NL2019780B1

NL2019780B1 - Binding composition for a ceramic glaze, glaze composition, glazing method and ceramic material

Info

Publication number: NL2019780B1
Application number: NL2019780A
Authority: NL
Inventors: Biryukova Daria
Original assignee: Mineralz B V
Priority date: 2017-10-23
Filing date: 2017-10-23
Publication date: 2019-04-29

Abstract

The present invention relates to a binding composition for a ceramic glaze comprising a binding agent, wherein the binding agent comprises a glass powder, and wherein the glass powder having a particle size of less than 1 millimetre and/or the binding composition further comprises a silicate mineral. The present invention further relates to a glaze composition comprising the binding composition of the present invention, optionally comprising a raw material, such as bottom ash, as well as a ceramic material coated with the glaze composition of the present invention. The present invention further relates to a method of glazing a ceramic material, ceramic glaze obtainable by such method and a ceramic material. The present invention further relates to the use of the binding composition in the manufacturing of glazed ceramic materials.

Description

Binding composition for a ceramic glaze, glaze composition, glazing method and ceramic material

The present invention relates to a binding composition for a ceramic glaze, a glaze composition comprising the binding composition of the present invention as well as a ceramic material coated with the glaze composition of the present invention. The present invention further relates to a method of glazing a ceramic material, ceramic glaze obtainable by such method and a ceramic material. The present invention further relates to the use of the binding composition in the manufacturing of glazed ceramic materials.

Ceramic glaze is an impervious layer or coating of a vitreous substance which has been fused to a ceramic body through firing. Glaze can serve to colour, decorate or waterproof an item. Glazing renders earthenware vessels suitable for holding liquids, sealing the inherent porosity of unglazed biscuit earthenware. It also gives a tougher surface. In addition to their functionality, glazes can form a variety of surface finishes, including degrees of glossy or matte finish and colour.

The application of ceramic glaze is not only restricted to pottery. A well-known application of glaze is the glazing of tiles. But also building material, such as glazed bricks, are well-known in the art.

Glazes need to include a ceramic flux which functions by promoting partial liquefaction in the clay bodies and the other glaze materials. Fluxes lower the high melting point of the glass formers silica, and sometimes boron trioxide. These glass former may be included in the glaze materials, or may be drawn from the clay beneath.

Raw materials of ceramic glazes generally include silica, which will be the main glass former. Various metal oxides, such as sodium, potassium and calcium, act as a flux to lower the melting temperature. Alumina, often derived from clay, stiffens the molten glaze to prevent it from running off the piece. Colorants, such as iron oxide, copper carbonate or cobalt carbonate, and sometimes opacifiers such as tin oxide or zirconium oxide, are used to modify the visual appearance of the fired glaze.

An important ingredient of ceramic glaze compositions is frit. Frit is a ceramic composition that has been fused in a special fusing oven, quenched to form a glass, and granulated. It is believed that frits are indispensable constituents of most industrial ceramic glazes which mature at temperatures below 1 lOO'C.

Certain frits can be added to high-tech ceramics. Such frits are made by milling zinc oxide (ZnO) and boric acid (H3BO3) with zirconium (Zr) beads and heating this mixture to 1100°C. Subsequently, the mixture is quenched and grinded. The frit obtained is then added to a lithium titanate (Li2Ti03) ceramic powder, which enables the ceramic to sinter at a lower temperature while still keeping its microwave dielectric properties.

The present invention now provides, in a first aspect of the invention, a binding composition for a ceramic glaze comprising a binding agent, wherein the binding agent comprises a glass powder and wherein the glass powder having a particle size of less than 1 millimetre and/or the binding composition further comprises a silicate mineral. It was found that by providing the binding composition of the present invention, ceramic glaze composition can be produced substantially free of frit. The binding composition of the present invention facilitates the method of glazing a ceramic material at any temperature.

