Methods for producing carbon-bonded and / or carbon-containing, refractory shaped bodies or masses with improved thermomechanical properties

Abstract

The invention relates to a method for producing carbon-containing and / or carbon-bonded refractory shaped bodies or masses with improved thermomechanical properties, the use of lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase in the production of carbon-containing and / or carbon-bonded refractory shaped bodies or masses, and a carbon-containing and / or carbon-bonded refractory product.

Description

[0001] The invention relates to a method for producing carbon-containing and / or carbon-bonded refractory shaped bodies or masses with improved thermomechanical properties, the use of lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase in the production of carbon-containing and / or carbon-bonded refractory shaped bodies or masses, and a carbon-containing and / or carbon-bonded refractory product.

[0002] Carbon-bonded and / or carbon-containing products are widely used as linings in metallurgical vessels, such as carbon-bonded magnesia bricks in converters with approximately 5 to 12 wt% carbon, or as key components, such as dip plugs or stoppers with approximately 25 to 32 wt% carbon in continuous casting, or as crucible materials in foundries with more than 20 wt% carbon. Carbon-bonded or carbon-containing refractory products are also used in blast furnaces, in transport vessels such as ladles, in the chemical industry, in the waste incineration industry as temperature-resistant pipes, and in the cement industry as lining material.

[0003] The binders used are known binder systems, preferably phenolic resins such as resoles or novolacs, synthetic pitches such as carbores, bitumen or coal pitches.

[0004] To optimize the oxidation resistance of carbon-containing products, predominantly metallic additives, such as Si, Al or Mg, or intermetallic phases or boron-containing phases, or, among other things, external protective glazes are used for dip spouts, stoppers and crucibles.

[0005] German patent DE 10 2009 005 629 A1 discloses a combined addition of carbon nanotubes with at least one antioxidant and a specific inorganic additive based on at least one oxide and / or non-oxide and / or carbon with a particle size between 50 and 500 nm, resulting in extremely high strengths accompanied by low porosity. The effect of this addition is further enhanced if at least the carbon nanotubes are first dispersed in a liquid resin and then added to the refractory mixture consisting of oxide and / or non-oxide and / or carbon, along with other binders. However, the dispersion of the carbon nanotubes in the liquid resin presents challenges.

[0006] DE 199 54 893 A1 describes carbon-bonded products with improved oxidation behavior. By adding a catalytically active substance from the group of readily reducible compounds of transition elements, in particular metallocenes or metal benzoates, octoates or naphthenates, especially of copper, chromium, nickel or iron or cobalt and / or metallic catalysts, such as nickel, platinum, rhodium or similar, to the synthetic resin component, a highly graphitized carbon is produced below 1000 °C, which contributes to improved chemical properties.

[0007] In their publication, Jamaguchi et al. mixed graphite and amorphous carbon without a binder with refractory oxides Al₂O₃, MgO, TiO₂, and ZrO₂ and investigated their exothermicity using thermal analysis up to 1000°C (Jamaguchi et al. 1996). Jamaguchi et al. described an acceleration of graphite oxidation by Al₂O₃, an inhibition by TiO₂, ZrO₂, and MgO, and a slight inhibition by SiO₂. The aforementioned oxides had no effect on the oxidation of amorphous carbon.

[0008] EP 1 275 626 A1 discloses carbon-bonded refractory materials produced from a mixture of 50 to 85 wt.% carbon, 5 to 15 wt.% aluminum oxide, 5 to 15 wt.% metallic silicon particles, and 5 to 20 wt.% of at least one titanium carbide powder, titanium nitride powder, and / or titanium carbonitride powder. The mixture is combined with a binder, kneaded, shaped, and pressed into a body, which is then coked at 1250°C. A disadvantage is the high cost of the finished titanium-based synthetic raw materials.

[0009] DE 199 35 251 A1 discloses the use of TiO2-containing particulate materials as an additive for refractory products, in which the TiO2-containing materials are added to the mixture of aggregates and binders. The crystalline TiO2 remains in the product and reacts upon penetration of liquid slag or melt, dissolving the TiO2 and reacting to form titanium nitride or titanium carbonitride. This reaction affects both the stability of the refractory product and the slag or melt in contact with it.

