FR3033555A1 - NON-FORMED PRODUCT FOR REPAIR OF GLASS FUSION OVENS - Google Patents

Abstract

Unshaped product comprising in percentages by weight, and for a total of 100%, A) particles (a) of at least one refractory material different from a glass whose main constituent (s) is alumina (Al2O3) and and / or zirconia (ZrO 2) and / or silica (SiO 2) and / or chromium oxide (Cr 2 O 3), the particles (a) constituting the 100% complement, B) 2% to 15% of particles (b ) of a hot binder selected from glass-ceramic particles, particles of a glass, in particular a glass-ceramic precursor glass, and mixtures of these particles, the mass quantity of glass-ceramic particles and / or glass particles glass-ceramic precursor in all the particles (b) being greater than 10%, based on the mass of all the particles (b), the hot binder not being in the solid state at 1500 ° C, C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, all of said by (a) and (b), preferably the fraction of all the particles of the unshaped product having a size less than 40 μm being distributed, in percentages by weight relative to the mass of the unshaped product, in the manner next - fraction <0,5 μm: ≥1%, - fraction <2 μm: ≥ 4%, - fraction <10 μm: ≥ 13%, - fraction <40 μm: 25% - 52%.

Description

TECHNICAL FIELD The present invention relates to an unshaped product, particularly for the repair of a sole of a glass melting furnace. The invention also relates to a glass melting furnace repair method comprising a step of processing said unshaped product, and a glass melting furnace comprising at least a portion obtained from said unshaped product.

STATE OF THE ART The glass industry generally uses melted and sintered refractory products, obtained by sintering, which are highly resistant to glass corrosion, and which are in the form of blocks or slabs, for the construction of its furnaces. The molten glass is very corrosive and the refractory products, in particular those constituting the melting tank, in particular the bottom of said tank, undergo significant wear, which can lead to the creation of molten glass leaks. These leaks are dangerous and may cause the oven to shut down. In order to increase the life of the oven, the glassmaker may need to carry out repairs. EP 0 739 861 B1 discloses a product for repairing glass melting furnaces. This product has poor hot flowability. For any repair, the oven must be cooled, which significantly increases the time required for repair. In addition, this product requires consolidation sintering at a high temperature for a long time. For this reason also, this product does not allow a quick repair.

EP 2 358 650 discloses a self-pourable concrete (ie, with cement) which can be used for the manufacture of a glass furnace hearth. Particles smaller than 40 μm may be distributed, in percentages by mass relative to the mass of unshaped concrete, in the following manner: fraction <40 μm: 34% - 52%, fraction <0, 5:> 4%, fraction <2 iam:> 5%, - fraction <10:> 19%, 3033555 2 - fraction between 2 iam and 40 iam: 26.5% - 34%. Like the product of EP 0 739 861, this unshaped concrete is however not suitable for hot application. In addition, unshaped products are used in the repair of metal making furnaces. The mechanical constraints in this application are however very different from those encountered in the application to glass furnaces. The conditions of corrosion of the furnaces by a glass or a molten metal are also different. Finally, some impurities, tolerated in metal-making furnaces, are unacceptable for the manufacture of glass. In particular, the refractory materials used in glassmaking furnaces 10 must not generate the release of stones by splitting or producing bubbles. An unshaped product intended for a metal-making furnace is therefore not, a priori, usable for a glass-making furnace, in particular in a zone in contact with the glass. There is a need for an unshaped product capable of forming, after addition of water, a wet blend suitable for rapid repair of a region of a glass melting furnace. The present invention aims to satisfy, at least partially, this need. SUMMARY OF THE INVENTION The invention proposes an unshaped product, intended in particular for producing a sole 20 of a glassware furnace, comprising, in percentages by weight, and for a total of 100%, A) particles (a) at least one refractory material different from a glass and a glass-ceramic, and whose main constituent (s) are alumina (Al 2 O 3) and / or zirconia (ZrO 2) and / or silica (SiO 2 ) and / or chromium oxide (Cr 2 O 3), the particles (a) constituting the 100% complement, B) 2% to 15% of particles (b) of a hot binder selected from glass-ceramic particles , particles made of a glass, in particular a glass-ceramic precursor glass, and mixtures of these particles, the hot binder not being in the solid state at 1500 ° C., C) less than 2% of particles ( c) hydraulic cement, 30 D) less than 7% of other constituents (d), 3033555 3 all of said particles (a) and (b), preferably all of the particles of the unshaped product being distributed, in percentages by weight relative to the mass of the unshaped product, as follows: fraction <0.5:> 1%, 5 - fraction <2 iam:> 4%, - fraction <10:> 13%, - fraction <40 iam: 25% - 52%. As will be seen in more detail in the following description, a wet mixture, obtained after adding water in the unshaped product according to the invention 10 - is pumpable with suction pressures less than or equal to 180 bar, - is "hot self-cast", - does not lead to harmful segregation, and thus, after sintering at low temperature, leads to a shaped product that has good crush resistance. An unshaped product according to the invention is therefore perfectly suitable for use in repairing a glass melting furnace, in particular for repairing a hearth of such an oven. In a first main embodiment, all the particles (b) comprise or even consist of glass particles. In a second main embodiment, all the particles (b) comprise or even consist of glass-ceramic particles and / or vitroceramic precursor glass particles. Preferably, the mass quantity of glass-ceramic particles and / or vitroceramic precursor glass particles in the set of particles (b) is greater than 10%, preferably greater than 20%, preferably greater than 30%, preferably greater than 50%, preferably greater than 70%, even greater than 90%, or even greater than 95%, or even substantially equal to 100%, based on the mass of all the particles (b). Advantageously, the corrosion resistance and the thermomechanical properties of the shaped product are improved. Preferably, all of the particles (b) consist of glass particles and comprise glass ceramic precursor glass particles. More preferably, all of the particles (b) consist of glass-ceramic precursor glass particles.

