Conformed composite comprising a mineral wool

Abstract

The present invention relates to a method for manufacturing a molded composite, comprising: i) the preparation of a mixture comprising: at least 30% by weight of recycled mineral wool including a sizing agent comprising a phenolic resin, 11 to 25% by weight of a hydraulic binder comprising clinker in a content of between 30% and 90% by weight, mineral fillers, and water; and ii) the shaping of said mixture into a molded composite. It further relates to a molded composite obtainable by such a method, as well as a method for manufacturing mineral wool using such a molded composite.

Description

Title of the invention: Conformed composite comprising a mineral wool

[0001] The invention relates to the field of valorization of mineral wool-based residues, particularly rock wool or glass wool. Typically, mineral wool production residues are agglomerated into formed composites, frequently referred to as "briquettes" (other terms are available, primarily depending on the geometry of the formed composite), for recycling in the mineral wool manufacturing process. These formed composites, particularly in the form of briquettes, can be introduced into a melting furnace, which in turn feeds a fiber-pulling device.

[0002] According to a process known as external centrifugation, mineral wool is obtained from a molten mineral mass poured onto a set of rotating rotors. The molten mass is ejected from the periphery of the rotors and drawn into a gas stream, thus transforming into fibers. The wool is then impregnated with a sizing composition. The sizing composition is sprayed onto the fibers during their formation, and the mass of smeared fibers is then collected on a receiving device and conveyed into a device for shaping mineral wool felt strips. The sizing is intended to give the wool its cohesion by forming bridges between the fibers after curing and cross-linking.This process produces a significant amount of waste, firstly during the fiber-making stage, where waste includes solidified mineral matter and sizing, this solidified mineral matter generally comprising fibers and granules (known as "shot" in English); and secondly after felt formation, due to cutting operations intended to correct the edges of the felt or to size the products. Finally, production sometimes fails to meet the expected quality, and some batches are discarded.

[0003] According to another process, called internal centrifugation, the molten material is fiberized through a fiber-forming element in the form of a plate with a perforation at its periphery. The material is ejected through the perforated wall of the plate in the form of filaments, which are then drawn out by a gaseous drawing stream. This technique produces a fiber-forming yield much higher than the external centrifugation technique and does not produce grains. However, cutting waste is unavoidable.

[0004] These mineral-based residues can be recovered in the mineral wool manufacturing process, particularly by remelting with the raw materials feeding the melting furnace. This recycling generally involves the preparation of composites containing these residues, said composites being produced by shaping, in particular molding, The process involves mixing mineral wool residue with a mineral binder, followed by a treatment to ensure the binder sets. Forming the residue into briquettes allows for easy transport and facilitates its reuse, particularly its reintroduction into a melting furnace.

[0005] In the case of rock wool, this furnace may be of the cupola type, in which the solid raw material charge, consisting of blocks of natural rock, forms a self-supporting column with alternating layers of solid fuel (coke), through which the combustion gases escape. As melting occurs in the lower part of the column, it is replenished from the top with fuel and rock. These furnaces do not allow the introduction of powdered or lightweight particle raw materials that lack the necessary ability to form a stable solid layer in the vertical column. Transformation into a shaped composite, such as a briquette, provides this ability. The aim is for the briquette to develop good mechanical strength relatively quickly after shaping and to not disintegrate during handling and transport.

[0006] To obtain good mechanical strength, high levels of hydraulic binders, themselves containing high levels of clinker, are generally used. However, such briquettes are not satisfactory from an environmental point of view. The use of clinker contributes significantly to the emission of greenhouse gases, particularly CO2 and SOx. There is therefore a real need to develop briquettes whose composition has a reduced environmental impact, but which retain good mechanical strength and remain fiber-reducible (for example, by external centrifugation). Summary of the invention

[0007] In this context, the inventors have surprisingly demonstrated that the hydraulic binder content and the clinker content in this hydraulic binder can be significantly reduced when mineral wool recycled materials containing a phenolic resin-based sizing are used, without affecting the mechanical strength of the briquette. Furthermore, the composition of the developed briquettes allows them to be fiber-reinforced (for example, by external centrifugation).