[0010] The task is therefore to provide a process for the production of carbon-containing and / or carbon-bonded, refractory shaped bodies or masses with improved thermomechanical properties, in particular improved pressure softening.

[0011] According to the invention, the problem is solved by the method, the use, and the product as defined in the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

[0012] A first aspect of the invention relates to a method for producing carbon-containing and / or carbon-bonded refractory shaped bodies or masses comprising the steps of: • Mixing of ◯ at least one refractory aggregate selected from oxide and non-oxide refractory aggregates, ◯ at least one binder, and ◯ Lanthanum-strontium manganate and / or at least one lanthanum-, strontium- and manganese-containing phase with a proportion in the range of 0.2 wt.% to 4 wt.% based on the total mass of the mixture, • Shaping the mixture into a molded body or using the mixture as a mass, and • Heat treatment of the molded part or mass at a temperature of at least 500 °C.

[0013] Lanthanum-strontium-manganate additives advantageously improve the thermomechanical properties of refractory components or materials. "Lanthanum-strontium-manganate," abbreviated LSM or LSMO, refers to an oxide ceramic with the general formula La 1-x Sr x MnO3 is understood, where x indicates the degree of doping. LSMO has a perovskite structure ABO3, where the A-sites are occupied by lanthanum and strontium, and the B-sites by the smaller manganese atoms. The term "thermomechanical properties" refers to the characteristics of a material that are influenced by both temperature changes and mechanical stresses, including thermal shock and creep resistance, as well as hot bending strength and pressure softening.

[0014] Advantageously, even at a reduced heat treatment temperature, especially at a coking temperature of 600 °C, improved printing softening properties are obtained compared to a reference mixture without LSMO.

[0015] The term "refractory components or masses" refers to a mixture of refractory raw materials and binders. Refractory components or masses should ideally meet the criteria for refractoriness and fire resistance as defined in DIN 51060.

[0016] The term "carbon-containing" refers to shaped bodies or masses that contain carbon as a substance, such as graphite or carbon black; or as a compound, such as silicon carbide or boron carbide. The term "carbon-bonded" refers to shaped bodies or masses that contain at least one carbon-containing binder.

[0017] In embodiments, the oxide refractory aggregate is selected from the group comprising calcium oxide (CaO), magnesium oxide (MgO), dolomite, chromium oxide, aluminum oxide (Al2O3), mullite, zirconium mullite, zirconium oxide (ZrO2), magnesium aluminate spinel, bauxite, yttrium oxide, titanium dioxide, lanthanum oxide and lanthanum chromide.

[0018] In embodiments, the refractory aggregate comprises at least aluminium oxide and zirconium dioxide, or magnesium oxide or mixtures thereof.

[0019] In embodiments, the refractory aggregate comprises at least Al2O3, ZrO2 and MgO.

[0020] In embodiments, the non-oxide refractory aggregate is selected from the group comprising silicon carbide, silicon nitride, boron nitride, boron carbide, aluminium nitride, titanium nitride, titanium carbide and carbon, preferably from the group comprising silicon carbide, silicon nitride, boron nitride, boron carbide, aluminium nitride and carbon.

[0021] In certain embodiments, the refractory aggregate has a maximum grain size of 30 mm. Advantageously, the grain size is selected according to the component thickness, i.e., the thickness of the molded body or the mass. In certain embodiments, the refractory aggregate has a grain shape selected from splintery, angular, rounded edges, or rounded; preferably, the refractory aggregate is splintery.

[0022] The term "particle size" refers to the size, particularly the diameter, of individual particles (also called grains) in a mixture. Particle size is conveniently determined as equivalent diameter or sieve diameter. For particles larger than 10 µm, sieving is a convenient method. This involves stacking a set of sieves with progressively finer meshes. For fine particles (< 10 µm), it is advantageous to measure the particles in a water column, determine the density of a sample suspension using a hydrometer or sediment balance, or measure the scattering of laser light by the particles. The measured particle size distribution is then analyzed, among other methods, by... 50 or d 90 -values ​​described. Under a “d 90 The value refers to the particle size at which 90% of the particles in a sample are smaller. A value of "d 50The “-value is understood to be the particle size at which 50% of the particles in a sample are smaller than this.