An unshaped product according to the invention may also comprise one or more of the following optional characteristics: the particles (a) and (b), preferably all the particles of the unshaped product, are distributed as follows in percentages by mass: 5-fraction <0.5: <7%, preferably <6%, preferably <5%, and / or even> 2%, and / or fraction <2 iam:> 5%, preferably> 6%, preferably> 7% and / or preferably <18%, preferably <16%, preferably <14%, preferably <12%, and / or fraction <10:> 16% preferably> 19%, preferably> 20% and / or preferably <40%, preferably <35%, preferably <33%, preferably <30%, preferably <28%, and / or - fraction <40 μm:> 27%, preferably> 29%, preferably> 30%, preferably> 33%, preferably> 35%, preferably> 37% and / or preferably <50%, preferably <47%, preferably <45%, of preferably <42%, and / or fraction between 2 μm and 40 μm:> 16% and / or <40%. The maximum size of all the particles (a) and (b), preferably the maximum size of all the particles of the unshaped product, is less than or equal to 2.5 mm, preferably less than or equal to at 2 mm, or even less than or equal to 1.5 mm. The set of particles (a) and (b) less than 500 μm in size, preferably all the particles of the unshaped product of size less than 500 μm, represents more than 50%, preferably more than 50 μm; 55%, preferably more than 60%, preferably more than 65% or even more than 70% of the mass of said unshaped product. All the particles (a) and (b) greater than 1 mm in size, preferably all of the particles of the unshaped product greater than 1 mm in size, represent between 0 and 22%, preferably between 0 and 22%. and 17%, preferably between 0 and 14%, or even between 7% and 14% of the mass of said unshaped product. All the particles (a) and (b) larger than 1.25 mm, preferably all the particles of the unshaped product larger than 1.25 mm, represent between 0 and 19%, preferably between 0 and 15%, or even between 0 and 12%, or even between 0 and 10%, or even between 5% and 10% of the mass of said unshaped product. The amount of particles (a) in the unshaped product is greater than 82%, preferably greater than 85%, preferably greater than 91% and / or less than 98%, preferably less than 97%. Preferably, all the particles (a) comprise, in mass percentages on the basis of the mass of the unshaped product: an AZS content of greater than 10%, greater than 20% and / or less than 95% % and / or - a reactive alumina content greater than 2%, greater than 3%, greater than 4%, and / or less than 13%, less than 10%, less than 8%; and / or a calcined alumina content greater than 5%, greater than 10%, and / or less than 38%, less than 35%; and / or - an electro-cast alumina content greater than 10%, greater than 20%, greater than 25%, and / or less than 70%, less than 65%; and / or particles having the following chemical analysis, in weight percent on the basis of the oxides: Cr 2 O 3 + Al 2 O 3 + ZrO 2 + MgO + Fe 2 O 3 + SiO 2 + TiO 2> 90%, preferably> 95%, and Cr 2 O 3 + A1203> 40%, even> 50%, even> 60%, even> 70%, even> 80%, even> 90%, or even> 95%, and Cr203> 9%, even> 15%, or even> 20 %, even> 29%, even> 39%, even> 49%, even> 59%, even> 70%, even> 80%, even> 90%, and 20%> Si02> 0.5%, and others Oxides: <10%, preferably <5%, the content of said particles being greater than 10%, greater than 20%, greater than 30% and / or less than 95%, and / or pigmentary chromium greater than 5%, greater than 10%, and / or less than 25%, less than 20%. The hot binder is chosen so as not to be in the solid state at a temperature of 1350 ° C., preferably 1300 ° C., preferably 1250 ° C., preferably 1200 ° C., preferably of 1150 ° C, the particles (b) represent more than 3% and less than 13%, preferably less than 12%, preferably less than 10%, preferably less than 9%, preferably less than 8% of the mass of said unshaped product. The particles (b) of the product are preferably distributed in the following manner, in percentages by weight, on the basis of the mass of the particles (b): fraction <1 mm:> 80%, preferably> 90%, even> 95%, even substantially 100%, and / or fraction <0.5 mm:> 80%, preferably> 90%, and / or - fraction <0.1 mm:> 25% and / or <48 %, preferably <45%, and / or fraction <0.04 mm: <30%, preferably <25%, or even <20%. - The particles (b) preferably have a melting point greater than 750 ° C, preferably greater than 800 ° C, preferably greater than 900 ° C, and / or less than 1650 ° C, preferably less than 1600 ° C, preferably below 1550 ° C, or even below 1500 ° C. Preferably, the particles (b) consist of a material whose chemical composition comprises more than 90%, preferably more than 94%, preferably more than 97% of oxides. In one embodiment, said material is substantially entirely composed of oxides. Particles (b) consist of a material whose chemical composition comprises more than 45%, preferably more than 50%, preferably more than 55% and / or less than 80%, preferably less than 75% of silica, in percent by mass. - Particles (b) of a glass-ceramic precursor glass and / or glass ceramic particles (b) have the following chemical composition, in weight percentages on the oxide basis and for a total of more than 95%, more than 98% preferably 100%: SiO 2: 45% - 75%, and - Al 2 O 3: 5% - 40%, and - CaO + MgO + Liz (): 3% - 30%, - nucleating agents, expressed in an oxide form: 0.1% - 20%. The amount of nucleating agents is preferably greater than 1% and / or less than 10%, preferably less than 5%. Preferably, said nucleating agents are selected from TiO 2, ZrO 2, P 2 O 5 and mixtures thereof. The amount of particles (c) of hydraulic cement is preferably less than 1%, preferably less than 0.5%. Preferably, the amount of particles (c) of hydraulic cement is substantially zero. The content of "other constituents" (d) is preferably less than 5%, preferably less than 3%, preferably less than 2%, preferably less than 1%. Preferably, the "other constituents" (d) consist of oxides. Preferably the "other components" (d) consist of surfactants, anti-segregation adjuvants and, optionally, fibers. The unshaped product comprises a surfactant, preferably between 0.075% to 1% of a surfactant. The surfactant is a modified polycarboxylate ether. The unshaped product preferably comprises an anti-segregation adjuvant, preferably in an amount between 0.05% and 0.5% of the mass of the unshaped product. In one embodiment, the unshaped product comprises fibers, preferably organic fibers, preferably between 0.01% and 0.06%, preferably between 0.01% and 0.03%. In one embodiment, the unshaped product has no fibers. The invention also relates to a wet mixture consisting of an unshaped product according to the invention and water in an amount of less than 13%, less than 12%, as a percentage by weight based on the wet mixture. Despite a limited amount of water, a wet mix according to the invention is self-flowable and does not lead to segregation. After sintering, it leads to a product perfectly suited for the repair of a region of a glassware furnace intended to be in contact with molten glass. The invention also relates to a glass melting furnace comprising at least one region, in particular in contact with molten glass, in particular the sole, obtained from an unshaped product according to the invention. The invention further relates to a method of repairing a glass melting furnace, and in particular to a hearth of such a furnace, the method comprising the following steps: 1) independently of steps 2) to 4), preparation of an unshaped product according to the invention; 2) emptying the molten glass contained in the furnace; 3) optionally, rinsing the hearth, in particular the waste zones, with a product adapted to melt the glass residues, 4) reducing the temperature in the oven to a temperature at which the hot binder is no longer in the solid state, preferably between 900 ° C and 1350 ° C; 5) moistening said unshaped product so as to obtain a wet mixture; 6) placing said wet mixture; 7) maintaining the oven temperature between 1250 ° C and 1400 ° C to allow sintering of said wet mixture, preferably for a time greater than 8 hours, preferably greater than 10 hours, and preferably less than 15 hours ; 8) introducing a glass composition to melt and increasing the temperature of the oven to its operating temperature.

Definitions - A "non-shaped product" is a dry or wet particulate mixture capable of forming into a mass so as to constitute a shaped product. - "Wet mixture" means a mixture of an unshaped product and a liquid, preferably water. By particle "of a material" or "of a material" is meant a particle made up for more than 95%, more than 98%, preferably substantially 100% of its mass of said material. - A hydraulic cement, or "hydraulic binder", is a binder that, upon activation, generates a setting and a hydraulic hardening. "Refractory material" means a material having a melting temperature above 1500 ° C. This definition is commonly used by those skilled in the art and cited in "Refractory materials and technical ceramics (ceramics and technology elements)", G. Aliprandi, Editions Septima Paris, 1979. This book also gives pages 297 to 301 of examples of refractory materials, in particular oxides, carbides and nitrides. The "glass" of the particles (b) is a non-crystalline material having a glass transition temperature of less than 1100 ° C. The term "glass transition temperature" of a glass means the temperature at which the material passes from the solid state to the viscous state. The glass transition temperature can be determined by differential thermal analysis (DTA). The glass transition temperature is the temperature at which the glass has a viscosity substantially equal to 10 12 steps. "Hot binder" means a component having a melting point greater than 600 ° C., and capable of binding together, after curing under the effect of a drop in temperature, particles (a) to which he was mixed. "Glass-ceramic" or "vitroceramic material" conventionally means a microcrystalline compound obtained by controlled crystallization of a "glass-ceramic precursor glass". Controlled crystallization of a glass-ceramic precursor glass is conventionally carried out in a next step, immediately or not, the step of obtaining said glass-ceramic precursor glass. A glass-ceramic precursor glass is a solid-state glass which, unlike other glasses, contains "nucleating agents". A nucleating agent is an agent capable of causing the formation of microcrystallizations or "microcrystallites" during the controlled crystallization thermal treatment, usually called "crystallization heat treatment" or "vitroceramization heat treatment", a microcrystallite being a crystal of which the half sum of the length and width is less than 10 μm. The length and width of a microcrystallite are conventionally evaluated from sectional views of the glass-ceramic.

The microstructure of a glass-ceramic thus consists of microcrystallites bathed in a residual vitreous phase. The melting temperature of a glass-ceramic material is the equilibrium temperature separating the area where coexist liquid and solid phases of the field where only a liquid phase is present.

Fusion-cooling products which during their manufacture do not pass through a step in which they are in the glass state are therefore not glass-ceramic materials. Molten corundum, fused alumina, molten spinels, molten magnesia, molten mullite, molten mullite-zirconia, molten aluminum titanate, possibly doped, and molten nitrides are not, in particular, materials 30 glass-ceramics. By "crystallization rate" of a glass-ceramic material is meant the mass percentage of crystallized phases contained in said material.

The degree of crystallization can be measured by X-ray diffraction, for example by the following method: The X-ray diffraction patterns are acquired with a Bruker D5000 diffractometer with copper anticathode. The acquisition is performed on an angular range of between 5 ° and 80 °, with a pitch of 0.02 ° and a time of I s / step. A reception slot of 0.6 mm is used and the sample is rotated on itself in order to limit the effects of preferential orientations. The acquisition time is multiplied by 2 in order to obtain a better counting statistic. The nature of the crystallized phases present is determined with the EVA software and the ICDD record database. The percentage of amorphous phases is measured with the High Score Plus software provided by PANalytycal. The method uses Rietveld refinement by adding in the sample a known percentage of a standard crystallized standard, in this case zinc oxide ZnO. The sample is a pellet obtained by mixing, in an agaric mortar, 0.4 g (ie 20% by weight) of ZnO particles of purity greater than 99% by mass and less than 1 μm in size and 1 , 6 g (80% by weight) of vitroceramic particles crushed to have a size less than 40 microns. The amorphous phases are not visible with the Rietveld method, only the crystallized phases are taken into account and their sum is normalized to 100%.

