CS212852B1 - Non-porous ceramic objects for being glazed and method of manufacturing same - Google Patents

Abstract

Glazable non-porous ceramic articles having a mechanical strength >= to that of good quality porcelain are made by sintering at 900 degrees C opt. accompanied by simultaneous moulding an intimate mixt. of 26-60% quartz and 45-75% silica glass having a thermal expansion coefit. >8 x 10-6/degrees C and a transition temp. 550 degrees C. Spec., the quartz contains >90% SiO2, =5% Al2O3, =4% Fe2O3, =1% alkali metal oxides, =0.5% alkaline earth carbonates and =0.1% water soluble salts. The components are ground so that >50 wt.% is 10 mu dia. prior to moulding. The material can be used for tableware, sanitary ware etc.

Description

The present invention relates to non-porous ceramic articles capable of glazing, and to mechanical mechatisms of at least good porcelain products made of material sintered at temperatures below 900 ° C, optionally formed, as well as to a method for producing these articles.

For the production of porcelain and porcelain ceramic materials, which are used for dishes and sanitary ware, respectively. · steatltOTých and porcelain products ae applied in electrical engineering as the IAD ^ 'm ^ !, trlA innovations are needed ^ ^T emperature more than ^{1 * 1200} ° C. These tall оНп ^ ос! temperatures, which naturally cause high firing costs, are needed because a certain amount is required to convert the punch body formed from the raw material mixture into a dense body. a melt phase, which is formed only by melting some of the so-called flux-reducing raw material components and dissolving other raw material components, respectively. their thermal decomposition and conversion products in primary melts at appropriate temperatures.

It is known that by using the flux-containing raw material components in a pre-reacted form, i.e. in the form of a glass frit, the sintering temperatures can be reduced in the production of ceramic products. Thus, U.S. Pat. No. 3,361,883 discloses that they are comprised of 40 to 95 weights. 5 to 40% by weight of a refractory ceramic matt, which may also be quartz. % wotlt8tonitž, 2 to 25 wt. % glass frit and 8 to 25 wt. After molding, they can be fed into dense ceramic products at knee temperatures of 1070 ° C. Achieving a dense, quartz-rich, solidified body at

212 852

However, 212,852 ' s at elimination temperatures below 900 [deg.] C. according to this patent are not legible, since at least a partial melting of the wax-talon component is required. .

Furthermore, US patent 2,862,827 can be identified, it can be produced ceramic article te Lot ^p «m. sintering MZI 35 ⁰ and ⁸⁷⁰ ° C of SRES MEREU e senselessness ze.4 ⁰ and ⁹⁵ wt.% of inorganic slsudenlny tvoříéí ceramic with melting point ', and the sintering temperature. from 60 to 5 weights. % pre-melted, after cooling finely comminuted glass frits. can be specially formulated, with a melting point below the sintering temperature. Inorganic ceramic-forming compounds are mentioned. According to this patent, the produced bodies have the disadvantage that they are still porous and that inexpensive raw materials are not usable for their production. , such as kernel, which in itself is not suitable for the production of sinoin products.

Production of sinnevm products at temperatures between ⁹⁰⁰ and 1 ° 00 ° C. smě! comminuted frits of relatively low melting aluminum fused and quartz-coated quartz NDH patent 20.914 DNDB patent 47.600 discloses the production of elutical stoned stones at temperatures between ⁶⁰⁰ and ⁷⁰⁰ ° ^C from mixtures pulverized by silhouette taot and with 45 to ⁶⁰ % by weight waste glass, which can no longer be made in the glassworks, cautiously with the scrap glass. however, these patents are exclusively concerned with the production of pored products. With relatively low mechanical injury, the frit used and the glass used by scrolling in the firing process lead to a certain sticking of the silica component or the binder. The material is crystallized. These patents do not disclose routes or references to the manufacture of metallurgical products. sintered bodies with a mechanics of foam that would correspond to this tray for good porcelain products.