[0023] In embodiments, the non-oxide refractory aggregate has a grain size of at most 0.6 mm, in particular a grain size fraction of 0.05 to 0.6 mm.

[0024] In this embodiment, the non-oxide refractory aggregate is a carbonaceous refractory aggregate, preferably selected from the group comprising anthracite, in particular calcined anthracite, coke, in particular calcined coke, graphite, graphene, carbon fibers and carbon black, preferably graphite, particularly preferably flake graphite, in particular wherein at least 50%, preferably at least 70%, of the particles have a grain size of at least 50 µm, or fine graphite, in particular with a d 90 -value in the range of 20 µm to 30 µm, and / or a d 50 -value in the range of 5 µm to 15 µm, preferably in the range of 8 µm to 12 µm.

[0025] In embodiments, the oxide refractory granules have a grain size of at most 7 mm, in particular a grain size fraction of 0 to 7 mm, preferably in the range of at most 5 mm, in particular a grain size fraction of 0 to 5 mm, preferably of at most 1 mm, in particular a grain size fraction of 0 to 1 mm, particularly preferably at most 0.6 mm, in particular a grain size fraction of 0 to 0.6 mm.

[0026] In embodiments, the oxide refractory aggregate has a combination of different grain sizes, in particular a grain size fraction of 0 to 0.2 mm and a grain size fraction of 0.2 to 0.6 mm.

[0027] In embodiments, the carbonaceous refractory aggregate comprises a combination of different grain sizes, in particular a combination of flake graphite, especially wherein at least 70% of the particles have a grain size of at least 160 µm, and fine graphite, especially with a d90 -value in the range of 20 µm to 30 µm, and / or a d 50 -value in the range of 5 µm to 15 µm, preferably in the range of 8 µm to 12 µm.

[0028] In embodiments, the refractory aggregate comprises at least one oxide refractory aggregate and at least one non-oxide refractory aggregate.

[0029] In preferred embodiments, the refractory aggregate comprises at least one oxide refractory aggregate and at least one carbonaceous refractory aggregate.

[0030] In embodiments, the mixture comprises the refractory granules in a proportion in the range of 60 wt.% to 95 wt.%, preferably 75 wt.% to 85 wt.%, based on the total mass of the mixture.

[0031] In embodiments, the mixture comprises the oxide refractory granules in a proportion in the range of 50 wt.% to 95 wt.%, preferably 55 wt.% to 70 wt.%, based on the total mass of the mixture.

[0032] In embodiments, the mixture comprises the carbon-containing refractory aggregate, wherein the carbon content in the mixture is at least 5 wt.%, preferably a proportion in the range of 5 wt.% to 30 wt.%, particularly preferably a proportion in the range of 20 wt.% to 30 wt.%, and especially a proportion in the range of 20 wt.% to 25 wt.%. In further preferred embodiments, the carbon content in the mixture is in the range of 5 wt.% to 12 wt.%.

[0033] In embodiments, the refractory aggregate is a recycled material from previously used refractory products and / or a recycled material from lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase.

[0034] The term "lanthanum-, strontium-, and manganese-containing phases" refers to an LSMO containing impurities, particularly from solid electrolytes, zirconium dioxide, or stabilizers such as yttrium (Y), europium (Eu), cerium (Ce), or similar substances. In some embodiments, the at least one lanthanum-, strontium-, and manganese-containing phase is recycled LSMO from recycled fuel cells or electrolyzers, or a recyclate from previously used refractory products.

[0035] The term "recycled material" refers to recycled materials that have been used at least once and are processed and used to manufacture new products.

[0036] The term "binder" refers to substances that establish or promote chemical bonds at the interfaces of other substances, or that trigger or enhance effects such as cohesion, adsorption, adhesion, and friction. They bind substances by absorbing, attaching, holding together, cross-linking, or bonding them.

[0037] In embodiments, this is at least one binder in powder or liquid form, or a mixture thereof.

[0038] In embodiments, the at least one binder is a hydraulically hardening compound with water, a reactive alkali silicate or phosphoric acid compound with a microfiller, an oxide in combination with a sulfate, chloride or phosphate solution or a calcium carbonate solution, or an activated SiO2 or aluminosilicate suspension.