In the case where at least one amorphous phase is also present, the quantity of crystallized phases must be corrected: The addition of a known quantity of the crystallized standard makes it possible to carry out a correction of the quantity of all the crystallized phases present, and thus allows the determination of the percentage of amorphous phases present,% CompAm.

The crystallization rate is given by the following formula: 100 -% CompAm, in percent by mass. Calcined aluminas, reactive and tabular are well known to those skilled in the art and commercially available. The calcined alumina is obtained from bauxite treated according to the Bayer process followed by calcination at a temperature typically between 1000 and 1250 ° C. in order to eliminate the hydrates and to obtain a predominantly crystallized powder in the Al 2 O 3 alpha form.

The tabular alumina is a calcined alumina sintered under air at a temperature above 1600 ° C and long enough for its shrinkage to increase further. The morphology of the crystals of this alumina in elongated hexagonal tablets is at the origin of its denomination.

Reactive alumina is conventionally obtained by grinding calcined alumina. The powders of reactive alumina particles conventionally have a median diameter of less than 2 microns, preferably less than 1 micron. The percentiles or "percentiles" (Dio), 50 (D50), and 90 (D99) are the particle sizes of a powder corresponding to percentages by weight, 10%, 50% and 90%, respectively. , on the cumulative particle size distribution curve of the particle sizes of the powder, the particle sizes being ranked in ascending order. For example, 90% by weight of the particles of the powder have a size less than D90 and 10% of the particles by mass have a size greater than or equal to D10. Percentiles can be determined using a particle size distribution made with a laser granulometer. The laser granulometer used can be a Partica LA-950 from the company HORIB A. D50 corresponds to the "median size" of a set of particles, that is to say to the size dividing the particles of this set in first and second populations being equal in mass, these first and second populations comprising only particles having a size greater than or equal to, or less than, the median size, respectively. The "maximum size" is the 99.5 percentile (D99.5) of a set of particles. It is clear that particles having a size of less than 10 μm (which constitute the "fraction <10") are accounted for in the 29% to 52% of particles having a size smaller than 40 μm, the particles having less than 2 μm are counted for particles smaller than 40 μm and those smaller than 10 μm, etc. "Impurities" means the inevitable constituents introduced involuntarily and necessarily with the raw materials or resulting from reactions with these constituents. Impurities are not necessary constituents, but only tolerated. Preferably the amount of the impurities is less than 2%, less than 1%, less than 0.5%, or even substantially zero. The AZS products are products, preferably electrofusion, the main constituents of which are alumina (Al 2 O 3), zirconia (ZrO 2) and silica (SiO 2). In other words, alumina, zirconia and silica are the constituents whose mass contents are the highest. These products are well suited for the manufacture of glass furnaces. More particularly, the present AZS products are mainly used for areas in contact with molten glass as well as for the superstructure of glass furnaces. AZS products include products marketed by Saint-Gobain SEFPRO, such as ER-1681, TER-1685 or ER-1711. When reference is made to ZrO 2 or zirconia, it is necessary to include ZrO 2 and the traces of HfO 2. Indeed, a little HfO2, chemically indissociable from ZrO2 in a melting process and having similar properties, is still naturally present in zirconia sources at levels generally less than 2%. Hafnium oxide is not considered an impurity. The content of HfO 2 in the AZS particles is preferably less than 5%, less than 3%, less than 2%. Elongated structures are called "fibers", typically having a diameter of 1 μm to 1 mm and a length of up to about 60 mm. - All percentages of this description are percentages by weight unless otherwise indicated. Detailed Description of the Unshaped Product General An unshaped product according to the invention can be packaged in bags or drums. Preferably, the unshaped product is ready for use, i.e., incorporates all components except water. Preferably, all the particles (a) and (b) are greater than 95%, preferably more than 97%, preferably more than 98%, or even more than 99% of the unshaped product mass. Preferably, the unshaped product has a chemical composition such that the sum Al 2 O 3 + ZrO 2 + SiO 2 + Cr 2 O 3> 85%, preferably> 90%, preferably> 92%, or even greater than 94%, or even greater than 95%.

In one embodiment, the unshaped product has a chemical composition such that the sum Al 2 O 3 + ZrO 2 + SiO 2> 85%, preferably> 90%, preferably> 92%, or even greater than 94%, or even greater than 95%. %. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%: A1203: 85% -97%, preferably> 90% %, and / or <94% - SiO2:> 1%, preferably> 2% and / or <11%, preferably <9%, preferably <7%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%: Al 2 O 3: 43% - 60% - ZrO 2 20% 43% - SiO2: 10% - 26%. Preferably, Al 2 O 3:> 45%, preferably> 50% and / or <58%, preferably <55%, and / or - ZrO 2> 25% and / or <35%, and / or - SiO 2: > 12%, preferably> 14%, preferably> 15% and / or <23%, preferably <19%.

In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%: A1203: 5% -60%, ZrO2 <35% SiO2: 5% - 25%, 25 - Cr203 10% - 90%. Preferably, Al 2 O 3:> 40%, preferably> 50% and / or <60%, and / or - ZrO 2> 5%, preferably> 10% and / or <30%, or even <20%, and or - SiO2:> 10% and / or <20%, and / or 30 - Cr203:> 15%, preferably> 20% and / or <65%, or even <60%. In a preferred embodiment, all the particles (a) and (b) have a composition whose complement to 100% of the oxides Al 2 O 3, SiO 2, ZrO 2 and Cr 2 O 3 is made up of CaO and / or B 2 O 3 and / or Na20 and / or P205 and / or MgO and / or K20 and / or BaO and / or Sr ° and / or ZnO and / or Li20 and / or TiO2 (which conventionally result from the presence of a glass) and impurities . The impurities may be, for example, metal particles. Preferably, the maximum size of all the particles (a) and (b), preferably the maximum particle size of an unshaped product according to the invention is less than or equal to 2 mm, or even less than or equal to at 1.5 mm. Advantageously, the flowability of the wet mixture at high temperature is improved. Preferably, all the particles (a) and (b), preferably all of the particles of the unshaped product are distributed as follows, in percentages by weight: fraction <0.5: <7%, preferably <6%, preferably <5%, and / or> 2%, and / or fraction <2 iam:> 5%, preferably> 6%, preferably> 7% and / or preferably <18 %, preferably <16%, preferably <14%, preferably <12%, and / or fraction <10:> 16%, preferably> 19%, preferably> 20% and / or preferably <40%, preferably <35%, preferably <33%, preferably <30%, preferably <28%, and / or - fraction <40 μm:> 27%, preferably> 29%, preferably> 30%, preferably> 33%, preferably> 35%, preferably> 37% and / or preferably <50%, preferably <47%, preferably <45%, preferably <42%, and / or or - fraction between 2 i.tm and 40 i.tm:> 16% and / or <40%. Preferably, the particles of the unshaped unshaped product are distributed as follows: fraction <0.5: 1% - 6%, and - fraction <2 iam: 6% - 16%, and - fraction <10 : 16% - 35%, and - fraction <40 iam: 27% - 47%, and - maximum particle size: <2.5 mm, preferably <2 mm.

More preferably, the particles of the unshaped product are distributed as follows: fraction <0.5: 1% - 5%, and fraction <2 iam: 7% - 12%, and - fraction < 10: 19% - 28%, and - fraction <40 iam: 29% - 45%, and - maximum particle size: <2.5 mm, preferably <2 mm.

Conventional compaction models such as the Fuller-Bolomey model or the Andreasen model can be used to determine the most suitable particle size distribution. Particles (a) The particles (a) may have different compositions from each other. In one embodiment, all the particles (a) preferably have the same composition. Preferably, they are homogeneous. The particles (a) can be made from one or more sources of raw materials, having different chemical analyzes. Particle size distributions may also differ according to said sources.

