Refractory curable composition

Abstract

The present invention relates to a refractory curable composition (RCC) [refractory curable composition (RCC) herein after], suitable for use as coating in metallurgical vessels such as ladle and tundish, said refractory curable composition (RCC) being prepared by mixing at least one refractory powder composition [composition (RP) herein after] with an amount of 0.1 - 10.0 % by weight (wt. %) of water, relative to the total weight of the composition (RCC), wherein the at least one composition (RP) comprises, relative to the total weight of the composition (RP) from 86.0 to 99.9 wt.% of at least one refractory material and from 0.1 to 14.0 wt.% of at least one compound of formula (I) [compound (C) of formula (I) herein after].

Description

[0001] Refractory curable composition

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a refractory curable composition and its use for coating a metallurgical vessel. The present invention further relates to a method for manufacturing a refractory coating and the products obtained by this method.

[0004] BACKGROUND OF THE INVENTION

[0005] In metallurgical processes, such as casting, molten metal is transported between unit operations in metallurgical vessels. For example, in continuous casting processes, molten steel is tapped from a steelmaking furnace into a ladle. The ladle functions as a transporting vessel within which the molten steel moves from the steelmaking furnace to a casting platform. At the casting platform, the molten steel transfers from the ladle to a tundish. The tundish functions as a metering device that distributes the molten steel through one or more nozzles into moulds in a continuous flow.

[0006] Metallurgical vessels, such as, for example, ladles and tundishes, must physically contain molten metal at relatively high temperatures, for example, in steelmaking processes, at temperatures greater than 1400°C. Additionally, the molten metal-contacting surfaces of metallurgical vessels should be as chemically inert as possible with respect to the molten metal contained within the vessels.

[0007] Accordingly, metallurgical vessels are lined with refractory materials to provide physically-stable and chemically-stable molten metal-contacting surfaces and insulation between the molten metal and the vessel shells, which are typically made of solid steel and therefore susceptible to overheating and loss of mechanical integrity if contacted by molten metal.

[0008] For example, US7078360 discloses a magnesia-based refractory composition which is used for production or repair of refractory linings in metallurgical vessels. The refractory composition disclosed in this document have improved performance characteristics in terms of hot strength, slag resistances and overall durability. A magnesia-based refractory material is admixed with sulfamic acid and a calcium source such as calcium hydroxide and / or calcium oxide. Optionally a wetting agent is added. The use of sulfamic acid in combination with calcium hydroxide and / or calcium oxide results in a magnesia based refractory composition, having improved physical properties, at temperatures from about 110 degrees Celsius to about 1760 degrees Celsius. However, sulfamic acid is difficult to handle since it produces toxic and corrosive fumes including nitrogen oxides and sulphur oxides. This is an acid which may violently react with bases and generates fire or explosion hazard.

[0009] Other compositions exist and are produced by the mixing of MgO containing material, organic binder, inorganic binder, additives and density reducer (if needed). These compositions may be shipped as a dry powder to the steel plants where they are installed by vibration into the metallurgical vessel. However, these compositions require a well-engineered mandrel (form) in order to be shaped in the metallurgical vessel. Further, this mandrel should be equipped with a heat set since these compositions must be heated to 315 °C for hardening. This heating step lasts between 4 and 6 hours in total and requires energy which is neither economical nor environmentally friendly.

[0010] Therefore, there is thus a need for a new dry powder refractory composition which is easy to handle, which does not require an additional heating step and which provides a refractory coating having improved performance characteristics in terms of hot strength, slag resistances and overall durability.

[0011] SUMMARY OF THE INVENTION

[0012] The inventors have now surprisingly found that it is possible to provide a new composition fulfilling the above-mentioned needs.

[0013] Thus, there is now provided a refractory curable composition [refractory curable composition (RCC) herein after] prepared by mixing at least one refractory powder composition (RP) [composition (RP) herein after] with an amount of 0.1 - 10.0 % by weight (wt.%) of water, relative to the total weight of the composition (RCC), wherein the at least one composition (RP) comprises, relative to the total weight of the composition (RP):

[0014] (i) from 86.0 to 99.9 wt.% of at least one refractory material;

[0015] (ii) from 0.1 to 14.0 wt.% of at least one compound, wherein said compound is of formula (I) [compound (C) of formula (I), herein after]: Formula (I) wherein:

[0016] - Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3-6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3.

[0017] - R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and

[0018] - X is hydrogen or an inorganic cation.

[0019] DETAILED DESCRIPTION

[0020] Within the context of the present invention, the term “comprising” should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a composition comprising components A and B” should not be limited to compositions consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the composition are A and B. Accordingly, the terms “comprising” and “including” encompass the more restrictive terms “consisting essentially of” and “consisting of’.

[0021] As used herein, the terms "optional" or "optionally" means that a subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0022] Within the context of the present invention, “at least X wt. % of at least one compound A in a composition B“ refers either to the amount of the compound A, when the composition B contains only one compound A, or to the sum of the amounts of compounds A, when the composition B contains at least one compound A. This being said, it means that it is necessary that, when at least one compound A is present, then it is the sum of the amounts of each of said compound A that is at least X wt.%.

[0023] Refractory Curable Composition (RCC)

[0024] Within the context of the present invention, a refractory curable composition is intended to refer to a refractory composition which is capable of being cured, preferably capable of being cured in ambient conditions. Within the context of the present invention, the term “ambient conditions” refers to room temperature, atmospheric pressure and ambient relative humidity. In general, the term “room temperature” is intended to denote a temperature ranging from -5 °C to 50 °C and the “ambient relative humidity” is intended to denote a relative humidity ranging from ranging from 25 % to 75 %.

[0025] As said, the refractory curable composition [refractory curable composition (RCC) herein after] according to the present invention is prepared by mixing at least one refractory powder composition (RP) with an amount of 0.1 - 10.0 % wt. % of water, relative to the total weight of the composition (RCC).

[0026] Within the context of the present invention, the expression “at least one refractory powder” is intended to denote one or at least one refractory powder composition. In the rest of the text, the expression “refractory powder composition” is understood, for the purposes of the present invention, both in the plural and the singular

[0027] Within the context of the present invention, the term “powder” is intended to refer to any solid in a powder, granular, fragmented or equivalent state, with an average particle size of less than five millimetres (5 mm). For example, the term “powder” refers to a powder, fragments, particles, flakes, granules, grains or other components with an average particle size of less than 5 mm.

[0028] It is to be understood that the expression “particle size” is intended to refer to the average diameter of the particles.

[0029] In general, the average particle size can be measured by methods known in the art, for example by particle size analysers, methods such as measurement using light (light-scattering methods or turbidimetric methods), sedimentation methods (pipette analysis using an Andreassen pipette, sedimentation scales, photosedimentometers or sedimentation in a centrifugal force), pulse methods (Coulter counter), or sorting by means of gravitational or centrifugal force.

[0030] It is further understood that within the context of the present invention, the term “powder” is intended to refer to a powder comprising less than 1.0 wt.%, preferably less than 0.5 wt. %, more preferably less than 0.2 wt.% of water, relative to the total weight of the refractory powder composition (RP).

[0031] It goes without saying that any source of water or mixture thereof can be used according to the present invention. The water used in the composition of the invention can be natural water, treated water, recycled water or mixture thereof. Nonlimiting examples of natural water are rainwater, lakes and rivers water and groundwater. Non-limiting examples of treated water are potable water, faucet water (running water, municipal water) and demineralized water. In general, recycled water is a water which comes from municipal wastewater (sewage) or industrial wastewater which is optionally treated before being reused.