[0039] In embodiments, the at least one binder is a carbon-containing binder. In embodiments, the at least one binder is selected from the group comprising synthetic resin, bitumen, synthetic pitch, pitch, lactose, tannin, collagen, lignin, and fructose.

[0040] In embodiments, the at least one binder is novolak, preferably in combination with a binder activator, in particular a formaldehyde donor, especially preferably with hexamethylenetetramine (1,3,5,7-tetraazaadamantane) or resol.

[0041] In embodiments, the binder is used in combination with at least one oxide-containing binder.

[0042] In embodiments, oxide-containing binders are selected from the group comprising alginates, synthetic resins, organosilicate compounds, in particular sodium and potassium silicate; sulfite liquor, cellulose derivatives, nanocrystalline cellulose (NCC), fibrillar cellulose (CF), aluminate- or phosphate-containing binders, in particular H3PO4 or phosphates, magnesium salts, in particular magnesium sulfate or magnesium acetate.

[0043] The term "sulfite lye" refers to a lye produced during pulp production using the sulfite process, which has a solids content of approximately 10 wt.%, comprising as its main components 3 wt.% to 5 wt.% carbohydrates and 4 wt.% to 6 wt.% lignosulfonic acid.

[0044] The term “nanocrystalline cellulose” (NCC) refers to cellulose in the form of highly crystalline nanoparticles.

[0045] In embodiments, the mixture comprises the binder in a proportion in the range of 2 wt.% to 10 wt.%, preferably 2 wt.% to 9 wt.%, based on the total mass of the mixture.

[0046] In embodiments, the mixture comprises the binder activator in a proportion in the range of 0.5 wt.% to 1.5 wt.%, preferably 0.7 wt.% to 1.1 wt.%, based on the total mass of the mixture.

[0047] In some embodiments, at least one antioxidant is added to the binder. An "antioxidant" (also called an antioxidant agent) is a chemical compound that slows down or completely prevents the oxidation of other substances.

[0048] In embodiments, the antioxidant is selected from the group comprising Al, Si, Ti, Zr, Y, Mg, Fe, Mo, W, B4C, Borax, TiB2, AIN, SiC and Si3N4.

[0049] In embodiments, the antioxidant is a silicon (Si), boron (B) and / or aluminum (Al)-containing compound.

[0050] In embodiments, the antioxidant has a particle size of at most 0.1 mm to 8 mm, preferably of at most 0.2 mm to 1 mm, particularly preferably of at most 150 µm, in particular a particle size fraction of 0 to 150 µm.

[0051] In embodiments, the mixture comprises the at least one antioxidant with a proportion in the range of 2 wt.% to 5 wt.%, preferably 2.5 wt.% to 4 wt.%, based on the total mass of the mixture.

[0052] In various embodiments, the binder further comprises at least one filler, preferably SiO2, and particularly preferably SiO2 RW filler. The term "SiO2 RW filler" refers to a dry fine dust (amorphous silica) that is produced during the metallurgical production of silicon in an electric arc furnace. Advantageously, SiO2 RW filler prevents the negative effects of moisture, particularly in combination with hygroscopic powders such as MgO, CaO, etc.

[0053] In embodiments, the mixture comprises at least one filler with a proportion in the range of 0.1 wt.% to 4 wt.%, preferably 0.5 wt.% to 3.8 wt.%, based on the total mass of the mixture.

[0054] According to the invention, in the process according to the invention, lanthanum-strontium-manganate or at least one phase containing lanthanum, strontium, and manganese, or lanthanum-strontium-manganate and at least one phase containing lanthanum, strontium, and manganese, are mixed. The proportion of lanthanum-strontium-manganate and the at least one phase containing lanthanum, strontium, and manganese together is in the range of 0.2 wt.% to 10 wt.% based on the total mass of the mixture, preferably in the range of 0.2 wt.% to 4 wt.% based on the total mass of the mixture, and particularly preferably in the range of 0.2 wt.% to 2 wt.% based on the total mass of the mixture.

