Method of making conglomerate engobe

FIELD: construction.

SUBSTANCE: any type of clay can be used when making conglomerate angobes, provided it can dissolve in natrium liquid glass. The clay is unfurled in water with natrium liquid glass up to 50-70% moisture. The quantity of liquid natrium glass added to the unfurled clay is equal to the quantity necessary for maximum dissolution of the watery ceramic slip with 40-45% moisture of the same clay. The unfurled clay is settled until it fully separates into sediments and a sedimental-stable suspension of clay minerals. The obtained water suspension of clay minerals, Particles of which are mot more than 1 mcm in size, are taken to the surface of the formed dry clay products, dried and are burnt in an acidic medium at temperature of 900-1050°C. An engobe-gloss coating with low water absorption capacity is obtained on the surface of the product.

EFFECT: simplified method of obtaining conglomerate engobes of various colours while using a wide range of clay types.

3 cl, 6 tbl

The invention relates to the production of ceramic building products, cultural and artistic purposes.

There is a method of making fusible white engobe composition (wt.%): clay kasoverskaya - 20, kaolin glukhivtsi 4 pegmatite store - 16, glass fight - 35, chalk Belgorod - 6, sand, quartz - 19 (N.A. Sakharova, Cherepova O.V. Architectural ceramics with color engobed layer: Publishing house of the Academy of Architecture of the Ukrainian SSR, Kiev, 1952, p.20-21). Pegmatite and glass fight carefully washed in water, pegmatite calcined at a temperature of 900-960°C. Preliminary grinding pegmatite, glass fight and chalk to produce edge-runner mills, then after dosing, carry out joint wet grinding all original components in a ball mill with addition of 35% water. Fine grinding lead to residue on the sieve with 10000 resp./cm²no more than 5%. After grinding, the suspension is filtered through a sieve 900 resp./cm²and diluted with water with thorough stirring to a density of 1.6-1.7 g/cm³. Egoboo suspension is applied on cold-dried product, after which the product is calcined at a temperature of 900-1050°C.

The disadvantage of this method is its complexity due to the need for a sufficiently fine grinding, allowing to obtain fusible engobe up to the sufficient number of wetlands in its composition.

There is a method of making fusible engobe (Miklashevsky A.I. Technology of ceramic art. M., 1971, s), namely, that take 250 g of clay and roboscout it in 1 liter of distilled or rain water with the addition of 5 g of crystalline soda. After that, the clay give a day to settle. Some clays are separated after settling on a clear liquid and sediment, they are not good for cooking conglomerating engobe. Other after a day of settling divided into the sediment and water slurry, the slurry is drained, partially evaporated and then used as egoboo suspension for application to the surface of the molded ceramic articles. After drying and calcining in an oxidizing atmosphere at temperatures of 900-1000°products obtained glossy with low water absorption angonoa floor, its color can be white, beige or red depending on the amount of coloring oxides present in engobes suspension. The disadvantages of this method of preparation of conglomerating engobe are limited assortment of used clay or mixtures thereof, the complexity due to the need to attract additional operations - evaporation.

The technical object of the present invention is to develop a simple method of obtaining conglomerating engobes different colors with skin is of an extended range of used clay.

To solve the problem in the method of preparation of conglomerating engobe are encouraged to use any clay that is capable of liquefied sodium liquid glass, which dissolve in water this electrolyte to a moisture content of 50-70%. Sodium liquid glass take as much as you need to add it to the water slip relative humidity of 40-45% from the same clay, to the maximum slip is to thin out. The method of determining the amount of electrolyte required for maximum resizemode of the slip (the minimum time of expiration of the portions of the slip) using a viscometer of Engler found in the book "Technical analysis and the control of production of ceramics. Lukin E.S. Andrianov N.T., M.: stroiizdat. - 1975 - s [1]. Dissolute clay defend until complete separation of the precipitate and sedimentation-stable suspension of clay minerals. The resulting aqueous suspension of clay minerals, particles of which not more than 1 μm, is applied to the surface of the molded dry ceramic products, dried and calcined in an oxidizing atmosphere at a temperature of 900-1050°receiving on the surface of products engobe-gloss finish with low water absorption, composition (on calcined substance, wt.%):

Al₂O₃- 13÷5-35

Fe₂O₃+FeO - 0.01÷15

TO₂- 0.01÷5

CaO - 0.1÷8

MgO - 0.÷ 8

To₂O - 0.5÷5

Na₂O - 0.5÷5

SiO₂- rest

In the present method of making fusible engobe use the large assortment of clays, which is an advantage over the prototype and analogues. As a source of clay for the preparation of conglomerating engobes were taken clay in the following fields - Vladimir (Rostov region), Il'sky (Krasnodar Krai), Starokorsunskaya (Krasnodar territory). The first clay suitable for the production of thin and sanitary building ceramics, second and third low-melting, with a high content of coloring oxides, are used for the production of ceramic bricks by the plastic molding method. In tables 1, 2, 3 the results of sedimentation flowing clays with various moisture contents and different amounts of sodium liquid glass density 1.4 g/ml with silicate module 2,80 per 1 kg of dry clay in the tank with a height of 0.5 m within three days, respectively, for clays Vladimir, Il'sky and Starokorsunskaya fields.