[0032] As said, the refractory curable composition [refractory curable composition (RCC) hereinafter] according to the present invention is prepared by mixing at least one refractory powder composition (RP) with an amount of 0.1 - 10.0 % wt.% of water, relative to the total weight of the composition (RCC). It means that the at least one refractory powder composition (RP) is mixed with an amount of water ranging from 0.1 to 10.0 wt.%, relative to the total weight of the composition (RCC).

[0033] The inventors have surprisingly found that by mixing the refractory powder composition (RP) with an amount of 0.1 - 10.0 wt.% of water, it is possible to prepare a refractory curable composition (RCC) which solidify or cure without the use of additional external thermal energy. A composition which does not require additional thermal energy to cure can also be called a cold curing composition. The advantage of such a composition is that no additional step or energy is required to initiate binding in the composition. The inventors have found that it is possible to prepare a composition which cures under ambient conditions but which does not harden too quickly so that it can be applied on a surface prior to its solidification. Further, the refractory curable composition (RCC) according to the present invention allows the formation of a refractory coating having improved properties, such as an improved mechanical resistance.

[0034] Without being bound to this theory, the specific amount of water, as detailed above, allows the refractory curable composition (RCC) to cure. In other words, as soon as water, as detailed above, is mixed with the refractory powder composition (RP), as detailed above, the refractory curable composition (RCC) starts to cure and solidify in a period long enough to allow its application and short enough to be economically profitable whilst producing a coating with improved properties.

[0035] The inventors have found that the refractory curable composition (RCC) prepared, as detailed above, can be successfully applied on the inner surface of a metallurgical vessel and that the resulting coating forms an improved refractory coating which effectively withstand high temperatures while maintaining mechanical integrity.

[0036] The inventors have also found that when the refractory powder composition (RP) of the present invention is mixed with water as detailed above, the refractory curable composition (RCC) has the desirable consistency suitable to be used as a coating material in a metallurgical vessel. Indeed, the inventors have found that the refractory curable composition (RCC) of the present invention may have the characteristics of an “earth moist” composition which is like a damp sand. This means that the refractory curable composition (RCC) of the present invention does not flow under its own weight or under vibration, and will mound up when applied as a coating. In practice, some mechanical movement is preferred for consolidation of the coating.

[0037] If desired, the amount of water which is mixed with the refractory powder composition (RP) to prepare the refractory curable composition (RCC), can be further adjusted in order to steer the characteristics of the refractory curable composition (RCC).

[0038] Advantageously, the at least one refractory powder composition (RP) is mixed with an amount of at least 0.1 wt.%, preferably at least 0.5 wt.%, preferably at least 1 .0 wt.%, preferably at least 1 .5 wt.%, preferably at least 2.0 wt.%, preferably at least 2.5 wt.%, preferably at least 3.0 wt.%, more preferably at least 3.5 wt.%, most preferably at least 4.0 wt.% of water, relative to the total weight of the composition (RCC). It is further understood that the upper limit of the amount of water, as detailed above, relative to the total weight of the composition (RCC), is equal to or less than 9.5 wt.%, preferably equal to or less than 9.0 wt.%, preferably equal to or less than 8.0 wt.%, preferably equal to or less than 7.5 wt.%, preferably equal to or less than 7.0 wt.%, preferably equal to or less than 6.5 wt.%, preferably equal to or less than 6.0 wt.%, more preferably equal to or less than 5.5 wt.%, most preferably equal to or less than 5.0 wt.%, relative to the total weight of the composition (RCC).

[0039] In a preferred embodiment of the refractory curable composition (RCC) of the present invention, the at least one refractory powder composition (RP) is mixed with an amount of water ranging from 0.5 to 9.5 % wt.%, preferably from 1.0 to 8.0 wt.%, preferably from 1.5 to 7.5 wt. %, preferably from 2.0 to 7.0 wt.%, preferably from 2.5 to 6.5 wt.%, preferably from 3.0 to 6.0 wt.%, preferably from 3.5 to 5.5 wt.%, or from 3.5 to 5.0 wt.% or from 4.0 to 5.0 wt.% of water, relative to the total weight of the composition (RCC).

[0040] As said, according to the present invention, the composition (RP) comprises, relative to the total weight of the composition (RP) from 86.0 to 99.9 wt.% of at least one refractory material.

[0041] Within the context of the present invention, the expression “at least one refractory material” is intended to denote one or more than one refractory material. In the rest of the text, the expression “refractory material” is understood, for the purposes of the present invention, both in the plural and the singular.

[0042] Within the context of the present invention, the expression “refractory material” is intended to refer to a material which is chemically and physically stable at high temperatures.

[0043] In the context of the present invention, any refractory material which is suitable to withstand high temperatures and sudden changes in temperature while maintaining mechanical integrity may be used.

[0044] In general, refractory materials are known to the skilled person in the art and their nature may be chosen according to their application. In general, a refractory material is an inorganic which may have various structures: they may be porous or non-porous, and their crystallinity may vary: they may be crystalline, polycrystalline, amorphous, or composite.

[0045] It is further understood that the refractory material, as detailed above, may be commercially available, or may be chemically synthesized from commercially available starting materials according to any methods known to the skilled in the art.

[0046] In general, a refractory material may be synthetically prepared by a variety of methods known in the art or can be of natural origin.

[0047] Non-limiting examples of refractory materials mention can be made of alumina, silica, magnesia, magnesite, hydromagnesite, brucite, serpentine, dolime (calcined dolomite or dolomitic quick lime), dolomite (dolomitic limestone), quicklime, limestone, semi-hydrated or hydrated lime, semi-hydrated or hydrated dolime, chromia, zirconia, zircon, kaolin, mullite, andalusite, kyanite, sillimanite, olivine, dunite, talc or mixture thereof.

[0048] Preferably, the at least one refractory material is selected among alumina, silica, magnesia, olivine or mixtures thereof.

[0049] Non-limiting examples of magnesia are dead burned magnesia, caustic magnesia, magnesia fumes or mixture thereof.

[0050] Preferably, magnesia is dead burned magnesia.

[0051] The refractory materials, as detailed above, may comprise at least one refractory compound.

[0052] Within the context of the present invention, the expression “at least one refractory compound” is intended to denote one or at least one refractory compound. In the rest of the text, the expression “refractory compound” is understood, for the purposes of the present invention, both in the plural and the singular.

[0053] Non-limiting examples of refractory compounds mention can be made of oxides, carbonates, silicates, carbides or nitrides of the following elements: silicon, aluminium, magnesium, calcium, boron, chromium and zirconium. Other refractory compounds such as calcined clay (fired clay), spinel and refractory grog may also be used for the purpose of the invention. Advantageously, the at least one refractory compound comprised in the at least one refractory material is selected from the group consisting of aluminium oxide, silicon oxide, magnesium oxide, calcium-magnesium oxide, calcium-magnesium carbonate, magnesium silicate, calcium oxide, calcium carbonate, silicon carbide, chromium oxide, chromite, aluminosilicates, zirconium oxide, zirconium silicate, iron oxide or mixtures of two or more thereof.

[0054] Preferably, the at least one refractory compound comprised in the at least one refractory material is selected from the group consisting of aluminium oxide, silicon oxide, magnesium oxide, calcium oxide, aluminium silicate or mixtures of two or more thereof.

[0055] Preferably, the magnesia, as mentioned above, comprises at least 89.0 wt.% of magnesium oxide, relative to the total weight of the magnesia.

[0056] Preferably, the magnesia, as mentioned above, comprises at least 95.0 wt.% of magnesium oxide, relative to the total weight of the magnesia.

[0057] Preferably, the olivine, as mentioned above, comprises at least 35.0 wt.% of magnesium oxide and at least 35.0 wt.% of silicon oxide, relative to the total weight of the olivine.

