Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C1/00—Ingredients generally applicable to manufacture of glasses, glazes, or vitreous enamels
  • C03C1/002—Use of waste materials, e.g. slags
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C13/00—Fibre or filament compositions
  • C03C13/06—Mineral fibres, e.g. slag wool, mineral wool, rock wool
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/04—Glass compositions containing silica
  • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
  • C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
  • C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium

Definitions

• the invention relates to the field of melting a mixture of raw materials, in particular for the manufacture of glass fibers, in particular glass fibers E-glass.
• E-glass yarn is not only used in the textile industry but also for the reinforcement of composite elements.
• E-glass fiber thus has a low thermal conductivity.
• the fiber can withstand temperatures of over 600°C and is non-combustible. In addition, it has excellent chemical resistance.
• E-glass fibrous products are resistant to oils, solvents, and most chemical agents. In addition, they are rot-proof.
• the E-glass yarn is also insensitive to variations in temperature and humidity and its coefficient of expansion is low.
• E-glass fiber products are also particularly resistant to abrasion and vibrations, and have excellent flexibility.
• Glass yarn has a higher specific strength (tensile strength/density) than steel. This characteristic makes it possible today to develop glass yarns that will reinforce high-performance composites.
• E-glass is obtained by melting a bath of raw material comprising silica, lime, kaolin, a source of boron such as borax or boric acid and possibly dolomite, the basic components being judiciously chosen to provide a glass composition producing fibers which combine flexibility and strength under mechanical traction as to heat, to chemical agents as to electric potential.
• the choice of the raw materials mentioned above is necessary to obtain a good quality of glass, in particular after its fiber drawing.
• the properties judged to be essential mention may be made in particular of the yield of the melting (ratio between the quantity of glass produced and the quantity of raw materials charged), the quality of the refining which results in a minimal number of residual bubbles in the glass, the homogeneity of the glass (in particular the homogeneity in S1O2), as well as the number of unmelted particles.
• the energy consumption energy required to melt the mixture of raw materials can also be an element to be taken into account.
• glass is usually prepared by melting in a furnace raw materials comprising silica and at least one alkaline earth (to give the glass resistance to hydrolysis) in the form of limestone ( calcium carbonate).
• An alumina carrier such as kaolin
• a boron carrier for example borax or boric acid
• boric acid or borax As described in application EP1886978A1.
• the carbonate(s) give off carbon dioxide, the bubbles of which contribute to the mixing of the mass being melted.
• the elimination of bubbles in the glass may also require the addition of a refining agent such as sodium or calcium sulphate, the release of sulfur oxide from which brings the residual bubbles of carbon dioxide and carbon dioxide to the surface of the glass. water.
• a refining agent such as sodium or calcium sulphate
• the CO2 emission due only to the raw materials is generally l 15 to 20% of the total mass of raw materials used.
• Carbon dioxide is a greenhouse gas and it is desirable to develop glass manufacturing processes that generate as little CO2 as possible for environmental reasons, while leading to good quality glass at an acceptable cost.
• the object of the present invention is to contribute to solving such a technical problem by proposing a process for the manufacture of E-glass for which the CO2 emissions are effectively reduced, based on all the steps leading to the formation of the glass fiber and for which the material transformation steps before the melting of the bath have been optimized.
• the present invention relates to a process for manufacturing E-glass fiber having a target composition, comprising the fusion of a mixture of raw materials constituting a fusion bath, said target composition meeting the following criteria, in weight percentages:
• - CaO between 20 and 35%, preferably between 20 and 30% - Al2O3: between 10 and 20%, preferably between 12 and 18%
• - MgO less than 2%, preferably between 0 and 1%
• the process being characterized in that it comprises the following steps: a) the raw materials of said fusion bath are selected, including at least: - a source of silicon chosen in particular from silica, E-glass cullet or recycled mineral fibers or their mixture, preferably silica, a source boron preferably chosen from borax or a boron and calcium oxide, in particular colemanite, or a boron, sodium and calcium oxide, in particular ulexite and/or a boron and sodium oxide such as tincalconite and/or kernite, or mixtures thereof, in particular colemanite represents at least 70% by weight, preferably at least 80% by weight of all the sources of boron, more preferably a mixture of borax and colemanite.
