgO or Al2O3 -containning non-stoichiometric compounds, produced by electric fusion or sintering, the granularity of raw materials available.
[0038] 　As magnesia raw materials manufactured by electric fusion or sintering and grain-controlled raw materials to use. Can be used to digest magnesia raw materials during drying and to avoid cracks caused by volumetric expansion slaking resistance of magnesia ingredients preferred. Slaking resistance of magnesia ingredients and low in impurities in CaO and SiO2 and CaO/SiO2 , no fracture, surface-coated ones such as is.
[0039] 　Slow down the rate of spinel-magnesia spinel-magnesia material reacts with alumina raw material while using the resulting spinel fine magnesia raw materials used to produce the fine increases the corrosion resistance and slag corrosion resistance of the coarse raw materials show a volume expansion shows a continuous monolithic refractory residual expansibility and less crack.
[0040] 　Keiwa is raw materials 1 μm amorphous SiO2 particles called Silica fume, fumed silica, microsilica, evaporation silica, or silicadust, SiO gas generated during the manufacture of ZrO2 , Fe-SI and Si oxide in the air, the generated. Keiwa is alumina - spinel - magnesia monolithic Refractories in the purpose of the creep of reduction of spinel formation by prevention of digestive magnesia raw materials, when used, can be used as a percentage of less than 8 mm fireproof material 100 mass percent in grain size in the range of 2% less than desirable.
[0041] 　You can also use so-called recycled materials, reuse of monolithic refractories or refractory bricks used as the invention of monolithic refractories for refractory materials. Preferably as recycled materials, reusing spent refractories on alumina - spinel or alumina - magnesia, alumina - spinel - magnesia and monolithic refractories.
[0042] 　Is possible to use the particle size greater than 8 mm in order increase the corrosion resistance by large aggregate invention monolithic refractory, preventing crack extension to reduce the occurrence of cracks or peeling, or dense refractory materials. However, invention, above reasons particle refractory materials of less than 8 mm 100 mass %, this mass 100% proportion of the stipulated amounts of CaO and spinel.
[0043] 　Also invention monolithic refractories and other refractory materials used, zirconia, mullite, Zirconia - Alumina, chromia, etc. also possible in the usage of these is grain size less than 8 mm fire stuff 100 WT % in percentage by weight 10% or less preferable.
[0044] 　More than monolithic refractory of the invention described can be used suitably wet type sprayed concrete, concrete pour.
Implementation example [0045] 　Table 1 example 1 of the present invention-21 and comparative examples 1 to indicate the raw materials consist of 5. Table 2 the invention implementation example 22-40 and comparative examples 6-raw material structure of 9.
[0046] [Table 1]

[0047] [Table 2]

[0048] 　As a refractory material, Al2O3 content is 99. 3-99. 7 mass % particle size range is 8-0. 1 mm and 0. less than 1 mm sintered alumina, Al2O3 content is 99. 2-99. 7 mass % particle size range is 8-0. 1 mm and 0. less than 1 mm electro fused alumina, MgO content of 4-6 mass % particle size range is 8-0. 1 mm sintered spinel, MgO content of 26-28 WT % in the particle size range is 1-0. 3 mm and 0. content of less than 1 mm sintered spinel, grain size 3 µm is 18. 93. 2 WT % alumina A formal ware, grain size 3 µm or less content. 6 mass % alumina B formal ware, MgO content was 95. 0-95. 5 mass % particle size range is 1-0. 3 mm and 0. less than 1 mm sintered MgO, SiO2 content is 98. 4. mass percent average particle size is 0. Using a 2 μm keiwa. As well as refractory materials in spinel-containing high alumina cement and alumina cement using kerneos, CMA72 and SECAR71, respectively. CMA72 and SECAR71 are 99% 0... ranged from less than 1 mm. Also, as a plasticizer polyacrylate or sodium polycarboxylic acid, 0... 1 mass % was used. Total raw materials fire superplasticizer above, including 100 mass in %.