From U.S. Pat. No. 153,881, it can be seen that it is possible to produce internal linings and heat and electric arc. sini current, of ceramic material consisting of at least 30 scales. % of the crystalline body, preferably of alumina; or magnesium oxide and not more than 70% by weight. % of active glass component pre - melted; and. after 'cool down! comminuted, which ae OTAVA of glass frit and additive tavivových at ^{- 00} to '14 ° C were sintered pM tepottch MZI ⁴⁰⁰ and ¹⁰⁰⁰ ° C. An essential drawback of the method which can be ascertained in this patent specification is that, in order to achieve low ambient temperatures, the glass frit must first be provided with a flux in the first process so that it can be converted into the active glass component. The active glass component thus formed, as a result of the reaction with the kriatum, allows the formation of an euthalic melt phase which allows a low sintering temperature. Ways to reach a dense sintered product cannot be deduced from this patent even

Furthermore, GDR 81,363 discloses that low sintering ceramic values, in particular for electrical heating technology and protection against switching. It can be produced that the refractory hmooy, preferably chamotte or tortoiseshell of cullet of other ceramics, is mixed with the glass flowing at low temperatures, whose composition (in weight%) is in the range of SiO2 20 to 20 ° C. 50; to 15; PbO 30 to 50; ®2 ^ 3 1θ ’

CaO to 5; MhO to 5; NagO + KgO to 7; and this mixture is between 20 and 80 weight percent. % of refractory mBtrial or ceramic tortilla from shards and BO up to 20 weight. * Ae pLjβaifikutí glass ^powder, shapes and trypsinized výhotaě pH. '- ^t ěpl8tá8h ⁴⁰⁰ and ^{Z 100} O ®C. no ^d oata ^t e ^k

212,852 of the described process is characterized in that low-color glass having a significant Pb content is used to achieve low sintering temperatures, which is. is associated with a tonne at high cost.

Further, from the patent specification Vision, find out how. - are capable of producing dense sintered bodies with a flexural strength of about 900 kp. <m ‘or more.

SUMMARY OF THE INVENTION The object of the present invention is to provide non-porous ceramic articles capable of glazing which have high strength due to good porcelain products and which are obtainable from raw materials which can be regarded as waste or bursting in the process, in particular easy-to-use and inexpensive quartz-rich raw materials and SjOg envelopes at sintering temperatures below 900 ° C.

Were invented ceramic nepjrésní předVty capable glazing, e mechanical pevnootí odpρoídаjjβí least good porcelain products, 'from vatriálu sinovaného 9 at temperatures below ⁰⁰ ° C, ^the molded under opřípadě ^. This feature is characterized by the fact ^{that the} sinnovar façade consists thoroughly. mixed with VS from 25 to 60 weights. % of comminuted quartz-rich raw material with a chemical composition (in Mart.%) of SiOg of at least 90,

AlgO-j nnjvye5,

FegOj is less than 0.4, alkaline compounds, and 18L. caustic soils not more than 1, not more. 0,5, water-soluble salts not more than 0,1, with a zwntoati distribution:

p <oil grain with more than 98 hvo. % grain share with more than 75 hvo. % and yielded grains with more than 50 pots. %

and 40 to 75 hours. % Rozvlněného obsOiujícího _SiO2 glass having a linear temperature kofioient roztVnosti ^p res ^ lo ^ Halt). ¹ and the deformation temperature ^p from ⁵⁵⁰ ° C, with grain size distribution:

% of grain with more than 98 wt .-% of grain with more than 80 hvt. % and a grain fraction of more than 50 wt. %

The crushed quartz-rich raw material may preferably be quartz sand, quartz sand, glass sand, in the case of quality, effluent from the preparation of a rock with a corresponding composition, in particular waste from the preparation of kaolin, or sVs from said components.

The sintered glass having an SL10 is preferably produced by a method of melting glass, as is customary in frit production, and it is the following chemical. composition (in mass * <):

Si0 ₂ between 50 and 75, 0 ^ Oj VZI A10

KgO + NaJ vzi 10 a30,

BaC + MgO + CaO at 2 and 20.

