Product for repairing a furnace

Abstract

The invention relates to a packaged product comprising: - a sealed package; and - a wet unshaped product arranged in the sealed package and consisting, for more than 95% by weight: - of 4% to 15% water, in percentages by weight based on the weight of the wet unshaped product; - of 0.5% to 3.2% of a binder precursor, in percentages by weight based on the weight of the wet unshaped product; - of a ceramic powder, the binder precursor being chosen from among: - a colloidal silica having a specific surface area of at least 150 m2 / g; and a mixture consisting of: - a colloidal silica, in an amount of 0.5% or more by weight based on the weight of the wet unshaped product, having a specific surface area of at least 500 m2 / g; and - a hydrolysed silane and / or a siloxane, wherein the ceramic powder is made up of the ceramic particles without taking into account the colloidal silica particles.

Description

[0001] Description

[0002] Title: OVEN REPAIR PRODUCT

[0003] Technical field

[0004] The present invention relates to a packaged product consisting of a wet unshaped product placed in a hermetic package. The wet unshaped product is in particular intended for a glass furnace, in particular for the repair of a glass furnace.

[0005] Prior art

[0006] The industry, particularly the glass industry, generally uses melted and cast refractory products, or those obtained by sintering, for the construction of its furnaces, which are very resistant to corrosion by glass, and come in the form of blocks or slabs.

[0007] Unformed products can be used for the construction and / or repair of these furnaces. These unformed products are generally in the form of a dry powder, in order to facilitate their storage. This powder is moistened on site to obtain a wet unformed product which can then be installed:

[0008] Typically, a specific amount of powder, such as 500 kg of powder, a setting activator, and water are poured into a mixer. After mixing, the resulting batch of activated product can be poured into a pump hopper for transport to the destination site. The mixer can be refilled for the next cycle. To ensure the pump feed is as continuous as possible, a second mixer is typically used to supply activated product to the pump while the first mixer is being refilled. The two mixers work alternately so that the pump hopper is never empty.

[0009] Pouring dry powders into mixers generates dust, which can be detrimental to the safety of people.

[0010] Preparation is time-consuming, especially when large quantities of unprocessed products are to be used. It also requires tools such as large mixers and / or pumps, which clutter up the construction site.

[0011] There is therefore a need for an unshaped product which can be stored for a prolonged period and which, after storage, can be quickly implemented, with light installation, for example with a simple plasterer's mixer, and generating little dust.

[0012] An aim of the present invention is to satisfy, at least partially, this need.

[0013] Summary of the invention

[0014] According to the invention, this aim is achieved by means of a packaged product comprising:

[0015] - airtight packaging, and

[0016] - a wet unshaped product placed in said airtight packaging and consisting of more than 95% by mass:

[0017] - from 4% to 15% water, in mass percentages based on the mass of the wet unshaped product,

[0018] - from 0.5% to 3.2% of a binder precursor, in mass percentages based on the mass of the wet unshaped product,

[0019] - a ceramic powder, the binder precursor being chosen from:

[0020] - a colloidal silica with a specific surface area less than or equal to 150 m 2 / g, and preferably greater than 50 m 2 / g, and

[0021] - a mixture consisting of:

[0022] - colloidal silica, in a quantity greater than or equal to 0.5% by mass percentage based on the mass of the wet unshaped product, having a specific surface area of ​​less than 500 m 2 / g, preferably less than 320 m 2 / g, and preferably greater than 50 m 2 / g, and

[0023] - a hydrolyzed silane and / or a siloxane, the ceramic powder being made up of ceramic particles, without taking into account the colloidal silica particles.

[0024] As will be seen in more detail in the remainder of the description, the invention allows long-term storage of the unshaped product in a wet state. After storage, the wet unshaped product can be put in place very quickly, possibly after simple mixing, optionally after adding a setting activator.

[0025] In particular, when the unformed product is moved by means of a pump, said mixing can be carried out using the mixer conventionally fitted to the pump feed hopper. No mixer is required. The preparation can therefore be carried out on site, without expensive and bulky equipment, for example using a hand mixer. Finally, since the unformed mixture is wet, this preparation generates practically no dust.

[0026] A product packaged according to the invention may also include one or more of the following optional features:

[0027] - the binder precursor is chosen from:

[0028] - a colloidal silica with a specific surface area greater than 50 m 2 / g, and

[0029] - a mixture consisting of:

[0030] - colloidal silica, in a quantity greater than or equal to 0.5% by mass percentage based on the mass of the wet unshaped product, having a specific surface area of ​​less than 320 m 2 / g and greater than 50 m 2 / g, and

[0031] - a hydrolyzed silane and / or a siloxane;

[0032] - the binder precursor does not contain siloxane or hydrolyzed silane, and the colloidal silica has a specific surface area of ​​less than 130 m 2 / g, preferably less than 90 m 2 / g ;

[0033] - the total quantity of hydrolyzed silane and siloxane represents less than 20% and more than 3% of the mass of colloidal silica;

[0034] - the hydrolyzed silane comprises at least one hydrophobic functional group;

[0035] - preferably, said hydrolyzed silane is chosen from alkylsilanes, vinylsilanes, sulfur silanes, mercaptosilanes, epoxysilanes, methacrylate silanes, aromatic silanes, fluoroalkylsilanes, and mixtures thereof;

[0036] - preferably, said hydrolyzed silane is an aromatic silane chosen from arylsilanes, or is an alkylsilane chosen from methylsilanes, ethylsilanes, propylsilanes, butylsilanes, octylsilanes and mixtures thereof;

[0037] - preferably, said hydrolyzed silane is an alkylsilane chosen from methylsilanes;

[0038] - the siloxane comprises at least one hydrophobic functional group;

[0039] - preferably said siloxane is chosen from alkylsiloxanes, vinylsiloxanes, sulfur siloxanes, mercaptosiloxanes, epoxysiloxanes, methacrylate siloxanes, aromatic siloxanes, fluoroalkylsiloxanes, and mixtures thereof;

[0040] - the ceramic powder consists of more than 80% by mass of particles whose main constituents are alumina and / or zirconia and / or silica and / or chromium oxide; - the ceramic powder, the binder precursor and the water together represent more than 98% of the mass of the wet unshaped product.