The following sources may in particular be used: an electrofused refractory product such as JARGAL M, produced and marketed by the European Company of Refractory Products, having the following typical chemical analysis: A1203: 95%, 5iO2: 0.5% Na 2 O: 4%, other: 0.5%, the size of the JARGAL M particles being preferably greater than 50 μm and less than 10 mm; Refractory electro-cast products such as ER-1681 or ER-1711 produced and sold by the European Company of Refractory Products. These two products, called in Table 1 "AZS particles" (because of their contents of A1203, Zr02 and 5i02), contain in percentage by weight, on the basis of the oxides: 32 to 54% of ZrO 2, 36 to 51% Al 2 O 3, 10 to 16% Li 2 O and 0.2 to 1.5% Na 2 O; Melted or sintered mullite, for example a powder which contains 76.5% of Al 2 O 3 and 22.5% of TiO 2 and whose particle size varies from 0.7 to 1.5 mm; - products containing chromium oxide and having the following chemical analysis, in percentage by weight on the basis of the oxides: Cr 2 O 3 + Al 2 O 3 + ZrO 2 + MgO + Fe 2 O 3 + TiO 2 + TiO 2> 90%, preferably> 95% , and 30 Cr203 + A1203> 40%, even> 50%, even> 60%, even> 70%, even> 80%, even> 90%, or even> 95%, and Cr203> 9%, or even> 15 %, even> 20%, even> 29%, even> 3033555 16 39%, even> 49%, even> 59%, even> 70%, even> 80%, even> 90%, and 20%> Si02> 0.5%, and other oxides: <10%, preferably <5%; products with a high zirconia content, such as CC10 zirconia marketed by the European Company of Refractory Products. This product contains more than 99% ZrO 2 and the median size (D 50) of the zirconia particles is 3.5 μm; fused alumina, in the form of a powder whose particles have a size preferably of between 10 μm and 10 mm; tabular alumina, in the form of a powder whose particles have a size preferably of between 10 μm and 10 mm; Calcined alumina, which is in the form of a powder, the particles of which have a size preferably of between 1 μm and 50 μm; pigmentary chromium oxide, containing more than 98.5% of Cr 2 O 3, in the form of a powder having a median size of <10 μm, or even <5 μm, or even <1; Reactive alumina, or a mixture of reactive aluminas, containing more than 99% of Al 2 O 3, the median size of the reactive alumina particles preferably ranging from 0.5 μm to 3 μm. Particles (b) Particles (b) may have different compositions from each other.

In one embodiment, all glass ceramic particles (b) and / or all glass particles (b), especially glass ceramic precursor glass, are made of the same material. Preferably, the particles (b) of a glass have a glass transition temperature of less than 1000 ° C., preferably less than 900 ° C., or even less than 800 ° C.

An amount of particles (b) greater than 15% of the unshaped product mass decreases the corrosion resistance excessively. A quantity of particles (b) of less than 2% of the mass of the unshaped product does not allow the particles (a) to be bonded together satisfactorily after placing said unshaped product and does not make it possible to obtain a mixture wet self-flowable hot.

In a particular embodiment of the first main embodiment, all the particles (b) comprise glass particles, preferably consisting of glass particles having the following specific chemical composition: 3033555 17 - SiO2: 70% - 75%, - A1203: <2%, - CaO: 8% - 12%, - Na2O: 11% - 14%, 5 - 1 (20: - MgO: - Other: <3% .The unshaped product is then particularly well suited for use in a soda-lime glass melting furnace.

In a particular embodiment of the first main embodiment, all of the particles (b) comprise glass particles, preferably consisting of glass particles having the following specific chemical composition: SiO 2: 57% - 65 %, - A1203: <3%, 15 - CaO: 6% - 8%, - Na2O: 14% - 18%, - 1 (20: - MgO: 3% - 5%, - B203: 5% - 12% , 20 - Other: <3% The unshaped product is then particularly well suited for use in a glass melting furnace for the insulation, or even a melting furnace of soda-lime glass.In a particular embodiment of the first main embodiment, all the particles (b) comprise glass particles, preferably consisting of glass particles having the following specific chemical composition: SiO 2: 54% -63%, Al 2 O 3: 14% - 20%, - CaO: 4% - 17%, - Na2O: - MgO: B203: 6% - 12%, - Sr0 + Ba0 + ZnO: 3% - 12%.

The unshaped product is then particularly well suited for use in a reinforcing glass melting furnace, and in a glass furnace for insulation, or even a soda-lime glass melting furnace. Preferably more than 50%, preferably more than 70%, more preferably more than 90%, preferably more than 95%, preferably substantially 100% of the glass ceramic particles (b), as a percentage by mass on the basis of vitroceramic particles, have a degree of crystallization greater than 5%, preferably greater than 10%, even greater than 15% and preferably less than 80%, preferably less than 70%, preferably less than 60%, preferably less than at 50%.

Preferably, the glass-ceramic particles (b) have microcrystallites of wollastonite and / or pseudowollastonite and / or anorthite and / or gehlenite and / or virgilite and / or spodumene and / or indialite and / or of cordierite and / or beta-quartz and / or cristobalite and / or tridymite and / or mullite and / or clinoenstatite and / or spinel and / or diopside and / or zirconolite and / or protoenstatite and and / or forsterite and / or sapphirine and / or rankinite and / or bredigite and / or alite and / or enlargement and / or albite. Preferably, the glass ceramic precursor glass particles (b) have a chemical analysis capable of forming, by thermal crystallization treatment, microcrystallites of wollastonite and / or pseudowollastonite and / or anorthite and / or gehlenite and / or of virgilite and / or spodumene and / or indialite and / or cordierite and / or beta-quartz and / or cristobalite and / or tridymite and / or mullite and / or clinoenstatite and / or spinel and / or diopside and / or zirconolite and / or protoenstatite and / or forsterite and / or sapphirine and / or rankinite and / or bredigite and / or alite and / or grossite and / or albite. Preferably, the vitroceramic precursor glass has a glass transition temperature greater than 700 ° C, or even greater than 750 ° C.

In a particular embodiment of the second main embodiment, the set of particles (b) comprises particles of a glass-ceramic precursor glass, preferably consisting of particles of a glass-ceramic precursor glass having the following specific chemical composition. in weight percentages based on the oxides and for a total of greater than 95%, more than 98%, preferably substantially 100%: SiO 2: 45% -75%, and -Al 2 O 3: 5% -40% and 3033555 19 - CaO + MgO + Liz (): 3% - 30%, - nucleating agents, preferably selected from TiO 2, ZrO 2, P 2 O 5 and mixtures thereof, expressed in oxide form: 0.1% - 20% preferably 1% -10%, preferably 1% -5%.

In a particular embodiment of the second main embodiment, all the particles (b) comprise particles made of a glass-ceramic precursor glass, preferably consisting of particles of a glass-ceramic precursor glass having a chemical analysis suitable for forming, by thermal crystallization treatment, microcrystallites of wollastonite and / or pseudowollastonite and / or anorthite and / or gehlenite and / or virgilite and / or spodumene and / or indialite and / or cordierite and / or beta-quartz and / or cristobalite and / or tridymite and / or mullite and / or clinoenstatite and / or spinel and / or diopside and / or zirconolite and / or protoenstatite and / or of forsterite and / or sapphirine and / or rankinite and / or bredigite and / or alite and / or magnite and / or albite.In a particular embodiment of the second main embodiment, set of particles (b) has glass ceramic particles, preferably consisting of glass-ceramic particles having microcrystallites of wollastonite and / or pseudowollastonite and / or anorthite and / or gehlenite and / or virgilite and / or spodumene and / or indialite and and / or cordierite and / or beta-quartz and / or cristobalite and / or tridymite and / or mullite and / or clinoenstatite and / or spinel and / or diopside and / or zirconolite and / or protoenstatite and / or forsterite and / or sapphirine and / or rankinite and / or bredigite and / or alite and / or magnite and / or albite. Particles (c) Remarkably, an unshaped product according to the invention has less than 2% of particles (c) of hydraulic cement. As will be seen from the examples described hereinafter, the inventors have discovered that, surprisingly, hydraulic cement has a detrimental effect when associated with the other components of an unshaped product according to the invention. Although the addition of cement is a standard measure in products for the repair of glass furnaces, the content of hydraulic cement must be, according to the invention as low as possible.

The hydraulic cement may in particular be an aluminous cement, in particular having an alumina content of greater than 69%.