The rippling glass of SiOg VUte. also be in the shop of ordinary flat, container or building glass or waste glass.

212 BS2

Furthermore, a method for the production of non-porous ceramic articles capable of glazing, which is characterized by Se. a thoroughly blended mixture consisting of 25 and # 80 weights is prepared. % of the comminuted raw material. rich in quartz with chemicleate (in weight ·%:

SlOg of at least 90,

AI2O3 not more than 5,

FegOO ϊ · 2®3 not more than 0.4, alkaline oxides not more than 1, caustic earth carbonates not more than * 0.5, water-soluble salts not more than 0.1, with particle size distribution of:

grain content - with more than 98 wt. % below 60дт, grain fraction and more than 79 wt% *% below 20дт, and grain fraction with more than 50 wt ·% below Юд, and from 40 to 75 v £ h. % Milled glass oteauUícího SiO _2, which has a linear thermal expansion coefficient ^{of p} res kJeficient 8. ¹⁰ "^^ t <^^^ a ^ etvátecí te ^pl ol ^{p is} from 0 to 550 °, with the division siril.ltoeibii:

grain fraction with more than 98 tines ·% grain fraction with more than 80 tines ·% and grain fraction with more than 50 tines ·% below 40 µm, below 20див

optionally with the addition of known forming ye mediators, which are again odtrirniiel Né ^{BC With} temperatures of 500 ° C by reading out, fly ^{out of} the risen ^{and p} res. or the oxidized mixture thus prepared is produced using methods known per se in the ceramic industry. and - the shaped bodies, optionally with a dwell at a temperature between 100 and 200 ° C below the dense sulfurization temperature, are compacted in a temperature range between 600 and 900 ° C.

Changing the used raw material rich in cremon, respectively. The glass containing SiO2 for the desired distribution of the crystal may be carried out in one step or in several steps by means of various grinding pits known per se, in particular being possible. joint grinding and quarrying of the quartz-rich raw material. and glass containing SiO2. The firing and sintering of the moldings produced according to the invention can be carried out in firing units known per se in the ceramic industry and with respect to the size of the molded articles having a uniform temperature distribution, so that the glass ae can be carried out by first molding the molded articles. and then sinter.

The sintered shaped bodies comprise almost all of the quartz content with a feedstock mixture of approximately unchanged form, as determined by X-ray examination. and microscopically investigating the structure of the quartzogenephaline quartz determination. In the three common errors, the quartz content in the starting mixture and the sulfuric acid also confirmed that the large-scale observation confirmed that. the forms of germ and quartz in the sulfur bodies correspond to those in the starting bold. these findings suggest that the sulfurization of the reaction between the quartz fraction of the composition of the invention and the fractions of glass softened at the sintering temperatures is as low as possible, or is inferior. This behavior has the effect that, in order to achieve a non-porous body, the proportion of glass in the composition of the invention is at least as large as to completely wipe out all the cavities that are ignited during the process.

IS2 quartz formation. Said composition behavior according to the invention proves to be particularly advantageous on the other hand if the properties of the sintered body in question are to be intentionally influenced by the choice of the ordinate forms of the grains and, respectively, of the grain. or by dividing the granularity of the quartz.

After the valley achieved mechanical strength that would at least correspond to the strength of good porcelain products, and showed that there were no microscopic cracks between the quartz particles of the sintered structure and the ecla fraction acting as the bonding binder after the finished sintering and cooling. As found by microscopic, respectively. by electron microscopy of articles made according to the invention, this is reddened within the composition of the invention.

the articles produced according to the invention may be provided with glass coatings adapted to use with respect to the coefficient of expansion and viscosity at temperatures according to methods customary in the ceramics industry, for surface treatment in the form of a glaze layer.

The advantages of the invention are in particular that non-porous sintered bodies and the strength and chemical stability corresponding to these properties in good porcelain can be produced at temperatures below 900 ° C. and accordingly energy-saving from cheap euro notes, especially from the previously unused occurring materials. The articles may be provided with a surface treatment, such as a glaze or decor, in a known manner customary for ceramic articles. A further advantage of the articles made according to the invention is their temperature coefficient of extensibility, whereby they can in particular be combined in connection with metallic materials, in particular on an iron base.