[0041] The invention also relates to a method for manufacturing a packaged product according to the invention, comprising the following successive steps: a) preparation of the wet unshaped product; b) packaging of the wet unshaped product in the hermetic packaging so as to obtain said packaged product.

[0042] Preferably, step a) comprises a mixture of a starting charge consisting of more than 95%, by mass:

[0043] - from 4% to 15% water,

[0044] - from 0.5% to 3.2% of a binder precursor,

[0045] - a ceramic powder other than colloidal silica, in mass percentages based on the mass of the starting charge, the binder precursor being chosen from:

[0046] - a colloidal silica having a specific surface area less than or equal to

[0047] 150 m 2 / g, and preferably greater than 50 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and

[0048] - a mixture consisting of:

[0049] - colloidal silica, in a quantity greater than or equal to 0.5%, as a percentage by mass based on the mass of the wet unshaped product, having a specific surface area of ​​less than 500 m 2 / g, preferably between 50 m 2 / g and 320 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and

[0050] - a hydrolyzed silane and / or a siloxane and / or a hydrolyzable silane, so as to obtain the wet unshaped product.

[0051] The invention finally relates to a method for repairing a furnace, preferably a glass furnace, or for manufacturing a block, preferably intended for such a furnace, said method comprising the following successive steps:

[0052] 1) storage of a product packaged according to the invention or manufactured according to a manufacturing method according to the invention, for more than 2 weeks, preferably more than 1 month, preferably more than 2 months, preferably more than 4 months, preferably more than 6 months;

[0053] 2) unpacking a product packaged according to the invention so as to extract the wet unshaped product therefrom, a mixing of the wet unshaped product optionally being possible before or after said extraction;

[0054] 3) activating the binder precursor of the wet unshaped product, by mixing with a setting activator, and / or by placing the wet unshaped product at a temperature suitable for activating the binder precursor, so as to obtain an activated product;

[0055] 4) placing the activated product in a mold or in a region of an oven to be repaired;

[0056] 5) optionally, after curing and preferably after demoulding if the activated product has been cured in a mould, sintering.

[0057] The activation in step 3) may be simultaneous with step 4) if the mold or the region of an oven to be repaired is at a temperature suitable for activating the binder precursor. Step 5) may also be simultaneous with steps 3) and 4), in particular when the product is used to repair a hot oven, i.e. at a temperature typically above 500°C.

[0058] Definitions

[0059] By "binder precursor" is meant a constituent capable of forming a binder rigidly holding the particles of this powder together, so as to form a solid mass. In the wet unshaped product, the binder precursor is in a "non-activated" state, i.e. in a state in which it does not ensure cohesion between the particles of the ceramic powder (unlike the binder to which activation of the binder precursor leads, in the hardened product). The binder precursor is also not in a process leading to such cohesion, in which it is called an "activated binder precursor". The binder precursor can be transformed into an activated binder precursor by "activation" using a "setting activator" or if it is placed in an environment at a sufficiently high temperature. The activated binder precursor tends to harden the initially wet unshaped product.By extension, the wet unshaped product containing the activated binder precursor is called the "activated product". In the hardened product, the binder therefore results from a reaction of the binder precursor with the setting activator and / or from a transformation under the effect of a sufficiently high temperature.

[0060] Although the binder precursor is usually supplied in the form of a suspension, its quantity is measured without taking water into account. For example, in a colloidal silica suspension, a distinction is made between water and colloidal silica (binder precursor).

[0061] For the sake of clarity, a distinction is made between "packaged product", "wet unshaped product", "activated product" and "cured product". The wet unshaped product is the product to be stored and intended for the manufacture of a block or for a repair. Once packaged, it is called "packaged product". After being unpacked, and after activation of the binder precursor, the wet unshaped product enters a curing phase, which may be of short duration, particularly during a hot repair; it is then called "activated product". After curing, it is called "cured product".

[0062] For clarity, unless otherwise specified, “ceramic powder” means “ceramic powder other than colloidal silica”.

[0063] By "ceramic powder" we mean a powder made up of particles of a ceramic material, i.e. neither organic nor metallic.

[0064] Colloidal silica is a collection of silica particles suspended in a liquid, preferably water, each having a size less than 200 nm, the size being deduced from the specific surface area measurement assuming that all particles are spherical and of the same size, the specific surface area being evaluated using the Sears method, as described in "Determination of specific surface area of ​​colloidal silica by titration with sodium hydroxide", G.W. Sears, Anal. Chem. 1956, 28, 12, 1981-1983.

[0065] “Hermetic” packaging is packaging that isolates the wet unformed product it contains from the ambient air, particularly under storage conditions.

[0066] A "hydrolyzed silane" is a silane that contains at least one Si-OH silanol group. A hydrolyzed silane can be a fully or partially hydrolyzed silane.

[0067] A "hydrolyzable silane" is a silane other than a hydrolyzed silane, and which, upon contact with water, forms a hydrolyzed silane (in other words, a hydrolyzable silane does not contain an Si-OH group and upon contact with water, it forms a silane containing at least one Si-OH group).

[0068] A compound containing one or more Si-O-Si bonds in its molecule is called a "siloxane". Conventionally, and within the meaning of this description, polysiloxanes are therefore siloxanes. A siloxane can be obtained by polycondensation of a silane.

