RU2599652C1 - Method for maintaining natural colour of ceramic facing articles - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to production of ceramic facing construction materials, primarily, to methods of preventing contamination of the front surface, and can be used in production of facing bricks and facing ceramic tiles and other building ceramic products. Front surface of freshly molded articles as a protective film-forming component is applied with waste or off-grade fusible plastic barium lubricants or low-melting mixtures of waste and/or off-grade plastic barium lubricants, which before application are stirred until a homogeneous mass, the drop temperature is determined, and application on the front surface is carried out within the temperature range from the dropping temperature up to 100 °C.

EFFECT: maintaining quality of ceramic articles for a long service life, reduced production cost due to usage of an off-grade raw material.

1 cl, 1 ex

Description

The invention relates to the production of facing ceramic building materials, mainly to methods for preventing pollution of the front surface, and can be used in the production of facing bricks, ceramic tiles and other building ceramic products.

As practice has shown, the surface of ceramic products during the drying process can be contaminated with impurities contained in the flue gases, which masks the natural color of the product (Alperovich I.A. et al. Methods of preventing efflorescence on clay brick. M., 1977, pp. 8-11 )

The authors were faced with the task of developing a reliable and economical way to preserve the natural color of facing ceramic products.

In the process of analyzing patent technical documentation, a known method was revealed for preserving the natural color of the shard of facing ceramic products, including applying protective coatings on freshly formed raw materials from an aqueous suspension of ground glass, or alumina, or lime (US Pat. Germany No. 1272207, 80 b-23/04, 1963).

The disadvantage of this method is the partial masking of the natural color of the applied coating and the appearance of efflorescence in places of surface damage during operation.

The closest in technical essence and taken as a prototype is a method of preserving the natural color of shards of facing ceramic products, including applying to the front surface of freshly formed products of film-forming 15-30% solutions of solid synthetic resin or bitumen in a volatile solvent (USSR No. 299493, С04В 33/08, 1971).

The disadvantages of this method include its limited use - only for low-saline clays, since otherwise the salts stored in the product, after drying and firing, migrate to the surface over time, violating the uniformity of color. In addition, the use of solid synthetic resins and volatile solvents increases the cost of production, increases fire hazard and worsens working conditions.

The technical result is the preservation of product quality over a long period of operation while reducing production costs through the use of waste materials.

This technical result is achieved by the fact that in the known method of preserving the natural color of facing ceramic products, including applying an organic film-forming component to the front surface of freshly molded products and subsequent drying and firing at a given temperature, according to the invention, spent or substandard low-melting plastic barium greases are used as a film-forming component or fusible mixtures of spent and / or substandard plastic barium greases, before application which matured stirred until a homogeneous mass, determine the temperature dropping, and applying to the front surface is carried out in the temperature range from the temperature dropping to 100 ° C.

Plastic barium greases are complex colloidal systems formed by mineral, synthetic or vegetable oils, thickened with barium salts of higher fatty acids with the addition of various modifying additives. The terms of operation and storage of lubricants are usually small, which leads to the accumulation of waste and substandard (GOST 26098-84) lubricants from consumers. Moreover, the presence of toxic barium causes serious problems with the disposal and storage of these lubricants (fuels, lubricants, industrial fluids. Assortment and application. / Ed. By V. M. Shkolnikov. - M., Chemistry, 1989, S. 293, 302, 318, 319).

To implement the method, used and substandard low-melting plastic barium greases are used (greases with a dropping point not exceeding 100 ° C), as well as low-melting mixtures of spent and / or substandard plastic barium greases. It should be noted that in the latter case, the composition of the mixture may include more refractory lubricants, for example, ShRB-4 lubricant, provided that the dropping point of the mixture remains below 100 ° C.

When implementing the method, representative samples are taken from barium greases received from consumers, mixed, mixed, and dropping temperature is determined by a known method. In the case of lubricants of various grades, the samples are mixed and the ratio of the components in the mixture is determined, ensuring a dropping point below 100 ° C. The required volume of the film-forming component is determined, the lubricants are loaded into an apparatus with a stirrer or a screw device and the composition is averaged by mixing to a homogeneous mass, dropping temperature is measured (input control) and applied to the front surface of a freshly molded facing ceramic product at a temperature above the dropping temperature, but not above 100 ° C. Heating above the dropping point is necessary for impregnation of the surface pores of the product with the liquid components of the lubricant, heating above 100 ° C leads to a violation of the uniformity of the film coating on the surface of the product. The resulting film coating in the course of further drying of the raw material protects the surface from contaminating deposits, formed under the influence of aggressive flue gases. In the process of further firing, the organic components of the lubricating coating completely burn out, restoring the natural color of the ceramic. Barium compounds that have penetrated into the surface pores during the impregnation process during the drying stage interact with soluble salts that are carried out by moisture from the bulk of the raw material to form insoluble compounds, in particular barium sulfate, clogging the pores and hinder further salt transfer to the surface both during drying and during further operation of ceramic products.

The method is as follows.

Example

A mixture of spent barium greases composition:

"Lubricant MS-70"  83% "Grease number 9"  2% MUS-3A grease  5% "ShRB-4 greasing"  6% and substandard barium grease "MGS lubricant"  four%

placed in a screw device and thoroughly mixed to average the composition to a homogeneous mass, a sample was taken and by a known method, according to GOST 6793, dropping temperature was determined, which amounted to 86 ° C. The mixture was heated to 91-93 ° C, applied to the front surface of freshly formed laboratory ceramic samples made of a mixture, which is a clay mixture of the Shishkeevsky deposit (Republic of Mordovia) composition:

and asbestos in a ratio of 9: 1, and was subjected to drying and firing in a furnace heated by flue gases in accordance with the norms of the technological regulations of the Ruzaevsky ZKM for the charge of the specified composition. At the same time, control samples processed in accordance with the prototype method with a solution of bitumen were dried and fired under the same conditions. The fired samples developed by the prototype method and the claimed claimed had plain front surfaces of the color of natural ceramics. To confirm the duration of color retention during operation, the samples were subjected to accelerated tests by sequential exposure in water and drying for 15 cycles. As a result, on the surfaces of 70% of the samples developed by the prototype method, efflorescence was formed. In the inventive method, subtle efflorescences had only 10% of the samples.

Thus, the claimed essential features of the invention: the use as a film-forming component of spent or substandard low-melting plastic barium greases or low-melting mixtures of spent and / or substandard plastic barium greases; mixing them to a homogeneous mass before application; determination of the dropping temperature and subsequent application to the front surface in the temperature range from the dropping temperature to 100 ° C are necessary and sufficient to achieve the technical task.

The use of the invention provides, in comparison with known methods, the following advantages:

expanding the raw material base for the production of facing ceramic products by involving more saline raw materials in the production;

makes it possible to dispose of spent and substandard toxic barium greases;

allows to reduce the cost of production through the use of waste materials;

improves working conditions in ceramic industries, due to the absence of fire hazardous and volatile organic solvents at the stage of applying film-forming substances.

Claims (1)

A method of preserving the natural color of facing ceramic products, including applying an organic film-forming component to the front surface of freshly formed products and subsequent drying and firing at a given temperature regime, characterized in that used or low-grade low-melting plastic barium greases or low-melting mixtures of spent and / or used as a film-forming component or substandard plastic barium greases, which are mixed until homogeneous before application mass, determine the dropping temperature, and application to the front surface is carried out in the temperature range from the dropping temperature to 100 ° C.