[0058] According to certain embodiments of the present invention, the refractory material, as detailed above, comprises the at least one refractory compound in an amount of at least 80.0 wt.%, relative to the total weight of the refractory material.

[0059] Advantageously, the refractory material, as detailed above, comprises the at least one refractory compound in an amount of at least 85.0 wt.%, preferably at least 90.0 wt.%, preferably at least 95.0 wt.%, preferably at least 97.0 wt.%, more preferably at least 98.0 wt.%, even more preferably at least 99.0 wt.%, relative to the total weight of the refractory material.

[0060] It is further understood that the upper limit of the amount of the refractory compound comprised in the refractory material, as detailed above, is not critical.

[0061] It goes without saying that the refractory material may comprise a minor amount of additional components or impurities, other than the refractory compound, which do not substantially modify the properties, in particular the refractory properties, of said refractory material.

[0062] If desired, the refractory material may consist essentially of the at least one refractory compound.

[0063] It is to be understood that the expression “consist essentially of” is intended to denote that any additional ingredient different from the at least one refractory compound, is present in minor amounts in said refractory material, being understood that these latter do not substantially modify the properties of said refractory material, i.e. these latter do not materially affect the essential characteristics of said refractory compound, in particular the refractory properties of said refractory material.

[0064] In particular, when the refractory material consists essentially of the at least one refractory compound, the refractory material comprises less than 3.0 wt.% of other components than the at least one refractory compound, preferably less than 2.0 wt.%, more preferably less than 1.0 wt.%, most preferably less than 0.5 wt.%, relative to the total weight of the refractory material.

[0065] Good results were obtained when the refractory material comprises, consists essentially, of a mixture of magnesia and olivine so as the total amount of the magnesium oxide and the silicon oxide in the refractory material is of at least 85.0 wt.%, preferably at least 90.0 wt.%, relative to the total weight of the refractory material, and wherein the magnesium oxide content is of at least 50.0 wt.%, preferably at least 60.0 wt.%, more preferably at least 65.0 wt.%, relative to the total weight of the refractory material.

[0066] As said, the refractory powder composition (RP) comprises from 86.0 to 99.9 wt.%, of the at least one refractory material, as detailed above, relative to the total weight of the refractory powder composition (RP).

[0067] Advantageously, the refractory powder composition (RP) comprises the refractory material, as detailed above, in an amount of at least 86.0 wt.%, preferably at least 87.0 wt.%, preferably at least 88.0 wt.%, preferably at least 89.0 wt.%, more preferably at least 90.0 wt.%, even more preferably at least 91 .0 wt.%, most preferably at least 92.0 wt.%, relative to the total weight of the refractory powder composition (RP). It is further understood that the upper limit of the amount of refractory material, as detailed above, in the refractory powder composition (RP) is desirably less than 99.9 wt.%, preferably less than 99.5 wt.%, more preferably less than 99.0 wt.%, even more preferably less than 98.5 wt.%, most preferably less than 98.0 wt.%, relative to the total weight of the refractory powder composition (RP).

[0068] In a preferred embodiment of the present invention, the refractory powder composition (RP) comprises the refractory material, as detailed above, in an amount from 87.0 to 99.9 wt.%, preferably from 88.0 to 99.5 wt.%, more preferably from 89.0 to 99.0 wt.%, even more preferably from 89.0 to 98.5 wt.%, even more preferably from 90.0 to 98.0 wt.%, most preferably from 91. O to 98.0 wt.%, most preferably from 92.0 to 96.0 wt.%, relative to the total weight of the refractory powder composition (RP).

[0069] It is to be understood that the refractory material is preferably a powder. It is further understood that the definition of powder, as described above, equally applies for the refractory material.

[0070] Advantageously, the refractory material, as detailed above, has an average particle size of less than 4.0 mm, preferably less than 3.0 mm, more preferably less than 2.0 mm, most preferably less than 1.5 mm.

[0071] It is further understood that the lower limit of the particle size of the refractory material, as detailed above, is at least 0.01 mm, preferably 0.02 mm, preferably 0.03 mm, preferably 0.04 mm, preferably 0.05 mm.

[0072] In a preferred embodiment of the present invention, the refractory material, as detailed above, has an average particle size ranging from 0.01 to 4.0 mm, preferably from 0.02 to 3.0 mm, preferably from 0.03 to 2.0 mm, more preferably from 0.04 to 1.5 mm.

[0073] It is to be understood that the expression “average particle size” is intended to refer to the average diameter of the particles.

[0074] As to the amount of the refractory powder composition (RP) in the refractory curable composition (RCC), it is understood that the skilled person in the art will practise said refractory powder composition (RP) in a suitable amount according to standard and general practice known by said skilled person in the art. According to some embodiments of the present invention, the refractory curable composition (RCC) comprises the at least one refractory powder composition (RP) in an amount of at least 90.0 wt.%, preferably at least 91 .0 wt.%, preferably at least 92.0 wt.%, more preferably at least 93.0 wt.%, even more preferably at least 94.0 wt.%, most preferably at least 95.0 wt.%, relative to the total weight of the refractory curable composition (RCC).

[0075] It is further understood that the upper limit of the used amount of the refractory powder composition (RP), as detailed above, in the refractory curable composition (RCC) is desirably less than 99.9 wt.%, preferably less than 99.5 wt.%, preferably less than 99.0 wt.%, preferably less than 98.5 wt.%, preferably less than 98.0 wt.%, preferably less than 97.5 wt.%, preferably less than 97.0 wt.%, relative to the total weight of the refractory curable composition (RCC).

[0076] According to a particular embodiment of the present invention, the amount of the refractory powder composition (RP), as detailed above, in the refractory curable composition (RCC) is from 90.0 wt.% to 99.9 wt. %, preferably from 91.0 wt.% to 99.5 wt.%, preferably from 92.0 wt.% to 99.0 wt.%, preferably from 93.0 wt.% to 98.5 wt.%, more preferably from 94.0 wt.% to 98.0 wt.%, even more preferably from 95.0 wt.% to 97.5 wt.%, most preferably from 95.0 to 97.0 wt.%, relative to the total weight of the refractory curable composition (RCC).

[0077] As said, the refractory powder composition (RP), as detailed above, further comprises from 0.1 to 14.0 wt.% of the at least one compound (C) of formula (I), as detailed above, relative to the total weight of the composition (RP).

[0078] Within the context of the present invention, the expression “at least one compound of formula (I) [compound (C) of formula (I) herein after]” is intended to denote one or at least one compound (C) of formula (I). Mixtures of compounds (C) of formula (I) can also be used for the purpose of the invention.

[0079] In the rest of the text, the expression “at least one compound (C) of formula (I)” is understood, for the purposes of the present invention, both in the plural and the singular, that is to say the refractory powder composition (RP) according to the present invention may comprise one or at least one compound (C) of formula (I). The inventors have surprisingly found that when the composition (RP) of the present invention further comprises from 0.1 to 14.0 wt.% of the at least one compound (C) of formula (I), as detailed above, the refractory curable composition (RCC) of the present invention can successfully be used as a refractory coating in metallurgical vessels. Furthermore, when mixed with water, as detailed above, the composition (RP) cures under ambient conditions and no external heat is required. Moreover, the refractory curable composition (RCC) can be installed at a thickness which is a suitable thickness for a refractory coating used in metallurgical vessels. Further, the resulting coating, after curing of the composition (RCC), is characterized by a markedly improved mechanical resistance and is well consolidated. Furthermore, the refractory coating has an excellent surface profile and a homogeneous appearance.