[0069] The 10 (Dio), 50 (D50), 90 (D90) and 99.5 (099.5) percentiles or "percentiles" of a powder are the particle sizes corresponding to the percentages, by mass, of 10%, 50%, 90% and 99.5% respectively, on the cumulative particle size distribution curve of the powder particles, the particle sizes being ranked in ascending order. For example, 10%, by mass, of the particles in the powder have a size less than D 10 and 90% of the particles by mass have a size greater than Dio. The percentiles can be determined using a particle size distribution performed using a laser particle size analyzer.

[0070] By "main constituents" we mean the constituents whose mass proportions are the highest.

[0071] Zirconia refers to zirconium oxide ZrO2. When referring to Z1O2, it should be understood as (ZrO2+HfO2). Indeed, a small amount of HIO2, chemically inseparable from Z1O2 in a conventional zirconia manufacturing process, and having similar properties, is always naturally present in zirconia sources at levels generally lower than 2%. Hafnium oxide is then not considered an impurity.

[0072] “Behave” or “include” or “present” shall be interpreted in a non-limiting manner.

[0073] Detailed description

[0074] Wet unshaped product

[0075] The packaged product comprises a sealed package and a wet unshaped product contained within the sealed package.

[0076] Any hermetic packaging, whether rigid or flexible, may be suitable. Preferably, the hermetic packaging is a sealed plastic drum or bag. It preferably has a volume sufficient to contain more than 1 kg, more than 5 kg, more than 10 kg, more than 20 kg, and / or less than 500 kg, preferably less than 250 kg, preferably less than 100 kg, preferably less than 50 kg of wet unformed product.

[0077] The wet unshaped product comprises a mixture of a ceramic powder, a binder precursor and water.

[0078] The nature and particle size distribution of the ceramic powder are chosen according to the destination of the wet unshaped product. All ceramic powders used for the manufacture of hardened products intended for glass furnaces can be considered in particular.

[0079] Preferably, the ceramic powder consists, for more than 80%, preferably for more than 90%, preferably for more than 95% by mass of particles whose main constituents are alumina (AI2O3) and / or zirconia (ZrO2) and / or silica (SiO2) and / or chromium oxide (CnCh).

[0080] Preferably, the fraction of particles of the ceramic powder having a size less than 40 pm is distributed, in percentages by mass relative to the mass of the ceramic powder, as follows: fraction < 0.5 pm: > 4%, preferably > 5%, and / or < 6.5%, and fraction < 2 pm: > 5%, preferably > 8%, preferably > 10%, preferably > 13% and / or < 18%, and fraction < 10 pm: > 16%, preferably > 22%, preferably > 24% and / or < 35%, preferably < 34%, and fraction < 40 pm: 29-45%, preferably > 30% and / or < 40%.

[0081] These fractions can be determined using a particle size distribution carried out using a laser particle size analyzer.

[0082] Preferably, the 99.5 percentile of the ceramic powder is less than or equal to 10 mm, preferably less than or equal to 8 mm, preferably less than or equal to 5 mm.

[0083] Preferably, the fraction of particles of the ceramic powder with a size of less than 500 μm represents more than 50% by mass of said ceramic powder.

[0084] Preferably, the fraction of particles of the ceramic powder with a size between 40 pm and 500 pm is between 15 and 30%, preferably greater than 17%, greater than 18% and / or less than 28%, less than 25%, less than 22%, relative to the mass of said ceramic powder.

[0085] Ceramic powder may contain particles:

[0086] - electrocast refractory products such as ER-1681 or ER-1711 produced and marketed by the Société Européenne des Produits Réfractaires. These two products contain, in percentage by mass, on the basis of oxides, 32 to 54% of ZrO2, 36 to 51% of Al2O3, 10 to 16% of SiO2 and 0.2 to 1.5% of Na2O;

[0087] - mullite;

[0088] - zirconia;

[0089] - alumina;

[0090] - chromium oxide.

[0091] In one embodiment, the ceramic powder does not comprise silica particles. The binder precursor is chosen from:

[0092] - a colloidal silica with a specific surface area less than or equal to 150 m 2 / g, and

[0093] - a mixture of colloidal silica with a specific surface area of ​​less than 500 m 2 / g, on the one hand, and a hydrolyzed silane and / or a siloxane on the other hand.

[0094] The inventors have in fact discovered that a colloidal silica is only suitable if it has a specific surface area less than or equal to 500 m 2 / g, provided that it is associated with a hydrolyzed silane and / or a siloxane if its specific surface area is greater than 150 m 2 / g. Of course, a hydrolyzed silane and / or a siloxane may also be present if said specific surface area is less than or equal to 150 m 2 / g, but this presence is then optional.

[0095] Preferably, the colloidal silica is such that it gels when mixed with 15% magnesia, as a percentage of the mass of silica contained in the colloidal silica.

[0096] In practice, the binder precursor is supplied in suspension, i.e. supplied with water.

[0097] The amount of binder precursor, particularly when the binder precursor is made of colloidal silica, is greater than or equal to 0.5%, preferably greater than or equal to 0.8%, preferably greater than or equal to 1%, preferably greater than 1.2%, preferably greater than 1.4%, and less than 3.2%, preferably less than 3.0%, preferably less than 2.8%, preferably less than 2.4%, in mass percentages based on the mass of the wet unshaped product.

[0098] All colloidal silicas can be considered.

[0099] Preferably, the colloidal silica has, in suspension, a negative zeta potential value.

[0100] Preferably, when the binder precursor contains neither siloxane nor hydrolyzed silane, the colloidal silica has a specific surface area greater than 60 m 2 / g and preferably less than 130 m 2 / g, preferably less than 110 m2 / g, preferably less than 90 m 2 / g.