• a source of silicon chosen in particular from silica, E-glass cullet or recycled mineral fibers or their mixture, preferably silica, a source boron preferably chosen from borax or a boron and calcium oxide, in particular
• At least one source of calcium selected from a mixed oxide of calcium with at least one element selected from the group consisting by Si, Al, in particular a calcium silicate and/or a calcium aluminum silicate, optionally an additional source of aluminum such as kaolin, optionally hydrated alumina or pyrophyllite, optionally limestone CaCC> 3 or calcium hydroxide Ca(OH)2 or quicklime CaO, said calcium source(s) being natural mineral matter, that is to say coming from a natural geological environment and unprocessed, b) the composition of said natural calcium source(s) is determined, c) on the basis of said composition(s) determined according to point b), the quantities of said raw materials necessary to obtain a glass of said target composition are determined, d) the said materials are mixed according to the said quantities, e) the melting, the fiber drawing of the said mixture and its cooling are carried out under the conditions allowing the production of the said glass fibres.
• a source of calcium selected from a mixed oxide of calcium with at least one element selected from the group consist
• Said source of calcium is a natural mineral calcium silicate comprising, by weight percentage, at least 30% by weight of S1O2 and at least 30% by weight of CaO, S1O2 and CaO together representing more than 70% and preferably more than 75% or even more than 80% of said calcium silicate.
• - Said source of calcium is a natural mineral material having the following composition, in percentages by weight:
• - CO2 between 0 and 20%, for example between 0 and 15% - less than 5% of other oxides, preferably less than 3% of other oxides.
• Said source of calcium is a natural mineral calcium aluminum silicate comprising, in weight percentage, more than 30% by weight of S1O2, more than 15% by weight of CaO and more than 20% of ALCb, S1O2, CaO and
• - Said source of calcium is a natural mineral material having the following composition, in weight percentages: - S1O2: between 40 and 60%, preferably between 45 and 55%,
• - CaO between 10 and 30%, preferably between 12 and 20%
• Said source of boron comprises and preferably consists essentially, or even consists of a boron and calcium oxide comprising, in percentage by weight, more than 30% of B2O3 and more than 20% by weight of CaO.
• the source of boron consists mainly of an oxide of boron and calcium and in particular colemanite.
• said boron and calcium oxide, in particular colemanite represents more than 80%, preferably more than 85% or even more than 90% of the total weight of the boron source.
• only said one oxide of boron and calcium is used as source of boron.
• a mixture of an oxide of boron and calcium such as colemanite can be used.
• borax in which said boron and calcium oxide predominates, in particular the borax/boron and calcium oxide mass ratio of which is less than 0.2, or even less than 0.1.
• a source of calcium is calcium aluminum silicate.
• a source of calcium is constituted by a silicate of aluminum and calcium.
• the calcium source comprises a mixture of a calcium aluminum silicate and a calcium silicate.
• the source of calcium is a mixture of aluminum and calcium silicate and a calcium silicate.
• - Boron source includes colemanite and calcium source includes calcium aluminum silicate.
• a source of boron is an oxide of boron and calcium, in particular colemanite, and the source of calcium comprises and preferably consists of an aluminum and calcium silicate and a calcium silicate.
• the source of boron consists mainly of or consists of colemanite and the source of calcium consists of a mixture of aluminum and calcium silicate and a calcium silicate as previously described.
• - Said bath comprises a calcium silicate, an aluminum and calcium silicate and a source of boron consisting of a boron and calcium oxide, in particular colemanite.
• All the silicates present in the bath represent more than 30% of the total weight of said bath, preferably more than 35%, or even more than 40% or even more than 45% of the total weight of said bath, or even more than 50% of the total weight of said bath.
• the mixture of raw materials contains less than 12% by weight of CO2, preferably less than 10% of CO2, even more preferably less than 5% of CO2.
• recycled E-glass cullet or mineral fibers in particular recycled glass wool or recycled rock wool, are introduced into the molten pool, the recycled E-glass cullet or recycled mineral fibers representing preferably between 10 and 50% of the total weight of the melt.
• the recycled mineral fibers have the following composition: S1O2: between 30 and 50%, preferably between 35 and 45%,
• Na20 between 0 and 10%, preferably between 0.4 and 7%
• CaO between 10 and 35%, preferably between 12 and 25%,
• MgO between 1 and 15%, preferably between 5 and 13%
• AI2O3 between 10 and 27%
• K2O between 0 and 2%, preferably between 0 and 1%
• Iron oxide between 0.1 and 3%
• other oxide(s) between 0 and 5% cumulatively, preferably less than 3%, the remainder being made up of unavoidable impurities.
• the invention also relates to the mixture of raw materials described above.