[0049] 　"CaO in cement" in table 1 and table 2 show in mass % percentage of total as a percentage above refractory raw materials 100 mass percent of the spinel-containing high alumina cement (CMA72) and in alumina cement (SECAR71).
　Spinel-containing high alumina cement in the ratio of spinel to spinel-containing high alumina cement as a percentage above refractory raw materials 100 mass percent of the indicating in mass %.
　see 0. less than 1 mm spinel ", included in spinel-containing high alumina cement as a percentage above refractory raw materials 100 mass percent of the spinel and particle diameter 0. percentage of the total amount of less than 1 mm spinel raw material (sintered spinel) and indicating in mass %.
　see 0. less than 1 mm of magnesia ", as a percentage above refractory raw materials 100 mass percent of the grain size 0. percentage of less than 1 mm magnesia raw materials (sintered magnesia) show in mass %.
　Where's the grain size 0. amounts of less than 1 mm and 0 is opening eyes. is the amount of under 100 mm sieve.
[0050] 　Table 1 and table 2 "of 3 μm or less formal fired alumina" the percentage of formal ware alumina as a percentage above refractory raw materials 100 weight % of the 3 μm indicates mass %. Where formal ware alumina of 3 μm or less, in the values calculated from each of 3 μm or less amount and use of formal ware alumina and formal ware alumina B ware alumina A provisional and temporary ware alumina B particle size distribution measured by laser diffraction scattering particle size distribution Analyzer.
[0051] 　Prepared specimens of monolithic refractories by each ingredient composition of table 1 and table 2, respectively, evaluated the melting loss on depth, slug invasion depth, strength and thermal spalling resistance of. Molding and casting each ingredient of table 1 and table 2 for proper moisture mixing specimens, and casting in the frame of the given shape, plus 2 G vibration frame specimen listed in table 1, table 2 specimen frame vibration 4 g degassed sufficiently and, 24-hour care and the got.
[0052] 　Molten damage depth, implement the slag erosion tests at 1650 ° C 10 hours of table 1 specimen using BOF slag and, conducted slag erosion tests at 1700 ° C 8 hours of basic oxygen furnace slag using table 2 specimen melt loss depth 7 mm or less was A larger than 7 mm, 10 mm or less than 10 mm B, C and. Molten damage depth in indicator of corrosion resistance.
[0053] 　Slug invasion depth slag Rotary erosion test measured the depth of loss, slug invasion depth is less than 2 mm A, greater than 2 mm and less than 4 mm, 4 mm greater than the C was.
[0054] 　Bending strength is 40 x 40 x 160 mm and de養生 shaped specimens above method, then escape frames and dried at 110 ° C for 24 hours, fired at 1200 ° C 3 hours less than a 15 MPa 15 MPa or more measured after a 10 MPa or more smaller than B, 10 MPa is the C.
[0055] 　Thermal spalling resistance of 230 x 114 x repeated heating and cooling using 65 mm and de養生 shaped specimens above method, then escape frame and dried at 110 ° C for 24 hours, 6 hours at a temperature of 350 ° C heat treated specimens, observed the occurrence of cracks. Electric arc furnace was heated to 1400 ° C, 114 x 65 mm side heated for 30 minutes to 30 minutes and air operation repeated five times, was the minor with the occurrence of cracks A little crack raised what was C and B a large crack was caused.
[0056] 　A is one of at least two A, C is not outside of them were B, C C assumed the score a ratings loss of depth, slug invasion depth, strength, thermal spalling, all in A without C at A+, and other. Indicating a worse rating to A+, A, B, and C.
[0057] 　Table 1 example 1-21 is the embodiment of the present invention, obtained C no melt damage depth, slug invasion depth, strength and thermal spalling resistance of each evaluation, high corrosion resistance and infiltration of slag corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractory products.