[0101] When the binder precursor is a mixture consisting of a colloidal silica on the one hand, and a hydrolyzed silane and / or a siloxane on the other hand, the amount of colloidal silica is greater than or equal to 0.5%, preferably greater than or equal to 0.8%, preferably greater than or equal to 1%, preferably greater than 1.2%, preferably greater than 1.4%, and less than 3.2%, preferably less than 3.0%, preferably less than 2.8%, preferably less than 2.6%, preferably less than 2.4%, in mass percentages based on the mass of the wet unshaped product.

[0102] The total amount of hydrolyzed silane and siloxane preferably represents less than 20%, preferably less than 15%, preferably less than 10%, and / or more than 3%, preferably more than 4% of the mass of colloidal silica.

[0103] The total amount of hydrolyzed silane and siloxane is preferably greater than 0.05%, preferably greater than 0.07%, and preferably less than 1%, preferably less than 0.8%, preferably less than 0.6%, preferably less than 0.5%, preferably less than 0.4%, preferably less than 0.3%, in mass percentages based on the mass of the wet unshaped product.

[0104] Preferably, the hydrolyzed silane comprises at least one hydrophobic functional group.

[0105] More preferably, said hydrolyzed silane is chosen from:

[0106] - alkylsilanes,

[0107] - vinylsilanes,

[0108] - sulfur silanes

[0109] - mercaptosilanes,

[0110] - epoxysilanes,

[0111] - methacrylate silanes,

[0112] - aromatic silanes (or “aromatic silanes” in English),

[0113] - fluoroalkylsilanes, and

[0114] - their mixtures.

[0115] Preferably, the alkylsilanes are chosen from methylsilanes, ethylsilanes, propylsilanes, butylsilanes, octylsilanes and mixtures thereof, preferably from methylsilanes.

[0116] Preferably, the alkylsilane is potassium methylsilanetriolate.

[0117] In one embodiment, the aromatic silanes are selected from arylsilanes.

[0118] Preferably the hydrolyzed silane is potassium methylsilanetriolate.

[0119] Preferably, the siloxane comprises at least one hydrophobic functional group. More preferably, said siloxane is chosen from:

[0120] - alkylsiloxanes, - vinylsiloxanes,

[0121] - sulfur siloxanes,

[0122] - mercaptosiloxanes,

[0123] - epoxysiloxanes,

[0124] - methacrylate siloxanes,

[0125] - aromatic siloxanes,

[0126] - fluoroalkylsiloxanes, and

[0127] - their mixtures.

[0128] The water preferably comes from the added raw materials, and in particular from the colloidal silica suspension, and from a specific addition of water. Preferably, the total amount of water in the wet unshaped product is greater than 5%, preferably greater than 6%, and / or preferably less than 14%, preferably less than 12%, preferably less than 10%, in mass percentages based on the mass of the wet unshaped product.

[0129] The ceramic powder, the binder precursor and the water together preferably represent more than 95%, more than 96%, more than 97%, more than 98%, more than 99% of the mass of the wet unshaped product. The balance to 100% preferably consists of an optional surfactant, an optional anti-segregation adjuvant, an optional biocide and constituents, preferably organic, different from the binder precursor, said optional surfactant, said anti-segregation adjuvant and said biocide.

[0130] Any conventional surfactant may be used, for example a modified polycarboxylate ether, a polyacrylate, in particular a sodium polyacrylate, a polyphosphate, in particular a sodium polyphosphate.

[0131] The choice of a surfactant from among the surfactants generally used by those skilled in the art can be guided by the results of simple tests, such as those described in the present description, depending on the desired performance (ease of installation, density of the wet unshaped product after installation).

[0132] Preferably, the amount of surfactant in the wet unshaped product is greater than 0.05%, preferably greater than 0.1%, preferably greater than 0.15%, and / or preferably less than 0.30%, preferably less than 0.25%, preferably less than 0.20%, in mass percentages based on the mass of the wet unshaped product. Any conventional anti-segregation adjuvant may be used, for example starch ethers.

[0133] Preferably, the amount of anti-segregation adjuvant in the wet unshaped product is greater than 0.02%, preferably greater than 0.03%, and / or preferably less than 0.5%, preferably less than 0.35%, preferably less than 0.25%, preferably less than 0.20%, preferably less than 0.15%, preferably less than 0.10%, in mass percentages based on the mass of the wet unshaped product.

[0134] Any conventional biocide can be used. Examples of known biocides are the Preventol® range of biocides, including Preventol® P301, marketed by Lanxess, and the Adins range of biocides marketed by Toisa.

[0135] Preferably, the amount of biocide in the wet unshaped product is greater than 0.01%, preferably greater than 0.02%, preferably greater than 0.03%, and / or preferably less than 0.15%, preferably less than 0.10%, in mass percentages based on the mass of the wet unshaped product.

[0136] Manufacturing process

[0137] The method of manufacturing the packaged product according to the invention does not pose any particular difficulty.

[0138] This process comprises the following successive steps: a) mixing of a starting charge consisting of more than 95%, preferably more than 96%, preferably more than 97%, preferably more than 98%, preferably more than 99% by mass:

[0139] - from 4% to 15% water,

[0140] - from 0.5% to 3.2% of a binder precursor,

[0141] - optionally, from 0.05% to 0.30% of a surfactant,

[0142] - optionally, from 0.02% to 0.5% of an anti-segregation adjuvant,

[0143] - optionally, from 0.01% to 0.15% of a biocide,

[0144] - a ceramic powder other than colloidal silica, in mass percentages based on the mass of the starting charge, the binder precursor being chosen from:

[0145] - a colloidal silica having a specific surface area less than or equal to

[0146] 150 m 2 / g, and preferably greater than 50 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and - a mixture consisting of:

[0147] - colloidal silica, in a quantity greater than or equal to 0.5%, as a percentage by mass based on the mass of the wet unshaped product, having a specific surface area of ​​less than 500 m 2 / g, preferably between 50 m 2 / g and 320 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and

[0148] - a hydrolyzed silane and / or a siloxane and / or a hydrolyzable silane, so as to obtain a wet unshaped product, b) placing the wet unshaped product obtained in step a) in a hermetic package.