As can be seen from tables 1-3, the composition№2, 3, 4, 5, 10, 15 for each of the three clays, after settling divided into clear liquid and sludge. Compositions№1, 6, 11, 12, 13, for each of the three clays, after settling on visual characteristics are not changed and remained sedim stationno-stable suspensions. Compositions No. 7, 8, 9, 14, for each of the three clays, after settling divided into sedimentation-resistant suspension and precipitation. Experimentally it was found that the maximum resizemode water slurries relative humidity from 40% to 45% of clay Vladimir, Il'sky and Starokorsunskaya fields defined using a viscometer of Engler, is also achieved respectively at 15 ml, 8 ml and 12 ml of sodium liquid glass 1 kg of dry clay, when the density of the liquid glass 1.4 g/ml and silicate module 2.80 [1]. Of all the resulting sedimentation sedimentation-stable suspensions of the compounds№1, 6, 7, 8, 98, 11, 12, 13, 14 for the considered three clays were formed by the method of slip casting in plaster moulds the plate thickness of 1-3 mm Plates after drying was fired at a temperature of 900°in an oxidizing atmosphere. After firing was measured, water absorption plates according to the method set forth in GOST 530-95. Table 4 shows the results of measurements. From table 4 it is seen that plates made of compositions No. 7, 8, 9 all three clays have a very low water absorption. These compositions humidity 50 to 70%, the amount of electrolyte 8-15 ml per 1 kg of dry clay. Low water absorption provided no larger than 1 micron particles of clay minerals in suspension.

Table 5 shows the results of the serenia water absorption plates, formed from suspensions resulting from settling of the compositions No. 7, 8, 9, and fired in an oxidizing atmosphere at temperatures of 900°C, 950°, 1000°C, 1050°C, 1100°C. From table No. 5 shows that the highest value of water absorption is less than 0.2% for compositions No. 7, considered three clays after firing at a temperature of 900°C. At higher temperatures the values of water absorption of not more than 0.1%. Given that the product construction, cultural and artistic ceramics are fired at temperatures of 900°-1050°C, from table No. 5 we can conclude that the use of suspension formulations No. 7, 8, 9 as agonoy suspension for these products after firing at these temperatures will get on the surface of the cover - slip with low water absorption. Lifting up to 1100°With the firing temperature of the building products and household ceramics, the main component of which are low-melting clays often leads to deformation of the products.

Plates made from compositions№1, 6, 11, 12, 13, have high water absorption, as in suspensions of these compounds has not been the loss of large particles in the sediment. Plate made of compounds No. 14, have an intermediate result, which is due to incomplete precipitation of large particles due to the excessive amount of sodium fluid is th glass, caused salustiana suspensions.

Compositions№2, 3, 4, 5, 10, 15 from tables 1-3 after re-mixing was applied to the dried pottery and burned in an oxidizing atmosphere at 900-1050°C. Coating had the characteristics of composition No. 1 in table 4, i.e. they were not fusible), and therefore it is impractical to use as engobes.

Compositions No. 7, 8, 9, three clays have after firing a minimum water absorption less than 0.2% for all three considered clays. This suspension was applied to the surface of the molded dry ceramic products, then the products are fired in an oxidizing atmosphere at a temperature of 900-1050°C. After firing, the product has gained a glossy coating with low water absorption.

Based on the performed experiments, we can conclude from the amount of sodium water glass added to dissolute clay and moisture dependent particle of any size will be sedimentation-stable suspensions of clay minerals, which are applied to ceramic products.

After firing color glossy coating produced by using as a source - Vladimir clay, was a white, clay Troops and Starokorsunskaya - red-brick.

Table 6 shows the chemical composition (wt.%) the engobes with low water absorption, is received from Vladimir, Ilskiy and Starokorsunskaya clay.

Based on the above we conclude that the inventive method of making fusible engobe has novelty, inventive step and is industrially applicable.

1. The way the cooking is conglomerating engobe, including the dissolution of the clay in water with addition of sodium electrolyte, settling, separation of the aqueous suspension and the sediment, causing the suspension to the surface of the dry ceramic products, drying and firing in an oxidizing atmosphere, characterized in that as the sodium electrolyte used sodium silicate, take any clay, capable of liquefied sodium liquid glass, humidity dissolved clay is 50-70%, the amount of liquid sodium glass added to dissolve the clay is necessary for maximum dilution of aqueous ceramic slurry humidity of 40-45% from the same clay, the defending carried out before the separation of the precipitate and sustainable water sedimentation suspension having particles no more than 1 microns.

2. The method according to claim 1, characterized in that the sodium silicate added to the water before the dissolution of the clay to a moisture content of 50-70%.

3. The method according to claim 1, characterized in that the firing temperature of not more than 1050°C.