RU2440318C1 - Method of making ceramic items - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method of making ceramic items includes preparation of ceramic slurry by mixing of the following components: quartz sand, clay, chamotte, wollastonite, soda ash and a glass-containing component, tempering with water, drying, forming of items, baking. When making ceramic slurry, the first batch is prepared separately: quartz sand, clay and soda ash are tempered with water and mixed, and the second batch: wollastonite, chamotte and the glass-containing component. Components of the first batch are processed in a ball mill for 1.5-2 hours until grinding coarseness with residue on a sieve No. 100 is 18-21 % and moisture is 40-42 %, then components of the second batch are added and processed for another 1-1.5 hours. The produced slurry is soaked in a flow pool for 1.5-2 days, the mass is poured into moulds and soaked for 16-18 hours. Items are baked in a muffle furnace at the temperature of 1000-1100°C for 18-20 hours. The slurry includes Veselovskaya clay, and a glass-containing component is liquid glass at the following ratio of components, wt %: quartz sand - 17-20; Veselovskaya clay - 30-35; wollastonite - 5-8; chamotte - 40-45; soda ash - 0.2-0.3; liquid glass - 0.3-0.5.

EFFECT: increased resistance to damage in case of shock.

3 cl, 1 ex

Description

The solution relates to the field of manufacturing building ceramics, in particular to the manufacture of decorative objects, tiles and tiles.

A known method of producing ceramic products based on wollastonite, kaolin, clay with the addition of water, water glass and soda ash with simultaneous grinding of the components and obtaining an aqueous slip in the following ratio of the components of the slip. wt.%: wollastonite - 75-80, kaolin 12-15, clay - 8-10, water glass and soda ash - 0.3 and 0.2, respectively, with slip moisture 29-30 wt.%, molding products into porous gypsum molds, drying and firing, expanded vermiculite with a grain composition of 0.6-2.5 mm in an amount of 2.0-3.0% by weight of the slip is additionally introduced into the slip (RF patent No. 2358951, C04B 33/28, publ. 06/20/2009).

However, this method is intended to obtain products operating in difficult production conditions, for example, aluminum ducts having high strength and heat resistance, which is ensured by a high content of wollastonite 75-80%. It does not require fine grinding and uniform distribution of components in the mass of the slip.

As a prototype adopted a patent of the Russian Federation No. 2309924, C04B 33/13, publ. 11/10/2007 on ceramic mass for the manufacture of electrical products, utensils, decorative items. Ceramic mass contains in wt.%:

quartz-feldspar sand 12.0-16.0,

clay 20.0-30.0,

wollastonite 5.0-7.0,

fireclay (kaolin) 20.0-30.0,

soda ash 1.0-2.0,

cullet 1.0-2.0.

This patent is selected as a prototype as closer in purpose and in mass composition of the slip.

The patent does not describe a method of manufacturing products. However, it obviously includes traditional methods: preparing a slip by mixing the components: silica sand, clay, fireclay, wollastonite, soda ash and glass-containing component, mixed with water, drying, molding, firing.

The disadvantages of this solution are the use of cullet and ceramic combat, which complicates the technology due to the need to grind them and the inability to achieve fine grinding, which affects the quality of the final product, rough surface, the formation of stress concentration centers, and consequently, destruction upon impact, although their strength is high enough.

These shortcomings are eliminated by the proposed solution.

The problem of expanding the raw material base and improving the quality of ceramic products, in particular tiles.

EFFECT: obtaining products with a smooth surface and resistant to damage upon impact.

This technical result is achieved by the fact that in the method of manufacturing ceramic products, comprising preparing a slip by mixing the components: quartz sand, clay, chamotte, wollastonite, soda ash and glass-containing component, molding the products and firing, the 1st curtain is separately prepared: quartz sand is shut with water , clay and soda ash, and the 2nd curtain: wollastonite, chamotte and glass-containing component, the components of the 1st curtain are processed in a ball mill for 1.5-2 hours, to a fineness of grinding with a residue on It is 100 18-21% and humidity 40-42%, then the components of the 2nd curtain are added and treated for another 1-1.5 hours, the resulting slurry is kept in the flow pool for 1.5-2 days, the mass is poured into molds and withstand 16-18 hours, the products are fired in a muffle furnace at a temperature of 1000-1100 ° C for 18-20 hours, the finished products are glazed and final fired at a temperature of 900-990 ° C for 15-18 hours, while clay is used in the slip Veselovskaya, and as a glass-containing component - liquid glass in the following ratio of components, wt.%:

quartz sand 17-20,

clay Veselovskaya 30-35,

wollastonite 5-8,

fireclay 40-45,

soda ash 0.2-0.3,

liquid glass 0.3-0.5.