[0149] The process can be adapted, without any particular difficulty, so that the packaged product obtained at the end of step b) has one or more of the optional characteristics described above.

[0150] In particular, it is preferably adapted so that the resulting packaged product has one or more of the following optional characteristics:

[0151] - the binder precursor is chosen from:

[0152] - a colloidal silica with a specific surface area greater than 50 m 2 / g, and

[0153] - a mixture consisting of:

[0154] - colloidal silica, in a quantity greater than or equal to 0.5% by mass percentage based on the mass of the wet unshaped product, having a specific surface area of ​​less than 320 m 2 / g and greater than 50 m 2 / g, and

[0155] - a hydrolyzed silane and / or a siloxane;

[0156] - the binder precursor does not contain siloxane or hydrolyzed silane, and the colloidal silica has a specific surface area of ​​less than 130 m 2 / g, preferably less than 90 m 2 / g ;

[0157] - the total quantity of hydrolyzed silane and siloxane represents less than 20% and more than 3% of the mass of colloidal silica;

[0158] - the hydrolyzed silane comprises at least one hydrophobic functional group;

[0159] - preferably, said hydrolyzed silane is chosen from alkylsilanes, vinylsilanes, sulfur silanes, mercaptosilanes, epoxysilanes, methacrylate silanes, aromatic silanes, fluoroalkylsilanes, and mixtures thereof;

[0160] - preferably, said hydrolyzed silane is an aromatic silane chosen from arylsilanes, or is an alkylsilane chosen from methylsilanes, ethylsilanes, propylsilanes, butylsilanes, octylsilanes and mixtures thereof;

[0161] - preferably, said hydrolyzed silane is an alkylsilane chosen from methylsilanes; - the siloxane comprises at least one hydrophobic functional group;

[0162] - preferably said siloxane is chosen from alkylsiloxanes, vinylsiloxanes, sulfur siloxanes, mercaptosiloxanes, epoxysiloxanes, methacrylate siloxanes, aromatic siloxanes, fluoroalkylsiloxanes, and mixtures thereof;

[0163] - the ceramic powder is made up of more than 80% by mass of particles whose main constituents are alumina and / or zirconia and / or silica and / or chromium oxide;

[0164] - ceramic powder, binder precursor and water together represent more than 98% of the mass of the wet unshaped product.

[0165] In the starting charge, the binder precursor may, however, be not only a hydrolyzed silane and / or a siloxane (as in the wet unshaped product), but also a hydrolyzable silane. Indeed, during the preparation of the wet unshaped product, the hydrolyzable silane comes into contact with water and is transformed into hydrolyzed silane. The hydrolyzable silane may in particular be chosen so as to be hydrolyzable in the form of a hydrolyzed silane chosen from the hydrolyzed silanes described above.

[0166] The hydrolyzed silane and / or siloxane preferably has the preferred characteristics relating to the hydrolyzed silane and / or siloxane described above for the packaged product, respectively.

[0167] Preferably, the hydrolyzable silane is chosen from hydrolyzable silanes comprising at least one hydrophobic functional group, preferably from:

[0168] - alkylsilanes,

[0169] - vinylsilanes,

[0170] - sulfur silanes,

[0171] - mercaptosilanes,

[0172] - epoxysilanes,

[0173] - methacrylate silanes,

[0174] - aromatic silanes (or “aromatic silanes” in English),

[0175] - fluoroalkylsilanes, and

[0176] - their mixtures.

[0177] Preferably, the hydrolyzable silane comprises at least one group selected from alkoxy groups, the chloro group and mixtures thereof. Preferably, the alkoxyl group is selected from the methoxy group, the ethoxy group, the propoxy group and mixtures thereof.

[0178] Preferably, the hydrolyzable silane is chosen from alkylsilanes, vinylsilanes, sulfur silanes, mercaptosilanes, epoxysilanes, methacrylate silanes, aromatic silanes, fluoroalkylsilanes and mixtures thereof, and said hydrolyzable silane comprises at least one group chosen from alkoxyl groups, the chloro group and mixtures thereof.

[0179] The colloidal silica is provided in the form of an aqueous suspension. Conventional colloidal silica suspensions may be used. Preferably, the amount of colloidal silica represents more than 10%, more than 20%, more than 30%, more than 40% or more than 45%, and / or less than 55% of the mass of said aqueous suspension.

[0180] In step b), the packaging is chosen so that, during storage, typically at atmospheric pressure and at a temperature between 10°C and 30°C, the wet unshaped product is isolated from the ambient air, i.e. there is no gas exchange between the inside and the outside of the packaging.

[0181] Implementation

[0182] The product packaged according to the invention is very simple to implement.

[0183] In step 1), the wet unshaped product can be advantageously stored for a long period. Storage is preferably at atmospheric pressure and at a temperature between 10°C and 30°C.

[0184] In step 2), it is extracted from the packaging. The humidity advantageously prevents the emission of dust. Preferably, in particular if the wet unshaped product has been stored for more than 2 weeks, more than 1 month, more than 3 months, more than 4 months or more than 6 months, it is mixed. It can be mixed before being removed from the packaging, i.e. between steps 1) and 2), in particular if the packaging is rigid, for example if the packaging is a drum, or after this extraction, i.e. between steps 2) and 3), for example if the packaging is a bag.

[0185] In step 3), in one embodiment, the wet unshaped product is mixed with a setting activator after removal from the package. The setting activator may also be mixed with the wet unshaped product in the package after it has been opened, for example if the wet unshaped product is contained in a drum. Preferably, the amount of setting activator is greater than 0.2%, preferably greater than 0.4% and less than 2%, preferably less than 1.5%, preferably less than 1%, preferably less than 0.8%, as a percentage by mass based on the mass of the wet unshaped product.