The invention will be further elucidated by the following non-limiting examples.

Example 1

The raw materials used were quartz sand from Hohenbock and more than 98% SiO ₂ and flat glass shards and chemical composition (in wt.%): SiO ₂ 71.8; Al ₂ O? 1.01; Ve ₂ O? 0.12;

TiO ₂ 0.83; CaO 7.74; MgO 4.39; K ₂ 0 0.13 and Na ₂ 0 13.5. The flat glass had a deformation temperature of 528 ° C and a linear thermal expansion factor

50-500 ° C »8.9.10“ ⁶ deg. ¹ .

The quartz sand was pre-ground by grinding for 10 minutes on a disk vibratory mill. The flat glass shards were pre-ground on a jaw crusher, first to a grain size below 0.8 mm, and the iron particles were removed from the crusher by passing through a magnetic separator.

35 g of pre-ground quartz sand and 40 g of pre-ground glass were each placed in a vibratory disk mill and comminuted and mixed further by grinding for 10 minutes. The mixture thus prepared had the following particle size distribution:

99.5 wt. % below 60 µm,

98.9 wt. % below 40 yum, wt. % below 20 yum, wt. % below 10 yum

An X-ray examination of the Christian content in the individual grain fractions showed that the ratio of the mixing of the quartz sand with the slag of the individual grain fractions deviated

212 aS2 less than t 10% of the mixing ratio of all spikes.

To One weight part finely pulverized. 0.15 part by weight of water was added to the mixture and mixed with a pestle. At the end of the day, a total of 0.5 mm sieves were made through another homoenissum that was connected to a certain granule. The granulated mixture was eluted in a conventional manner for dry pressing into cylindrical and rotary bodies. Vždy- more shaped bodies to be pivoted and e ^ ktricky ^{- YTA} capacity foams in soapy furnace wj Leno ^{600 -} ° C and 3 ° prodlwé 'and ⁶⁰ for the purpose of softening-straightening, Melting furnace, Vol ^ ovtata temperature by 2 ° C was fired to the temperatures below, at which time also the sols were left to sinter for a specified period of time.

Sintering temperatures

Firing 1 725 ° C 7 hodLn Firing 2 750 ° C 4 clock Firing 3 · 775 ° C 1 hour Firing 4 (comparative example) 725 ° C 1 hour

After the furnace had cooled after such firing, the shaped bodies obtained were not deformed by having the following properties:

Firing 12 3 4

Linear firing based on raw shaped body in%

Apparent density in% of theoretical density

The result of testing the porosity of the luchsin solution

Flexural strength in M M and -2 (mean of 10 ukoumotych rod)

Unoární temperature coefficient roztožnooti 50-4 ⁰⁰ ° ^C No et en ^ u ^{p -1}

10.1 10.2. 10,0 8,5

95 95 88 metallurgical metallurgical metallurgy

95.0 98.0 100.0 -

1.2.10 ^-6 -б 14 ^, 3.10 ^-6

14,5.10

As used surovi.n ^y Tyty dried spotaí t.ok. of . hydrooylclónu ^OD ^ ^p ^ r and ^y of kaolin (Short ozročenn :: sandy sludge dried) with the chemical composition (in% Probe *) 94.9 SiO; А1дОз 3,26; Рп ₂ О ₃ 0.12; TiOg 0.2; CaO 0.06; MgO -; KgO 0.05; NagO 0.04, with a loss on ignition of 1.21, as well as with a mineral composition (in wt.%,%) Of quartz 91.4 and tao-oinite 8, and flat burrs - glass mentioned in Example 1. Sand sludge - as a raw material rich in the quartz has been comminuted by the third. dry in a laboratory vibrating ball mill for 48 hours. Preliminary roztóěnovfcd plécMho glass Tylo done, yeah Jok udtao ^- in pHkladu first

In each case, 201 g of pre-ground sand sludge of 193 g before »the ground glass was put into a vibrating ball mill and further comminuted for 48 hours.