• the raw materials are selected in such a way that in the final composition of the E-glass according to the invention:
• the B203/(Na20+K20) mass ratio is between 5 and 15, more preferably is between 6 and 10.
• the B203/(Na20+K20+Mg0) mass ratio is between 4.0 and 8.0.
• a low alkali content makes it possible not to degrade the dielectric performance of the glass with a constant boron content and a low magnesium content makes it possible not to raise the temperature of the liquidus of the glass.
• the mixture of raw materials according to the invention is intended to be heated to a temperature and under conditions allowing its melting in order to obtain a glass corresponding to said target composition.
• the originality of the present invention lies in the choice of raw materials. Indeed, it was discovered that it was possible to use natural mineral oxides, that is to say under their initial geological composition after their extraction from their deposit, including their possible impurities, in particular without chemical alteration aimed at modifying the initial composition, that is to say mineral materials not chemically transformed, as a source of calcium and possibly of aluminium, this choice advantageously leading to a reduction in the release of CO2 during the fusion reaction.
• the basis is initially based on the exact composition of these untransformed geological mineral materials, as determined precisely by any suitable technique (for example chemical analysis, X-ray diffraction, etc.) for determine the composition of the initial bath.
• the necessary proportions of the other components of said bath are calculated to arrive at a target composition of the final glass, so as to minimize the quantity of CO2 released, such as than measured on all the steps leading to the formation of the glass, and not only on the basis of the final melting step.
• said mineral oxides can of course undergo steps prior to their use as raw material for fusion, but without chemical transformation, such as crushing, screening, magnetic separation, washing or even flotation or any other physical separation, provided that it does not or substantially change the chemical composition of the initial mineral compound.
• the mixture of raw materials is introduced into the mixture of raw materials.
• the sum of the weight of carbonate(s) is less than 20%, and preferably less than 10%, and preferably less than 5%, and preferably less than 1% by weight, or even zero in the mixture of raw materials.
• the mixture of raw materials is free of any carbonate. It is advantageously capable of giving off substantially no carbon monoxide during its heating and its melting into glass, for example less than 2% or less than 1%.
• the Si carrier is very preferably introduced into the mixture of raw materials in the form of sand.
• the calcium carrier is provided in the form of a calcium silicate and/or a calcium aluminum silicate.
• the Al carrier can advantageously be introduced into the mixture of raw materials in the form of a calcium and aluminum silicate, identical to or different from the previous one.
• Each feedstock is introduced into the feedstock mixture in an amount such that the mole percentage of its cation (such as Si, Ca, Al, B, etc.) relative to the sum of moles of all cations is the same as in the final drink.
• the raw materials of the mixture are chosen to lead to a glass whose target composition falls within the scope (the percentage ranges of the different oxides) described above.
• the mixture of raw materials is heated until a molten glass is obtained, usually in a furnace.
• the temperature is heated more or less high and for more or less time depending on the quality of the glass you are looking for, in particular according to the degree of tolerance of unmelted particles (called "unmelted") and bubbles.
• the maximum heating temperature of molten glass is between 1400 and 1700°C.
• glass melting techniques well known to those skilled in the art. This transformation can be carried out in any type of oven such as an electric oven with electrodes, a furnace with overhead burners such as a furnace with transverse burners or a loop furnace, a furnace with submerged burners.
• the mixture of raw materials in particular pulverulent, can possibly be humidified before introduction into a furnace in order to reduce the flights of raw materials in the furnace due to the currents of combustion gases.
• the mixture of raw materials if necessary humidified, can be introduced into a furnace in a powder state, which implies that each raw material it contains is in a powder state.
• the mixture of raw materials moistened if necessary, can be introduced into a furnace in the state of composition comprising cullet and the mixture of raw materials, the latter being powdery if necessary.
• the mixture of raw materials may not be shaped by mechanical pressure. It is also not necessary to use a technique for granulating the raw material according to which the material is put into rotation (in particular in a tank of the rotating drum type) generally in the presence of a binder so as to lead to pellets.
• the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400°C then until the glass melts at 1500°C with a one-hour plateau at the maximum temperature.
• the amount of CO2 released is 155 grams.
