A glass batch with reduced calcium content

Abstract

The invention relates to a glass batch for a glass article. The glass batch comprises, by weight, a first raw material group containing 0-65% SiO2, a second raw material group containing 5-60% AI2O3, a third raw material group containing 10-45% MgO, a fourth raw material group containing 0-13% CaO or CaCO3, a fifth raw material group containing 0-20% Na2CO3 and / or 10-30% Na2O or combinations thereof, and a sixth raw material group containing 0-5% B2O3.

Description

[0001] A GLASS BATCH WITH REDUCED CALCIUM CONTENT

[0002] TECHNICAL FIELD

[0003] The present invention relates to a batch with reduced CO2emissions for the manufacture of glass articles (flat glass, glass packaging, and glassware), and in particular to a batch in which the calcium content is reduced.

[0004] BACKGROUND ART

[0005] Glass articles are widely used in various applications such as architecture, windows, packaging, storage, serving, presentation, and decoration. Such glass products belong to the soda-lime silicate glass family and are commonly found across a wide range including windows, plates, sheets, bottles, jars, household items, tableware, laboratory ware, and decorative objects. Traditionally, glass production methods include float, molding, blowing, and casting techniques.

[0006] To produce a glass article, a mixture of raw materials (the batch), typically together with cullet, is fed onto an existing glass melt in a furnace. The cullet may consist of recycled glass bottles, jars, tableware, flat glass, and other glass types that have been broken into small pieces. These materials are melted in melting furnaces operated at temperatures of about 1500 °C to produce glass.

[0007] The batch is obtained by weighing and mixing raw materials in specific proportions according to the desired final glass chemical composition. The mixture of raw materials that will yield the desired glass composition after melting and forming is referred to as the batch. In most mixtures for glass article production, the main component is silicon dioxide (SiO2). Pure silicon dioxide has a high melting point above 1710 °C. To complete dissolution of silicon dioxide particles, the glass melt must be brought to high temperature (> 1500 °C). To lower the melting temperature to approximately < 1500 °C, sodium carbonate (Na2CO3), also known as soda ash, is added to the mixture. However, sodium carbonate reduces the chemical durability of the glass and makes the glass water-soluble. To overcome this disadvantage, calcium carbonate (CaCO3), magnesium carbonate (MgCO3) and / or aluminum oxide (AI2O3) are added to the batch. Many glasses also contain additional components added to modify the properties of the melt depending on their intended functions. US8746012B2 relates to the production of a glass product with reduced greenhouse gas emissions; however, the process concerns melting raw materials that have been pre-reacted prior to use in the glass production process. A raw material composition is prepared comprising at least one silicon dioxide or silicon-dioxide-containing compound and at least one pre-reacted compound; this pre-reacted compound contains a calcium silicate together with volcanic glass, and the total amount of volcanic glass and calcium silicate is about 5% to 65% by weight of the raw material mixture. No added calcium carbonate is present in the raw material mixture. This raw material mixture is melted to obtain a melt and a glass product is formed from this melt. Compared to a process where a raw material mixture containing about 5% limestone is used, this process reduces greenhouse gas emissions by about 20% to 84%.

[0008] BRIEF DESCRIPTION OF THE INVENTION

[0009] The object of the invention is to provide a batch composition prepared using carbonate-free raw materials for glass articles, enabling environmentally friendly production with reduced CO2emissions.

[0010] In order to achieve the above objective, the invention relates to a glass batch for glass articles. The glass batch comprises, in terms of weight ratio, a first raw material group containing 0- 65% SiO2,a second raw material group containing 5-60%, preferably 5-55%, more preferably 5-50% AI2O3, a third raw material group containing 0-13%, preferably 0-11 %, more preferably 0-9% CaO or CaCO3, a fourth raw material group containing 10^15% MgO, preferably 15- 45%, more preferably 20-45%, most preferably 10-25%, a fifth raw material group containing 0-20%, preferably 0-18%, more preferably 0-15% Na2CO3and / or 10-30%, preferably 10- 28%, more preferably 10-15% Na2O, or a combination thereof, and a sixth raw material group containing 0-5% B2O3. With the described batch, an environmentally friendly glass production is provided. Furthermore, CO2release of the batch is reduced down to 0%. This is particularly advantageous in terms of environmental impact.

[0011] In a preferred embodiment of the invention, the first raw material group containing SiO2is one selected from, or a combination of, sand, quartz, quartzite, quartz sand, and kaolin.