3033555 20 Other constituents (d) The content of "other constituents" is acceptable when it is less than 7%. The content of "other constituents" is preferably 5%, 3%, 2%, 1%. Preferably, the unshaped product according to the invention comprises a surfactant, preferably in a mass content of 0.1% to 1%, preferably greater than or equal to 0.2% and / or less than 0. , 5%, more preferably less than 0.4%. The role of this surfactant is in particular to modify the rheological properties of the unshaped product to facilitate pumping. Surfactants preferably selected from long chain sodium polyphosphates, sodium polyacrylates, ammonium polyacrylates, modified polycarboxylates, and mixtures thereof are preferably used. Preferably, the surface-active agents are chosen from modified polycarboxylates, preferably of modified polycarboxylate ether type, more preferably based on polyethylene glycol. Preferably, the unshaped product according to the invention also comprises at least one anti-segregation adjuvant, preferably in a proportion of 0.05% to 0.3%. The anti-segregation adjuvant may in particular be chosen from starch ethers. The choice of a surfactant and an anti-segregation adjuvant among the surfactants and anti-segregation adjuvants generally used by those skilled in the art is guided by the results of simple tests, such as those described in US Pat. this request, depending on the performance sought.

In one embodiment, the fibers, preferably organic, are, for example, polypropylene, polyacrylonitrile or polyvinyl alcohol fibers. In one embodiment, the unshaped product has more than 0.01% fiber. Preferably the average length (arithmetic mean) of these fibers is greater than 6 mm, preferably between 18 and 24 mm.

These fibers are however not essential. Preferably, the unshaped product has no fibers. Particular Embodiments In one embodiment, the unshaped product has a chemical composition such that the sum Al 2 O 3 + ZrO 2 + SiO 2> 85%, preferably> 90%, preferably> 92%, or even greater than 94%, even greater than 95%.

In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of more than 97%: A1203: 85% -97%, preferably 90%, and / or <94% - SiO2:> 1%, preferably> 2% and / or <10%, preferably <9%, preferably <7%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%: - A1203: 43% - 60% - ZrO2 20% - 43 % 10 - SiO2: 10% - 26%. Preferably, Al 2 O 3:> 45%, preferably> 50% and / or <58%, preferably <55%, and / or - ZrO 2> 25% and / or <35%, and / or 15 - SiO 2: > 12%, preferably> 14%, preferably> 15% and / or <23%, preferably <19%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%: Al 2 O 3: 5% - 60%, 20 - ZrO 2 SiO2: 5% - 25%, - Cr203: 10% - 90%. Preferably, A1203:> 40%, preferably> 50% and / or <60%, and / or 25 - ZrO2> 5%, preferably> 10% and / or <30%, or even <20%, and / or - SiO 2:> 10% and / or <20%, and / or - Cr 2 O 3:> 15%, preferably> 20% and / or <65%, or even <60%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%, preferably more than 99%: A1203: 85% 97%, preferably> 90%, and / or <94% 3033555 22 - SiO2:> 1%, preferably> 2% and / or <10%, preferably <9%, preferably <7%, and preferably, all the particles (a): - comprises reactive alumina in a mass quantity greater than 2%, greater than 4%, greater than 5%, and / or less than 13%, less than 10 %, based on the mass of the unshaped product, and / or - comprises calcined alumina in a mass quantity greater than 20%, greater than 25%, and / or less than 38%, less than 35%, on the basis of the mass of the unshaped product, and / or 10 - comprises fused alumina in a mass quantity greater than 50%, greater than 55%, and / or less than 70%, less than 65%, based on the mass of the unshaped product, and preferably all the particles (b) of the unshaped product has the following chemical composition: SiO 2: 70% -75%, Al 2 O 3: <2%, - CaO: 8% - 12%, - Na2O: 11% - 14%, - 1 (20: 20 - MgO: - Other: <3%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%, preferably more than 99%: Al 2 O 3: ZrO 2 - SiO 2: Preferably - Al 2 O 3: 30 - ZrO 2 43% - 60% 20% - 43% 10% - 26%. > 45%, preferably> 50% and / or <58%, preferably <55%, and / or> 25% and / or <35%, and / or 3033555 23 SiO2:> 12%, preferably> 14 %, preferably> 15% and / or <23%, preferably <19%. and preferably, all of the particles (a): comprise AZS particles in a mass quantity greater than 80%, preferably greater than 85% and / or less than 95%, based on the mass unshaped product, and / or - comprises reactive alumina in a mass quantity greater than 3%, greater than 5%, and / or less than 10%, less than 8%, based on the mass of the product unshaped, and preferably all of the particles (b) has the following chemical composition: SiO 2: 70% -75%, Al 2 O 3: <2%, CaO: 8% -12%, Na 2 O: 11% - 14%, 15 - 1 (20: - MgO: - Other: <3% In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably a total of greater than 97%, preferably more than 99%: - Al 2 O 3: - ZrO 2 - SiO 2: - Cr 2 O 3: Preferably - Al 2 O 3: - ZrO 2 - SiO 2: - Cr 2 O 3: 5% - 60%, % - 25%, 10% - 90%,> 40%, preferred this> 50% and / or <60%, and / or> 5%, preferably> 10% and / or <30%, or even <20%, and / or> 10% and / or <20%, and / or> 15%, preferably> 20% and / or <65%, or even <60%, and preferably all of the particles (a) of the unshaped product: - comprises particles having the following chemical analysis as a percentage by mass on the basis of the oxides: Cr 2 O 3 + Al 2 O 3 + ZrO 2 + MgO + Fe 2 O 3 + SiO 2 3033555 24 TiO 2> 90%, preferably> 95%, and Cr 2 O 3 + Al 2 O 3> 40%, even> 50%, or> 60%, even> 70%, even> 80%, even> 90%, or even> 95%, and Cr203> 9%, even> 15%, even> 20%, even> 29%, or even> 39%, even> 49%, even> 59%, even> 70%, even> 80%, or even> 90%, and 20%> SiO2> 0.5%, and other oxides: 5 <10%, preferably <5% in a mass quantity greater than 10%, greater than 20%, greater than 30% and / or less than 95%, based on the mass of the unshaped product, and / or - comprises reactive alumina in one higher mass quantity at 2%, greater than 3%, greater than 4%, and / or less than 13%, less than 10%, less than 8%, based on the mass of the unshaped product, and / or - comprises calcined alumina in a mass quantity greater than 5%, greater than 10%, and / or less than 38%, less than 35%, less than 30%, less than 25%, less than 20%, based on of the unshaped product mass, and / or 15 - comprises fused alumina in a mass quantity greater than 10%, greater than 20%, greater than 25%, and / or less than 50%, less than 40% , based on the mass of the unshaped product, and / or - comprises AZS particles in a mass quantity greater than 10%, greater than 20% and / or less than 50%, less than 40%, based on the mass of the unshaped product, and / or - comprises pigmentary chromium oxide particles in a mass quantity greater than 5%, greater than 10%, and / or less at 25%, less than 20%, based on the bulk of the unshaped product, and preferably all of the particles (b) has the following chemical composition: SiO 2: 57% -65%, A1203: <3%, - CaO: 6% - 8%, - Na2O: 14% - 18%, - 1 (20: 30 - MgO: 3% - 5%, - B203: 5% - 12%, - Other : <3%.

