RU2310624C2 - Raw material mix for manufacture of ceramic articles - Google Patents

Abstract

FIELD: materials for manufacture of ceramic articles for sanitary purposes, for floors, manufacture of acid-resistant and clinker brick, hollow-ware, electric-grade porcelain and other articles.

SUBSTANCE: proposed raw material mix contains the following components, mass-%: clayish component, 15-50; felsite, 35-80; enriched kaoline, 0-20; chamotte, 0-15.

EFFECT: extended range of raw material sources; improved quality of articles.

2 tbl, 3 ex

Description

The invention relates to the production of ceramic products for various purposes, for example, sanitary ceramic products, ceramic tiles for floors, acid-resistant and clinker bricks, as well as utensils, medical devices, electrophore and other products.

For the ceramic industry, the task of finding cost-effective raw materials to obtain a wide range of quality products remains relevant.

For these purposes, feldspar rock is known - granodiorite (RF Patent No. 2137731, publ. 1999) / 1 /.

Granodiorite mixed with clay components is used for the manufacture of ceramic products for industrial purposes - clinker and acid-resistant bricks, as well as ceramic tiles for floors, sanitary ceramic products.

Granodiorite contains more than 3% of coloring oxides, including iron, titanium and other oxides, which apparently determine the color of the rock, almost black. The range of products obtained from granodiorite is limited by its color.

It is economically feasible to make brick for this purpose from industrial raw materials, however, the share of consumer goods, such as sanitary products, will be limited, and such as utensils, generally excluded. In addition, the manufacture of consumer products from such a material requires special glazes.

Natural material for the manufacture of ceramic products is known - porcelain stone, known in China for more than four centuries.

Porcelain stone is quite stable in composition and does not require the addition of numerous additives, which greatly simplifies the manufacturing technology. Its quantitative content in the raw mix often reaches 80% or more.

The content of coloring oxides in porcelain stone is less than 1%, and after enrichment - 0.1-0.2%, therefore, products from it have a brightness level of about 90%. In addition, porcelain stone products have a low specific gravity, great mechanical strength, and practically zero water absorption. From such material make thin graceful dishes of high quality.

The Chinese porcelain stone deposit was fully developed 350 years ago.

Currently, there are two deposits of porcelain stone, one in Japan and the other "Marinskoe" in southern Russia / 2 /.

However, the widespread use of porcelain stone in the manufacture of ceramic products is limited by its high sintering temperature, which is more than 1350 ° C and the high cost of the raw material itself. In the world market, one ton of porcelain stone is estimated at $ 490.

The high price limits the use of this raw material for products that do not require a high degree of whiteness. High sintering temperatures require special equipment and increased fuel consumption, while the manufacture of ceramic products in many cases does not require such temperatures.

The objective of the present invention is to identify a new type of developed natural raw materials, corresponding in its main indicators to the stringent requirements of manufacturers of ceramic products and its capabilities for the manufacture of cost-effective quality ceramic products.

The problem was solved as a result of research that allowed to identify the rock - felsite.

Felsite is a cryptocrystalline, partially microcrystalline bulk of acidic effusion rocks, consisting mainly of plagioclase, quartz and orthoclase, as well as currently undetectable components, such as glass. This breed refers to raw materials with a high, more than 25%, free quartz content.

In its chemical composition felsite differs sharply from granodiorite, but is quite close to porcelain stone. Table 1 shows the chemical composition of granodiorite, felsite, and porcelain stone.

The content of coloring oxides in felsite is less than 3%, which is much less than in granodiorite, but more than in porcelain stone. Therefore, today products from felsite in terms of whiteness will be inferior to products from porcelain stone, but as the technology for preparing raw materials, including cleaning it from coloring oxides, improves, this disadvantage will most likely be eliminated.

In terms of mineral composition and ceramic properties, felsite differs sharply from porcelain stone. Table 2 shows the mineral composition of felsite and porcelain stone.

The mineral composition of felsite provides a relatively low sintering temperature of 1100 ° C. At the same time, the presence in felsite of varying degrees of more aluminous and less alkaline compared to feldspars layered silicates, provides a wide temperature range of sintering, which is more than 150 ° C. In the experiment, after firing at a temperature of 1250 ° C, the test samples did not show signs of the onset of deformation.

In addition, it should be noted the high activity of felsite for sintering with clays and enriched kaolins of various compositions. In the experiment, after firing at a temperature of 1250 ° C, the studied samples based on various compositions had zero water absorption.