[0080] The inventors have thus found that it is due to the specific nature of the compound (C) of formula (I) in the specific amount, as detailed above, that enables preparing a refractory curable composition (RCC) which does not require any additional heating step to cure and which may be used to form a refractory coating having improved performance characteristics in terms of hot strength, slag resistances and overall durability.

[0081] Without being bound to this theory, upon mixing the specific amount of water, as detailed above, with the refractory powder composition (RP), as detailed above, the refractory material might react with the compound (C) of formula (I), as detailed above, to form a new refractory structure with enhanced mechanical strength and greater resistance during curing. In other words, the compound (C) of formula (I) might act as a chelating agent of ions comprised in the refractory material such as Mg2+and thereby induce the generation of a new refractory structure.

[0082] In particular, the compound (C) of formula (I) as comprised in the composition (RP), as detailed above, functions as a binder, thereby especially assuring optimal curing properties upon mixing of said composition (RP), as detailed above with water in specific amounts in such a way that the resulting refractory coating demonstrates good mechanical properties in terms of hardness and integrity.

[0083] As said, the compound (C) is of formula (I) : Formula (I) wherein:

[0084] - Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3-6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3;

[0085] - R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and

[0086] - X is hydrogen or an inorganic cation.

[0087] As used in the foregoing and hereinafter, the following definitions apply unless otherwise noted.

[0088] The term halo - alone or in combination means all halogens, that is, chloro (Cl), bromo (Br), fluoro (F), and iodo (I).

[0089] The term alkyl - alone or in combination means an alkane-derived radical containing from 1 to 6 carbon atoms, unless otherwise specified, for example CF-G alkyl defines a straight or branched alkyl radical having from F to G carbon atoms, e.g., C1-4 alkyl defines a straight or branched alkyl radical having from 1 to 4 carbon atoms such as for example methyl, ethyl, 1 -propyl, 2-propyl, l-butyl, 2-butyl, 2-methyl-1 -propyl. An alkyl group may be a straight chain alkyl or branched alkyl.

[0090] The term cycloalkyl refers to a cyclic or polycyclic alkyl group containing 3 to 6 carbon atoms. Preferably, cycloalkyl groups are monocyclic ring systems of 3-6 carbon ring members per ring, such as cyclopropyl, cyclopentyl, cyclohexyl, and the like.

[0091] Unless otherwise mentioned or indicated, the chemical designation of a compound (C) of formulae (I) as specified herein, as specified herein, encompasses the mixture of all possible stereochemically isomeric forms, which said compound may possess. Said mixture may contain all diastereomers and / or enantiomers of the basic molecular structure of said compound. All stereochemically isomeric forms of the compounds of the present invention both in pure form or mixed with each other are intended to be embraced within the scope of the present invention.

[0092] In a preferred embodiment of the present invention, Ri in the compound (C) of formula (I) is selected from hydrogen or C1-6 alkyl, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3.

[0093] Preferably, R1 is selected from hydrogen or C1-6 alkyl.

[0094] More preferably, R1 is selected from hydrogen or C1-4 alkyl.

[0095] Even more preferably, R1 is selected from hydrogen, methyl or ethyl.

[0096] Even more preferably, R1 is methyl.

[0097] In a preferred embodiment of the present invention, R2 in compound (C) of formula (I) is selected from hydrogen or C1-6 alkyl, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3.

[0098] Preferably, R2 is selected from hydrogen or C1-6 alkyl.

[0099] More preferably, R2 is selected from hydrogen or C1-4 alkyl.

[0100] Even more preferably, R2 is selected from hydrogen, methyl or ethyl.

[0101] Even more preferably, R2 is hydrogen.

[0102] Preferably, X is hydrogen or an inorganic cation selected from the group consisting of an alkali metal cation, an alkaline earth metal cation, a transition metal cation, a silver cation, an aluminium cation, and an ammonium cation.

[0103] Preferably X is hydrogen, or a cation selected from the group consisting of a lithium cation, a sodium cation, a potassium cation, a calcium cation, a magnesium cation, an iron cation, a copper cation, a nickel cation, a silver cation, an aluminium cation, and an ammonium cation.

[0104] More preferably X is hydrogen, or a cation selected from the group consisting of a magnesium cation, a sodium cation, a calcium cation and an aluminium cation.

[0105] Even more preferably, X is an aluminium cation. It is further understood that the compound (C) of formula (I), as detailed above, may be commercially available, or may be chemically synthesized from commercially available starting materials according to any methods known to the skilled in the art.

[0106] According to a preferred embodiment, the compound (C) is aluminium lactate.

[0107] As said, the refractory powder composition (RP), as detailed above, comprises the at least one compound (C) of formula (I) in an amount from 0.1 to 14.0 wt.%, relative to the total weight of the composition (RP).

[0108] Advantageously, the refractory powder composition (RP) of the present invention comprises the compound (C) of formula (I), as detailed above, in an amount of at least 0.1 wt.%, preferably at least 0.5 wt.%, preferably at least 1.0 wt.%, preferably at least 1.5 wt.%, preferably at least 2.0 wt.%, preferably at least 2.5 wt.%, more preferably at least 3.0 wt.%, most preferably at least 3.5 wt.%, relative to the total weight of the refractory powder composition (RP).

[0109] It is further understood that the upper limit of the amount of the compound (C) of formula (I), as detailed above, comprised in the refractory powder composition (RP) of the present invention is desirably less than 14.0 wt.%, preferably less than 13.0 wt.%, preferably less than 12.0 wt.%, preferably less than 11.0 wt.%, preferably less than 10.0 wt.%, preferably less than 9.0 wt.%, preferably less than 8.0 wt.%, more preferably less than 7.0 wt.%, even more preferably less than 6.0 wt.%, most preferably less than 5.0 wt.%, relative to the total weight of the refractory powder composition (RP).

[0110] In a preferred embodiment of the invention, the refractory powder composition (RP) comprises the compound (C) of formula (I), as detailed above, in an amount from 0.5 to 13.0 wt.%, preferably from 1.0 to 12.0 wt.%, preferably from 1.5 to 11 .0 wt.%, preferably from 2.0 to 10.0 wt.%, more preferably from 2.5 to 9.0 wt.%, more preferably from 3.0 to 8.0 wt.%, more preferably from 3.5 to 7.0 wt.%, even more preferably from 3.5 to 6.0 wt.%, most preferably from 3.5 wt.% to 5.0 wt.%, relative to the total weight of the refractory powder composition (RP). It is to be understood that the compound (C) of formula (I), as detailed above, is preferably a powder. It is further understood that the definition of powder, as described above, equally applies for the compound (C).

[0111] According to a preferred embodiment of the present invention, the refractory curable composition (RCC), as detailed above, is prepared by mixing at least one refractory powder composition (RP), as detailed above, with an amount of 1 .0 - 8.0 % by weight (wt.%) of water, relative to the total weight of the composition (RCC), wherein the composition (RP) comprises, relative to the total weight of the composition (RP):

[0112] (iii) from 88.0 to 99.5 wt.% of at least one refractory material;

[0113] (iv) from 0.5 to 12.0 wt.% of at least one compound, wherein said compound is of formula (I) [compound (C) of formula (I), herein after]: Formula (I) wherein:

[0114] - R1 is selected from the group consisting of hydrogen, C1-6 alkyl, C3-6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3.

[0115] - R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and

[0116] - X is hydrogen or an inorganic cation.