[0186] Preferably, the setting activator is chosen to activate the binder precursor. It is then preferably chosen from magnesia, sodium silicate, a cement, and mixtures thereof. In one embodiment, the setting activator is a mixture of cement and magnesia. Preferably, the cement is an alumina cement.

[0187] Preferably, the setting activator is magnesia.

[0188] The invention also relates to the activated mixture resulting from the addition of a setting activator to a wet unshaped product according to the invention.

[0189] Mixing with a setting activator is particularly useful when the wet unshaped product is used in an environment at a temperature of 500°C or lower. At a higher temperature, silica can act as a hot binder. There is then no need to add a setting activator. Activation then results from the application of this temperature.

[0190] The activated product sets in mass. It can therefore be handled immediately after activation, which, in step 4), allows it to be placed and shaped on the site where it is to harden. The site may be, for example, an area to be repaired, resulting for example from wear due to the flow of molten glass or metal or from corrosion due to contact with molten glass or metal or with slag.

[0191] The site can be a floor, preferably a glass furnace floor. The activated product is advantageously self-leveling, which allows it to be poured, for example by gravity.

[0192] The activated product can also be poured into a mold to make a block, for example a block of more than 1 kg or more than 5 kg and / or preferably less than 1000 kg. After hardening, the block is removed from the mold.

[0193] In step 5), in a preferred embodiment, the hardened product is sintered, preferably at a temperature of 900°C and / or less than 1600°C. Sintering may result from the temperature prevailing in the furnace, in particular the operating temperature of the furnace.

[0194] The following non-limiting examples are given to illustrate the invention. Characterization protocols

[0195] The specific surface area of ​​colloidal silica in suspension form is evaluated using the Sears method, as described in "Determination of specific surface area of ​​colloidal silica by titration with sodium hydroxide", G.W. Sears, Anal. Chem. 1956, 28, 12, 1981-1983.

[0196] The “self-leveling” character and segregation are assessed by the following test:

[0197] 25 kg of activated product are prepared as follows.

[0198] 24.875 kg of wet unshaped product that has been stored for 6 months are introduced into a container. Said wet unshaped product is then mixed for one minute using a portable electric plasterer's mixer (with a maximum power of 1600W, equipped with a turbine for mortar and paint with a diameter equal to 140 mm). 0.125 kg of a "dead burned B / C" magnesia powder marketed by the company Grecian Magnesite, acting as a setting activator and having a median size equal to 20 μm, are then added and the whole is mixed for 1 minute using said plasterer's mixer. An "activated" product is thus obtained. The preparation of the activated product is advantageously quick and simple.

[0199] The activated product is then immediately poured into a pre-oiled hopper, in the shape of a truncated pyramid, arranged point downwards, and having a height of 320 mm, an upper inlet opening with a square section of 350 mm x 350 mm and a lower outlet opening (towards the tip of the pyramid) with a square section of 130 x 130 mm initially closed by a hatch.

[0200] The hopper hatch is then opened with a sharp blow and the activated product pours under its own weight, through the outlet opening, into the upper end (700 mm from the ground) of a previously oiled semi-circular straight PVC gutter, with a diameter of 170 mm and a length of 1600 mm, the lower end of the gutter being 380 mm from the ground.

[0201] The activated product flows into the gutter and pours into a mold placed under the gutter, under the lower end of the gutter. The mold is a wooden mold measuring 300 mm x 300 mm x 60 mm, oiled and placed horizontally on the ground.

[0202] The activated product is then waited for to harden into a slab. On each of the four side faces of the slab, the thickness of the slab is measured at both ends and in the middle of the length of the face.

[0203] The self-leveling character (“AN”) is acquired if the upper surface of the slab appears substantially smooth to the eye and if, for each of the four side faces, the difference “E” between the smallest measured thickness and the largest measured thickness is less than or equal to 2 mm.

[0204] After baking at 110°C for 24 hours, the slab is sawn in half through its center, exposing two sawn faces. Segregation causes the larger particles to migrate away from the upper face of the slab. Segregation is considered to have occurred when the sawn faces reveal a surface layer of laitance extending from the upper face of the slab to a depth "e" of 3 mm or more.

[0205] The shelf life of the unshaped wet product is assessed by the following test.

[0206] After manufacturing, the unformed wet product is packaged in a hermetic container in the form of a 500 ml jar with a diameter of 90 mm, closed with a lid. The packaged product is stored in a room at an average temperature of between 21°C and 25°C for six months.

[0207] At the end of this period, the packaging lid is removed, and the wet unshaped product is placed on the tray of a TX700 texture analyzer model 151500 equipped with a cleaver probe reference 130064, marketed by the company Lamy Rheology.

[0208] The tip of the cleaver probe is positioned so as to touch the upper surface of the wet unshaped product, in the center of said surface.

[0209] Then the following different steps are carried out:

[0210] - select the “COMPRESSION” tab on the digital display,

[0211] - select the “simple compression” program,

[0212] - enter the following parameters: descent speed: 0.1 mm / s, detection threshold: 0.1 N, X axis: distance, maximum depth: 45 mm, high position: 10 mm, force at: 0 mm,

[0213] - To validate,

[0214] - Press “zero force”,

[0215] - Start the measurement execution by pressing “start”.

[0216] The probe then gradually descends into the wet unformed product to a depth of 45 mm and the maximum force required for this purpose is recorded. If the consistency of the wet unformed product strongly opposes the penetration of the probe, the force applied by the analyzer reaches or even exceeds 380 N. The analyzer then temporarily stops applying the penetration force. The measurement is then stopped. The depth reached by the probe is then measured for the maximum force applied.