To date, felsite is mined and used in the form of gravel of various fractions for the manufacture of concrete and reinforced concrete products and structures, and mainly for the construction and repair of highways and railroad tracks. The use of felsite for the manufacture of polished slabs for flooring is known.

In the Sverdlovsk and Chelyabinsk regions, two developed felsite deposits have been identified. This is the Pokrovskoye field, located 130 km from the city of Yekaterinburg, and the Kizilskoye field, which is located 80 km from the city of Magnitogorsk. The cost of felsite today is ten times less than the cost of porcelain stone.

The insufficient knowledge of the chemical and mineral composition of felsite, as well as its physical and ceramic properties, did not allow its earlier use in the manufacture of ceramic products. As a result of a deeper study of the properties of this material, it turned out that this rock can provide a relatively low temperature for the onset of sintering of the raw material mass.

The presence in the rock of more aluminous and less alkaline compared to feldspars layered minerals provides a wide temperature range of sintering, which is favorable for the manufacture of a wide range of products. A significant amount of free quartz gives the rock non-shrink properties. The use of this breed to obtain ceramic products does not require the introduction of special corrective sintering additives. The volume of felsite deposit, relatively low cost, wide temperature range of sintering, as well as the unnecessity of corrective additives, will allow to obtain a wide range of ceramic products with their high quality and low cost of production.

Known ceramic mass for the manufacture of clinker (SU No. 1534034) / 3 / containing rhyolite rock in composition with clay, quartz sand and cullet. The known mass can only be used to solve particular, specifically posed problems, for example, the task of producing clinker bricks with quality indicators several times higher than the regulatory requirements of the standard. It is known that rhyolites, perlites, feldspars in ceramic masses play the role of fluxes. From the composition of the known mass / 3 / it is clear that rhyolite is not enough to perform this function, therefore, cullet was added to it in large quantities (up to 20% by weight). Felsit, on the other hand, discovered the properties of intense flux, which can be used as an independent one without adding other fluxes.

Known mass / 3 / cannot be extended to the production of other types of ceramics, such as, for example, dishes or sanitary products, because for these products there is no need to obtain the properties achieved by this mass.

A new technical result achieved by the claimed solution is to expand the raw material base in the manufacture of a wide range of ceramic products, characterized by quality indicators that meet the requirements.

Example 1. The raw material mixture for the manufacture of sanitary ceramics - washbasins and toilets - was prepared by grinding felsite in a ball mill by wet and dissolving clay and kaolin in a mixer, followed by mixing the components. The number of components of the raw mix: Felsit - 65%, clay - 15%, enriched kaolin - 20%.

The resulting slurry with a moisture content of 30% was poured into gypsum molds corresponding to the products obtained, and the composition was fixed by holding in molds until a layer with a thickness of 10-12 mm was obtained on its walls.

The remaining slurry was poured for later use. The resulting semi-finished product was dried, removed from the mold and dried at a temperature of 105-110 ° C. Then it was covered with a layer of glaze, dried and fired at a temperature of 1250 ° C. The resulting products had a total shrinkage of 13% (shrinkage can be reduced to 10%), water absorption - 0.1%, compressive strength - 110 MPa, acid resistance - 99.6%. (Empirically, it is possible to select other raw material formulations, preferably in the range: felsite - from 50 to 80%, clay component - from 20 to 50%).

Example 2. The raw mixture for the manufacture of ceramic unglazed tiles for floors was prepared by grinding felsite and clay in ball mills by wet and dissolving clay in mixers, followed by mixing the components, further drying in spray dryers to obtain a press powder with a moisture content of 6-8%. The number of components of the raw mix: Felsit - 50%, clay - 50%.

Tiles of the required dimensions were pressed from the powder, dried and calcined at a temperature of 1160 ° C. Quality indicators of the obtained tiles: water absorption - 3.0%, shrinkage - 4-4.5%, tensile strength in bending - 36 MPa, wear resistance - 25 g / cm ² , frost resistance - 40 cycles.

Example 3. The raw material mixture for the manufacture of acid-resistant bricks was prepared by joint or separate grinding of the constituent components to a grain size of less than 3 mm in ball or shaft mills. The particles ground during separate grinding were mixed in a predetermined proportion and moistened with water to a moisture content of 17-18%. The number of components of the raw mix: Felsit - 35%, clay - 50%, chamotte - 15%.