[0055] In embodiments, the lanthanum-strontium-manganate and / or the at least one lanthanum-, strontium-, and manganese-containing phase has a d 50 -value in the range of 10 µm to 100 µm, preferably in the range of 20 µm to 80 µm, particularly preferably in the range of 45 µm to 50 µm.

[0056] In embodiments, the addition of lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase takes place after mixing the refractory aggregate and the at least one binder.

[0057] In some embodiments, at least one pressing or sliding aid is added to the mixture. Advantageously, these pressing and sliding aids improve the forming properties during pressing. In some embodiments, the pressing aid is Zusoplast®. In others, the sliding aid is sodium stearate.

[0058] In embodiments, the mixture comprises the pressing or sliding aid in a proportion in the range of 0.5 wt.% to 1.5 wt.%, preferably 0.7 wt.% to 1.1 wt.%, based on the total mass of the mixture.

[0059] In some embodiments, shaping takes place after mixing.

[0060] In some embodiments, the shaping process involves extrusion, pressing, or stamping of the mixture, particularly mechanical stamping. Stamping the mixture advantageously results in compaction.

[0061] In some embodiments, the mixture is a ramming compound and / or the mixture is used as a ramming compound. The term "ramming compound" refers to a mixture comprising at least one refractory aggregate and a binder, which has a low water content and has been compacted by ramming, either by hand or with appropriate mechanical equipment.

[0062] In some embodiments, the mass is pressed uniaxially. In other embodiments, isostatic pressing is performed, in particular cold isostatic pressing.

[0063] In some embodiments, the heat treatment is coking. The term "coking" refers to a heat treatment carried out in the absence of air at temperatures in the range of 600 °C to 1400 °C, whereby the volatile components are driven off and partially thermally decomposed, or carbon phases are formed.

[0064] In some embodiments, the heat treatment takes place at a temperature in the range of 600 °C to 800 °C.

[0065] In some embodiments, the heat treatment takes place in oxidizing or reducing atmospheres, or alternately in oxidizing and reducing atmospheres. In other embodiments, the heat treatment takes place in a reducing atmosphere (coking) followed by an oxidizing atmosphere.

[0066] In embodiments, the refractory shaped bodies or masses are cold-isostatically pressed products, in particular immersion castings, plugs or shadow tubes; MgO bricks, slide plates, electrode materials for metallurgy or carbon-containing crucibles.

[0067] In embodiments, the process after heat treatment comprises a step for producing at least one outer protective glaze, preferably a boron-containing outer protective glaze. The steps for producing an outer protective glaze are known to those skilled in the art, and these include the application of a coating or slip and the subsequent heat treatment.

[0068] Another aspect of the invention relates to the use of lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase in the production of carbon-containing and / or carbon-bonded refractory molded bodies or masses.

[0069] Another aspect of the invention relates to a carbon-containing and / or carbon-bonded refractory product, manufactured according to a method according to the invention, wherein the product comprises the following components: • at least one refractory aggregate selected from oxide and non-oxide refractory aggregates, • at least one binder, and • Lanthanum-strontium manganate and / or at least one lanthanum-, strontium- and manganese-containing phase with a proportion in the range of 0.2 wt.% to 10 wt.%, preferably in the range of 0.2 wt.% to 4 wt.%, particularly preferably in the range of 0.2 wt.% to 2 wt.%, based on the total mass of the mixture, wherein the product • exhibits a maximum printer yield according to DIN EN ISO 1893 in the range of 0.5 %dL / L0 to 0.7 %dL / L0.

[0070] In certain embodiments, the carbon content of the product is at least 5 wt.%, preferably in the range of 5 wt.% to 30 wt.%, particularly preferably in the range of 20 wt.% to 30 wt.%, and especially in the range of 20 wt.% to 25 wt.%. In further embodiments, the carbon content of the product is in the range of 5 wt.% to 12 wt.%.

[0071] Advantageously, the mixture according to the invention, particularly consisting of LSMO and an additional antioxidant (Si), exhibits oxidation resistance without an external protective glaze after an oxidation exposure of 3 hours at 1450 °C in the same range as a reference without LSMO. The oxidation resistance of the mixtures according to the invention with only the addition of LSMO or with LSMO and further antioxidants can be further improved by an external protective glaze, including boron-containing external protective glazes.