[0008] Thus, the present invention relates to a method for manufacturing a molded composite, comprising:

[0009] i) the preparation of a mixture comprising:

[0010] - at least 30% by weight of recycled mineral wool including a bonding including a phenolic resin,

[0011] - 11 to 25% by weight of hydraulic binder comprising clinker in a content comprising between 30 and 90% by weight,

[0012] - mineral fillers, and

[0013] - water; and

[0014] ii) the conformation of said mixture into a conformed composite.

[0015] In some embodiments, the hydraulic binder further comprises 10 to 50% by weight of one or more non-cementitious silica carriers distinct from mineral wool.

[0016] In certain embodiments, said non-cementitious silica carriers are selected from an alkali silicate, calcined or natural clay, kaolinite, illite, montmorillonite, calcined kaolin, dehydrated kaolin, silica fume, class C or F fly ash, biomass ash, blast furnace slag, steel slag, rice hull ash, rice husk, pozzolana, volcanic ash, diatomite, and a mixture of at least two of these.

[0017] In some embodiments, the hydraulic binder comprises silica fume, preferably in a content of 5 to 15% by weight relative to the total dry weight of the hydraulic binder.

[0018] In some embodiments, mineral wool recycling includes rock wool recycling, glass wool recycling, or a mixture thereof.

[0019] In some embodiments, the mineral wool recycled content is 40 to 60% by weight, relative to the total dry weight of the mixture.

[0020] In some embodiments, the sizing is present in the mineral wool recycling at a rate of 0.1 to 10% by weight, and more particularly at a rate of 0.5 to 7% by weight of dry sizing material relative to the total weight of dry mineral wool recycling.

[0021] In some embodiments, the phenolic resin is present in the gluing at a rate of 50 to 90% by weight of the dry matter of the gluing.

[0022] In some embodiments, the weight content of mineral fillers is between 5% and 60% by weight, preferably between 30% and 60%, relative to the total dry weight of the mixture.

[0023] In some embodiments, the mineral fillers are chosen from gravel, inert slag, and a mixture of these.

[0024] In some embodiments, the hydraulic binder represents 11 to 20% by weight, preferably 11 to 15% by weight, or even 12 to 14% by weight, of the total dry weight of the mixture.

[0025] In some embodiments, the hydraulic binder comprises clinker in a content of between 30% and 80% by weight.

[0026] The present invention also relates to a conformed composite formed from a mixture comprising:

[0027] - at least 30% by weight of recycled mineral wool including a bonding including a phenolic resin,

[0028] - 11 to 25% by weight of hydraulic binder comprising clinker in a content comprising between 30 and 90% by weight,

[0029] - mineral fillers, and

[0030] - water.

[0031] More particularly, the present invention relates to a conformed composite that can be obtained by the process as defined in this application.

[0032] Another object of the present invention is a method for manufacturing mineral wool, comprising:

[0033] - a step a) of feeding a melting chamber, such as a cupola furnace, with a a composite conformable as defined in this application, as a vitrifiable filler, and

[0034] - a step b) of melting said conformed composite in said melting chamber, to obtain a bath of molten material, and

[0035] - a step c) of fiberizing said molten material bath. DETAILED DESCRIPTION

[0036] Step i) of the process according to the invention comprises the formation of a mixture comprising:

[0037] - at least 30% by weight of recycled mineral wool including a bonding including a phenolic resin,

[0038] - 11 to 25% by weight of hydraulic binder comprising clinker in a content comprising between 30 and 90% by weight,

[0039] - mineral fillers, and

[0040] - water.

[0041] The weight content of mineral wool recyclates and hydraulic binder are dry weight contents expressed relative to the total dry weight of the mixture. The clinker content (and other components of the hydraulic binder described below) in the hydraulic binder is a dry weight content expressed relative to the total dry weight of the hydraulic binder.