The binding composition of the present invention comprises a glass powder, such as powdered glass or cullet, with or without the presence of a silicate mineral. The preferred amount of glass powder having a particle size of less than 1 millimetre is at least 50% by weight of the total weight of glass powder present in the composition. It was found that by providing a binding composition comprising a glass powder, wherein the glass powder has a particle size of less than 1 millimetre is at least 50% by weight of the total weight of the glass powder present in the composition, glaze compositions can be formed suitable for use in a method of glazing a ceramic material at any temperature. In such embodiment, the presence of a silicate mineral in the binding composition is optional.

It was further found that, irrespective the presence of a silicate mineral, by increasing the amount of glass powder having a particle size of less than 1 millimetre in the binding composition, the properties and product characteristics of the glazed ceramic material to be obtained are further improved. Therefore, preferred amounts of glass powder having a particle size of less than 1 millimetre include at least 60%, at least 70%, at least 80%, at least 90% by weight of the total weight of the glass powder present in the binding composition. Preferably, the amount of glass powder having a particle size of less than 1 millimetre is about 100% by weight of the total weight of the glass powder present in the binding composition.

The binding composition of the present invention may comprise a binding agent, said binding agent comprising a glass powder and a silicate mineral. It was found that, irrespective the properties (such as particle size) of the glass powder, the combination of a glass powder and a silicate mineral provides a binding composition suitable for use in a method of glazing a ceramic material at any temperature. Although not considered necessary, the particle size of the glass powder as defined above may play a role in further improving the product characteristics and properties of the glazed product to be obtained.

The silicate mineral suitable for use in the binding composition of the present invention may be selected from the group consisting inosilicates, tectosilicates and combinations thereof. Preferred inosilicates include single chain inosilicates, such as pyroxenes and pyroxenoids. Preferred tectosilicates include feldspathoids, zircons and feldspars. It was found that the use of inosilicates and tectosilicates is preferred in order to avoid the formation of bubbles in the glaze to be obtained. Also, by using a silicate mineral selected from the group consisting inosilicates, tectosilicates and combinations thereof, surface smoothness was further improved. Other mineral silicates, e.g. phyllosilicates, may result in a glaze having a bubbled, and rough surface.

Preferred silicate minerals include, but are not limited to, spodumene (UAISÏ206), wollastonite (CaSi03), petalite (LiAISi40io), nephelite (Na3KAI4Si40i6), zirconium silicate (ZrSi04), alkali feldspars and combinations thereof. It was found that the use of a silicate mineral comprising spodumene, petalite, nephelite and/or alkali feldspars is preferred.

The binding composition of the present invention may further comprise a whitening agent. Whitening agents are well-known in the art. Preferably the whitening agent is selected from the group consisting of metakaolin, kaolin and combinations thereof. For example, the metakaolin used in the binding composition of the present invention may be obtained from paper sludge as a residue from the paper recycling process.

In a second aspect of the invention, the present invention provides a glaze composition comprising the binding composition of the present invention. It was found that the glaze composition comprising the binding composition of the present invention is suitable for use in a method of glazing a ceramic material at any temperature.

In case a whitening agent is present in the binding composition or added during the formulation of the glaze composition, the whitening agent is preferably present in an amount up to 15% by weight of the total weight of the glaze composition. It was found that by increasing the amount of whitening agent, calcium carbonate in particular, gas formation during the setting of the ceramic glaze was observed resulting in a bubbled and/or rough surface.

The glaze composition of the present invention may comprise a raw material. Typically, raw materials include clay minerals, aggregates, such as sand, flint and dolomite. Preferably, the raw material comprises a waste material, in particular silicate based wastes such as: coal ash, slag, fly-ash and waste from incinerators.

In a preferred embodiment of the present invention the waste material is selected from the group consisting of bottom ash, bio-ash and combinations thereof. Bottom ash is part of the non-combustible residue of combustion in a furnace or incinerator. Bio-ash is the residue after incineration of biological waste, such as trees and plants. The raw material used in the glaze composition of the present invention may be subjected to a pre-treatment before application into the glaze composition. Such pre-treatment step may include a washing step to obtained a treated, non-polluted, clean raw material.