[0217] “D” is defined as the ratio of the maximum force, FMax, reached in the measuring cycle, in Newtons, to the penetration depth at which said maximum force is reached, p, in mm: D = FMax / p.

[0218] The measurement is carried out at room temperature.

[0219] The inventors consider that a value of D less than 40 N / mm, preferably less than 35 N / mm, preferably less than 30 N / mm, preferably less than 25 N / mm, preferably less than 20 N / mm, preferably less than 15 N / mm, corresponds to a wet unshaped product which can be quickly implemented, after a storage period of six months, without a long mixing operation.

[0220] In particular, after storage, the wet unshaped product of Example 2 outside the invention had a consistency such that it was impossible to fluidify it for casting. On the contrary, Examples 1 and 3 according to the invention below could be used, and even cast, after simple mixing using a portable electric plasterer's mixer (with a power of 1600W, equipped with a turbine for mortar and paint, with a diameter equal to 140 mm).

[0221] The following raw materials were used:

[0222] As constituents of ceramic powder different from colloidal silica:

[0223] - a powder of ER1681 grains having the following chemical analysis, in mass percentages: Z1O2: 32.5%, SiCL: 15%, AI2O3: 50.9%, 1.6% of other compounds, a percentile 10 (D10) equal to 2 mm, a percentile 90 (D90) equal to 3.5 mm and a median size (D50) equal to 2.5 mm,

[0224] - a powder of ER1681 grains having the following chemical analysis, in mass percentages: Z1O2: 32.5%, SiCL: 15%, AI2O3: 50.9%, 1.6% of other compounds, a percentile 10 (D10) equal to 0.46 mm, a percentile 90 (D90) equal to 1.7 mm and a median size (D50) equal to 1 mm,

[0225] - a powder of ER1681 grains having the following chemical analysis, in mass percentages: Z1O2: 32.5%, SiCL: 15%, AI2O3: 50.9%, 1.6% of other compounds, a percentile 10 (Dio) equal to 0.03 mm, a percentile 90 (D90) equal to 0.38 mm and a median size (D50) equal to 0.16 mm,

[0226] - a zirconia powder, marketed by the Société Européenne des Produits Réfractaires under the name CC10, the median size of which (D50) is equal to 3.5 pm, and having a mass content of ZrCh greater than 98.5%,

[0227] - an electrofused alumina powder, having a mass content of AI2O3 greater than 99%, a mass content of Na2O less than 0.2%, and a median size (D50) equal to 100 pm,

[0228] - a CL370 alumina powder marketed by the company ALMATIS,

[0229] - a CT3000SG alumina powder marketed by the company ALMATIS.

[0230] As other constituents:

[0231] - a suspension of colloidal silica LUDOX® PW 50 X marketed by the company GRACE, presenting, according to the technical data sheet, a specific surface area of ​​between

[0232] 60 m 2 / g and 90 m 2 / g and a mass content of colloidal silica equal to 50%, as a mass percentage based on the mass of the colloidal silica suspension,

[0233] - a suspension of colloidal silica LEVAS IL® FO 1440 marketed by the company NOURYON, with a specific surface area equal to 250 m 2 / g and a mass content of colloidal silica equal to 40%, as a mass percentage based on the mass of the colloidal silica suspension,

[0234] - SIKAGARD® facade protection, marketed by the company SIKA, containing the hydrolyzed silane potassium methylsilanetriolate,

[0235] - a modified polycarboxylate ether,

[0236] - an anti-segregation adjuvant from the starch ether family.

[0237] The following Table 1 provides the composition of wet unshaped products, in mass percentages based on the mass of said wet unshaped product.

[0238] [Table 1]

[0239] Wet unshaped products are manufactured as follows:

[0240] The colloidal silica suspension is introduced into the tank of a Perrier-type paddle mixer. Then, while the mixer is running, water (for examples 1 and 2 only) is added, then the modified polycarboxylate ether, then the SIKAGARD facade protection. Mixing continues for 1 minute. Then the ceramic powder is added and mixing continues for another 9 minutes.

[0241] The wet unshaped product is obtained at the end of this mixing time.

[0242] Each wet unformed product is then hermetically packaged to measure its shelf life, as described above. After storage for 6 months, self-leveling and segregation are measured.

[0243] Table 2 provides the results of the tests carried out.

[0244] [Table 2]

[0245] *: excluding invention nm: not measurable

[0246] The results allow us to make the following observations:

[0247] Example 1, according to the invention, the binder precursor of which is a colloidal silica having a specific surface area of ​​between 60 m 2 / g and 90 m 2 / g, has a D value equal to 15 N / mm measured after a storage period equal to 6 months.

[0248] Example 2, outside the invention, the binder precursor of which is a colloidal silica having a specific surface area equal to 250 m 2 / g, has a D value equal to 105 N / mm measured after a storage period equal to 6 months.

[0249] A comparison of examples 2, outside the invention, and 3, according to the invention shows the impact of adding 0.08% of hydrolyzed silane (potassium methylsilanetriolate): example 2 has a D value equal to 105 N / mm, much higher than that of example 3 (D value equal to 19 N / mm).

[0250] The products of Examples 1 and 3, after mixing using a portable electric plasterer's mixer and after activation by adding magnesia powder, have a self-leveling character and do not segregate after installation, their preparation generating only a small quantity of dust.

[0251] As is now clear, the invention provides a wet unshaped product which can be stored for an extended period and which after storage can be quickly and simply processed, substantially without dust emission.

[0252] Of course, the present invention is not limited to the embodiments described or represented, provided as illustrative and non-limiting examples.