[0117] According to a more preferred embodiment of the present invention, the refractory curable composition (RCC), as detailed above, is prepared by mixing at least one refractory powder composition (RP), as detailed above, with an amount of 2.0 - 7.0 % by weight (wt.%) of water, relative to the total weight of the composition (RCC), wherein the composition (RP) comprises, relative to the total weight of the composition (RP):

[0118] (v) from 89.0 to 98.5 wt.% of at least one refractory material; (vi) from 1 .5 to 11 .0 wt.% of at least one compound, wherein said compound is of formula (I) [compound (C) of formula (I), herein after]: Formula (I) wherein:

[0119] - Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3-6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3.

[0120] - R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and

[0121] - X is hydrogen or an inorganic cation.

[0122] According to a most preferred embodiment of the present invention, the refractory curable composition (RCC), as detailed above, is prepared by mixing at least one refractory powder composition (RP), as detailed above, with an amount of 3.0 - 6.0 % by weight (wt.%) of water, relative to the total weight of the composition (RCC), wherein the composition (RP) comprises, relative to the total weight of the composition (RP):

[0123] (vii) from 90.0 to 98.0 wt.% of at least one refractory material;

[0124] (viii) from 2.0 to 10.0 wt.% of at least one compound, wherein said compound is of formula (I) [compound (C) of formula (I), herein after]: Formula (I) wherein: - Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3-6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3.

[0125] - R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and

[0126] X is hydrogen or an inorganic cation

[0127] As said, the refractory curable composition (RCC) is prepared by mixing at least one refractory powder composition (RP), as detailed above with water, as detailed above.

[0128] The refractory curable composition (RCC) of the present invention can be prepared by a variety of methods known in the art involving mixing. It is understood that the skilled person in the art will carry out said mixing according to general practice such as notably using optimal times, speeds, weights, volumes and batch quantities.

[0129] Furthermore, it is understood that any order of mixing of the various components as comprised in the refractory curable composition (RCC), as detailed above, is acceptable.

[0130] When appropriate, the refractory material, as detailed above, and the compound (C) of formula (I), as detailed above, can be pre-mixed to form the refractory powder composition (RP) prior to the mixing with water.

[0131] Generally said mixing, as detailed above, may be carried out by using a variety of mixing means known in the art. Non-limiting examples of such mixing means are for example mechanical mixing such as traditional mixers and blenders, high intensity mixers, mixing conveyor and electric stirrers. Preferably, the mixing is carried out by a mixing conveyor. Said mixing conveyor can also be called a mixing screw conveyor or a blending conveyor.

[0132] Preferably, said mixing is carried out until a homogeneous mixture is obtained. Method for the manufacturing of the refractory Curable Composition (RCC)

[0133] Another aspect of the present invention is a method for the manufacturing of the refractory curable composition (RCC), as detailed above.

[0134] It is further understood that all definitions and preferences, as described above, equally apply for all further embodiments, as described below.

[0135] The refractory curable composition (RCC) of the present invention can be manufactured by a variety of methods known in the art. For manufacturing the refractory curable composition (RCC) of the present invention, several methods known in the art may adequately be used.

[0136] In one embodiment of the present invention, the method for the manufacturing of the refractory curable composition (RCC), as detailed above, comprises the following steps:

[0137] Step A: the at least one compound (C) of formula (I), as detailed above, is first mixed with at least part of the at least one refractory material, as detailed above, thereby forming the at least one refractory powder composition (RP);

[0138] Step B: the at least one powder composition (RP) is further mixed with the water, as detailed above, thereby forming the refractory curable composition (RCC).

[0139] It is further understood that all definitions and preferences of the mixing, as described above, equally apply for the manufacturing of the refractory curable composition (RCC).

[0140] Preferably, in Step A of the method for the manufacturing of the refractory curable composition (RCC), as detailed above, the at least one compound (C), as detailed above, is mixed with the total amount of the at least one refractory material, as detailed above.

[0141] Preferably, in Step A and in Step B of the method for the manufacturing of the refractory curable composition (RCC), as detailed above, the mixing of the components as comprised in the refractory curable composition (RCC) is carried out at 20 °C and at atmospheric pressure. Preferably, in Step A, as detailed above, the mixing of the components as comprised in the refractory powder composition (RP) is carried out prior to Step B and in Step B of the method for the manufacturing of the refractory curable composition (RCC), as detailed above, the mixing of the components as comprised in the refractory curable composition (RCC) is carried out in a mixing conveyor.

[0142] Preferably, prior to Step B, the refractory powder composition (RP) as obtained in Step A, as detailed above, and the water, as detailed above, are provided at the inlet of a mixing conveyor. In this way, Step B is carried out in the mixing conveyor wherein the refractory powder composition (RP), as detailed above, and the water, as detailed above, are mixed to manufacture the refractory curable composition (RCC) which may be collected at the outlet of the mixing conveyor.

[0143] Preferably, a metallurgical vessel is placed in the vicinity of the outlet of the mixing conveyor. This configuration facilitates the transfer of the refractory curable composition (RCC) to the metallurgical vessel.

[0144] If desired, prior to Step B, the refractory powder composition (RP) as obtained from Step A, as detailed above, is stored in a container such as a material hopper.

[0145] In a preferred embodiment, the method for the manufacturing of the refractory curable composition (RCC), as detailed above, comprises the following steps:

[0146] Step A: the at least one compound (C) of formula (I), as detailed above, in an amount from 0.1 to 14.0 wt.%, preferably from 0.5 to 13.0 wt.%, preferably from 1 .0 to 12.0 wt.%, preferably from 1 .5 to 11 .0 wt.%, preferably from 2.0 to 10.0 wt.%, more preferably from 2.5 to 9.0 wt.%, more preferably from 3.0 to 8.0 wt.%, more preferably from 3.5 to 7.0 wt.%, even more preferably from 3.5 to 6.0 wt.%, most preferably from 3.5 wt.% to 5.0 wt.%, relative to the total weight of the refractory powder composition (RP), is first mixed with an amount from 87.0 to 99.9 wt.%, preferably from 88.0 to 99.5 wt.%, more preferably from 89.0 to 99.0 wt.%, even more preferably from 89.0 to 98.5 wt.%, even more preferably from 90.0 to 98.0 wt.%, most preferably from 91 .0 to 98.0 wt.%, most preferably from 92.0 to 98.0 wt.%, relative to the total weight of the refractory powder composition (RP), of the at least one refractory material, as detailed above, thereby forming the at least one refractory powder composition (RP);

[0147] Step B: from 90.0 wt.% to 99.9 wt. %, preferably from 91 .0 wt.% to 99.5 wt.%, preferably from 92.0 wt.% to 99.0 wt.%, preferably from 93.0 wt.% to 98.5 wt.%, more preferably from 94.0 wt.% to 98.0 wt.%, even more preferably from 95.0 wt.% to 97.5 wt.%, most preferably from 95.0 to 97.0 wt.%, relative to the total weight of the refractory curable composition (RCC), of the at least one powder composition (RP), as detailed above, is further mixed with an amount of water, as detailed above, ranging from 0.5 to 9.5 % wt.%, preferably from 1.0 to 8.0 wt.%, preferably from 1.5 to 7.5 wt. %, preferably from 2.0 to 7.0 wt.%, preferably from 2.5 to 6.5 wt.%, preferably from 3.0 to 6.0 wt.%, preferably from 3.5 to 5.5 wt.%, or from 3.5 to 5.0 wt.% or from 4.0 to 5.0 wt.% of water, relative to the total weight of the composition (RCC), thereby forming the refractory curable composition (RCC).