[0042] In this application, the term "mineral wool recycling" means all residues from the production of mineral wool, including solidified mineral matter in granular or fibrous form, or recovered as solid flakes, or bundles of fibers recovered (by washing) from the various receiving or conveyor surfaces, as well as cut mineral wool felt. Mineral wool recycling may optionally be in the form of slightly ground fibers (but retaining a fibrous character). Mineral wool recycling is typically- pitting in the form of fibers longer than 5 mm.

[0043] Mineral wool recycles may in particular be recycled rock wool, glass wool (including in particular, low alumina and high alumina glass wool), or a mixture of these.

[0044] For the purposes of the invention, a mineral wool has a chemical composition comprising the following constituents:

[0045] SiO2: 30 to 75% by mass, CaO+MgO: 5 to 45% by mass, Al2O3: 0 to 30% by mass, Na2O+K2O: 0 to 20% by mass, Fe2O3: 0 to 20% by mass, B2O3: 0 to 14% by mass, MnO: 0 to 4% by mass.

[0046] The term rock wool generally refers to mineral wools having fibers whose chemical composition includes the following constituents:

[0047] SiO2: 30 to 50% by mass, Al2O3: 10 to 22% by mass, CaO+MgO: 20 to 45% by mass, Fe2O3: 0 to 20% by mass, Na2O+K2O: 0 to 10% by mass, B2O3: 0 to 1% by mass.

[0048] By contrast, the term glass wool generally refers to mineral wools with fibers whose chemical composition includes the following constituents:

[0049] - For so-called low-alumina glass wools:

[0050] SiO2: 50 to 75% by mass, Al2O3: 0 to 8% by mass, CaO+MgO: 5 to 20% by mass mass, Fe2O3: 0 to 3% by mass, Na2O+K2O: 6 to 20% by mass, B2O3: 0 to 14% by mass, MnO: 0 to 4% by mass.

[0051] - For glass wools known as high alumina:

[0052] SiO2: 35 to 55% by mass, Al2O3: 16 to 27% by mass, CaO+MgO: 3 to 30% by mass mass, Fe2O3: 0 to 15% by mass, Na2O+K2O: 5 to 17% by mass, B2O3: 0 to 5% by mass.

[0053] Mineral wool compositions are expressed here in oxide form by convention. In particular, if the (total) iron oxide content is expressed as Fe₂O₃, this does not mean that this iron oxide is necessarily and exclusively present in its ferric form. Iron oxide can be present in both its ferric (Fe₂O₃) and ferrous (FeO) forms, and it is purely by convention that Fe₂O₃ designates the total iron oxide content. Preferably, the sum of the mass concentrations of SiO₂, Al₂O₃, CaO, MgO, Fe₂O₃, Na₂O, K₂O, and MnO in the mineral wool compositions described above is greater than or equal to 90%, or even greater than or equal to 95%.

[0054] Mineral wool recycling includes a sizing comprising a phenolic resin.

[0055] The sizing is typically present in mineral wool recycles at a rate of 0.1 to 10% by weight, and more specifically at a rate of 0.5 to 7% by weight of dry sizing material relative to the total weight of dry mineral wool recycling.

[0056] The sizing containing the phenolic resin generally contains the latter at a rate of 50 to 90% by weight, preferably 70 to 90% by weight, of the dry matter of the sizing (% of dry phenolic resin on the total weight of dry sizing).

[0057] Phenolic resin-based adhesives are well known to those skilled in the art. Phenolic resin (also called "resol") is a thermosetting resin typically obtained by the condensation of phenol and formaldehyde. Other constituents may be added to the phenol and formaldehyde, particularly to adjust the properties of the resin. These constituents may, for example, be glycine, urea, an amine, or an amino alcohol. Alternatively, the aforementioned constituents may be added to the adhesive composition comprising the phenolic resin (i.e., after the formation of said phenolic resin).