[0072] In embodiments, a carbon-containing and / or carbon-bonded refractory product comprises at least one outer protective glaze, preferably a boron-containing outer protective glaze.

[0073] The pressure softening was appropriately determined according to DIN EN ISO 1893 and is a measure of the deformation behavior of refractory ceramic products under constant pressure and increasing temperature.

[0074] For the realization of the invention, it is also advantageous to combine the aforementioned inventive configurations, embodiments and features of the claims. Examples of implementation

[0075] The invention will now be explained in more detail using an exemplary embodiment. This exemplary embodiment will describe the invention without limiting its scope.

[0076] The invention is explained in more detail with the aid of drawings. These drawings show Fig.1. Pressure softening of pressed products according to the invention in length change per initial length (dL / L0) at 600 °C and a reference mixture without LSMO at 800 °C (I) and at 600 °C (II) (both references consist of the same composition, see “Reference” in Table 1).

[0077] Mixtures listed in Table 1 are homogenized in an intensive mixer in the laboratory. The homogenized mixtures are then formed into rods by uniaxial pressing at a pressure of 100 MPa. The reference mixture is coked at 800 °C (I) and at 600 °C (II). The two mixtures according to the invention contain a) 0.9 wt% LSMO and 3 wt% Si, and b) 1.8 wt% LSMO without Si, respectively, based on the total mass of the mixture. Tab. 1 Reference mass and two masses according to the invention comprising refractory aggregate (Schmelzkorund Treibacher, Tabular Alumina Almatis, Graphit Kropfmühl), binder (Novolak, Hexamethylenetetramine), lanthanum-strontium manganate and antioxidant (Si), filler (RW-Füller) and pressing aid (Zusoplast G 63). Reference mixture (4% Si) 1. Mixture according to the invention (3% Si 1% LSMO) 2. Inventive mixture (2% LSMO) Raw materials Mass (g) Mass(%) Mass (g) Mass(%) Mass (g) Mass(%) Fused corundum Treibacher (WRG 0-0.2 mm) 1.535,0 27,4 1.535,0 27,4 1.635,0 29,2 Tabular AluminaAlmatis (0.2-0.6 mm) 1.915,0 34,2 1.915,0 34,2 1.915,0 34,2 Graphite KropfmühlAF (C content 90-96%,d 90 ≤ 30µm, d 50 8.5-11µm) 575,0 10,3 575,0 10,3 575,0 10,3 Graphite KropfmühlNFL (C content 87-98%, min. 70% >160 µm) 575,0 10,3 575,0 10,3 575,0 10,3 Si (met.) ESK(0-150 µm) 200,0 3,6 150,0 2,7 - - RW filler 200,0 3,6 200,0 3,6 200,0 3,6 LSMO (d 50 : 45-50 µm) - - 50,0 0,9 100,0 1,8 Novolak liquid PF 9950 FL 500,0 8,9 500,0 8,9 500,0 8,9 Hexamethylenetetramine 50,0 0,9 50,0 0,9 50,0 0,9 Zusoplast G 63 (Pressing aid, liquid) 50,0 0,9 50,0 0,9 50,0 0,9 sum 5.600,0 100,0 5.600,0 100,0 5.600,0 100,0

[0078] After coking, the three-point flexural strength at room temperature in air is determined (see Table 2). The first mixture according to the invention, consisting of LSM and Si, shows an increase in strength after thermal shock (after five thermal shock quenches at 950 °C), as does the reference mixture coked at 600 °C (8.9 MPa in each case). Table 2. Flexural strengths at room temperature of the samples from Table 1. Reference mixture (4% Si) 1. mixture according to the invention (3% Si 1% LSMO) 2. Mixture according to the invention (2% LSMO) Flexural strength (MPa) coked at 600 °C 8,3 8,8 10,3

[0079] In Fig.Figure 1 records the pressure softening at a load of 0.2 MPa and a heating rate of 5 K / min. The samples with LSMO and Si (sample a) show better pressure softening behavior than reference I with 4 wt% Si, which cokes at 800 °C, even at a lower coking temperature. The sample according to the invention with only LSMO without Si shows the same result as reference I, although in this case it also only cokes at 600 °C. Non-patent literature cited:

[0080] Yamaguchi A, Zhang S, Yu J (1996) Effect of refractory oxides on the oxidation of graphite and amorphous carbon. Journal of the American Ceramic Society, 79: 2509-2511. https: / / doi.org / 10.1111 / j.1151-2916.1996.tb09009.x QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2009 005 629 A1

[0005] DE 199 54 893 A1

[0006] EP 1 275 626 A1

[0008] DE 199 35 251 A1

[0009] Cited non-patent literature

[0000] DIN EN ISO 1893 [0069, 0073] Yamaguchi A, Zhang S, Yu J (1996) Effect of refractory oxides on the oxidation of graphite and amorphous carbon. Journal of the American Ceramic Society, 79: 2509-2511. https: / / doi.org / 10.1111 / j.1151-2916.1996.tb09009.x

[0080]

Claims

[1] Method for producing carbon-containing and / or carbon-bonded refractory shaped bodies or masses comprising the steps: • Mixing of ◯ at least one refractory aggregate selected from oxide and non-oxide refractory aggregates, ◯ at least one binder, and ◯ Lanthanum-strontium manganate and / or at least one lanthanum-, strontium- and manganese-containing phase with a proportion in the range of 0.2 wt.% to 10 wt.% based on the total mass of the mixture, • Shaping the mixture into a molded body or using the mixture as a mass, and • Heat treatment of the molded part or mass at a temperature of at least 500 °C. [2] Method according to claim 1, characterized by, that the oxide refractory aggregate is selected from the group comprising calcium oxide, magnesium oxide, dolomite, chromium oxide, aluminum oxide, mullite, zirconium mullite, zirconium dioxide, magnesium aluminate spinel, bauxite, yttrium oxide, titanium dioxide, lanthanum oxide and lanthanum chromide. [3] Method according to claim 1 or 2, characterized by , that the non-oxide refractory aggregates are selected from the group comprising silicon carbide, silicon nitride, boron nitride, boron carbide, aluminium nitride, titanium nitride, titanium carbide and carbon. [4] Method according to any one of claims 1 to 3, characterized by that the refractory aggregate is a recycled material from previously used refractory products and / or a recycled material from lanthanum-strontium-manganate and / or at least one lanthanum-, strontium- and manganese-containing phase. [5] Method according to any one of claims 1 to 4, characterized by, that at least one binder is selected from the group comprising synthetic resin, bitumen, artificial pitch, pitch, lactose, tannin, collagen, lignin and fructose. [6] Method according to claim 5, characterized by that the binder is used in combination with at least one oxide-containing binder. [7] Method according to any one of claims 1 to 6, characterized by that at least one antioxidant is added to the binder. [8] Method according to claim 7, characterized by that the antioxidant is selected from the group comprising Al, Si, Ti, Zr, Y, Mg, Fe, Mo, W, B4C, Borax, TiB2, AIN, SiC and Si3N4. [9] Method according to any one of claims 1 to 8, characterized by that the addition of lanthanum-strontium manganate and / or at least one lanthanum-, strontium- and manganese-containing phase takes place after mixing the refractory aggregate and the at least one binder. [10] Method according to any one of claims 1 to 9, characterized by that the heat treatment takes place at a temperature in the range of 600 °C to 800 °C. [11] Method according to any one of claims 1 to 10, characterized by that the heat treatment takes place in oxidizing or reducing atmospheres or alternately in oxidizing and reducing atmospheres. [12] Use of lanthanum strontium manganate and / or at least one lanthanum, strontium and manganese-containing phase in the manufacture of carbon-containing and / or carbon-bonded refractory molded bodies or masses. [13] Carbon-containing and / or carbon-bonded refractory product, produced according to a process according to any one of claims 1 to 11, characterized by , that the product comprises the following components: • at least one refractory aggregate selected from oxide and non-oxide refractory aggregates, • at least one binder, and • Lanthanum-strontium manganate and / or at least one lanthanum-, strontium- and manganese-containing phase with a proportion in the range of 0.2 wt.% to 10 wt.% based on the total mass of the mixture, wherein the product has a maximum pressure softening according to DIN EN ISO 1893 in the range of 0.5 %dL / L0 to 0.7 %dL / L0.

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