[0148] In a more preferred embodiment, the method for the manufacturing of the refractory curable composition (RCC), as detailed above, comprises the following steps:

[0149] Step A: the at least one compound (C) of formula (I), as detailed above, in an amount from 0.5 to 13.0 wt.%, relative to the total weight of the refractory powder composition (RP), is first mixed with an amount from 88.0 to 99.5 wt.%, relative to the total weight of the refractory powder composition (RP), of the at least one refractory material, as detailed above, thereby forming the at least one refractory powder composition (RP);

[0150] Step B: from 92.0 wt.% to 99.0 wt.%, relative to the total weight of the refractory curable composition (RCC), of the at least one powder composition (RP), as detailed above, is further mixed with an amount of water, as detailed above, ranging from 1.0 to 8.0 wt.%, relative to the total weight of the composition (RCC), thereby forming the refractory curable composition (RCC). In a most preferred embodiment, the method for the manufacturing of the refractory curable composition (RCC), as detailed above, comprises the following steps:

[0151] Step A: the at least one compound (C) of formula (I), as detailed above, in an amount from 2.0 to 10.0 wt.%, relative to the total weight of the refractory powder composition (RP), is first mixed with an amount from 90.0 to 98.0 wt.%, relative to the total weight of the refractory powder composition (RP), of the at least one refractory material, as detailed above, thereby forming the at least one refractory powder composition (RP);

[0152] Step B: from 94.0 wt.% to 97.0 wt.%, relative to the total weight of the refractory curable composition (RCC), of the at least one powder composition (RP), as detailed above, is further mixed with an amount of water, as detailed above, ranging from 3.0 to 6.0 wt.%, relative to the total weight of the composition (RCC), thereby forming the refractory curable composition (RCC).

[0153] Method for coating a surface or at least part of a surface of a metallurgical vessel with the refractory curable composition (RCC)

[0154] Another aspect of the present invention is a method for coating a surface or at least part of a surface of a metallurgical vessel wherein said metallurgical vessel is coated with the refractory curable composition (RCC), as detailed above.

[0155] It is further understood that all definitions and preferences, as described above, equally apply for all further embodiments, as described below. It is to be understood that a metallurgical vessel is a vessel suitable to be used in steelmaking processes. In other words, a vessel which is subjected to high temperature.

[0156] Preferably, the metallurgical vessel is selected among a ladle and a tundish. Preferably, the metallurgical vessel is a tundish.

[0157] Preferably the surface of the metallurgical vessel, as detailed above, is an inner surface of a metallurgical vessel.

[0158] Among the suitable manners for applying the refractory curable composition (RCC), as detailed above, onto the surface or at least part of the surface of the metallurgical vessel, as detailed above, mention can be notably made of conventional application methods known to those skilled in the art of coating compositions. Non-limiting examples of conventional application methods suitable to apply a refractory curable composition onto a surface of a metallurgical vessel are projecting, spilling, spraying, spreading, using a mould in the metallurgical vessel and pouring the gap between said vessel and said mould. Preferably, the application of the refractory curable composition (RCC), as detailed above, onto the surface or at least part of the surface of the metallurgical vessel, as detailed above, is carried out by projecting the refractory curable composition (RCC), as detailed above, onto the surface or at least part of the surface of a metallurgical vessel.

[0159] As detailed above, the inventors have found that the refractory curable composition (RCC) of the present invention does not flow under its own weight or under vibration, and will mound up when applied as a coating onto the surface or at least part of the surface of a metallurgical vessel. If desired, a mechanical movement may be carried out after the application of the refractory curable composition (RCC), as detailed above, onto the surface or at least part of the surface of the metallurgical vessel, as detailed above, for consolidating the coating.

[0160] The refractory curable composition (RCC) can be applied onto the surface or at least part of the surface of the metallurgical vessel in low amounts, in particular for obtaining a homogeneous coating.

[0161] Advantageously, after the application of the refractory curable composition (RCC), as detailed above, the refractory curable composition (RCC) coated on the surface or at least part of a surface of a metallurgical vessel is cured, preferably at room temperature, more preferably at ambient conditions. It is further understood that the definition of room temperature and ambient conditions, as detailed above, equally apply for all further embodiments, as described below.

[0162] Advantageously, the curing of the refractory curable composition (RCC), as detailed above, is carried out during at least 10 minutes, or at least 20 minutes, or at least 30 minutes, or at least 40 minutes, or at least 50 minutes, or at least 60 minutes.

[0163] Good results were obtained when the refractory curable composition (RCC), as detailed above, is directly used for coating a surface or at least part of a surface of a metallurgical vessel. In other words, the time period between the formation of the refractory curable composition (RCC), as detailed above, and the use of this refractory curable composition (RCC) for coating a surface or at least part of a surface of a metallurgical vessel, is preferably less than 1 hour, preferably less than 45 minutes (min, herein after), preferably less than 30 min, preferably less than 20 min, more preferably less than 15 min, even more preferably less than 10 min, most preferably less than 5 min.

[0164] In a preferred embodiment of the present invention, the mixing of the at least one refractory powder composition (RP), as detailed above, with water, as detailed above, to manufacture the refractory curable composition (RCC), as detailed above, is followed by a coating of a surface or at least part of a surface of a metallurgical vessel with the refractory curable composition (RCC), as detailed above.

[0165] The inventors have found that the curing of the refractory curable composition (RCC), as detailed above, may start as soon as the refractory powder composition (RP), as detailed above, and the water, as detailed above, are mixed to manufacture the refractory curable composition (RCC), as detailed above. It is thus preferable to carry out the coating of the surface or at least part of the surface of the metallurgical vessel with the refractory curable composition (RCC), as detailed above, directly after the manufacturing of the refractory curable composition (RCC), as detailed above, so that the solidification of the refractory curable composition (RCC) takes place onto the surface of the metallurgical vessel. In other words, the formation of an uncoated solid refractory curable composition (RCC) is to be avoided.

[0166] Another aspect of the present invention is a refractory coating obtained by the method for coating the surface or at least part of the surface of the metallurgical vessel, as detailed above, wherein said metallurgical vessel is coated with the refractory curable composition (RCC), as detailed above.

[0167] It is further understood that all definitions and preferences, as described above, equally apply for all further embodiments, as described below.

[0168] The Applicant has surprisingly found that the composition (RCC), as described above, is effective in providing refractory coatings having a reduced tendency to forming holes during coating and curing and / or having improved surface appearance (e.g., having a lower amount of surface defects) and / or having an increased smoothness. Furthermore, the refractory coatings manufactured using the composition (RCC), as detailed above, effectively withstand high temperatures and have improved mechanical strength.

[0169] The application of the refractory curable composition (RCC) onto the surface or at least part of the surface of the metallurgical vessel can result in refractory coatings having an average thickness which may vary and which is typically determined by the end use of the coated metallurgical vessel.

[0170] Advantageously, the average thickness of said refractory coating is typically at least 10 mm, preferably at least 20 mm, more preferably at least 30 mm. It is understood that when the refractory coating has an average thickness below this lower limit, it is sometimes prone to hole formation.

[0171] It is further understood that the upper limit of the average thickness of the refractory coating is preferably less than 100 mm, preferably less than 75 mm, preferably less than 70 mm, preferably less than 50 mm, preferably less than 40 mm.

[0172] In a preferred embodiment of the present invention, the average thickness of said refractory coating, as detailed above, is from 10 to 100 mm, or from 20 to 75 mm, or from 20 to 70 mm, or from 20 to 50 mm, or from 30 to 50 mm, or from 30 to 40 mm.

[0173] Good results were obtained when the refractory coating has an average thickness of about 30 mm.

[0174] Advantageously, refractory coatings obtained from using the composition (RCC) detailed as above have a cold-crush strength (CCS) of at least 10 psi, preferably at least 20 psi, preferably at least 25 psi, preferably at least 30 psi, preferably at least 35 psi, preferably at least 40 psi, preferably at least 50 psi, more preferably at least 60 psi, preferably at least 70 psi, preferably at least 75 psi, preferably at least 100 psi, preferably at least 150 psi, more preferably at least 200 psi.