212 а 5 2 and mixed · The aroma thus prepared had the following sraitoati composition in mass. %:

99.8 below 60 µm below 40 µm, ppd 20 yum, below 10 yun.

X-ray examination of the silica content in the individual fraction fractions did not show any enrichment of quartz or glass in the 'single fraction swintoaSi'. To one weight part of the finely divided emulsion was added 0.09 weight part of a 10% solution of polyvinyl alcohol in water and 0.22 hmoonoot part of olein and mixed evenly as described in Example 1.

This obtained powder was preliminary. They were compressed into tablets which were then crushed to obtain a granulate having a grain size of 0.06 and 0.5 mm.

Made of pressed garnet was made isolataticky! lioovim, - respectively. lloováím- dry usual! cylindrical and rod bodies.

Vyppáein moldings was carried out analogously to Example 1 PR 85 ° C and at slinovacl ^p te ^ ch ch and ^Lot times · .sinnování ^- listed in the table below:

sintering Sintering time Firing 1 800 [deg.] C 7 hours Firing 2 825 ° C 4 o'clock Firing 3 850 DEG 1 hour

After the furnace has cooled after such firing, the mHa shaped bodies obtained have the following property:

Linear firing, based on - raw shaped body in%

Apparent density in% of theoretical density

Test results for porosity in phtachsin solutions

Flexural strength ®ia -2 (mean of 10 bars tested)

Linear temperature coefficient of expansion

X 50.4 ⁰⁰ ° ^C per a ^t upe ^n_ l ·

Example 3

Firing. 1 2 3 - 12,2 15.5 12.4 95 95 95 dense dense dense 117.0 115.0 120.0 13,3.10 ^-8 13 ^ .10 ^-6

13,2.10 ^-6

The quartz sand mentioned in Example 1 and the melted special glass with a chemical composition (in homt · 96) SiOg 53.8 were used as tulle raw materials; AlgO = 6.3; ®2θ3 ² >6; CaO 5.9;

PbO ^{3, 4;} ZnO ^{2, 7; ,} Kg ^{0 and Na} 2 ° ²¹ »7. ^- Special glass was ^- deforming ^t e ^t u ^pl about ⁴⁴⁹ ° C and lÍMtaní. - - - 9 ^ - ⁴⁰ ^ ^{and 3} ^, ⁰ .1 ^{0 8} rt · \

The preliminary grinding of the raw materials was carried out as described in Example 1. 34 g of pre-ground quartz sand and 41 g of pre-ground special glass were always - spo8;

212 2S2 was milled dry in a laboratory disc mill for 10 minutes. The mixture had the particle size distribution shown in Example 1.

To one part by weight of the finely divided mixture was added 0.09 part by weight of water in which it was dissolved or dissolved. suspended 0.009 part by weight of polyvinyl alcohol and 0.02 part by weight of olein. Further preparation of the mixture was carried out as in Example 1. The shaping was carried out as in Example 1. The shaped bodies were placed in an electrically heated muffle furnace, fired at 500 ° C and after a residence time of 30 to 60 minutes to equalize. temperature in the furnace fired by increasing the temperature by 2 ° C per minute further. When the specified final temperature was reached, sintering occurred during the dwell time:

Sintering time Firing 1 600 ° C 7 hours Firing 2 625 ° C 4 o'clock Firing 3 650 ° C 1 hour

After the furnace had cooled, the selected moldings were in perfect condition and had the following

Properties: Firing. .1 2 3, Linear firing shrinkage, relative per cheese shaped body in% 10.0 10.3 10.2 Apparent density in% of theoretical density 93 95 94 Test result of porésnoet fuohsino- faintly solution porous dense Dense Flexural strength in MPa -2 (mean value of 10 tested rods) 85.0 90.0 91.0 Linear temperature coefficient of expansion 14,8.10 ⁶ 15,0.1ο “ ⁶ 50-400 ° C 15.Ο.1Ο ' ⁶

Clay materials from the preparation of sand with chemical composition (in weight.) Of SiO ₂ 94.0 were used as raw materials; Al ₂ O ₃ 3.1; Fo ₂ 0 ₃ 0.4; TiO ₂ 0.3 · CaO 0.1 H 3 O 0.07; KgO 0.1; Ha ₂ 0 0.03 and annealing loss 1.5, as well as the mineral composition (in wt.%) Of quartz 90.0 and clay minerals 10.0 and flat glass shards mentioned in Example 1.