[0058] 　Furthermore, examples 1-21 of the "0. less than 1 mm-"the desirable range (5. 5-22 WT %) from outside examples 7, 10, and magnesia implementation example of ' 0... 1 mm or less magnesian "of desirable range (2-9 wt %) from outside the implementation example 12, 16, tend less implementation example 18 off the preferred range of formal ware 3 μm alumina (10 mass % less) than the other examples and results of each assessment each assessment c, but compared to the later comparison example invasive slag corrosion resistance and corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractory obtained.
[0059] 　Table 1 comparison example 1 is the example does not use a spinel-containing high alumina cement and corrosion resistance, low slag infiltration was greater.
　A comparative example 2-CaO in cement and in the spinel-containing high alumina cement is less than the scope of the invention example, and low strength.
　Comparing examples 3, CaO in cement than invention example, and corrosion resistance is low.
　Comparison example 4 is a spinel-containing cement in many more invention and, increase infiltration of slag, low thermal spalling resistance.
　Comparison example 5-CaO in cement and cement in the spinel content is greater than the range of the present invention example, reduces the corrosion resistance, increase infiltration of slag, and low thermal spalling resistance.
[0060] 　Implementation and comparative examples of table 2 is a high-range water-reducing agent and the vibration 4 g in addition to molding in addition, demonstrate precise monolithic refractories prepared by mixing of low moisture content.
[0061] 　Implementation example 22-40 is the embodiment of the present invention, obtained C no melt damage depth, slug invasion depth, strength and thermal spalling resistance of each evaluation, high corrosion resistance and infiltration of slag corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractory products. The implementation example 22-out of 40 ' 0... less than 1 mm-"the desirable range (5. 5-22 WT %) from examples using the implementation example 29 out of 33, and magnesia raw materials of "0. less than 1 mm of magnesia "of desirable range (2-9 wt %) from implementation example 40 out of desirable material for implementation example 35 out of 39, a dense irregular"of 3 μm or less formal fired alumina"range (less than 4 mass) than the other examples and the results of each evaluation inferior tend to each evaluation is C, but compared to the later comparison example invasive slag corrosion resistance and corrosion resistance, high strength, and thermal spalling resistance of high monolithic refractory obtained.
[0062] 　Table 2 comparative example 6 is the example does not use a spinel-containing high alumina cement and corrosion resistance, low slag infiltration was greater.
　Compare case 7-CaO in cement and in the spinel-containing high alumina cement is less than the scope of the invention example, and low strength.
　Comparison example 8 example CaO in cement than invention, and low corrosion resistance.
　Comparison example 9 is more invention in the spinel-containing cement-example, and greater infiltration of slag.
Of the claims
[Paragraph 1] 　Alumina cement include at least a spinel-containing high alumina cement particle size less than 8 mm fire stuff 100 WT % in total, contained in alumina cement CaO content is 0. 5-2. Amount of spinel-containing high alumina cement, 5 mass % 3... 5-10. 5 mass % in monolithic refractories.
[Paragraph 2] 　Spinel wherein refractory raw materials 100 mass percent total, included in spinel-containing high alumina cement and grain size 0. less than 1 mm spinel raw material and the total amount is 5. 5-claim 1 in 22% of monolithic refractory products.
[Invoice section 3] 　Wherein refractory raw materials 100 mass percent ratio in grain size 0... content of magnesia raw materials less than 1 mm 2-claim 1 in 9% of monolithic refractories.
[Paragraph 4] 　Claim 1 wherein refractory raw materials 100 mass percent total the particle size is 10% less than 3 μm or less formal fired alumina content-3 of amorphous in refractories.
[Bill 5] 　Claim 1 wherein refractory raw materials 100 mass percent total the particle mass 4% less than 3 μm or less formal fired alumina content-3 of amorphous in refractories.
[Bill 6] 　Wherein refractory raw material particle size is 0. less than 1 mm 8 mm alumina spinel raw material of at least one 50 in total-75 mass % contained claim 1-5 of amorphous in refractories.