[0012] In a preferred embodiment of the invention, the weight ratio of the first raw material group containing SiO2is 10% to 65%. In a preferred embodiment of the invention, the weight ratio of CaCO3is 0%. Thus, if CaCO3is not directly used in glass-making furnaces, the release of environmentally harmful CO2gas by decomposition is also prevented.

[0013] In a preferred embodiment of the invention, the weight ratio of the third raw material group containing CaO is 0% to 12%.

[0014] In a preferred embodiment of the invention, the third raw material group containing CaO is one selected from, or a combination of, wollastonite, anorthite, diopside, fluorite, gypsum, ulexite, amphibole, datolite, gehlenite, laumontite, prehnite, plagioclase, ulexite, boracite, howlite, colemanite, calcium hydroxide, calcined lime.

[0015] In a preferred embodiment of the invention, the weight ratio of the fourth raw material group containing MgO is 21% to 44%. In this way, by the use of magnesium oxide, viscosity at high temperature is reduced and melting is facilitated.

[0016] In a preferred embodiment of the invention, the fourth raw material group containing MgO is one selected from, or a combination of, calcined Dolomitee, Dolomitee, calcined magnesite, enstatite, forsterite, sepiolite, serpentine, brucite, pyrope, magnesium mica, biotite, clinochlore, seybertite, chondrodite, chrysolite, tremolite, boracite, hydroboracite, inderite, and talc.

[0017] In a preferred embodiment of the invention, the weight ratio of the second raw material group containing AI2O3is 5% to 55%. In this way, by the use of AI2O3, hardness and chemical durability of the glass are increased.

[0018] In a preferred embodiment of the invention, the second raw material group containing AI2O3is one selected from, or a combination of, feldspar, nepheline, pumice, Bentonitee, Zeolitee, pyrophyllite, gibbsite, jadeite, albite, kyanite, kaolinite, muscovite, montmorillonite, halloysite, heulandite, margarite, stilbite, chabazite, labradorite, diaspore, sillimanite, zoisite, corundum, andalusite, topaz, bauxite, andesite, allophane.

[0019] In a preferred embodiment of the invention, the fifth raw material group contains, by weight up to a maximum of 25%, sodium carbonate (soda ash, Na2CO3), sodium hydroxide (NaOH), sodium chloride (NaCI), sodium metasilicate, sodium disilicate, cryolite, pectolite, natrolite, sodalite, analcite, gmelinite, plagioclase, sodium nitrate, or combinations thereof. Thus, the melting temperature (i.e., viscosity) of the glass is lowered. In a preferred embodiment of the invention, the Na2CO3 / (Na2CO3+NaOH+NaCI+NaNO3) ratio is 0% to 1 %. Since the production of sodium carbonate — or soda ash — (Na2CO3) requires energy-intensive processes, it is both costly and involves CO2emissions in its production / consumption cycle. Thus, reductions are achieved in direct and indirect CO2emissions associated with the consumption of Na2CO3. Accordingly, the lower the given ratio, the more the CO2emissions can be reduced in line with the given ratio.

[0020] In a preferred embodiment of the invention, the weight ratio of a seventh raw material group containing Fe2O3is 0% to 5%. In this way, production in colorless, green, and amber shades can be achieved.

[0021] In a preferred embodiment of the invention, the weight ratio of an eighth raw material group containing Cr2O3is 0% to 5%. In this way, production in colorless and green shades can be achieved.

[0022] In a preferred embodiment of the invention, the weight ratio of the fifth raw material group containing B2O3is 0% to 5%. Thus, chemical durability, coefficient of thermal expansion, and melting temperature of the glass can be controlled as desired.

[0023] In order to achieve the above objective, the invention further relates to a glass article obtained with the above batch, in particular a glass article selected from flat glass, window, plate, sheet, glass packaging, bottle, jar, household item, tableware, goblet, bowl, and beverage set.

[0024] DETAILED DESCRIPTION OF THE INVENTION

[0025] In this detailed description, the invention is explained by way of examples without any limitation and solely to better describe the subject matter.