Next, the mixture was missed on a clay grinder, compacted on a vacuum tape press, cut billets, from which bricks were molded. The molded bricks were dried at a temperature of 105-110 ° C and burned in an open flame tunnel kiln at a final temperature of 1180 ° C. The resulting brick had the following indicators: water absorption - 4.2%, shrinkage 11-12%, compressive strength - 80 MPa, thermal resistance - more than 10 heat exchange, acid resistance - 99.5%.

In the above examples, felsite of the Pokrovsky and Kizilsky deposits was used as raw material. In example 1 used clay brand DNO Druzhkovsky field (Ukraine). In examples 2, 3, Nizhneuvelskoye clay grade NU 1 (Russia, Chelyabinsk region) was used. Quality indicators of the received products correspond to the standards accepted for them.

The results obtained suggest that the claimed mixture can be used for a wider range of ceramic products. This can be dishes, medical devices, electrophore, and others.

When developing the manufacturing technology for each specific product, depending on the properties of the components of the initial raw mix, mainly clay components, technology and equipment, including those already existing in ceramic production, it is necessary to select the raw mix, processing modes, etc.

Table 1 name of raw materials Sample number Name of components, content, wt.% ppp * SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Cao MgO K ₂ O Na ₂ O SO ₃ TiO ₂ Free SiO ₂ P ₂ O ₅ MnO Felsit
Pokrovsky field one 1.7 74.58 14.41 1.84 1.39 0.40 3.23 2,56 Not def. Not def. 38.70 Not def. Not def. 2 1,2 76.46 13.32 1.21 0.16 0.13 4.21 3.29 0.31 Not def. 42.40 Not def. Not def. Felsit
Kizilsky field 3 0.86 75.60 13.12 0.32 0.22 0.056 4.40 3.57 0.28 0.23 40.15 Not def. Not def. four 0.95 75.52 12.08 0.72 0.23 0.17 4.27 3.90 0.16 0.22 37,20 Not def. Not def. Porcelain stone of the Marinsky deposit 5 3.18 74.66 15.22 0.34 0.34 0.18 3.88 2.00 0.02 0,07 Not def. 0,027 0.013 Granodiorite / 1 / - - 63.37-67.98 13.5-17.99 0.40-2.28 - - 1.74-4.97 2.20-4.42 - - - - - * - loss on ignition
Note: The chemical composition of felsite samples was determined by the testing analytical laboratory for testing and certification at USTU (UPI), Yekaterinburg.

table 2 The name of the mineral Researched materials Felsit Pokrovsky field Felsite of the Kizilsky field Porcelain stone of the Mari deposit one 2 3 four 5 6 7 Free quartz 35-40 38.6 44,2 25-40 thirty 35 38,0 Plagioclase 30-33 31,0 23,2 55-75 34 39 - Potassium Feldspar 30-33 19.5 17.6 24 29th - Sericite 3-5 6.9 12.1 - 2 5 - Kalionite - 2,3 1,5 - - 2.7 23.0 Limonite - 1.4 1.4 - - - - Chlorite - - - 5-7 5 7 - Magnetite 2-3 - - 0-2 - 2 - Albite - - - - - 5 13.0 Microcline - - - - - - 5,0 Pyroxene - - - - - - 5.2 Amphibor - - - - - - 3.0 Halloysite - - - - - - 5,0 Carbonates - - - - - - 1.8 Mica - - - - - - 6.0 Accessory apatite, zircon - - sphene, leucoxene, zircon - - - Note 1: the data of columns 2, 3 of table 2 correspond to samples 2, 3 of table 1; the data of columns 5, 6 correspond to samples 3, 4 of Table 1; column 7 data correspond to sample 5 of table 1. Note 2: the data of columns 1, 4 for free quartz and sericite were taken from the geological reports of the Ural State Geological Survey "State Geological Exploration" of the Ministry of Natural Resources of the RSFSR in 1965 and 1980, data on the remaining specific minerals were determined at the Department of CMW of the Ural State Technical University (UPI), Yekaterinburg.

Claims (1)

A raw material mixture for the manufacture of ceramic products containing a clay component, characterized in that it further comprises felsite, enriched kaolin and chamotte in the following ratio of components, wt.%: clay component 15-50 felsit 35-80 enriched kaolin 0-20 fireclay 0-15