The waste material, such as bottom ash, may be present in an amount up to 40% by weight of the total weight of the glaze composition. It was found that at high temperatures (i.e. firing temperatures of at least 1100QC) a ceramic glaze can be obtained having good surface characteristics. An increased amount of the waste material, e.g. more than 40% by weight of bottom ash, resulted in ceramic glazes having a non-glossy, low transparent and high pigmented surface.

As already mentioned above, by using the binding composition of the present invention in formulating a glaze composition, the glaze composition may be substantially free of frit. It was found that by using waste material, such as bottom ash or bio-ash, the glaze composition may be substantially free of frit to obtain industrial applicable ceramic glazes. In particular, the use of frit is purely optional in case high temperatures (i.e. firing temperatures of at least 1100SC) are used in setting the ceramic glaze with the glaze composition of the present invention. One could opt, however, to use frit in order to provide a glaze having further improved properties or alternative product characteristics.

It was further found that the preferred amount of glass powder in waste material comprising glaze compositions is at least 40% by weight of the total weight of the glaze composition. It was found that by using high temperatures (i.e. firing temperatures of at least 1100eC), waste material comprising glaze compositions, bottom ash glaze composition in particular, comprising at least 40% by weight of glass powder resulted in high quality of ceramic glazes. Preferably the glass powder may be present in an amount up to 80% by weight of the total weight of the glaze composition. Optimal results are obtained by using a waste material comprising glaze composition having a glass powder amount of about 60% by weight of the total weight of the glaze composition.

In case low temperatures (i.e. firing temperatures up to 11009C) are used during the method of forming the glaze using a glaze composition comprising a waste material, such as bottom ash, good results are obtained in case the waste material is present in an amount up to 20% by weight of the total weight of the glaze composition. In order to further increase the product characteristics of the ceramic glaze to be formed, the waste material comprising glaze composition may preferably comprise a ceramic flux, such as frit or zinc borate (Boroflux). In an even preferred embodiment, the waste material comprising glaze composition the ceramic flux agent may be present in an amount up to 50% by weight of the total weight of the glaze composition. It was found that in case low temperatures are used, the waste materials, such as bottom ash, negatively affected the product properties of the ceramic glaze to be obtained. In order to compensate any negative effect of the, in particular relevant, surface characteristics of the ceramic glaze, the use of a ceramic flux, such as frit or zinc borate, is preferred.

It was further found that at low temperatures (i.e. firing temperatures up to 1100SC) the amount of glass powder present in the glaze composition is subject to any limitation. It was found that in case the glass powder is present in an amount of more than 40% by weight of the total weight of the glaze composition the obtained ceramic glaze showed craquelure and bubbles. Therefore, to avoid any craquelure and/or bubbles in the ceramic glaze, the waste material comprising glaze composition comprises glass powder preferably present in an amount up to 40% by weight of the total weight of the glaze composition. Such waste material comprising glaze composition is suitable for glaze forming methods using firing temperatures up to 1100SC.

In case binding compositions are used comprising a combination of a glass powder and a silicate mineral in formulating a glaze composition, the silicate mineral may be present in an any amount. Preferably, the silicate mineral is present in an amount up to 70% by weight of the total weight of the glaze composition. It was further found that in order to obtain similar ceramic glaze results, the percentage of silicate mineral present in the glaze composition may vary per temperature range.

At high temperatures (i.e. firing temperatures of at least 1100QC) the percentage of silicate mineral present in the glaze composition may vary 0 and 40% by weight of the total weight of the glaze composition. At such temperatures, the glaze composition preferably comprises a silicate mineral present in an amount of 5-30% by weight of the total weight of the glaze composition, preferably 10-20% by weight.

At low temperatures (i.e. firing temperatures up to 1100QC) the amount of silicate minera! present in the glaze composition is preferably at least 40% by weight of the total weight of the glaze composition. Particular good results are obtained using a glaze composition comprising silicate mineral present in an amount of 50-80% by weight of the total weight of the glaze composition, preferably 60-70% by weight.