[0026] A glass batch, in terms of weight ratio, is a glass batch wherein it comprises, by weight, a first raw material group containing 0-65% SiO2, a second raw material group containing 5-60% AI2O3, a third raw material group containing 0-13% CaO, a fourth raw material group containing 20-45% MgO, a fifth raw material group containing 0-20% Na2CO3and / or 10-30% Na2O, a sixth raw material group containing 0-5% Fe2O3, and a seventh raw material group containing 0-5% Cr2O3. In glass production, the raw materials are melted at temperatures between 1400-1600 °C. The energy provided in this process heats the incoming raw materials to their reaction temperatures and initiates the melting process. Depending on the composition of the raw materials, different components melt at different temperatures and through different mechanisms. For example, while cullet exhibits typical melting behavior, some substances such as sodium carbonate, potassium carbonate, calcium carbonate, carbonate and Dolomitee first decompose at temperatures below the melting point to form oxides. These oxides then dissolve in the melt. SiO2, with a melting temperature of 1723 °C, does not melt at furnace temperatures but dissolves in the melt by reacting with soda. In the initial region where the cold batch meets the hot furnace atmosphere, batch moisture evaporates and solid-state reactions begin at lower temperatures. As a result of these reactions, alkali / alkaline earth silicate complex components having eutectic points at low temperatures (Na2O-2SiO2and Na2Ca(CO3)2) are formed. In conventional soda-lime glass production, a typical sequence of reactions occurs in the batch as follows: As the batch heats up, residual water or moisture in the raw materials evaporates first. MgCO3decomposes at 365 °C into MgO and CO2. Then, within a certain temperature range, reactions take place among the components and the melting process begins. Between 630-780 °C, Na2CO3reacts with SiO2to form Na2O-SiO2and SiO2, releasing CO2. At this stage, SiO2also reacts with calcium carbonate, as it does with soda, to form CaO-SiO2. In addition, around 600 °C, sodium and calcium carbonates combine to form the compound Na2Ca(CO3)2. At 851 °C, Na2CO3melts and wets other raw materials. At this point, solid-state reactions accelerate. At 890 °C, calcium carbonate decomposes into CaO and CO2. At later stages, the resulting complex compounds melt around 1000-1100 °C and any SiO2not yet melted dissolves in this melt. Therefore, during the melting of these raw materials, a significant amount of carbon dioxide (approximately 0.2 kg CO2per 1 kg of glass produced) is released. Thus, by reducing the amount of sodium oxide (Na2O) in the molten phase, carbon dioxide emissions can be significantly reduced. In conventional soda-lime glass production, quartz is used as the source of SiO2, feldspar as the source of AI2O3, limestone (CaCO3) as the source of CaO, Dolomitee (CaMg(CO3)2) as the source of MgO, and soda ash (Na2CO3) as the source of Na2O. The present invention describes, as alternatives to these traditional raw materials, the use of certain proportions of natural / synthetic raw materials free of carbonates. As a detailed explanation of the description, without being limiting, the names of the second raw material group containing AI2O3, the third raw material group containing CaO, the fourth raw material group containing MgO, the fifth raw material group containing Na2O, and the sixth raw material group containing B2O3, and / or the minerals constituting them, that may be used in preparing the batch are given in Table 1 , and examples of the proportions of these materials that can be used in preparing the batch for glass production are given in Tables 2, 3, 4, 5, and 6. Table 1. Chemical structures usable in preparing the glass batch

[0027]

[0028] The use examples of some chemical structures given in Table 1 in the glass batch are presented for Na2O alternative raw materials in Table 2, for AI2O3raw materials in Table 3, for MgO raw materials in Table 4, for CaO raw materials in Table 5, and for B2O3raw materials in Table 6.

[0029] 5

[0030] Table 2. Example glass batches according to the invention (with alternative Na2O-containing raw materials)

[0031]

[0032] The tables above show the values of the materials used for the glass batch as percentage by weight. The examples in Table 2 show example batches obtained from raw materials that do not contain Na2CO3, CaO and / or CaCO3in the batch and that can be used as alternatives to

[0033] 5 Na2CO3.

[0034] In example 2.1 shown in Table 2, the glass batch contains, by percentage by weight, 12,11 % sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,80% calcined Dolomitee, 3,11 % calcined magnesite, 4,8% colemanite, 11 ,85% talc, 14,39% NaOH, 47,16% pyrophyllite, and 0,37% 10 sodium sulfate. Theoretical CO2release of the batch obtained with the given example is 0%, and water vapor release is 7, 12 g / 100 g glass.