In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%, preferably more than 99%: A1203: 85 % - 97%, preferably> 90%, and / or <94% 5 - SiO 2:> 1%, preferably> 2% and / or <10%, preferably <9%, preferably <7%, and preferably, all the particles (a): - comprises reactive alumina in a mass quantity greater than 2%, greater than 4%, greater than 5%, and / or less than 13%, less than 10% on the basis of the mass of the unshaped product, and / or - comprises calcined alumina in a mass quantity greater than 20%, greater than 25%, and / or less than 38%, less than 35%, based on the mass of the unshaped product, and / or - comprises fused alumina in a mass quantity greater than 50%, greater than 55%, and / or less than 70%, less than 65%, based on the mass of the unshaped product, and preferably all the particles (b) of the unshaped product have the following chemical composition, in weight percentages based on the oxides and for a total of more than 95% more than 98%, preferably substantially 100%: 20 - SiO 2: 45% - 75%, and - Al 2 O 3: 5% - 40%, and - CaO + MgO + Liz (): 3% - 30%, - nucleating agents, preferably selected from TiO 2, ZrO 2, P 2 O 5 and mixtures thereof, expressed in oxide form: 0.1% to 20%, preferably 1% to 10%, preferably 1% to 5%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of more than 97%, preferably more than 99%: Al 2 O 3: 43% 60% 30 - ZrO 2 20% - 43% - SiO 2: 10% - 26%. Preferably, 3033555 26 - A1203:> 45%, preferably> 50% and / or <58%, preferably <55%, and / or - ZrO2> 25% and / or <35%, and / or SiO2: > 12%, preferably> 14%, preferably> 15% and / or <23%, preferably <19%. and preferably, all of the particles (a): - comprises particles of AZS in a mass quantity greater than 80%, preferably greater than 85% and / or less than 95%, on the basis of the mass of the unshaped product, and / or comprises reactive alumina in a mass quantity greater than 3%, greater than 5%, and / or less than 10%, less than 8%, based on the mass of the product unshaped, and preferably all of the particles (b) has the following chemical composition, in weight percentages on the oxide basis and for a total of more than 95%, more than 98%, preferably substantially 100%. %: - SiO 2: 45% - 75%, and - Al 2 O 3: 5% - 40%, and - CaO + MgO + Liz (): 3% - 30%, - nucleating agents, preferably selected from TiO 2, ZrO 2, P205 and their mixtures, expressed in oxide form: 0.1% -20%, preferably 1% -10%, preferably 1% -5%. In one embodiment, the unshaped product has the following mass composition, for a total of greater than 95%, preferably for a total of greater than 97%, more preferably more than 99%: Al 2 O 3: 5% - 60%, ZrO 2 <35%, - SiO 2: 5% - 25%, - Cr 2 O 3: 10% - 90%, preferably 30 - Al 2 O 3:> 40%, preferably> 50% and / or <60%, and / or - ZrO2> 5%, preferably> 10% and / or <30%, even <20%, and / or - SiO2:> 10% and / or <20%, and / or 3033555 27 - Cr203: > 15%, preferably> 20% and / or <65%, even <60%, and preferably all of the particles (a) of the unshaped product: - comprises particles having the following chemical analysis, mass percentage on the basis of the oxides: Cr 2 O 3 + Al 2 O 3 + ZrO 2 + MgO + Fe 2 O 3 + SiO 2 TiO 2> 90%, preferably> 95%, and Cr 2 O 3 + Al 2 O 3> 40%, even> 50%, or even> 60%, even> 70%, even> 80%, even> 90%, or even> 95%, and Cr203> 9%, even> 15%, even> 20%, even> 29%, even> 39%, even> 49 %, vo > 59%, even> 70%, even> 80%, or even> 90%, and 20%> SiO2> 0.5%, and other oxides: <10%, preferably <5%, in a higher mass quantity at 10%, greater than 20%, greater than 30% and / or less than 95%, based on the mass of the unshaped product, and / or - comprises reactive alumina in a mass quantity greater than 2 %, greater than 3%, greater than 4%, and / or less than 13%, less than 10%, less than 8%, based on the mass of the unshaped product, and / or calcined alumina in a mass quantity greater than 5%, greater than 10%, and / or less than 38%, less than 35%, less than 30%, less than 25%, less than 20%, based on mass unshaped product, and / or - comprises fused alumina in a mass amount greater than 10%, greater than 20%, greater than 25%, and / or less than 50%, less than 40%, basis of the mass of the product unshaped, and / or - comprises AZS particles in a mass quantity greater than 10%, greater than 20% and / or less than 50%, less than 40%, based on the mass of the unshaped product, and or comprises pigmentary chromium oxide particles in a mass quantity greater than 5%, greater than 10%, and / or less than 25%, less than 20%, based on the mass of the unshaped product, and preferably all of the particles (b) have the following chemical composition, in weight percentages on the oxide basis and for a total of greater than 95%, more than 98%, preferably substantially 100%: SiO2: 45% - 75%, and - A1203: 5% - 40%, and 3033555 28 - CaO + MgO + Liz (): 3% - 30%, - nucleating agents, preferably selected from TiO 2, ZrO 2, P 2 O 5 and mixtures thereof, expressed in oxide form: 0.1% -20%, preferably 1% -10%, preferably 1% -5%.

Detailed Description of the Repair Method A repair method according to the invention comprises the steps 1) to 8) described above. Preferably, in step 1), the various raw materials are mixed in a kneader. The optional surfactant may be mixed at this stage or introduced at step 5). Preferably, in step 1), the chemical composition of the particles (b) is chosen so that their melting temperature is lower than the temperature of the region to be repaired. In one embodiment, the particles (b) have substantially the same composition as the molten glass in the furnace to be repaired.

Preferably, in step 2), the melted glass is emptied at a temperature close to the melting temperature of the glass. Said emptying can be carried out for example through holes drilled in the hearth, or through holes created by the disassembly of one or more electrodes present. In step 3), optional rinsing of the hearth, in particular of the waste zones, is preferably carried out by spraying a product suitable for melting the glass residues. Preferably said product is selected from sodium sulfate, sodium carbonate, sodium hydroxide and mixtures thereof. The products make it possible to increase the fluidity of the glass, which facilitates its evacuation outside the oven. Preferably, the repair method according to the invention comprises a step 3).

In step 4), the temperature in the oven is reduced to a temperature at which the hot binder is no longer in the solid state, preferably between 900 ° C and 1350 ° C, preferably between 1000 ° C. C and 1300 ° C, preferably between 1150 ° C and 1250 ° C. In step 5), the unshaped product is moistened so as to obtain a wet mixture, adding to it a quantity of water preferably greater than 8%, preferably greater than 9% and / or less than 13%. , less than 12% by weight relative to the mass of said unshaped product.

In step 6), the wet mixture is preferably pumped by means of a pump producing a suction pressure of less than or equal to 180 bar and conveyed into the oven, preferably by means of a cane cooled by water. The wet mixture is poured into the furnace on the existing hearth, the holes made for the emptying of the glass in step 2) being pre-filled. Said casting can be carried out so as to carry out repairs in different areas of said sole. The wet mixture is preferably cast over the entire surface of the oven hearth. In step 7), the oven is maintained at a temperature of between 1250 ° C and 1400 ° C, preferably between 1300 ° C and 1400 ° C, to allow sintering of said wet mixture, preferably for a period of time. greater than 8 hours, preferably greater than 10 hours and preferably less than 15 hours. Preferably, when the unshaped product contains glass ceramic precursor glass particles (b), the oven is maintained at a temperature to promote nucleation and growth of the microcrystallites. Those skilled in the art can determine the temperature range for this nucleation and growth. The unshaped product according to the invention advantageously allows a low sintering temperature and / or a holding time at said reduced temperature. During this step, it is possible to pierce the sole in order to install electrodes. In step 8) the glass melt composition is introduced into the oven and the temperature thereof is increased to its operating temperature. Examples The following nonlimiting examples are given to illustrate the invention. The hot "self-flowable" character, the segregation and the after temperature drop appearance are evaluated by the following test: A flat-bottomed refractory crucible having an internal diameter of 170 mm and an internal height equal to 45 mm is mounted in a metal tank having a diameter equal to 400 mm. The space between the wall of the tank and the wall of the crucible is filled by insulating materials. A removable refractory concrete cover with a thickness of 100 mm is suspended above the crucible at a height of between 20 mm and 30 mm. This cover has a hole 100 mm in diameter at its center which allows to pass the flame of a gas burner positioned above said lid and to introduce the wet mixture.

The gas burner is ignited and the interior of the refractory crucible is heated to 1300 ° C. at a temperature rise rate of 500 ° C./h. Then the tank + crucible assembly is rotated at a speed of 6 revolutions per minute. 5 kg of wet mix are prepared in a rotary blade and fixed bowl mixer with a mixing time of 5 minutes. The wet mixture is then poured into a metal bracket having a length of 600 mm and edges of a height of 40 mm. Said angle has an inclination of 45 ° and one of its ends is supported on the edge of the central hole of the lid, to allow the hot introduction of the wet mixture in the crucible. The maximum height of 10 falls, at the beginning of the spill, is about 175 mm. The supply of wet mixture is stopped when it reaches the top of the refractory crucible. For the tests in which the particles (b) are glass particles, the temperature is then raised to 1450 ° C. with a temperature rise rate equal to 100 ° C./h, and is maintained for a time equal to 10 hours. to allow sintering of the wet mixture.

For the tests in which the particles (b) are glass-ceramic precursor particles, the temperature is then raised to 1350 ° C with a temperature rise rate of 50 ° C / h, and is maintained for an equal period of time. at 10 hours in order to allow the sintering of the wet mixture and the growth of the microcrystallites. The temperature decrease is carried out gradually at a rate equal to 100 ° C./h and the sintered product cake is then demolded. The appearance of the cake is then observed. The hot self-flow character is acquired if the sintered product wafer has a diameter substantially equal to the internal diameter of the refractory crucible, and if the wafer does not present, with the naked eye, a hole or a recess in its center.