In a third aspect of the invention, the present invention provides a method of glazing a ceramic material. The present invention provides a high temperature method and a low temperature method. The high temperature method comprises the steps of: a) providing a glaze composition of the present invention; b) providing a ceramic material; c) coating the ceramic material with the glaze composition; and d) fusing the coating of glaze composition to the ceramic material by firing, wherein the temperature in step d) is at least 1100SC, preferably at least 1150QC, more preferably at least 1200QC. It was found that such method can be applied to all types of glaze compositions, either or not including waste materials, such as bottom ash. Preferred temperatures to be applied in step d) include a temperature of 1100-1300SC, preferably 1150-1250QC, more preferably 1200-1230eC.

Optionally, different temperatures may be applied in step d), e.g. a first temperature of about 1150QC followed by a second temperature of about 1200SC.

It is further noted that in case no waste material, such as bottom ash, is present in the glaze composition of the present invention, the temperature restriction defined above is no longer of relevance. In such case a low temperature method may be used.

The low temperature method comprises the steps of: a) providing a waste mineral comprising glaze composition; b) providing a ceramic material; c) coating the ceramic material with the glaze composition; and d) fusing the coating of glaze composition to the ceramic material by firing, wherein the temperature in step d) is up to 1100QC, preferably up to 10509C. Preferably, the temperature in step d) is 700-1100-C, preferably 850-1080QC, more preferably 1000-1060eC.

In a fourth aspect of the invention, the present invention provides a ceramic glaze obtainable by the above methods. The ceramic glaze obtained by the methods defined above have good surface properties.

In a fifth aspect of the invention, the present invention provides a ceramic material comprising a ceramic body glazed with the ceramic glaze of the present invention. The ceramic body comprises a material which may be selected from the group consisting of earthenware, stoneware, porcelain, tiles, building materials, such as bricks, and combinations thereof.

The ceramic body may comprise a raw material, such as a waste material including coal ash, slag, fly-ash and waste from incinerators. The waste material is preferably selected from the group consisting of bottom ash, bio-ash and combinations thereof. The ceramic body of the ceramic material of the present invention may comprise bottom ash and/or bio-ash in an amount of 20-50% by weight of the total weight of the ceramic body.

In a sixth aspect of the invention, the present invention provides the use of the binding composition of the present invention in the manufacturing of glazed ceramic materials.

Examples

Different glaze compositions were tested in preparing ceramic glazed tiles (5 by 10 centimetre) made of fine stoneware material. The glaze compositions were applied to the tiles using different firing temperatures: 1200QC (high temperature) and 1080SC (low temperature).

Table 1. Ceramic glaze compositions fired at high temperature

Given the results provided in table 1 it was found that glaze compositions A and B comprising more than 40 weight-% of bottom ash did not resulted in a ceramic product having low transparent, high pigmented and rough surface. By lowering the

amount of bottom ash to an amount of up to 40 weight-% (compositions C-l), positive results were obtained.

The silicate mineral used in compositions D-l was petalite optionally in combination with another silicate mineral including alkali feldspar (compositions E, H and I) and nephelite (compositions G and H).

Additionally, different types of glass powder, i.e. glass powder with a particle size of less than 1 millimetre and glass powder with a particle size of at least 1 millimetre, were tested. The results are provided in table 2 showing that the glass powder having a particle size of at least 1 millimetre resulted in an unwanted bubbled and porous surface.

Table 2. Comparing different types of glass powder

Also, different types of silicate minerals were tested (table 3) selected from inosilicates (spodumene and wollastonite), phyllosilicates (bentonite and talc) and tectosilicates (petalite, zirconium silicate and alkali feldspar).

Table 3. Comparing different types of silicate minerals

Given the results provided in table 3, it was found that silicate minerals selected from the group of phyllosilicates did not result in industrial applicable glazed ceramic tiles. The surface of the glaze ceramic tiles obtained by using phyllosilicates was bubbled and porous.

It was further found that by increasing the amount of suitable silicate minerals, e.g. spodumene (compositions M and N) and petalite (compositions R and s), sufficiently improved the glossiness of the surface of the glazed ceramic tile.