[0035] In example 2.2 shown in Table 2, the glass batch contains, by percentage by weight, 11 ,37% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,44% calcined Dolomitee, 2,92% calcined 15 magnesite, 4,50% colemanite, 12,69% talc, 19,62% NaCI, 50,52% pyrophyllite, and 0,35% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 14,1 g / 100 g glass.

[0036] In example 2.3 shown in Table 2, the glass batch contains, by percentage by weight, 0% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,91 % calcined Dolomitee, 3,13% calcined magnesite, 4,87% 20 colemanite, 12,03% talc, 7,89% NaOH, 16,07% NaSi (Mod 2), 49,30% pyrophyllite, and 0,38% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 5,53 g / 100 g glass.

[0037] In example 2.4 shown in Table 2, the glass batch contains, by percentage by weight, 0% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,90% calcined Dolomitee, 3,12% calcined magnesite, 4,85% 25 colemanite, 11 ,96% talc, 10,16% NaOH, 14,10% NaSi (Mod 3), 52,10% pyrophyllite, and 0,40% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 6,09 g / 100 g glass. In example 2.5 shown in Table 2, the glass batch contains, by percentage by weight, 0% sand, 15,58% Na2CO3, 0% CaO, 0% CaCO3, 3,27% calcined Dolomitee, 53,10% feldspar, 27,27% talc, and 0,36% sodium sulfate. Theoretical CO2release is 7,1 1 %, and water vapor release is 1 ,57 g / 100 g glass.

[0038] 5

[0039] Table 3. Example glass batches according to the invention (with alternative AI2O3-containing raw materials)

[0040] The tables above show the values of the materials used for the glass batch as percentage by weight. The examples in Table 3 show example batches obtained from raw materials that do not contain Na2CO3, CaO and / or CaCO3in the batch and that can be used as alternative AI2O35 sources.

[0041] In example 3.1 shown in Table 3, the glass batch contains, by percentage by weight, 28,5% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 43,5% feldspar, 5,48% calcined Dolomitee, 7,27% calcined magnesite, 4,93% colemanite, 9,45% NaOH, and 0,38% sodium sulfate. Theoretical

[0042] 10 CO2release is 0%, and water vapor release is 4,29 g / 100 g glass.

[0043] In example 3.2 shown in Table 3, the glass batch contains, by percentage by weight, 58,34% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 9,47% gibbsite, 5,58% calcined Dolomitee, 6,79% calcined magnesite, 4,70% colemanite, 14,03% NaOH, and 0,38% sodium sulfate. Theoretical

[0044] 15 CO2release is 0%, and water vapor release is 9,34 g / 100 g glass.

[0045] In example 3.3 shown in Table 3, the glass batch contains, by percentage by weight, 20,81 % sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 46,24% pyrophyllite, 5,88% calcined Dolomitee, 6,89% calcined magnesite, 4,92% colemanite, 14,47% NaOH, and 0,38% sodium sulfate. Theoretical 20 CO2release is 0%, and water vapor release is 6,45 g / 100 g glass.

[0046] In example 3.4 shown in Table 3, the glass batch contains, by percentage by weight, 26,32% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 38,74% feldspar, 6,88% pumice, 5,43% calcined Dolomitee, 7,25% calcined magnesite, 4,91 % colemanite, 9,62% NaOH, and 0,38% sodium 25 sulfate. Theoretical CO2release is 0%, and water vapor release is 4,52 g / 100 g glass.

[0047] In example 3.5 shown in Table 3, the glass batch contains, by percentage by weight, 29,96% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 39,92% feldspar, 5,08% zeolite, 5,15% calcined Dolomitee, 7,30% calcined magnesite, 4,92% colemanite, 9,84% NaOH, and 0,38% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 4,37 g / 100 g glass.

[0048] In example 3.6 shown in Table 3, the glass batch contains, by percentage by weight, 28,48% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 41,31% feldspar, 2,22% bentonite, 4,35% calcined Dolomitee, 7,25% calcined magnesite, 4,92% colemanite, 9,63% NaOH, and 0,38% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 4,4g / 100 g glass.

[0049] Table 4. Example glass batches according to the invention (with alternative MgO-containing raw materials)

[0050] The tables above show the values of the materials used for the glass batch as percentage by weight. The examples in Table 4 show example batches obtained from raw materials that do not contain Na2CO3, CaO and / or CaCO3in the batch and that can be used as alternatives to MgCO3.