The slab is then sawn so as to seek segregation. It is considered that segregation occurs when the sawn faces reveal a surface layer of laitance extending from the top face of the slab to a depth of 3 mm or more. The cold compressive strength is measured by means of an LR150K press marketed by AMETEK-LLOYD, on rolls with a diameter of 30 mm and a height equal to 30 mm taken from the wafer.

Table 1 provides the composition of the particulate mixtures (a) + (b) + (c). It also indicates the particle size distribution of the fused alumina particles and the AZS particles used. The calcined alumina used is alumina HVA FG marketed by Almatis.

Silica fume is a silica fume comprising more than 90% by mass silica, in the form of a powder whose particles have a size of between 0.1 and 5 μm and a median size of less than 0. , 6 pm, marketed by the European Society of Refractory Products. The cement used is CA25R cement marketed by Almatis.

The glass particles (b) are made of a soda-lime glass having the following chemical analysis: - Other: 0.3%. The glass transition temperature of this glass is 580 ° C. The glass transition temperature is determined by differential thermal analysis (DTA) on an STA409C device marketed by Netsch. The sample holders are each equipped with a thermocouple enabling a direct measurement of the temperature of the glass placed in a dense sintered alumina crucible of capacity equal to 300 μm, and of an identical empty crucible considered as reference. The glass to be analyzed is milled so as to pass through a sieve of aperture equal to 160 μm. The thermal cycle applied during the measurement consists of a rise at a rate of 10 ° C./min, under air, up to at 1650 ° C. On the thermogram obtained, the glass transition appears as the first endothermic event. The glass transition temperature is equal to the temperature of the point of inflection of the curve in said first endothermic event (ie "Tinfl" in the program used).

After grinding, the glass particles have the following particle size distribution: - fraction <0.5: 0%, and - fraction <2 iam: 0%, and - 5iO 2: 72.3%, - Al 2 O 3: 0.5% CaO: 9.5%, Na 2 O: 13.4%, MgO 4%, 3033555 fraction <10: 5%, and fraction <40 μm: 16%, and fraction <100 μm: 35%, and fraction <200 μm: 58%, and 5 - maximum particle size: 1 mm. Particles (b) of a vitroceramic precursor glass are prepared in the following manner: A starting charge consisting, in mass percentages, of 60.4% of a silica powder of purity equal to 98%, 23.4% an alumina powder of purity greater than 98%, 12.8% of a lithium carbonate powder, 1.6% of a titanium oxide powder and 1.8% of a powder of zirconia is melted in a crucible placed in an electric oven. The crucible is then taken out hot and its contents are poured into a water tank, allowing rapid quenching and avoiding crystallization. This results in a powder of glass ceramic precursor glass particles. The amorphous state of these particles is verified by X-ray diffraction. These particles are then dried at 110 ° C. for 48 hours. After drying, the glass-ceramic precursor glass particles are crushed with the jaw crusher and screened so as to obtain a set of particles (b) having the following particle size distribution: fraction <0.5: 0%, and 1%, and 7%, and 15%, and 62%, and 20 - fraction <2 μm: - fraction <10: - fraction <40 μm: - fraction <200 μm - maximum particle size: 1 mm.

The glass ceramic precursor precursor glass particles (b) obtained have the following chemical composition in percentages by weight: SiO 2: 64.2% Al 2 O 3: 24.8% LiO 2: 5.5% TiO 2: 1.7 % - ZrO 2: 1.9% - Other: 1.9%.

The glass transition temperature of this glass-ceramic precursor glass is less than 1100 ° C. This composition allows the precursor glass to form microcrystallites of ZrTiO4, beta-quartz and beta-spodumene during sintering of the unshaped product. Said sintering is thus a crystallization heat treatment of the glass-ceramic precursor glass. Comparative example 1, "Comp 1", is rammed earth described in EP 0 739 861 Bi, in particular used in the repair of glass melting furnaces. Comparative example 2, "comp 2", is a self-leveling concrete according to WO2013132442 to which glass particles (b) have been added, the particles (b) representing 5% of the total mass of the self-leveling concrete and added glass. Table 2 provides the chemical compositions of the wet unshaped products tested, as well as the results of the tests performed. Examples "Comp 2" and 1 to 5 incorporate as the particles (d) 0.2% of a surfactant of the family of modified polycarboxylate ethers and 0.2% of an anti-dopant adjuvant. segregation of the family of starch ethers. In Table 2: for the example "comp 1", the 100% complement of Al 2 O 3 + SiO 2 + ZrO 2 consists of P 2 O 5 and impurities, for the example "comp 2" the complement to 100 % of Al 2 O 3 + SiO 2 + ZrO 2 + surfactant + anti-segregation additive consists of CaO provided by the hydraulic cement and the glass, as well as Na 2 O, K 2 O and MgO provided by the glass, and impurities, - for Examples 1 to 4, the 100% complement of Al 2 O 3 + SiO 2 + ZrO 2 + surfactant + anti-segregation adjuvant consists of CaO, Na 2 O, K 2 O and MgO provided by the glass, as well as impurities, and - for example 5, the 100% complement of Al 2 O 3 + SiO 2 + ZrO 2 + surfactant + anti-segregation adjuvant consists of Li 2 O and TiO 2 brought by the glass, as well as impurities.

The addition of water (g) is provided as a percentage by weight based on the unshaped product. Table 2 also provides the particle size distribution, measured using a HORIB A laser granulometer.

34 Particulate mixture (a) + (b) + (c), in percentages by weight Ex. No. Alumina Alumina Calcined alumina Reactive alumina Smoke Cement Particles Particles Particles Powder Fused electro-fused water glass powder AZS 0.5 mm AZS 40 μm - AZS <40 glass precursor glass 0.5 mm - 3.5 mm 10 itm - 200 lim silica -2 mm 500 irons vitroceramic Comp 1 - - - - - - - - - - - Comp 2 44.7 14.2 16.1 12.35 2.85 4.8 0 0 0 5 0 1 0 0 0 5 0 0 27 31 34 3 0 2 0 0 0 6 0 0 27 31 31 5 0 3 0 0 0 3 0 0 27 31 31 8 0 4 0 0 0 6 0 0 34 38 17 5 0 5 0 0 0 3 0 0 27 31 31 0 5 Table 1 Unformed dry product Add Distribution of particles (a) + (b) + (c) (percentages Massages) (percentages by mass) N ° A1203 Si02 Zr02 Water <0.5 <2 <10 <40 <500 Inn> 1 size Auto- - Appearance after Appearance descending in temperature Resistance to (ci /) Pin illn lim ini min maximum flowable segregation compression. (mm) hot? cold (MPa) Comp 1 57.2 12.5 25.1 5 10.1 11.7 37.1 53.9 80.3 8 2 non-porous 45 Comp 2 91 6.3 0.1 11 7 11 , 7 30.2 38.2 55.5 32.8 3.5 yes not very cracked and resistance, very low mechanical 1 52.4 15.8 29.7 11 2.5 9.5 24.6 41.5 76.2 11.9 2 yes no good 70 2 51.8 16.8 28.7 11 2.4 8.9 22.9 39 76.1 11.9 2 yes no good 65 3 48.9 18.9 28.7 11 1.8 7.7 21.3 37.8 75.8 11.9 2 yes no good 60 4 51.8 16.8 28.7 11 2.3 6.9 16.4 28.6 69.8 15.1 2 yes no good n / a 5 53.1 16.4 28.8 11 3 9.3 23.5 39.2 76.5 12 2 yes no good 80 n / a: not determined Table 2 3033555 Results allow to make the following observations: - The example "Comp 1", which does not include particles (b) does not have a hot self-flow character. - The example "Comp 2" has a self-flow character, but after descending in 5 temperature, the slab is very cracked and has a very low mechanical strength: some areas can be broken manually. Without being bound by any theory, the inventors attribute this phenomenon to the presence of 4.8% hydraulic cement in the product of the example "Comp 2". The "Comp 1" example has a lower cold compressive strength than the unshaped products of the examples according to the invention. The example "Comp 1" requires a sintering temperature greater than 1350 ° C. to develop a cold compressive strength similar to that of the products according to the invention: the reintroduction of the glass melting composition of step 8 ) can therefore be carried out more quickly with the products according to the invention. The return to production is thus faster than for the product of the example "Comp 1". The unshaped products of Examples 1, 2 and 5 are the preferred examples. As now clearly apparent, the invention provides an unshaped product for making a self-flowable, non-segregated, wet blend which, after sintering, exhibits good cold compressive strength even after sintering at 1350 ° C. In addition, this unshaped product, after wetting, can be pumped with suction pressures less than or equal to 180 bar. Finally, other tests have shown that an unshaped product according to the invention, after sintering, generates little or no defects when in contact with molten glass.