The applicability of above compositions at low firing temperatures was tested. The results are provided in table 4. It was found that the glaze compositions provided in table 4 did not result in industrial applicable glaze compositions. It is noted that composition V corresponds with composition N (table 3), composition W corresponds with composition S (table 3) and composition X corresponds to composition L (table 2).

Table 4. Ceramic glaze compositions fired at low temperature

Given the results provided in table 5, it was found that by providing glaze composition wherein the amount of glass powder is 40 weight-% or less (compositions AA and BB) or, in case bottom ash is present, up to 50 weight-% frit is present (composition DD) in the glaze composition, such glaze compositions

resulted in glazed ceramic tiles having a positive water resistance test score and a surface which is not bubbled or has craquelure.

Compositions CC, FF and GG did not result in industrial applicable glazed ceramic tiles due to the high amount (40 weight-%) of glass powder. Composition EE did not result in industrial applicable glazed ceramic tiles due to the high amount (70 weight-%) of frit.

Table 5. Ceramic glaze compositions fired at low temperature

Claims

1. Bindingssamenstelling voor een keramisch glazuur omvattende een bindmiddel, waarbij het bindmiddel een glaspoeder omvat, met het kenmerk dat het glaspoeder een deeltjesgrootte heeft van kleiner dan 1 millimeter en/of de bindingssamenstelling verder een silicaatmineraal omvat.A ceramic glaze binding composition comprising a binder, the binder comprising a glass powder, characterized in that the glass powder has a particle size of less than 1 millimeter and / or the binding composition further comprises a silicate mineral.

2. Bindingssamenstelling volgens conclusie 1, met het kenmerk dat de hoeveelheid glaspoeder met een deeltjesgrootte kleiner dan 1 millimeter ten minste 50 gewichtsprocent is van het totale gewicht aan in de samenstelling aanwezig glaspoeder.Binding composition according to claim 1, characterized in that the amount of glass powder with a particle size of less than 1 millimeter is at least 50% by weight of the total weight of glass powder present in the composition.

3. Bindingssamenstelling volgens conclusie 1 of 2, met het kenmerk dat het silicaatmineraal is gekozen uit de groep bestaande uit inosilicaten, tectosilicaten en combinaties daarvan.A binding composition according to claim 1 or 2, characterized in that the silicate mineral is selected from the group consisting of inosilicates, tectosilicates and combinations thereof.

4. Bindingssamenstelling volgens één van de voorgaande conclusies, met het kenmerk dat het silicaatmineraal is gekozen uit de groep bestaande uit inosilicaten met enkele keten, bij voorkeur pyroxenen en pyroxenoïden, veldspatoïden, zirconen, veldspaten en combinaties daarvan.Binding composition according to one of the preceding claims, characterized in that the silicate mineral is selected from the group consisting of single-chain inosilicates, preferably pyroxenes and pyroxenoids, field spatoids, zircones, feldspars and combinations thereof.

5. Bindingssamenstelling volgens één van de voorgaande conclusies, met het kenmerk dat het silicaatmineraal spodumeen (LiAISi206), wollastoniet (CaSiOs), petaliet (LiAISi40io), nefeliet (Na3Kal4Si40i6), zirconiumsilicaat (ZrSiCU), alkaliveldspaten en combinaties daarvan omvat.Binding composition according to one of the preceding claims, characterized in that it comprises silicate mineral spodumene (LiAISi206), wollastonite (CaSiOs), petalite (LiAISi40io), nephelite (Na3Kal4Si40i6), zirconium silicate (ZrSiCU), and alkalivial split.

6. Bindingssamenstelling volgens één van de voorgaande conclusies, met het kenmerk dat het silicaatmineraal spodumeen, petaliet, nefeliet en/of alkaliveldspaten omvat.A binding composition according to any one of the preceding claims, characterized in that the silicate mineral comprises spodumene, petalite, nephelite and / or alkali field splits.