[0051] In example 4.1 shown in Table 4, the glass batch contains, by percentage by weight, 20,82% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,89% calcined dolomite, 6,9% calcined magnesite, 4,83% colemanite, 46,26% pyrophyllite, 14,43% NaOH, and 0,38% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 6,42 g / 100 g glass.

[0052] In example 4.2 shown in Table 4, the glass batch contains, by percentage by weight, 20,76% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 3,78% calcined lime, 5,9% calcined magnesite, 4,83% colemanite, 14,44% NaOH, 46,33% pyrophyllite, and 0,38% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 6,40 g / 100 g glass.

[0053] In example 4.3 shown in Table 4, the glass batch contains, by percentage by weight, 12,16% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,8% calcined dolomite, 3,11 % calcined magnesite, 7,8% colemanite, 11 ,85% talc, 14,39% NaOH, 47,12% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 7,12 g / 100 g glass.

[0054] In example 4.4 shown in Table 4, the glass batch contains, by percentage by weight, 0% sand, 15,34% Na2CO3, 0% CaO, 0% CaCO3, 6,25% dolomite, 25% talc, and 0,13% sodium sulfate. Theoretical CO2release is 10,43%, and water vapor release is 2, 19 g / 100 g glass.

[0055] Table 5. Example glass batches according to the invention (with alternative CaO-containing raw materials)

[0056] The tables above show the values of the materials used for the glass batch as percentage by weight. The examples in Table 5 show example batches obtained from raw materials that do not contain Na2CO3, CaO and / or CaCO3in the batch and that can be used as alternatives to CaO.

[0057] In example 5.1 shown in Table 5, the glass batch contains, by percentage by weight, 10,4% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 8,87% wollastonite, 0,85% calcined dolomite, 4,86% calcined magnesite, 11 ,98% talc, 14,54% NaOH, 47,16% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 5,91 g / 100g glass.

[0058] In example 5.2 shown in Table 5, the glass batch contains, by percentage by weight, 12,11% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 4,8% colemanite, 5,80% calcined dolomite, 3,11% calcined magnesite, 11 ,85% talc, 14,39% NaOH, 47,16% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 7,12g / 100g glass.

[0059] In example 5.3 shown in Table 5, the glass batch contains, by percentage by weight, 13,02% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 9% anorthite, 5,04% calcined dolomite, 3,55% calcined magnesite, 11 ,02% talc, 14,60% NaOH, 28,43% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 5,51 g / 100g glass.

[0060] In example 5.4 shown in Table 5, the glass batch contains, by percentage by weight, 15,04% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 3% ulexite, 6,86% calcined dolomite, 2,81% calcined magnesite, 11 ,92% talc, 13,95% NaOH, 45,58% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 6,38 g / 100 g glass.

[0061] Table 6. Example glass batches according to the invention (with alternative B2O3-containing raw materials) The tables above show the values of the materials used for the glass batch as percentage by weight. The examples in Table 6 show example batches obtained from raw materials that do not contain Na2CO3, CaO and / or CaCO3in the batch and that can be used as alternatives to B2O3.

[0062] In example 6.1 shown in Table 6, the glass batch contains, by percentage by weight, 12,11 % sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 5,80% calcined dolomite, 3,1 1 % calcined magnesite, 4,8% colemanite, 11 ,85% talc, 14,39% NaOH, 47,16% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 7,12 g / 100 g glass.

[0063] In example 6.2 shown in Table 6, the glass batch contains, by percentage by weight, 13,82% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 6,04% calcined dolomite, 3,1 1 % calcined magnesite, 3,83% borax, 1 1 ,85% talc, 13,30% NaOH, 46,84% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 6,65 g / 100 g glass.

[0064] In example 6.3 shown in Table 6, the glass batch contains, by percentage by weight, 13,83% sand, 0% Na2CO3, 0% CaO, 0% CaCO3, 6,04% calcined dolomite, 3,1 1 % calcined magnesite, 3,30% boric acid, 1 1 ,85% talc, 14,39% NaOH, 46,83% pyrophyllite, and 0,37% sodium sulfate. Theoretical CO2release is 0%, and water vapor release is 7,25 g / 100 g glass.