Claims

CLAIMS 1. Packaged product comprising: - airtight packaging, and - a wet unshaped product placed in said airtight packaging and consisting of more than 95% by mass: - from 4% to 15% water, in mass percentages based on the mass of the wet unshaped product, - from 0.5% to 3.2% of a binder precursor, in mass percentages based on the mass of the wet unshaped product, - a ceramic powder, the binder precursor being chosen from: - a colloidal silica with a specific surface area less than or equal to 150 m 2 / g, and - a mixture consisting of: - colloidal silica, in a quantity greater than or equal to 0.5% by mass percentage based on the mass of the wet unshaped product, having a specific surface area of ​​less than 500 m 2 / g, and - a hydrolyzed silane and / or a siloxane, the ceramic powder being made up of ceramic particles, without taking into account the colloidal silica particles.

2. Packaged product according to claim 1, in which the binder precursor is chosen from: - a colloidal silica with a specific surface area greater than 50 m 2 / g, and - a mixture consisting of: - colloidal silica, in a quantity greater than or equal to 0.5% by mass percentage based on the mass of the wet unshaped product, having a specific surface area of ​​less than 320 m 2 / g and greater than 50 m 2 / g, and - a hydrolyzed silane and / or a siloxane.

3. Packaged product according to any one of the preceding claims, wherein the total amount of hydrolyzed silane and siloxane represents less than 20% and more than 3% of the mass of colloidal silica.

4. Product according to any one of the preceding claims, in which the hydrolyzed silane comprises at least one hydrophobic functional group and / or in which the siloxane comprises at least one hydrophobic functional group.

5. Packaged product according to the immediately preceding claim, in which the hydrolyzed silane is chosen from: - alkylsilanes, - vinylsilanes, - sulfur silanes, - mercaptosilanes, - epoxysilanes, - methacrylate silanes, - aromatic silanes, - fluoroalkylsilanes, and - their mixtures, and / or in which the siloxane is chosen from: - alkylsiloxanes, - vinylsiloxanes, - sulfur siloxanes, - mercaptosiloxanes, - epoxysiloxanes, - methacrylate siloxanes, - aromatic siloxanes, - fluoroalkylsiloxanes, and - their mixtures.

6. Packaged product according to the immediately preceding claim, in which the hydrolyzed silane is an aromatic silane chosen from arylsilanes, or is an alkylsilane chosen from methylsilanes, ethylsilanes, propylsilanes, butylsilanes, octylsilanes and mixtures thereof.

7. Packaged product according to the immediately preceding claim, in which the hydrolyzed silane is an alkylsilane chosen from methylsilanes.

8. Packaged product according to any one of claims 1 and 2, in which the binder precursor does not contain siloxane or hydrolyzed silane, and the colloidal silica has a specific surface area of ​​less than 130 m 2 / g.

9. Packaged product according to the immediately preceding claim, in which the colloidal silica has a specific surface area of ​​less than 90 m 2 / g.

10. Packaged product according to any one of the preceding claims, in which the ceramic powder consists, for more than 80% by mass, of particles whose main constituents are alumina and / or zirconia and / or silica and / or chromium oxide.

11. A packaged product according to any preceding claim, wherein the ceramic powder, binder precursor and water together represent more than 98% of the mass of the wet unshaped product.

12. Method for manufacturing a packaged product according to any one of the preceding claims, comprising the following successive steps: a) preparation of the wet unshaped product; b) packaging of the wet unshaped product in the airtight packaging so as to obtain said packaged product.

13. Manufacturing method according to the preceding claim, in which step a) comprises a mixture of a starting charge consisting for more than 95%, by mass: - from 4% to 15% water, - from 0.5% to 3.2% of a binder precursor, - a ceramic powder other than colloidal silica, in mass percentages based on the mass of the starting charge, the binder precursor being chosen from: - a colloidal silica with a specific surface area less than or equal to 150 m 2 / g, and preferably greater than 50 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and - a mixture consisting of: - colloidal silica, in a quantity greater than or equal to 0.5%, as a percentage by mass based on the mass of the wet unshaped product, having a specific surface area of ​​less than 500 m 2 / g, preferably between 50 m 2 / g and 320 m 2 / g, said colloidal silica being provided in the form of an aqueous suspension, and - a hydrolyzed silane and / or a siloxane and / or a hydrolyzable silane, so as to obtain the wet unshaped product.

14. Method for repairing an oven, said method comprising the following successive steps: 1) storage of a product packaged according to any one of claims 1 to 11 or manufactured according to the method according to any one of claims 12 and 13, for more than 2 weeks; 2) unpacking the packaged product so as to remove the wet unshaped product; 3) activating the binder precursor of the wet unshaped product, by mixing with a setting activator, and / or by placing it at a temperature suitable for activating the binder precursor, so as to obtain an activated product; 4) placing the activated product in the region to be repaired, simultaneously with step 3) provided that the region of an oven to be repaired is at a temperature suitable for activating the binder precursor, or after step 3), until a hardened product is obtained.

15. Method according to the immediately preceding claim, comprising, after step 4), the following step: 5) sintering of the hardened product.

16. A method according to any one of the two immediately preceding claims, wherein, in step 1), the packaged product is stored for more than 4 months.

17. Method of manufacturing a block intended for a furnace, said method comprising the following successive steps: 1) storage of a product packaged according to any one of claims 1 to 11 or manufactured according to the method according to any one of claims 12 and 13, for more than 2 weeks; 2) unpacking the packaged product so as to remove the wet unshaped product; 3) activating the binder precursor of the wet unshaped product, by mixing with a setting activator, and / or by placing it at a temperature suitable for activating the binder precursor, so as to obtain an activated product; 4) placing the activated product in a mold, simultaneously with step 3) provided that the mold is at a temperature suitable for activating the binder precursor, or after step 3), until a hardened product is obtained.

18. Method according to the immediately preceding claim, comprising, after step 4), the following step: 5) sintering of the hardened product.

19. A method according to any one of the two immediately preceding claims, wherein, in step 1), the packaged product is stored for more than 4 months.

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