[0058] Phenolic resin can also be formed in the presence of a crosslinkable thermoplastic homopolymer or copolymer (e.g. acrylic resins, poly(vinyl acetates), polyurethanes and their homo- and copolymers, in particular copolymers based on acrylic acid esters also using acrylonitril).

[0059] Generally, the sizing also includes other components besides the phenolic resin. In particular, it may include a catalyst (e.g. ammonium sulfate or sulfamate), a coupling agent (e.g. a silane, more particularly an ami-nosilane), a water-repellent agent (e.g. a silicone), a dust-repellent agent (e.g. an oil), a hydrophobic agent, a polycondensation retardant (e.g. ammonia), a stabilizer (e.g. metal oxide nanogels, glass particles), a flame retardant (e.g. ammonium phosphates or polyphosphates), clays (in particular kaolinites, montmorillonites, kaolin and / or bentonite), a thixotropic agent (e.g. polysaccharides such as starch, potato starch, polysaccharide derivatives such as methylcellulose), or pigment dispersers.

[0060] In a particular mode, the gluing comprises:

[0061] - 50 to 90% by weight, preferably 70 to 90% by weight, of phenolic resin,

[0062] - 5 to 30% by weight, preferably 10 to 20% by weight, of urea,

[0063] - from 0.01 to 5% by weight, preferably from 0.5 to 2% by weight, of catalyst (e.g. a sulfate),

[0064] - from 0.01 to 2% by weight, preferably from 0.1 to 1% by weight, of retardant (e.g. ammonium),

[0065] - from 0.001 to 1% by weight, preferably from 0.01 to 0.5% by weight, of coupling agent (e.g., silane)

[0066] These contents being expressed as a percentage of the total dry weight of the sizing.

[0067] The concentration of dry extracts in the sizing is generally between 5 and 40%, preferably between 10% and 20%.

[0068] By way of illustration of documents describing phenolic resin-based gluing compositions, the following documents may be cited: EP2609129, EP2091986, EP1289901, and EP1551892.

[0069] The sizing comprising the phenolic resin is preferably non-thermosetting. However, in some embodiments, the sizing is in its thermosetting form. The term "thermosetting" describes a sizing in an insoluble and infusible form, typically obtained by heating the sizing. In some embodiments, the mixture comprises both mineral wool recycled materials with a non-thermosetting sizing and mineral wool recycled materials with a thermosetting sizing.

[0070] Mineral wool recycling including the sizing comprising the phenolic resin represents at least 30% by weight, in particular at least 35% by weight, preferably from 40% to 60% by weight, for example from 40% to 50% by weight, relative to the total dry weight of the mixture (percentages of dry mineral wool recycling).

[0071] The hydraulic binder represents 11 to 25% by weight, for example 11 to 20%, or 11 to 15%, in particular 12 to 14% by weight, of the total dry weight of the mixture. The hydraulic binder comprises clinker in a weight content of between 30% and 90%, preferably between 30% and 80%, for example between 40% and 60%, or between 65% and 80% (i.e., relative to the total dry weight of the hydraulic binder). The clinker is a mixture of silicates (in particular, tricalcium silicate and dicalcium silicate) and aluminates (in particular, tricalcium aluminate and tetracalcium aluminoferrite). The clinker generally has a D90 of 100 µm or less, in particular 0.2 to 100 µm.

[0072] The hydraulic binder generally also comprises one or more non-cementitious materials, advantageously in a content of between 10% and 70% by weight, preferably between 20% and 70% by weight, for example between 40% and 60% by weight, or between 20% and 35% by weight (i.e., relative to the total dry weight of the hydraulic binder). Typically, the sum of the weight of non-cementitious materials and the weight of clinker amounts to 100% of the dry weight of the hydraulic binder.