[0175] It is further understood that the upper limit of the cold-crush strength (CCS) of the refractory coating is preferably less than 1000 psi, preferably less than 750 psi, preferably less than 700 psi, preferably less than 500 psi, preferably less than 400 psi, preferably less than 300 psi, more preferably less than 250 psi. In a preferred embodiment of the present invention, the cold-crush strength (CCS) of said refractory coating, as detailed above, is from 10 to 1000 psi, preferably from 20 to 750 psi, preferably from 25 to 700 psi, preferably from 30 to 500 psi, preferably from 35 to 400 psi, or from 40 to 400 psi, or from 50 to 400 psi, or from 60 to 300 psi, or from 70 to 300 psi, or from 75 to 300 psi, preferably from 35 to 300 psi, more preferably from 35 to 250 psi, most preferably from 40 to 250 psi.

[0176] For the purpose of the present invention, the term " cold-crush strength " is intended to be a measurement of the mechanical strength of the refractory coating of the present invention. It is understood that the skilled person in the art will measure the coldcrush strength according to standard and general practice known by said skilled person in the art. Preferably, unless otherwise mentioned or indicated, according to the present invention, the measurement of the cold-crush strength is performed by measuring the compressive strength of a sample according to ASTM C133-97(2021 ) (Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories). Preferably, the measurement of the cold-crush strength is performed 60 minutes after the manufacturing of the refractory curable composition (RCC), as detailed above. In general, the sample is a 5.1 cm (2”) diameter by 7.6 cm (3”) tall cylindrical specimen. In general, the cold-crush strength may be determined using a universal testing machine using the respective equipment, for example, 120K Super L from the company Tinius Olsen.

[0177] Refractory coatings thus obtained are another object of the present invention.

[0178] Another aspect of the present invention is a use of the refractory curable composition (RCC), as detailed above, in the method for coating the surface or at least part of the surface of the metallurgical vessel, as detailed above.

[0179] Another object of the invention is the refractory powder composition (RP), as detailed above. It is understood that the use of the refractory powder composition (RP) to manufacture the refractory curable composition (RCC), as detailed above, is another aspect of the present invention. EXAMPLES

[0180] The invention will now be described in more detail with reference to the following examples, whose purpose are merely illustrative and not intended to limit the scope of the invention.

[0181] Raw materials

[0182] The following raw materials were used in the examples (Table 1 ). These compounds are commercially available.

[0183] Table 1: Compounds used in the examples

[0184] Test methods

[0185] Measurements of the cold-crush strength (CCS)

[0186] The measurement of the cold-crush strength was performed by measuring the compressive strength of a sample according to ASTM C133-97(2021 ) (Standard Test Methods for Cold Crushing Strength and Modulus of Rupture of Refractories). The measurement of the cold-crush strength was performed 60 minutes after the manufacturing of the refractory curable composition (RCC). The sample was a 5.1 cm (2”) diameter by 7.6 cm (3”) tall cylindrical specimen. The cold-crush strength was determined using a 120K Super L from the company Tinius Olsen.

[0187] Measurements of the density

[0188] The density was measured by means of weighing a specimen, 5.1 cm (2”) diameter by 7.6 cm (3”) tall, made with freshly prepared refractory curable composition (RCC), compacted by hand using moderate force. To calculate the density, the weight was divided by the volume.

[0189] Procedure for manufacturing refractory curable composition (RCC)

[0190] The following section details how the refractory composition according to the invention was prepared.

[0191] The exact compositions of the Examples and the exact compositions of the Comparative Examples, with respect to the type of components contained therein and the related quantities thereof, are described in Table 2 below.

[0192] In a first step (i.e., Step A of the method for the manufacturing of the refractory curable composition (RCC)), the refractory material or the mixture of two refractory materials was mixed with the compound (C) (compound (C) of formula (I)), at room temperature and at atmospheric pressure and using a mixer, thereby forming the refractory powder composition (RP). In a following step (i.e., Step B of the method for the manufacturing of the refractory curable composition (RCC), the obtained refractory powder composition (RP) was further mixed with water, at room temperature and at atmospheric pressure. Cold-crush strength performance of refractory curable compositions after 60 minutes curing

[0193] In order to evaluate the cold-crush strength via the compressive test, as detailed above, 5.1 cm (2”) diameter by 7.6 cm (3”) tall cylindrical samples, were made with freshly prepared refractory curable composition (RCC) and compacted by hand using moderate force. The examples relate to the preparation of cylindrical samples, although they equally apply to the preparation of a tundish working coating. The cold-crush strength performance of these samples was measured 60 minutes after mixing the refractory powder composition (RP) with water.

[0194] The experimental results are shown below in Table 2. Table 2

[0195] The compositions of Examples 1 - 12 (E1 - E12) according to the invention and Comparative Examples 13 and 14 (CE 13 - 14) were manufactured according to the general procedure described above. The composition of Comparative Example 14 (CE 14) does not contain any compound (C). The compositions of Examples 1 - 12 (E1 - E12) according to the invention and Comparative Examples 13 and 14 (CE 13 - 14) were manufactured by mixing the respective components of the composition as described in Table 2 above.

[0196] In particular, the compositions of Examples 1 and 2 (E1 - E2) and Comparative Example 14 (CE 14) were manufactured as follows. The first refractory material, i.e. , dead burned magnesia (DBM), and the second refractory material, i.e., olivine, were first mixed to form a mixture of two refractory materials. This mixture of two refractory materials was then mixed with the compound (C), i.e., Al-lactate for Examples 1 and 2 (E1 -E2) or with Al-Acetate for comparative example 14 (CE 14) for obtaining a refractory powder composition (RP). This refractory powder composition was subsequently mixed with 4.25 wt.% of water to form the refractory curable composition (RCC) which was used to prepare the samples, as detailed above.

[0197] The experimental results as shown in Table 2 first of all clearly demonstrate that the presence of the compound (C) in the refractory curable compositions (RCC) according to the present invention, i.e., E1 to E12, provides an increased mechanical strength after curing, i.e., 60 minutes after the mixing between the refractory powder composition (RP) and the water. Furthermore, the experimental results for E1 to E12 demonstrate that these compositions showed strength development in less than 1 hour under ambient conditions. For example, Examples 3 - 7 (E3 - E7) according to the present invention differ only in the amount of compound (C) which is respectively, 2.0, 3.0, 4.0, 5.0 and 6.0 wt.% while Examples 6 and 8 - 12 (E6, E8 - 12) differ only in the amount of water which is respectively, 4.25, 2.50, 3.25, 4.00, 4.75 and 5.50 wt.%. Upon comparison with the comparative composition which contains Al-acetate instead of the compound (C), i.e., CE14, no strength development was observed even after 24 hours. This comparative composition, CE14, remained damp even after a time period of 24h which suggests that the water is not being incorporated into any binding phase. Regarding the comparative composition, CE13, wherein the compound (C) was partly substituted by a binder known in the art, i.e., potassium phosphate, it is clear that it provides a decrease of the mechanical strength of the resulting cured refractory composition.

[0198] Further, these experimental results as shown in Table 2 demonstrate that a mixture of refractory materials, examples 1 and 2 (E1 - E2), can be used without damaging the mechanical strength of the resulting cured refractory composition.

[0199] Procedure for coating a surface of a metallurgical vessel with the refractory curable composition (RCC)

[0200] The following section details how a metallurgical vessel was coated with the refractory curable compositions of examples, as detailed above.