The raw material with the soft quartz was already in the desired, pre-pulverized form, so that it did not need any special grinding. Flat-glass shards were first crushed to a grain size below 0.8 mm and then pre-passed in a vibratory ball mill for 72 hours as shown in Example 1. The grain size distribution for this material was as follows:

99.5 wt. % below 20 µm,

90.0 wt. % below 6 / µm,

40.0 wt. % below 2 µm.

In order to thoroughly mix the two masses, 40 g of pre-ground glass and 35 g of clay waste from the sand preparation were milled dry for 10 minutes in a disc mill. Ros9

212 ЯК 9 division grain! the mixture obtained was:

tip%% below 20 µm, weight% l pcOl 6 yum, tip%% pot. 2 / um ·

After the addition of molding proetitics, as in Example 3, the preparation of the molding and the molding took place. As described in Example 1.

The sintered bodies were sintered in an electrically heated copper cup with an analogous experiment as described in Example 1.

Firing 1

Firing 2

Elinating temperature

750 ^O C

800 ⁰ C

Duration 81 hours ² hours

After cooling in the pad, the shaped body and the surface had a smooth surface as from eamo-agazing and was dimensionally ethical ·

On the shaped bodies of speech were found- the following wastes:

Firing 1 2 Unequal firing by firing, based on eyr shaped body in% 12.0 12.2 It decreases the value in% of the theoretical density 95 96 Flexural strength in MPa (median value) of 10 rods tested) 65.0 68.0 Test result for porosity with fuchein solution dense dense LLnalar expansion coefficient of temperature Á 50-400 ° C ^per · ¹ 13,0.10 ^-6 13,1.10 ^-6

Example. ^

The quartz peak shown in Example 1 and the coating aloe by chemical elution (at tip 2 - SiOg 66.7; AlgO? 6.0; CaO 9.8; NagO? 15.1; Kg0 2.5 were used as euros). Container should Eklo BC ^ 'tv <N <^ <^ :(' ^- the pulse of ^- 533 ° ^{C -} a coefficient lirerérní tepotní distending 1О 50-400 ° ^C, 1.1 81 ^{0-6 -} \ Ex ^beta. rava EUROVIN was ^p rovedona ^- as mentioned ^- in ^Preparation KLA at ^d 1, and the management of fire as in example 4.

Vastnooti eH.New shaped bodies:

Firing 1 2 Linear firing by firing, based on eyr shaped body ^ eeo in% 10.3 10.5 Decay density in% of theoretical density 95 96 Result of fuohsinoi test of pooroity dense dense Flexural strength in №a (Conflict value of 10. of tested rods) 95.0 96.0

212 BS2 аво .... i________2___

Linear temperature coefficient of expansion

50-400 ° C per st. ¹ 14.3.10® 14.1.10®

»Ί »βδ-6.

The raw materials listed in Example 1, including the preliminary comminution described therein, were used as raw materials. In each case 30 g of the ground quartz furnace and 45 g of the pre-ground glass were co-ground and dry for 10 minutes in a disc mill. The mixture had the particle size distribution shown in Example 1 and was, as also described therein, prepared for pre-sintering. in order to equalize the temperature and then increase the temperature by 2 ° C per minute, the sintering temperatures were further heated.