[0073] The term "non-cementary" indicates that the compound to which it is attached is not a cement. A cement is an anhydrous powdered material comprising crystalline calcium silicate or crystalline calcium taluminate. It is a hydraulic mineral compound that, in the presence of water, forms hydrated calcium silicate or hydrated calcium aluminate. A cement is essentially crystalline and contains less than 10% by weight of amorphous material. In a cement, calcium silicate or calcium taluminate are crystalline phases. A slag and a silicate Alkaline substances are not considered by a person skilled in the art to be cements.

[0074] In a preferred embodiment, said non-cementitious material comprises one or more non-cementitious silica carriers, distinct from the mineral wool. In such an embodiment, the hydraulic binder may comprise from 10% to 50% by weight, in particular from 15% to 45% by weight, of one or more non-cementitious silica carriers, distinct from the mineral wool (i.e., relative to the total dry weight of the hydraulic binder).

[0075] The non-cementitious silica carrier is a material with hydraulic properties that forms silicate ions in the presence of water. The non-cementitious silica carrier may optionally exhibit crystalline characteristics if it dissolves readily in water. This is particularly true of sodium silicate, which can notably be introduced into the mixture as an aqueous solution. Conversely, if slag is used as the non-cementitious silica carrier, it is preferable that the slag be more than 80% amorphous by weight, and even more preferably more than 90% by weight, that it contain at least 10% silica by weight, and that it have a fine particle size distribution, in particular such that its D50 is less than or equal to 100 µm, and even more preferably less than or equal to 50 µm. Such slags can be obtained as by-products of the steel industry.They derive their vitreous structure, that is, their essentially amorphous character, from the water quenching treatments applied to them after collection, which confers latent hydraulic properties. When dry, the non-cementitious silica carrier is preferably a solid mineral compound that is totally or partially amorphous. It is preferably more than 80% amorphous by weight, and even more preferably more than 90% by weight. It preferably comprises at least 10% by weight of silica (SiO2), and even more preferably at least 20% by weight of silica. It may optionally contain alumina. It may contain, in smaller quantities, iron oxide, alkali metal oxide, alkaline earth metal oxide, a phosphate, a sulfate, a sulfide, or titanium oxide. It is preferably fine enough to dissolve at least partially in an aqueous medium.Thus, the particle size of the non-cementitious silica carrier is preferably such that the D50 is less than or equal to 100 µm and even more preferably less than or equal to 50 µm. In glassmaking applications, this silica carrier is a source of SiO2 in the final glass.

[0076] The non-cementitious silica carrier may in particular be selected from: an alkali silicate, a calcined or natural clay, kaolinite, illite, montmorillonite, calcined kaolin or dehydrated kaolin such as mainly amorphous metakaolin which may contain kaolinite crystals, silica fume, fly ash (e.g., Class C or Class F), biomass ash, slag (e.g., blast furnace slag, steel slag), rice hull ash, rice chaff, pozzolan (e.g., calcined natural or synthetic pozzolan), natural or calcined volcanic ash, diatomite, or a mixture at least of these.

[0077] It is preferred that the non-cementitious silica carrier be a slag (e.g. blast furnace slag), a pozzolan (e.g. natural or calcined synthetic), silica fume, or a mixture of at least two of these.

[0078] Slag is a by-product of the steel industry and generally has a SiO2 / CaO ratio (by weight) < 1.5 and the sum of its CaO and SiO2 content represents more than 45% of its weight.

[0079] In a particular embodiment, the hydraulic binder comprises silica fume, preferably in a content of 5% to 15% by weight, for example 6% to 12% by weight (i.e. relative to the total dry weight of the hydraulic binder).

[0080] In a more particular embodiment, the hydraulic binder comprises (relative to the total dry weight of the hydraulic binder):

[0081] - 5% to 15% by weight, for example 6% to 12% by weight of silica fume, and

[0082] - 10% to 50% by weight, for example 15% to 45% by weight of pozzolana or slag blast furnace.

[0083] Said non-cementitious material may further comprise one or more non-cementitious alkali-earth carriers. In such a mode, the hydraulic binder may comprise from 1% to 25% by weight, in particular from 10% to 20% by weight, of one or more non-cementitious alkali-earth carriers (i.e., relative to the total dry weight of the hydraulic binder).