[0201] The refractory curable compositions (RCC) of examples 1 , 2 and 5 (E1 , E2, E5) according to the present invention, were used to prepare a refractory coating in a tundish (Lab scale).

[0202] In particular, in order to evaluate the properties of the coating manufactured by using the refractory curable composition (RCC) according to the present invention, compositions according to examples 1 , 2 and 5 (E1 , E2, E5) were prepared, as detailed above, by using a mixing conveyor equipped with a material hopper. The refractory powder composition (RP) was fed into the material hopper which uses a screw to discharge the refractory powder composition (RP) at the inlet of the mixing conveyor where water is added. The refractory powder composition (RP) was thus mixed with water at the inlet of the mixing conveyor and was further mixed until the resulting RCC was ready to be applied to a surface of a metallurgical vessel . The tundish was placed in the vicinity of the outlet of the mixing conveyor so that the refractory curable composition RCC) was used as soon as it left the mixing conveyor. Directly after manufacture, the RCC was applied onto all the inner surfaces of a tundish at laboratory scale, to form a refractory coating having an average thickness of 30 mm. Then, some mechanical movements were carried out for consolidation of the coating. The resulting refractory coatings had a sufficient strength withing 60 minutes.

[0203] These experimental results demonstrate that the refractory curable composition (RCC) according to the present invention can be used for coating a tundish and obtaining a refractory coating on the inner surfaces of a tundish which has an excellent surface profile, a homogeneous appearance and which is well consolidated with no voids.

Claims

CLAIMS1. A refractory curable composition [hereinafter refractory curable composition (RCC)] prepared by mixing at least one refractory powder composition [hereinafter composition (RP)] with an amount of 0.1 - 10.0 % by weight (wt. %) of water, relative to the total weight of the composition (RCC), wherein the at least one composition (RP) comprises, relative to the total weight of the composition (RP):(i) from 86.0 to 99.9 wt.% of at least one refractory material;(ii) from 0.1 to 14.0 wt.% of at least one compound, wherein said compound is of formula (I) [compound (C) of formula (I) hereinafter]:Formula (I) wherein:- Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3- 6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3;- R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and- X is hydrogen or an inorganic cation.

2. The refractory curable composition (RCC) according to claim 1 wherein the at least one refractory material is selected among alumina, silica, magnesia, olivine or mixtures thereof.

3. The refractory curable composition (RCC) according to claim 1 or claim 2 wherein the at least one refractory material comprises at least one refractory compound in an amount of at least 80.0 wt.%, relative to the total weight of the refractory material, and wherein said at least one refractory compound is selected from the group consisting of aluminium oxide, silicon oxide, magnesium oxide, calcium-magnesium oxide, calcium-magnesium carbonate, magnesium silicate, calcium oxide, calcium carbonate, silicon carbide, chromium oxide, chromite, aluminosilicates, zirconium oxide, zirconium silicate, iron oxide or mixtures of two or more thereof.

4. The refractory curable composition (RCC) according to any one of claims 1 to 3 wherein Ri in the compound (C) of formula (I) is selected from hydrogen or C1-6 alkyl and wherein R2 in the compound (C) of formula (I) is selected from hydrogen or C1-6 alkyl.

5. The refractory curable composition (RCC) according to any one of claims 1 to 4 wherein X in the compound (C) of formula (I) is hydrogen, or a cation selected from the group consisting of a lithium cation, a sodium cation, a potassium cation, a calcium cation, a magnesium cation, an iron cation, a copper cation, a nickel cation, a silver cation, an aluminium cation, and an ammonium cation.

6. The refractory curable composition (RCC) according to claim 5 wherein the compound (C) of formula (I) is Aluminium lactate.

7. The refractory curable composition (RCC) according to any one of claims 1 to 6 wherein the at least one refractory powder composition (RP) is mixed with an amount of water ranging from 2.0 to 7.0 wt.%, preferably from 2.5 to 6.5 wt.%, preferably from 3.0 to 6.0 wt.%, preferably from 3.5 to 5.5 wt.%, relative to the total weight of the composition (RCC).

8. The refractory curable composition (RCC) according to any one of claims 1 to 7 wherein the refractory powder composition (RP) comprises the refractory material in an amount from 87.0 to 99.9 wt.%, preferably from 88.0 to 99.5 wt.%, more preferably from 89.0 to 99.0 wt.%, even more preferably from 89.0 to 98.5 wt.%, even more preferably from 90.0 to 98.0 wt.%, most preferably from 91.0 to 98.0 wt.%, most preferably from 92.0 to 98.0 wt.%, relative to the total weight of the refractory powder composition (RP).

9. The refractory curable composition (RCC) according to any one of claims 1 to 8 wherein the refractory powder composition (RP) comprises the compound (C) of formula (I) in an amount from 0.5 to 13.0 wt.%, preferably from 1.0 to 12.0 wt.%, preferably from 1.5 to 11.0 wt.%, preferably from 2.0 to 10.0 wt.%, more preferably from 2.5 to 9.0 wt.%, more preferably from 3.0 to 8.0 wt.%, more preferably from 3.5 to 7.0 wt.%, relative to the total weight of the refractory powder composition (RP).

10. A method for the manufacturing of the refractory curable composition (RCC) according to any one of claims 1 to 9, wherein the method comprises the following steps:Step A: mixing from 0.1 to 14.0 wt.% of at least one compound (C) of formula (I), with an amount from 86.0 to 99.9 wt.% of at least one refractory material, thereby forming the at least one refractory powder composition (RP), wherein the wt. % is relative to the total weight of the refractory powder composition (RP);Step B: mixing from 90.0 wt.% to 99.9 wt. % of the at least one powder composition (RP) with an amount of water ranging from 0.1 to 10.0 % wt.% thereby forming the refractory curable composition (RCC), wherein the wt. % is relative to the total weight of the refractory curable composition (RCC).11 . A method for coating a surface or at least part of a surface of a metallurgical vessel wherein said metallurgical vessel is coated with the refractory curable composition (RCC) according to any one of claims 1 to 9 or obtained by the method of claim 10.

12. A refractory coating obtained by the method for coating a surface or at least part of a surface of a metallurgical vessel according to claim 11 wherein said metallurgical vessel is coated with the refractory curable composition (RCC) according to any one of claims 1 to 9 or obtained by the method of claim 10.

13. The refractory coating according to claim 12 wherein said refractory coating has an average thickness ranging from 10 to 100 mm.

14. The refractory coating according to claim 12 or 13 wherein said refractory coating has a cold-crush strength ranging from 30 to 500 psi, preferably from 35 to 300 psi, more preferably from 35 to 250 psi.

15. A use of a refractory curable composition (RCC) in the method for coating the surface or at least part of the surface of the metallurgical vessel according to claim 11 , wherein the refractory curable composition (RCC) is according to any one of claims 1 to 9 or is obtained by the method according to claim 10.

16. A use of a refractory powder composition (RP) for preparing the refractory curable composition (RC) according to any one of claims 1 to 9, wherein the refractory powder composition (RP) comprises, relative to the total weight of the composition (RP):(iii) from 86.0 to 99.9 wt.% of at least one refractory material;(iv) from 0.1 to 14.0 wt.% of at least one compound, wherein said compound is of formula (I) [hereinafter compound (C) of formula (I)]:Formula (I) wherein:- Ri is selected from the group consisting of hydrogen, C1-6 alkyl, C3- 6 cycloalkyl, wherein said alkyl and cycloalkyl are optionally substituted with one or more substituents independently selected from halo or CF3;- R2 is selected from the group consisting of hydrogen, C1-6 alkyl and CF3, wherein said alkyl is optionally substituted with one or more substituents independently selected from halo or CF3; and- X is hydrogen or an inorganic cation.

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