7. Bindingssamenstelling volgens één van de voorgaande conclusies, met het kenmerk dat de bindingssamenstelling verder een witmaker omvat, gekozen uit de groep bestaande uit metakaolien, kaolien en combinaties daarvan.The binding composition according to any of the preceding claims, characterized in that the binding composition further comprises a whitener selected from the group consisting of metakaolin, kaolin and combinations thereof.

8. Glazuursamenstelling omvattende de bindingssamenstelling volgens één van de voorgaande conclusies.A glaze composition comprising the binding composition according to any one of the preceding claims.

9. Glazuursamenstelling volgens conclusie 8, met het kenmerk dat de glazuursamenstelling een grondstof, zoals een afvalmateriaal omvat.Glaze composition according to claim 8, characterized in that the glaze composition comprises a raw material, such as a waste material.

10. Glazuursamenstelling volgens conclusie 9, met het kenmerk dat het afvalmateriaal is gekozen uit de groep bestaande uit bodemas, bioas en combinaties daarvan.The glaze composition according to claim 9, characterized in that the waste material is selected from the group consisting of bottom ash, bio ash and combinations thereof.

11. Glazuursamenstelling volgens één van de conclusies 8 tot en met 10, met het kenmerk dat de witmaker aanwezig is in een hoeveelheid tot 15 gewichtsprocent van het totale gewicht van de glazuursamenstelling.Glaze composition according to any of claims 8 to 10, characterized in that the whitener is present in an amount of up to 15% by weight of the total weight of the glaze composition.

12. Glazuursamenstelling volgens één van de conclusies 9 tot en met 11, met het kenmerk dat het afvalmateriaal aanwezig is in een hoeveelheid tot 40 gewichtsprocent van het totale gewicht van de glazuursamenstelling.Glaze composition according to one of claims 9 to 11, characterized in that the waste material is present in an amount of up to 40% by weight of the total weight of the glaze composition.

13. Glazuursamenstelling volgens één van de conclusies 8 tot en met 12, met het kenmerk dat de glazuursamenstelling in hoofdzaak vrij is van fritte.Glaze composition according to one of claims 8 to 12, characterized in that the glaze composition is substantially free of frits.

14. Glazuursamenstelling volgens één van de conclusies 8 tot en met 13, met het kenmerk dat de hoeveelheid glaspoeder ten minste 40 gewichtsprocent van het totale gewicht van de glazuursamenstelling is.Glaze composition according to any of claims 8 to 13, characterized in that the amount of glass powder is at least 40% by weight of the total weight of the glaze composition.

15. Glazuursamenstelling volgens één van de conclusies 9 tot en met 11, met het kenmerk dat het afvalmateriaal aanwezig is in een hoeveelheid tot 20 gewichtsprocent van het totale gewicht van de glazuursamenstelling.Glaze composition according to any of claims 9 to 11, characterized in that the waste material is present in an amount of up to 20% by weight of the total weight of the glaze composition.

16. Glazuursamenstelling volgens conclusie 15, met het kenmerk dat de glazuursamenstelling een keramisch smeltmiddel, zoals fritte of zinkboraat omvat.16. Glaze composition according to claim 15, characterized in that the glaze composition comprises a ceramic melting agent, such as frit or zinc borate.

17. Glazuursamenstelling volgens conclusie 15 of 16, met het kenmerk dat het glaspoeder aanwezig is in een hoeveelheid tot 40 gewichtsprocent van het totale gewicht van de glazuursamenstelling.17. Glaze composition according to claim 15 or 16, characterized in that the glass powder is present in an amount of up to 40% by weight of the total weight of the glaze composition.