[0084] The non-cementitious alkali-earth carrier contains an alkali-earth compound and forms alkali-earth ions in the presence of water. It preferably comprises at least 10% by weight of an alkali-earth compound (this refers to the percentage of the alkali-earth element such as Ca or Mg, and not the percentage of its oxide) and preferably at least 20% by weight of an alkali-earth compound. The non-cementitious alkali-earth carrier may be selected from limestone or chalk (CaCO3), quicklime CaO or slaked lime Ca(OH)2, magnesium lime or dolomite (CaMg(CO3)2), aragonite, vaterite or other polymorphs of CaCO3, or a mixture of at least two of these, preferably limestone.

[0085] The particle size distribution of the non-cementitious alkali-earth carrier is preferably such that the D50 is less than 100 µm and even more preferably less than 50 µm. In glassmaking applications, this alkali-earth carrier is a source of alkali-earth oxide (in particular CaO or MgO) in the final glass.

[0086] The non-cementitious material of the hydraulic binder may further comprise additives (or equivalently, "addition elements"). These additives are well known to those skilled in the art. They are typically chosen from gypsum and organic admixtures (e.g., plasticizers, air-entraining agents, water-retaining agents).

[0087] These additives generally represent less than 5% by weight of the hydraulic binder (i.e., relative to the total dry weight of the hydraulic binder).

[0088] The mixture further comprises mineral fillers. These mineral fillers may be selected from mineral materials inert to the composite binder, which may be aggregates useful for the mechanical stability of the formed composite or components useful for the vitrifiable filler with a view to its potential use in glass smelting, particularly due to its iron content. The aggregates generally have a D50 greater than 200 µm, in particular greater than 1 mm.

[0089] In a particular mode, the mineral fillers are chosen from gravel, inert slag (or equivalently "non-reactive slag"), and a mixture of these.

[0090] More specifically, this may refer to aggregates from industrial recycling channels that recover industrial by-products (or co-products) or from the demolition of buildings or roads (concrete chips, bricks, recycled railway ballast, road surface crusts or millings, or mine spoil heaps). Inert slag, as a mineral filler, is coarse and is not considered to carry non-cementitious silica in the sense given above, as it does not particularly form silicate ions in the presence of water and is, moreover, crystalline to more than 20% of its weight and has a large particle size with a median diameter D50 greater than 50 µm, for example, a D50 greater than 200 µm, in particular greater than 1 mm. The same applies to gravel. This can include LD slags from converters, which are solidified without quenching treatment after collection, causing them to crystallize.This mineral filler, inert insofar as it does not participate in the chemistry of the solidification of the formed composite, is nevertheless a source of raw material for the mineral fiber that will be manufactured when the formed composites are reused for melting.

[0091] The weight content of mineral fillers is advantageously between 5% and 60% by weight, preferably between 30% and 60%, more particularly between 40% and 55% by weight, relative to the total dry weight of the mixture.

[0092] Typically, mineral wool recycling (including sizing comprising a phenolic resin), hydraulic binder and mineral fillers together represent at least 90%, in particular at least 95%, or even at least 98%, or at least 99% of the total dry weight of the mixture.

[0093] The mixture for preparing the molding compound can be made in any suitable mixer. It is generally unnecessary to heat the mixture by adding external heat. The temperature of the mixture may rise due to the solubilization of certain ingredients. Sufficient water is added to ensure that the hydraulic binder is distributed throughout the molding compound, but not so much that the formed composite retains its shape upon demolding, if applicable after compaction.

[0094] The water can largely originate from the moisture content of the residues collected in the fiber processing plant, which uses large quantities of water, particularly for collecting the residues. Water can also be introduced into the mixture to achieve both good mixing quality and good moldability, or even compaction.