Sintering temperature Sintering time Firing 1 725 ° C 4 o'clock Firing 2 750 ° C 2 hours Properties of sintered shaped bodies: Firing 1 2 Linear firing shrinkage, based on raw shaped body% 10.5 10.3 Apparent density in% of theoretical density 96 96 Result of examination of porosity with fuchsin solution dense dense Flexural strength in NPa (mean value of 10 poles) 85, P 90.0 Linear temperature coefficient of expansion <50-400'C per st. ¹ . 13.8.10 “® 13,7.10®

OF THE INVENTION

Claims (5)

1. Non-porous ceramic articles capable of glazing, having a mechanloclocking strength corresponding to at least good porcelain products, which are made of a material sintered below 900 ° C and / or shaped, characterized in that the sintered material consists of a thoroughly mixed mixture of 25 to 60 weight. % of comminuted quartz-rich raw material and of the fire-retardant composition (in wt. *) SiO ₂ at least 90, Ai ₂ 03 not more than _5> f. ₂ o ₃ Not more than 0.4 alkaline oxides maximum corrosive earth carbonates maximum water-soluble salts maximum 212 852 and grain size distribution: grain fraction 8 of more than 98% by weight; the grain fraction changes with more than 75% by weight; and grain fraction in more than 50% by weight and 40 to 75% by weight. % of ground glass containing SiO _{2> ы linear temperature coefficient} . W.1 nád expansion expansion factor 8. 10 at · and the deformation temperature below 550 C, e by the distribution of the difference: grain size with more than 98 wt. % podium changes with more than 80 wt. % and the proportion changes with more than 50 wt. % below 20 µm, below 10 µm. Non-porous ceramic articles capable of glazing according to claim 1, characterized in that the quartz-rich comminuted material is preferably quartz sand, quartz flour, glass sand and, optionally, quality grades, especially mineral waste from kaolin, or a mixture of said components. 3. Non-porous ceramic articles capable of glazing according to Claims 1 and 2, characterized in that the ground glass containing SiO ₂ has been advantageously produced by a simplified glass melting process as is customary in frit production and has the following chemical composition (in weight%): SiOg mehi 50 a75 Al ₂ 0 ₃ between 0 and 10, KjO + Na ₂ 0 between 10 and 30, BaO + MgO CaO between 2 and 20 and other components in low amounts with little effect on the linear coefficient of expansion. Fourth Neporésní capable glazing ceramic articles according to claim 1 or 2, wherein the comminuted glass containing SiO _2, commercially available flat, container or etavební glass or waste glass. 5. A process for the production of non-porous ceramic articles capable of glazing according to Claims 1 to 4, characterized in that ее prepares a thoroughly mixed amium consisting of 25 to 60 scales. Crushed quartz - rich comminuted raw material with a chemical composition (% by weight). S10 ₂ at least 90, Al ₂ 0 ₃ not more than 5, Fe ₂ 0 ₃ not more than 0.4, alkaline oxides not more caustic earth carbonates not more than water-soluble eols not more than with a particle size distribution of: grain fraction in more than 98 wt. % share changes with more than 75 hmat. % and the proportion changes with more than 50 wt. % and 40 to 75 wt. % Milled glass containing SiO _2, 1, 0,5, 0.1, below the below / µm, / µm, / µm having a linear temperature coefficient of 852 cient extending beyond ⁸ W ⁶ Wed ^"1 přetvftfeeí 5O temperature below ⁵ ° C, the grain size distribution: grain ratio and more than 98 hmoo. % applied to a grain β of more than 80 hmoo. % and podium grain and more than 50 hmoo. % Below 40 / Um below 20 / um, below 10 / Um, optionally with the addition of known prostife <Get for forming that at temperatures below 5 ^ ^C for ^P., et removed by ^ ares .mu.m decomposing NETA : k ^y βl ^IE en L ^m, as follows ^p s ^{p Raven} mixture is shaped molding processes conventional in keramičkám prdmslu and vytvarovanátělesa is densely sintered in te ^p lotním range msi 6ДО and ⁹⁰⁰ ° C, ^P o ^{p at} pH and ^DE for inserting delays at ^yp s m »Z 1 ⁰⁰ and ^{200 DEG} C by Otto ^H te ^pl Utne ^h of sintering. Printed by Moravian Printing Works, plant 12, Leninova 21, Olomouc