An unshaped product according to the invention is therefore perfectly suitable for use in repairing a glass melting furnace, in particular for repairing a hearth of such an oven. Of course, the present invention is not limited to the embodiments described, provided by way of illustrative and non-limiting examples. 30

Claims (34)

REVENDICATIONS1. Unshaped product comprising in percentages by weight, and for a total of 100%, A) particles (a) of at least one refractory material different from a glass and a glass-ceramic, and whose main constituent (s) are alumina (Al 2 O 3) and / or zirconia (ZrO 2) and / or silica (SiO 2) and / or chromium oxide (Cr 2 O 3): 100% complement, B) 2% to 15% of particles (b) of a hot binder selected from glass-ceramic particles, particles of a glass, in particular a glass-ceramic precursor glass, and mixtures of these particles, the mass quantity of glass-ceramic particles and / or precursor glass particles of glass-ceramic in all the particles (b) being greater than 10%, based on the mass of all the particles (b), a glass being a non-crystalline material having a glass transition temperature of less than 1100 ° C, the hot binder not being in the solid state at 1500 ° C, C) mo 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, all of said particles (a) and (b) being distributed, in percentages by weight relative to the mass of the unshaped product, as follows - - - - <40 μm fraction: 25% - 52%. 2. Unformulated product according to the preceding claim, wherein the mass quantity of glass-ceramic particles and / or glass-ceramic precursor glass particles in the set of particles (b) is greater than 95%, on the basis of mass. of all the particles (b). fraction <0.5:> 1%, fraction <2 pm:> 4%, fraction <10:> 13%, 3033555 37 Unformulated product according to any one of the preceding claims, wherein the amount of hydraulic cement is less than or equal to 1%. 4. Unshaped product according to the preceding claim, wherein the amount of hydraulic cement is substantially zero. 5 5. Unformulated product according to any one of the preceding claims, in which the particles of the unshaped product are distributed as follows, in percentages by weight: fraction <0.5: <7% and / or - fraction <2 pm:> 5% and / or 10 - fraction <10:> 16% and / or - fraction <40 pm:> 27% and / or - fraction between 2 i.tm and 40 i.tm:> 16% and / or <40%. An unshaped product according to any one of the preceding claims, wherein the particles of the unshaped product are distributed in the following manner, in mass percentages: fraction <0.5: <6% and / or fraction < 2 μm: <18% and / or fraction <10: <40% and / or fraction <40 μm:> 29%. 20 Unformulated product according to any one of the preceding claims, wherein the particles of the unshaped product are distributed as follows, in percentages by weight: fraction <2 μm: <14% and / or fraction <10: <35% and / or fraction <40 μm: <50%. Unformulated product according to any one of the preceding claims, wherein the particles of the unshaped product are distributed as follows, in percentages by weight: fraction <2 μm: <12% and / or 3033555 fraction - 10: <30% and / or - fraction <40 iam: <42%. Unformulated product according to any one of the preceding claims, wherein the maximum size of all the particles of the unshaped product is less than or equal to 2.5 mm. 10. Unformed product according to the preceding claim, wherein the maximum size of all the particles of the unshaped product is less than or equal to 2 mm. 11. The unshaped product according to any one of the preceding claims, wherein the amount of particles (a) is greater than 82% and / or less than 98% of the unshaped product mass. An unshaped product according to any one of the preceding claims, wherein the amount of particles (b) is greater than 2% and less than 13% of the mass of the unshaped product. 13. Unformulated product according to the preceding claim, wherein the amount of particles (b) is greater than 3% and less than 12%, preferably less than 10%, preferably less than 8% of the mass of the non-product. shaped. Non-shaped product according to any one of the preceding claims, in which the particles (b) have a melting temperature above 750 ° C, preferably above 800 ° C and below 1650 ° C, preferably below 1550 ° C. 20 15. Unformulated product according to any one of the preceding claims, in which the particles (b) consist of a glass whose chemical composition comprises, as a percentage by weight, more than 90%, preferably more than 94% of oxides. 16. Unshaped product according to any one of the preceding claims, in which the particles (b) consist of a glass whose chemical composition comprises, in mass percentage, more than 45%, preferably more than 50%, and less than 80%, preferably less than 75% of silica. An unshaped product according to any one of the preceding claims, wherein the particles (b) of a glass ceramic precursor glass and / or glass ceramic particles (b) have the following chemical composition, in percentages by weight on the base of the oxides and for a total of more than 95%, more than 98, preferably of substantially 100%: - SiO 2: 45-75%, and 5 - Al 2 O 3: 5-40%, and - CaO + MgO + Liz ( ): 3 - 30%, - nucleating agents, expressed in oxide form: 0.1-20%. 18. The unshaped product according to the immediately preceding claim, wherein the mass amount of nucleating agents is greater than 1% and less than 10%. 10 19. Unformed product according to any of the two immediately preceding claims, wherein said nucleating agents are selected from TiO 2, ZrO 2, P 2 O 5 and mixtures thereof. 20. Unshaped product according to any one of the preceding claims, in which the particles (b) are distributed in the following manner as a percentage by mass on the basis of particles (b): fraction <1 mm:> 80% preferably> 90% and / or fraction <0.5 mm:> 80%, preferably> 90% and / or - fraction <0.1 mm:> 25% and / or <48%, and / or fraction <0.04 mm: <30%, preferably <25%. 20 21. Unformulated product according to any one of the preceding claims, which has a chemical composition such that the sum Al 2 O 3 + ZrO 2 + SiO 2 + Cr 2 O 3> 85%, preferably> 90%. 22. Non-shaped product according to the preceding claim, which has a chemical composition such that the sum Al 2 O 3 + ZrO 2 + SiO 2> 85%, preferably> 90%. 25 23. Unformulated product according to any one of the preceding claims, which has a following mass composition, for a total of more than 95%: - Al 2 O 3: 85% - 97% - SiO 2:> 1% and <11%. 3033555 40 24. Unformulated product according to any one of claims 1 to 22, which has a mass composition such that - Al 2 O 3: 43% - 60% ZrO 2 20% - 43% 5 - SiO 2: 10% - 26%. Unformulated product according to any one of claims 1 to 22, which has a mass composition such that - Al 2 O 3: 5% - 60%, ZrO 2 <35%, 10 - SiO 2: 5% - 25%, - Cr 2 O 3 % - 90%. 26. An unshaped product according to any one of the preceding claims which comprises a surfactant in an amount of from 0.075% to 1% of the mass of said unshaped product. 15 Unformulated product according to any one of the preceding claims, wherein the fraction of particles smaller than 500 μm is more than 50% of the mass of said unshaped product. 28. The unshaped product according to any one of the preceding claims, wherein the fraction of the particles larger than 1 mm is between 0 and 22% of the bulk of said unshaped product. A method of repairing a region of a glass melting furnace comprising the steps of: 1) independently of steps 2) to 4), preparing an unshaped product according to any one of the preceding claims; 2) emptying the molten glass contained in the oven; 3) optionally, rinsing the hearth, in particular the waste zones, using a product adapted to melt the glass residues, 4) reducing the temperature in the oven to a temperature at which the binder to hot is no longer in the solid state, preferably between 900 ° C and 1350 ° C; 5) moistening said unshaped product so as to obtain a wet mixture; 6) placing said wet mixture; 7) maintaining the oven temperature between 1250 ° C and 1400 ° C to allow sintering of said wet mixture, preferably for a time greater than 8 hours, preferably greater than 10 hours, and preferably less than 15 hours ; 8) introducing a glass composition to melt and increasing the temperature of the oven to its operating temperature. 30. Method according to the preceding claim, wherein, in step 7), the temperature is maintained for a time greater than 8 hours and less than 15 hours. 10 31. A method according to any one of the two immediately preceding claims, wherein, in step 1), the chemical composition of the particles (b) is chosen so that the melting temperature of said particles is below the temperature. blocks of the area to repair. 32. A process according to any one of the three immediately preceding claims, wherein in step 5) said unshaped product is moistened with the addition of a quantity of water of between 8% and 13% by mass percentage. relative to the mass of said unshaped product. 33. A method according to any one of the four immediately preceding claims, wherein in step 6) said unshaped product is poured over the entire surface of the hearth 20 of the furnace. 34. A glass melting furnace comprising at least one part, in particular in contact with molten glass, in particular sole, obtained from an unshaped product according to any one of claims 1 to 28 or obtained by a method according to any one of the five preceding claims. 25