[0095] Generally, water is present in the mixture at a rate of 2 to 30% by weight (preferably 4 to 15% by weight), relative to the dry weight of the mixture.

[0096] The pH of the mixture is generally basic, typically at least equal to 8 or even at least equal to 10, or even at least equal to 11.

[0097] The mineral wool recycling includes the sizing agent (comprising the phenolic resin) even before being introduced into the mixture and coming into contact with the other ingredients of the mixture (except, where applicable, for a small amount of water already present on the mineral wool recycling). The introduction of the mineral wool and the sizing agent comprising the phenolic resin into the mixture is therefore simultaneous, these ingredients being combined within the mineral wool recycling prior to their introduction into the mixture.

[0098] The molding mass obtained from the mixture is then transformed into a formed composite, in particular into briquettes, by molding and optionally compaction. In particular, the molding mass can be placed in a mold, vibrated to remove trapped air, and then optionally compacted by applying pressure to one of the moving faces of the mold.

[0099] The formed composite then hardens naturally. It can dry out over time, so its water content can be significantly reduced with storage time. Its water content can vary depending on its storage conditions.

[0100] The formed composite may, for example, have a volume greater than 1 cm3, for example greater than 20 cm3, in particular between 100 and 1000 cm3.

[0101] The present invention also relates to a conformed composite formed from a mixture comprising:

[0102] - at least 30% by weight of recycled mineral wool including a bonding including a phenolic resin,

[0103] - 11 to 25% by weight of hydraulic binder comprising clinker in a content comprising between 30 and 90% by weight,

[0104] - mineral fillers, and

[0105] - water.

[0106] More particularly, the present invention relates to a conformed composite that can be obtained by the process as defined in this application.

[0107] Another object of the present invention is a method for manufacturing mineral wool, comprising:

[0108] - a step a) of feeding a melting chamber, such as a cupola furnace, with a a composite conformable as defined in this application, as a vitrifiable filler, and

[0109] - a step b) of melting said conformed composite in said melting chamber, to obtain a bath of molten material, and

[0110] - a step c) of fiberizing said molten material bath.

[0111] In one particular mode, the molten material bath is immediately fiberized to obtain mineral wool. In another particular mode, the molten material bath is cooled and transformed into cullet, which is subsequently remelted to be fiberized to obtain mineral wool.

[0112] The step of fiberizing the molten material mixture can be carried out by internal or external centrifugation, preferably by external centrifugation.

[0113] For example, reference can be made, for external centrifugation, to patent applications EP195725, EP 0465310 or EP 0439385. For example, reference can be made, for internal centrifugation, to patent applications EP 0189354 or EP 0519797.

[0114] It is understood that the various aspects, particular and preferred embodiments described above for the manufacturing process of the molded composite also apply to the molded composite according to the invention as well as to the manufacturing process of mineral wool which uses such a molded composite.

[0115] In the present application, a range defined with the expression "between (X) and (Y)" includes the lower bound (X) and upper bound (Y), and is equivalent to "from (X) to (Y)".

[0116] The following examples illustrate the invention in a non-limiting manner. EXAMPLES

[0117] The ingredients listed in Table 1 are mixed in a mixer. The briquettes were formed by vibration molding, followed by compression and demolding. The quantities indicated are percentages by weight of dry matter in the briquette, excluding, of course, the "total water" column, which includes all water introduced into the mixture, regardless of the method. The water content is expressed as a percentage of the total dry weight of the mixture.

[0118] Cylindrical test pieces measuring 11 cm (diameter) x 7 cm were formed. Compressive strength tests (measured in MPa) were carried out on these briquettes at 3 days and 21 days.

[0119] Mineral wool recycles comprise 3% by weight of dry phenolic resin-based sizing residues (relative to the total weight of dry mineral wool recycles).