18. Werkwijze voor het glazuren van een keramisch materiaal, waarbij de werkwijze de stappen omvat: a) het verschaffen van de glazuursamenstelling volgens één van de conclusies 12 tot en met 17; b) het verschaffen van een keramisch materiaal; c) het bedekken van het keramische materiaal met de glazuursamenstelling; en d) het smelten van de deklaag van de glazuursamenstelling op het keramische materiaal door middel van stoken, waarbij de temperatuur bij stap d) ten minste 1100-C, bij voorkeur ten minste 1150QC, met grotere voorkeur ten minste 1200SC is.A method of glazing a ceramic material, the method comprising the steps of: a) providing the glaze composition of any one of claims 12 to 17; b) providing a ceramic material; c) covering the ceramic material with the glaze composition; and d) melting the coating of the glaze composition on the ceramic material by firing, wherein the temperature in step d) is at least 1100 ° C, preferably at least 1150 ° C, more preferably at least 1200SC.

19. Werkwijze volgens conclusie 18, met het kenmerk dat de temperatuur bij stap d) 1100-1300eC, bij voorkeur 1150-1250QC, met grotere voorkeur 1200-1230eC is.A method according to claim 18, characterized in that the temperature in step d) is 1100-1300 ° C, preferably 1150-1250 ° C, more preferably 1200-1230 ° C.

20. Werkwijze voor het glazuren van een keramisch materiaal, waarbij de werkwijze de stappen omvat: a) het verschaffen van de glazuursamenstelling volgens één van de conclusies 15 tot en met 17; b) het verschaffen van een keramisch materiaal; c) het bedekken van het keramische materiaal met de glazuursamenstelling; en d) het smelten van de deklaag van de glazuursamenstelling op het keramische materiaal door stoken, waarbij de temperatuur bij stap d) tot 1100SC, bij voorkeur tot 1050eC bedraagt.A method for glazing a ceramic material, the method comprising the steps of: a) providing the glaze composition of any one of claims 15 to 17; b) providing a ceramic material; c) covering the ceramic material with the glaze composition; and d) melting the coating of the glaze composition on the ceramic material by firing, wherein the temperature in step d) is up to 1100SC, preferably up to 1050 ° C.

21. Werkwijze volgens conclusie 20, met het kenmerk dat de temperatuur bij stap d) 700-1100SC, bij voorkeur 850-1080SC, met grotere voorkeur 1000-1060eC is.A method according to claim 20, characterized in that the temperature in step d) is 700-1100SC, preferably 850-1080SC, more preferably 1000-1060 ° C.

22. Keramisch glazuur verkrijgbaar door middel van de werkwijze volgens één van de conclusies 18 tot en met 21.A ceramic glaze obtainable by the method according to any one of claims 18 to 21.

23. Keramisch materiaal omvattende een keramisch lichaam en het keramische glazuur volgens conclusie 22.Ceramic material comprising a ceramic body and the ceramic glaze according to claim 22.

24. Keramisch materiaal volgens conclusie 23, met het kenmerk dat het keramische lichaam een materiaal omvat dat is gekozen uit de groep bestaande uit aardewerk, steengoed, porcelein, tegels, bouwmaterialen, zoals bakstenen, en combinaties daarvan.A ceramic material according to claim 23, characterized in that the ceramic body comprises a material selected from the group consisting of earthenware, stoneware, porcelain, tiles, building materials such as bricks, and combinations thereof.

25. Keramisch materiaal volgens conclusie 23 of 24, met het kenmerk dat het keramische lichaam een grondstof omvat, waarbij de grondstof is gekozen uit de groep bestaande uit bodemas, bioas en combinaties daarvan.A ceramic material according to claim 23 or 24, characterized in that the ceramic body comprises a raw material, the raw material being selected from the group consisting of bottom ash, bioas and combinations thereof.

26. Keramisch materiaal volgens conclusie 25, met het kenmerk dat de hoeveelheid bodemas en/of bioas 20-50 gewichtsprocent van het totale gewicht van het keramische lichaam is.Ceramic material according to claim 25, characterized in that the amount of bottom ash and / or bio ash is 20-50% by weight of the total weight of the ceramic body.

27. Gebruik van de bindingssamenstelling volgens één van de conclusies 1 tot en met 7 bij de vervaardiging van geglazuurde keramische materialen.Use of the binding composition according to any of claims 1 to 7 in the manufacture of glazed ceramic materials.