[0065] In the reference soda-lime silicate glass batch given as examples in Tables 2, 3, 4, 5, and 6, the batch contains, by percentage by weight, 57±5% sand, 20±5% Na2CO3, 8±2% CaCO3, 10±2% dolomite, 4±2% feldspar, and 1 ±0,5% sodium sulfate. The theoretical CO2release of the batch obtained with the given reference example is 20±2 g / 100 g glass. In the examples given in Tables 2, 3, 4, 5, and 6 according to the invention, by eliminating the use of CaCO3and by eliminating or reducing the use of Na2CO3compared to the reference case, and preferably by the use of natural carbonate-free raw materials, the CO2release originating from decomposition has been reduced or eliminated.

[0066] With the said raw material mixtures, glasses can be obtained having chemical compositions by weight of 60±10% SiO2, 10±5% AI2O3, 10±5% MgO, 12±7% Na2O, 4±4% CaO, and 2±2% B2O3.

Claims

CLAIMS1. A glass batch for a glass article, characterized in that, by weight ratio, comprising a first raw material group containing 0-65% SiO2; a second raw material group containing 5-60%, preferably 5-55%, more preferably 5-50% AI2O3; a third raw material group containing 0-13%, preferably 0-11 %, more preferably 0- 9% CaO or CaCO3; a fourth raw material group containing 10—45%, preferably 15-45%, more preferably 10-25% MgO; a fifth raw material group containing 0-20%, preferably 0-18%, more preferably 0- 15% Na2CO3and / or 10-30%, preferably 10-28%, more preferably 10-15% Na2O, or a combination thereof; and a sixth raw material group containing 0-5% B2O3.

2. The batch according to claim 1 , wherein the first raw material group containing SiO2is selected from, one or a combination of sand, quartz, quartzite, quartz sand, and kaolin.

3. The batch according to any one of the preceding claims, wherein the weight ratio of the first raw material group containing SiO2is 10% to 65%.

4. The batch according to any one of the preceding claims, wherein the weight ratio of CaCO3is 0%.

5. The batch according to any one of the preceding claims, wherein the weight ratio of the third raw material group containing CaO is 0% to 12%.

6. The batch according to claim 4, wherein the third raw material group is containing CaO which is selected from, one or a combination of, wollastonite, anorthite, diopside, fluorite, gypsum, ulexite, amphibole, datolite, gehlenite, laumontite, prehnite, ulexite, boracite, howlite, and colemanite.

7. The batch according to any one of the preceding claims, wherein the weight ratio of the fourth raw material group containing MgO is 21 % to 44%.

8. The batch according to claim 6, wherein the fourth raw material group containing MgO is one selected from, or a combination of, calcined dolomite, calcined magnesite, enstatite, forsterite, sepiolite, serpentine, brucite, pyrope, magnesium mica, biotite, clinochlore, seybertite, chondrodite, enstatite, chrysolite, tremolite, brucite, boracite, hydroboracite, inderite, and talc.

9. The batch according to any one of the preceding claims, wherein the second raw material group containing AI2O3is one selected from, or a combination of, feldspar, nepheline, pumice, bentonite, zeolite, pyrophyllite, gibbsite, jadeite, albite, kyanite, kaolinite, muscovite, montmorillonite, halloysite, heulandite, margarite, stilbite, chabazite, labradorite, diaspore, sillimanite, zoisite, corundum, andalusite, topaz, bauxite, andesite, and allophane.

10. The batch according to any one of the preceding claims, wherein the fifth raw material group contains up to 25% by weight of Na2CO3, NaOH, NaCI, cryolite, pectolite, natrolite, sodalite, analcite, gmelinite, sodium metasilicate, sodium disilicate, plagioclase, sodium nitrate, or combinations thereof.

11. The batch according to claim 10, wherein the Na2CO3 / (Na2CO3+NaOH+NaCI+NaNO3) ratio is between 0% and 1 %.

12. The batch according to any one of the preceding claims, wherein the weight ratio of a seventh raw material group containing Fe2O3is 0% to 5%.

13. The batch according to any one of the preceding claims, wherein the weight ratio of an eighth raw material group containing Cr2O3is 0% to 5%.

14. The batch according to any one of the preceding claims, wherein the weight ratio of a sixth raw material group containing B2O3is 0% to 4.5%.

15. A glass article obtained with a batch according to any one of the preceding claims, in particular a glass article selected from the group consisting of flat, plate, hollow, corrugated, flat glass, glass packaging, window, plate, sheet, bottle jar, household item, tumbler, goblet, container, and vase.

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