• Example 2 In this example the mixture of raw materials is this time as described in Table 3 below.
• Example 1 the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum.
• the amount of CO2 released this time is 94 grams, a decrease of 40% compared to the reference example.
• the mixture of raw materials is this time as described in Table 4 below.
• this initial mixture we introduced as a reagent, to replace the limestone, a natural mineral matter of a calcium silicate directly from a quarry located in Sonora.
• This material is introduced directly, without any chemical transformation and after simple grinding aimed at adapting the particle size, mixed with the other constituents in proportions adjusted accordingly to obtain a glass with a composition very close to that of glass.
• reference example 1 This material is introduced directly, without any chemical transformation and after simple grinding aimed at adapting the particle size, mixed with the other constituents in proportions adjusted accordingly to obtain a glass with a composition very close to that of glass.
• Example 1 the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum. No CO2 release is observed for this example.
• the mixture of raw materials is this time as described in Table 5 below.
• this initial mixture was introduced as reagent, to replace all the limestone, mineral matter comprising a mixture of calcium silicate according to Example 3 and calcium silicate and natural aluminum of Example 2.
• composition in oxides of this mineral matter is given below.
• Example 5 As for Example 1, the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum. No release of CO2 is observed for this example.
• Example 5 As for Example 1, the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum. No release of CO2 is observed for this example.
• Example 5 Example 5:
• the mixture of raw materials is this time as described in Table 6 below.
• Example 1 the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum. No CO2 release is observed for this example.
• the mixture of raw materials is this time as described in Table 7 below.
• Example 1 the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum.
• the amount of CO2 released this time is 30 grams, a decrease of 81% compared to the reference example.
• the mixture of raw materials is this time as described in Table 8 below.
• Example 8 As for Example 1, the mixture of raw materials is brought under air in a platinum crucible in 1 hour up to 1400° C. then until the glass melts at 1500° C. with a one-hour plateau at the temperature maximum. The amount of CO2 released this time is 44 grams, a decrease of 72% compared to the reference example.
• Quantity of sand this is the quantity of sand used compared to reference example 1 (in percentage weight saved).
• reducing the quantity of sand used in favor of other mineral materials such as natural silicates makes it possible to reduce the energy to melt the glass, the most refractory raw material in the bath generally being silica.
• the number of bubbles per kilogram of molten glass is measured at 1410° C. for 240 minutes. The higher this index, the better the quality of ripening.
• the quality index is proportional to the S1O2 homogeneity (as measured by microprobe/EDS) of the molten glass at 1410°C for 240min.
• Homogeneity is measured by a series of measurements of the amount of S1O2 at different points in the glass and a standard deviation is then determined.
• This measurement corresponds to the energy required to melt the mixture of raw materials, as measured by DSC (as a percentage saved compared to the reference example 1)
• Example 2 according to the invention shows that the use of a natural calcium and aluminum silicate in combination with colemanite makes it possible to obtain a glass quality and especially with a low degree of unmelted, and even lower than the reference, which is essential for its use. Such a result appears surprising, if we look at the melting point of colemanite (around 1100°C) used in combination with a calcium and aluminum silicate in the melt.
• Example 3 the use of a natural calcium silicate in combination with colemanite has particular advantages and in particular a very strong reduction in the quantity of sand required, improved homogeneity and a certain energy gain but in return the presence of a greater quantity of unmelted particles than the reference.
• MgO, Na20, Fe203 and K2O remain extremely low, despite the use of unprocessed mineral materials in the melt. It is observed in particular that the MgO levels and the Na20 + K2O sum are between 0 and 1% and an Fe203 level of less than 0.5% in the composition of the final glass, which also makes it possible to guarantee low resistivity. electric glass.

Landscapes

• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Glass Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=77710818

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (5)

• 2021
  • 2021-04-28 FR FR2104437A patent/FR3122418B3/fr active Active
• 2022
  • 2022-04-28 WO PCT/FR2022/050819 patent/WO2022229569A1/fr not_active Ceased
  • 2022-04-28 EP EP22726489.2A patent/EP4330201A1/de active Pending
  • 2022-04-28 CN CN202280031680.6A patent/CN117222603A/zh active Pending

Also Published As

Similar Documents

Legal Events