The use of Veselovskaya clay is known (e.g., auth. Certificate of the USSR No. 823346, C04B 33/16, publ. 23.04.81), where it, together with wollastonite, cullet, quartz sand, nifelin-syenite and lithium carbonate, reduces water absorption and increases heat resistance. However, nifelin-syenite and lithium carbonate are quite expensive and rare components.

In the proposed solution, it is used in another combination, affecting the obtaining of a smooth surface.

Liquid glass and soda in the aggregate are stabilizers and contribute, along with the technological mode of the method, to increase the resistance against destruction upon impact.

Glazing reduces water absorption and gives products a presentation

An example of the method

Prepare components for the slip. Clods of clay are broken into pieces not exceeding 80-100 mm. Wollastonite is sieved through a sieve with an inclined mesh of 1 mm. Fireclay is sieved through a vibrating screen with a mesh of 0.9-1 mm. The first curtain is prepared: quartz sand - 17.5%, clay Veselovskaya - 34%, water - 29% of the loaded components (by dry weight), soda ash - 0.3%. A second curtain is prepared: wollastonite - 6.2%, fireclay - 42.3%, water glass - 5%.

Such separate mixing is more even and allows you to select components according to their physicochemical properties.

The components of the 1st curtain are loaded into a ball mill. Grinding lead for 2 hours. The size of the grinding should be characterized by a sieve residue of 100 18-21%, humidity 40-42%. The components of the 2nd curtain are loaded there. Liquid glass is poured gradually along with the gradual filling of chamotte. The grinding time is 1 hour. The slip is drained through a magnetic separator into a propeller stirrer. The aged slurry is pumped by a diaphragm pump to a consumable pool, where it is held for 2 days.

Porous gypsum forms are prepared that provide air removal from the flooded mass.

The ceramic mass is poured into molds, where it is held for 17 hours until the product is formed, for example, facing tiles. Products are removed from the mold, dried to a moisture content of not more than 1% in a room with a temperature of at least 25 ° C and a relative humidity of 60-70%.

The products are fired in a muffle hearth furnace at a temperature of 1100 ° C for 20 hours.

After this, the products are ready for use, have a smooth surface. To increase their presentation and reduce water absorption, the products are coated with glaze, which is applied with a spray. Various glazes may be used, for example based on frits using clay, water and pigments. After applying the glaze, the final firing is carried out in a muffle furnace at a temperature of 990 ° C for 15-18 hours.

Finished products are stacked on pallets with the glazed side up.

In other examples, the process parameters were changed. When jointly mixing the components of the slip, it was difficult to exclude clumping, the same was observed when the mixing mode of the components of the specified formulation was violated, the strength of the tiles upon impact decreased, cracks appeared. With an increase in the number of components, unmixed lumps were observed. The same was observed with insufficient screening and violation of the moisture regime, which negatively affected the smoothness of the surface.

Holding the slip in the consumable pool for less than 1.5 days did not provide sufficient mass uniformity, and more than 2 days was not practical, because the result has already been achieved.

Exposure in the form of less than 16 hours did not provide sufficient hardening, and more than 18 hours was not practical, because the result has already been achieved.

If the firing temperature is less than 1000 ° C, the ceramics are not fully cured, and more than 1100 ° C, burnout and cracks are possible. The same can be said about the firing time of 18-20 hours.

At a glaze firing temperature of less than 900 ° C, it may be detached from the product. At a temperature of 1000 ° C microcracks formed. The same can be said about the annealing time of 15-18 hours.

The resulting products are durable, relatively inexpensive material, have an attractive presentation.

Claims (3)

1. A method of manufacturing ceramic products, including the preparation of a slip by mixing components: quartz sand, clay, fireclay, wollastonite, soda ash and glass-containing component, mixing with water, drying, molding of products, firing, characterized in that the 1st curtain is separately prepared: shut quartz sand, clay and soda ash and the 2nd curtain are mixed with water and mix: wollastonite, chamotte and glass-containing component, the components of the 1st curtain are processed in a ball mill for 1.5-2 hours to a fineness of grinding with residue m on a sieve No. 100 of 18-21% and a moisture content of 40-42%, then the components of the 2nd curtain are added and treated for another 1-1.5 hours, the resulting slurry is kept in the consumable pool for 1.5-2 days, the mass is poured they are kept in the molds and kept for 16-18 hours, the products are fired in a muffle furnace at a temperature of 1000-1100 ° С for 18-20 hours, while clay Veselovskaya is used as a part of the slip, and liquid glass is used as a glass-containing component in the following ratio of components, wt .%:
quartz sand 17-20 clay Veselovskaya 30-35 wollastonite 5-8 fireclay 40-45 soda ash 0.2-0.3 liquid glass 0.3-0.5 2. A method of manufacturing ceramic products according to claim 1, characterized in that after firing the product is glazed and final firing is carried out. 3. A method of manufacturing ceramic products according to claim 1, characterized in that the slurry is cast into gypsum forms.