[0120] [Tables 1] Briquette 1 Briquette 2 Briquette 3 Comparison Mineral wool recycling 40% 40% 40% 40% Hydraulic binder comprising: 15% 12% 12% 9.5% Clinker 76% 70% 46% 46% Pozzolan 20% 18% - - Blast furnace slag - - 40% 40% Addition 4% 3.7% - - Limestone fillers - - 14% 14% Silica fume - 8.3% - - Gravel 21% 24% 24% 25.5% LD slag (inert) 24% 24% 24% 25% Total water 13% 13% 13% 13% Compressive strength: - at 3 days (in MPa) 5.0 5.1 4.6 2.3 - at 21 days (in MPa) 8.4 6.9 7.6 -

[0121] Table 1 shows that briquettes 1, 2, and 3, formed with a hydraulic binder having a clinker content of 46-76%, exhibit good compressive strength at 3 days (>3 MPa) and at 21 days (>6 MPa). In contrast, the comparative briquette with a lower binder content exhibits low compressive strength, less than 3 MPa at 3 days.

Claims

Claims

1. A method of manufacturing a shaped composite, comprising: i) preparing a mixture comprising: - at least 30% by weight of mineral wool recyclates comprising a sizing comprising a phenolic resin, - 11 to 25% by weight of hydraulic binder comprising clinker in a content of between 30% and 90% by weight, - mineral fillers, and - water; and ii) shaping said mixture into a shaped composite.

2. The method of claim 1, wherein the hydraulic binder further comprises 10 to 50% by weight of one or more non-cementitious silica carriers distinct from the mineral wool.

3. The method of claim 2, wherein said non-cementitious silica carriers are selected from an alkali silicate, calcined or natural clay, kaolinite, illite, montmorillonite, calcined kaolin, dehydrated kaolin, silica fume, class C or F fly ash, biomass ash, blast furnace slag, steel mill slag, rice husk ash, rice husk, pozzolan, volcanic ash, diatomite, and a mixture of at least two thereof.

4. A method according to any one of claims 1 to 3, wherein the hydraulic binder comprises silica fume, preferably in a content of 5 to 15% by weight relative to the total dry weight of the hydraulic binder.

5. A method according to any one of claims 1 to 4, wherein the mineral wool recyclates comprise rock wool recyclates, glass wool recyclates, or a mixture thereof.

6. A method according to any one of claims 1 to 5, wherein the content of mineral wool recyclates is 40 to 60% by weight, relative to the total dry weight of the mixture.

7. A method according to any one of claims 1 to 6, wherein the sizing is present in the mineral wool recyclates in an amount of 0.1 to 10% by weight, and more particularly in an amount of 0.5 to 7% by weight of dry sizing matter relative to the total weight of dry mineral wool recyclates.

8. A method according to any one of claims 1 to 7, wherein the phenolic resin is present in the size in an amount of 50 to 90% by weight. dry matter weight of the sizing.

9. Process according to any one of claims 1 to 8, in which the weight content of mineral fillers is between 5% and 60% by weight, preferably between 30% and 60%, relative to the total dry weight of the mixture.

10. A method according to any one of claims 1 to 9, wherein the mineral fillers are selected from gravel, inert slag, and a mixture thereof.

11. Method according to any one of claims 1 to 10, in which the hydraulic binder represents from 11 to 20% by weight, preferably from 11 to 15% by weight, or even from 12 to 14% by weight, of the total dry weight of the mixture.

12. A method according to any one of claims 1 to 11, wherein the hydraulic binder comprises clinker in a content of between 30% and 80% by weight.

13. Shaped composite formed from a mixture comprising: - at least 30% by weight of mineral wool recyclates comprising a sizing comprising a phenolic resin, - 11 to 25% by weight of hydraulic binder comprising clinker in a content of between 30 and 90% by weight, - mineral fillers, and - water.

14. A method of manufacturing mineral wool, comprising: - a step a) of feeding a melting chamber, such as a cupola furnace, with a shaped composite as defined in claim 13, as a vitrifiable charge, and - a step b) of melting said shaped composite in said melting chamber, to obtain a bath of molten material, and - a step c) of fiberizing said bath of molten material.